Earthwork
Remade for neutrality: every choice explained, project facts as parameters, scope boundaries linked both ways
Showing changes from Rev 6
to Rev 7
in Earthwork.
−---
−title: Earthwork
−category: Sitework
−toc_depth: 3
−description: >
− When to use: Earthwork for commercial, institutional, and industrial building projects covering site clearing and demolition, rough grading, mass excavation, structural excavation for foundations and slabs, trench excavation for utilities, classification of in-situ and imported materials, structural fill and backfill placement, compaction and moisture conditioning, subgrade preparation, dewatering, temporary excavation support and shoring, and erosion and sediment control. Intended to be read alongside the geotechnical investigation report and the civil grading drawings, both of which govern design-specific values throughout this standard.
− Not intended for: Highway and roadway embankment construction governed by state DOT specifications; earthen dam and levee construction; contaminated soil remediation and hazardous material excavation (those require a project-specific remediation specification); deep foundation installation including driven piles and drilled shafts (see [[sync/cast-in-place-concrete]] for caissons coordinated with structural concrete); aggregate base course and subbase under paved surfaces (see [[sync/aggregate-base-course]]); below-grade waterproofing of foundation walls (see [[sync/below-grade-waterproofing]]); or storm drainage piping and structures (see [[sync/storm-drainage]]).
−---
−
−# Scope {toc}
−
−## This specification covers the materials, execution, testing, and quality control for all earthwork operations on the project site. {note}
−## Earthwork is the first construction scope to begin and the last to be fully closed out — it directly conditions every subsequent scope, from foundations and utilities to paving and landscaping. {note}
−## Errors in earthwork, particularly inadequate compaction or failure to honor geotechnical recommendations, propagate forward through the project as structural distress, settlement, utility misalignment, pavement failure, and warranty claims. {note}
−## The investment in doing earthwork correctly is always less than the cost of remediation. {note}
−
−## This standard addresses site clearing and demolition of existing improvements, cut and fill grading operations, excavation by type and purpose, classification of materials encountered, fill and backfill materials and placement, compaction requirements, subgrade preparation, groundwater management and dewatering, temporary excavation support, and erosion and sediment control throughout the construction period. {note}
−
−## All work shall conform to the recommendations of the geotechnical investigation report prepared for this project.
−
−## In cases of conflict between this standard and the geotechnical report, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
−
−## The Contractor shall recognize that the geotechnical investigation report is based on a limited number of borings and test pits that characterize but do not fully describe the subsurface, and that actual conditions encountered may differ from those reported.
−
−## The Contractor shall promptly notify the Engineer of Record of any differing site condition that materially affects work under this specification, including unexpected groundwater, rock, soft or organic soils, buried utilities, obstructions, or contaminated materials not identified in the geotechnical report.
−
−## The Contractor shall coordinate work under this specification with [[sync/cast-in-place-concrete]] for foundation bearing surface preparation and concrete placement over prepared subgrades, with [[sync/below-grade-waterproofing]] for backfill restrictions adjacent to waterproofed foundation walls, with [[sync/aggregate-base-course]] for subbase and base course work under pavements, and with [[sync/storm-drainage]] for pipe trench requirements and inlet protection.
−
−# Referenced Standards {toc}
−
−## Equipment, materials, testing, and execution shall comply with the latest adopted edition of the following standards.
−## Where project documents, adopted codes, and referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
−
−| Standard | Title |
−|----------|-------|
−| ASTM D698 | Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 ft-lbf/ft³) |
−| ASTM D1557 | Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort (56,000 ft-lbf/ft³) |
−| ASTM D1556/D1556M | Standard Test Method for Density and Unit Weight of Soil in Place by Sand-Cone Method |
−| ASTM D2167 | Standard Test Method for Density and Unit Weight of Soil in Place by the Rubber Balloon Method |
−| ASTM D2216 | Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass |
−| ASTM D2487 | Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System) |
−| ASTM D2488 | Standard Practice for Description and Identification of Soils (Visual-Manual Procedures) |
−| ASTM D4318 | Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils |
−| ASTM D6938 | Standard Test Methods for In-Place Density and Water Content of Soil and Soil-Aggregate by Nuclear Methods (Shallow Depth) |
−| ASTM D7928 | Standard Test Method for Particle-Size Distribution (Gradation) of Fine-Grained Soils Using the Sedimentation (Hydrometer) Analysis |
−| ASTM C136/C136M | Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates |
−| IBC Chapter 18 | Soils and Foundations (International Building Code, currently adopted edition) |
−| OSHA 29 CFR 1926 Subpart P | Excavations (Safety and Health Regulations for Construction) |
−| EPA NPDES CGP | Construction General Permit (National Pollutant Discharge Elimination System) |
−| AASHTO T 99 | Standard Method of Test for Moisture-Density Relations of Soils Using a 2.5-kg Rammer and a 305-mm Drop |
−| AASHTO T 180 | Standard Method of Test for Moisture-Density Relations of Soils Using a 4.54-kg Rammer and a 457-mm Drop |
−
−# Submittals {toc}
−
−## Action Submittals {toc}
−
−### The Contractor shall submit the following for the Engineer of Record's review prior to beginning work:
−
−- Geotechnical investigation report (if not included in the contract documents): the Contractor shall confirm receipt of the current geotechnical report and shall flag any conflicts between the report and the contract documents before beginning earthwork
−- Excavation safety plan prepared or reviewed by a competent person as defined in OSHA 29 CFR 1926 Subpart P, describing the method for protecting workers in every excavation exceeding 5 feet in depth, including the classification of soils, the selected protective system, and the means of access and egress
−- Shoring and sheeting design where a designed system is required: engineer-stamped drawings and calculations for all temporary support systems that cannot be designed from OSHA Appendix B tables
−- Dewatering plan where groundwater is anticipated at or near excavation depth: describe the proposed method, equipment, discharge point, and permits; include calculations for anticipated inflow where the system is designed
−- Temporary erosion and sediment control plan conforming to the project SWPPP, showing the location and type of all BMPs, sequencing with grading activities, and maintenance protocol
−- Imported fill material certifications: gradation analysis and Proctor test results for each proposed import source, confirming compliance with material requirements of this specification; materials shall not be imported until approved
−
−```datasheet
−label: Action Submittals Required
−type: checkbox
−options:
− - "Geotechnical investigation report confirmation / conflict log"
− - "Excavation safety plan (OSHA Subpart P competent person)"
− - "Shoring / sheeting design drawings and calculations (where applicable)"
− - "Dewatering plan and discharge permits (where applicable)"
− - "Erosion and sediment control plan / SWPPP conformance"
− - "Imported fill material certifications and Proctor test data"
−default: "Excavation safety plan (OSHA Subpart P competent person)"
−```
−
−### Excavation and fill operations shall not proceed on any portion of the site until the submittals relevant to that portion are reviewed and returned.
−
−### Submittal review does not relieve the Contractor of responsibility for compliance with contract documents.
−
−## Closeout Submittals {toc}
−
−### Prior to substantial completion the Contractor shall provide the following:
−
−- Field testing reports for all compaction testing, including test locations, test method, lift number, tested dry density, moisture content, percent compaction, and pass/fail against the applicable criterion; reports shall be signed by the testing technician
−- As-built grading survey confirming that final grades conform to the drawings within the tolerances specified herein
−- Certification from the geotechnical engineer of record (or the Owner's special inspector) that earthwork operations were observed and conform to the geotechnical report recommendations and this specification
−- Erosion and sediment control closeout documentation: confirmation that all temporary BMPs have been removed, permanent stabilization has been established, and the site is in compliance with permit requirements
−
−```datasheet
−label: Required Closeout Submittals
−type: checkbox
−options:
− - "Field compaction testing reports (signed by technician)"
− - "As-built grading survey"
− - "Geotechnical engineer of record earthwork conformance certification"
− - "Erosion and sediment control closeout documentation"
−default: ["Field compaction testing reports (signed by technician)", "As-built grading survey", "Geotechnical engineer of record earthwork conformance certification", "Erosion and sediment control closeout documentation"]
−```
−
−# Quality Assurance {toc}
−
−## Geotechnical Engineer of Record {toc}
−
−### The Owner shall retain a licensed geotechnical engineer of record to provide construction observation and materials testing services for earthwork.
−
−### The geotechnical engineer shall observe subgrade conditions at the base of every foundation excavation before concrete or fill is placed.
−
−### The geotechnical engineer shall observe proof-rolling operations.
−
−### The geotechnical engineer shall evaluate any differing site condition reported by the Contractor.
−
−### The geotechnical engineer shall interpret the project geotechnical report in light of actual conditions.
−
−### The geotechnical engineer shall direct adjustments to materials or procedures when warranted.
−
−### The geotechnical engineer's authority to halt earthwork operations that do not conform to the recommendations of the geotechnical report is binding on the Contractor.
−
−## Competent Person {toc}
−
−### The Contractor shall designate a competent person as defined in OSHA 29 CFR 1926 Subpart P to be present at all excavation work exceeding 5 feet in depth.
−
−### The competent person shall classify soils, evaluate excavation stability, inspect the excavation daily and after every rain event or other occurrence that could affect stability, and direct immediate corrective action when hazardous conditions are observed.
−
−### The Contractor shall not substitute personnel without ensuring that the replacement meets the competent person qualification.
−
−## Special Inspection {toc}
−
−### Where the adopted building code or the structural drawings require special inspection for earthwork, the Owner shall retain a special inspector approved by the Authority Having Jurisdiction.
−
−### The special inspector shall perform periodic and continuous observation as required by the inspection program, document observations and test results, and report non-conformances to the Owner and to the Engineer of Record.
−
−### Special inspection under the building code does not relieve the Owner's geotechnical engineer of record of the separate obligation described above.
−
−## Pre-Construction Conference {toc}
−
−### Prior to beginning earthwork operations the Contractor shall participate in a pre-construction conference attended by the Contractor's superintendent responsible for earthwork, the Owner's geotechnical engineer of record, the Owner's special inspector, and the Engineer of Record.
−
−### The conference shall review the geotechnical report recommendations, the compaction requirements and testing program, the excavation safety plan, the dewatering plan, the erosion and sediment control plan, the requirements for dealing with differing site conditions, and the lines of communication for field decisions.
−
−## Testing Frequencies {toc}
−
−### Compaction testing frequencies shall conform to the geotechnical engineer's recommendations.
−### In the absence of project-specific direction, minimum testing frequencies shall be as follows: one test per 2,500 square feet of fill surface per lift for areas under footings, slabs, and pavements; one test per 100 linear feet of trench per lift for utility trenches; and one test per 500 square feet of fill surface per lift for general site grading not within a building footprint.
−
−```datasheet
−label: Compaction Testing Standard
−type: radio
−options:
− - "ASTM D698 (Standard Proctor — 12,400 ft-lbf/ft³)"
− - "ASTM D1557 (Modified Proctor — 56,000 ft-lbf/ft³)"
−default: "ASTM D1557 (Modified Proctor — 56,000 ft-lbf/ft³)"
−```
−
−```datasheet
−label: Field Density Test Method
−type: select
−options:
− - "Nuclear gauge per ASTM D6938"
− - "Sand cone per ASTM D1556/D1556M"
− - "Rubber balloon per ASTM D2167"
− - "As directed by geotechnical engineer"
−default: "Nuclear gauge per ASTM D6938"
−```
−
−### The geotechnical engineer shall increase testing frequency in areas showing variability or failing tests.
−
−### Modified Proctor (ASTM D1557) shall be used for structural fill under foundations, floor slabs, and pavements, and for all trench backfill under or adjacent to structures.
−
−### Standard Proctor (ASTM D698) may be used for general site grading, landscaped areas, and non-structural fill remote from buildings and utilities.
−
−### When in doubt, use Modified Proctor — specifying the wrong test method is one of the most common earthwork errors, and a compaction result referenced against the wrong Proctor value is meaningless. {note}
−
−### The nuclear gauge method (ASTM D6938) is the standard production testing method because it is fast and non-destructive, allowing the same location to be re-tested after additional compaction effort if the first test fails; the sand cone method (ASTM D1556/D1556M) is the reference method for calibration and for locations where nuclear gauge use is restricted or impractical. {note}
−
−### The testing technician shall perform gauge count standard checks at the beginning and end of each testing session in accordance with ASTM D6938.
−
−# Soil Materials and Classification {toc}
−
−## Unified Soil Classification System {toc}
−
−### All soils encountered during excavation and all imported fill materials shall be classified in accordance with ASTM D2487, using the Unified Soil Classification System (USCS).
−
−### Visual identification in the field shall conform to ASTM D2488.
−
−### Where the geotechnical engineer determines that laboratory testing is needed to confirm field classification, tests shall include gradation per ASTM C136/C136M and ASTM D7928, and Atterberg limits per ASTM D4318.
−
−### USCS classification governs the acceptability of materials for specific fill applications as described herein.
−
−### The USCS designation shall be recorded on all field logs, boring logs, and test pit logs.
−
−### It is not sufficient to describe soils generically as "good," "bad," or "clay" — the USCS symbol (GW, GP, GM, GC, SW, SP, SM, SC, ML, CL, MH, CH, OL, OH, PT) provides a precise, universally understood language that carries information about drainage, compressibility, and suitability for specific applications. {note}
−
−## Classification of Materials for Excavation Payment {toc}
−
−### For payment and excavation planning purposes, materials encountered shall be classified as soil, soft rock / rippable rock, rock, or unsuitable material.
−
−```datasheet
−label: Rock Encountered — Action Required
−type: radio
−options:
− - "Blast (where permitted by local ordinance)"
− - "Hydraulic breaker / hoe-ram"
− - "Mechanical ripping"
− - "Not anticipated — confirm with geotechnical engineer if encountered"
−default: "Not anticipated — confirm with geotechnical engineer if encountered"
−```
−
−### The Contractor shall notify the Engineer of Record when material of a different classification than anticipated is encountered, before changing excavation methods.
−
−### Soil is naturally occurring or previously placed earth material that can be excavated with conventional earthmoving equipment (hydraulic excavators, dozers, motor graders, scrapers) without blasting or special treatment, and includes clay, silt, sand, gravel, and mixtures thereof, and previously placed fill. {note}
−
−### Soft rock / rippable rock is material that cannot be efficiently excavated with conventional earthmoving equipment but can be broken and removed by ripping with a heavy dozer-mounted ripper, or by hoe-ramming, including weathered or highly fractured rock, shale, hardpan, cemented gravels, and caliche. {note}
−
−### Classification of soft rock / rippable rock requires judgment by the geotechnical engineer based on observed seismic velocity, rock quality designation, and equipment performance.
−
−### Rock is solid material of mineral origin that cannot be excavated by ripping and requires drilling and blasting, hydraulic breaking, or other special methods for removal. {note}
−
−### Classification as rock shall be confirmed by the geotechnical engineer.
−
−### Unsuitable material is material that is unacceptable as a foundation bearing surface or as fill regardless of classification, including organic soils, topsoil, peat and muck, material with organic content by weight greater than 3 percent, frozen material, materials with liquid limit greater than 50 or plasticity index greater than 25 (unless specifically evaluated by the geotechnical engineer for a particular application), and materials with a swell potential that exceeds the bearing capacity design assumptions. {note}
−
−## Topsoil {toc}
−
−### Topsoil is the upper zone of naturally occurring soil containing organic matter, root systems, and biological activity. {note}
−
−### Topsoil shall be stripped from all areas to be occupied by fills, structures, pavements, and utility trenches.
−
−### Stripping depth shall be [[drawing: as indicated on the grading drawings or as directed by the geotechnical engineer in the field]], typically 4 to 12 inches depending on site conditions.
−
−```datasheet
−label: Topsoil Stripping Depth
−type: range
−unit: inches
−drawing_ref: true
−options:
− min: 4
− max: 18
− step: 2
−default: 6
−```
−
−### Stripped topsoil shall be stockpiled separately from other excavated material for later use in landscaping and permanent vegetative stabilization, unless the geotechnical report indicates that site topsoil is unsuitable for reuse.
−
−### Topsoil stockpiles shall be located outside of fill areas and drainage swales, protected from erosion with perimeter silt fence, and seeded or covered if stockpiled for more than 30 days.
−
−# Site Clearing and Preparation {toc}
−
−## Clearing Limits {toc}
−
−### Site clearing shall be performed within the limits [[drawing: as indicated on the site plan and demolition drawings]].
−
−```datasheet
−label: Tree and Vegetation Protection
−type: radio
−options:
− - "Protective fencing at drip line — all designated trees"
− - "Protective fencing at drip line plus root pruning where excavation approaches protected zones"
− - "Not applicable — no trees designated for preservation"
−default: "Protective fencing at drip line — all designated trees"
−```
−
−### The Contractor shall stake clearing limits before beginning work.
−
−### The Contractor shall protect trees and vegetation designated for preservation with protective fencing installed at the drip line.
−
−### No equipment shall operate, no material shall be stockpiled, and no soil shall be compacted within the drip line of trees designated for preservation.
−
−## Demolition of Existing Improvements {toc}
−
−### Existing structures, pavements, curbs, walks, underground utilities, and other improvements within the work area shall be demolished and removed as shown on the drawings and as required for the work.
−
−```datasheet
−label: Concrete Rubble Reuse as Fill
−type: radio
−options:
− - "Not permitted — remove all demolished concrete from site"
− - "Permitted in designated non-structural areas only — with Engineer of Record approval"
−default: "Not permitted — remove all demolished concrete from site"
−```
−
−### The Contractor shall verify the locations of all underground utilities before demolition begins, using utility locates (one-call) and hand-digging as required within tolerance zones.
−
−### Existing underground storage tanks, septic systems, wells, and similar structures shall be decommissioned and removed in accordance with applicable regulations before earthwork proceeds.
−
−### The Contractor shall notify the Owner immediately if any previously unidentified underground storage tank or regulated structure is discovered.
−
−### Demolished concrete and masonry shall be removed from the site.
−
−### Concrete rubble shall not be used as fill unless specifically approved in writing by the Engineer of Record, limited to applications where the material can be adequately compacted and tested, and prohibited beneath buildings and slabs.
−
−## Subsurface Obstruction Discovery {toc}
−
−### The Contractor shall immediately notify the Owner and Engineer of Record upon discovery of any subsurface obstruction, buried structure, contaminated material, or other condition not shown on the contract documents.
−
−### Work in the affected area shall be suspended until the Engineer of Record issues written direction.
−
−### The Contractor shall not remove, disturb, or backfill around any discovered condition pending direction, except as required for immediate safety.
−
−# Excavation {toc}
−
−## General Excavation Requirements {toc}
−
−### Excavation shall be performed to the lines, grades, and dimensions shown on the drawings or directed by the Engineer of Record, with a tolerance of plus or minus 0.10 foot vertically for unformed excavation unless otherwise noted.
−
−### Excavated material suitable for reuse as structural fill shall be stockpiled separately from unsuitable material and protected from contamination, precipitation, and excessive drying.
−
−### All excavated material not to be reused shall be removed from the site and legally disposed.
−
−### The Contractor shall maintain all excavations in a dry condition and in a stable configuration.
−
−### Standing water shall not be permitted in excavations at the time fill or concrete is placed.
−
−### The bottom of all excavations shall be observed by the geotechnical engineer of record before placing fill, concrete, or other materials.
−
−### The Contractor shall not proceed past the geotechnical engineer's observation without written authorization.
−
−## Mass Grading and Cut Excavation {toc}
−
−### Mass grading operations remove soil and rock from areas to be lowered in elevation to achieve design grade, or strip and stockpile topsoil, or provide material for placement as fill elsewhere on the site. {note}
−
−### Cut areas shall be shaped to drain away from any exposed subgrade.
−
−### Where cut slopes are required, temporary and permanent slope angles shall conform to the geotechnical report recommendations.
−
−### Temporary cut slopes shall be classified and designed in accordance with OSHA 29 CFR 1926 Subpart P, Appendix B.
−
−```datasheet
−label: Maximum Temporary Cut Slope — Soil (No Shoring)
−type: select
−drawing_ref: true
−options:
− - "1.5H:1V — Type A soils (geotechnical confirmation required)"
− - "1H:1V — Type B soils"
− - "0.5H:1V — Type C soils"
− - "Per geotechnical engineer — site-specific analysis"
−default: "Per geotechnical engineer — site-specific analysis"
−```
−
−### OSHA soil type classifications (Type A, B, C) are distinct from USCS classifications and are used specifically for determining safe temporary slope angles and excavation support requirements. {note}
−
−### The competent person shall determine the OSHA soil classification for every excavation based on visual and manual tests described in OSHA Appendix A.
−
−### Wet or overloaded cut slopes that begin to move or ravel shall be immediately brought to the attention of the competent person and the geotechnical engineer.
−
−### The Contractor shall not allow personnel to work below an unstable cut slope.
−
−## Structural Excavation {toc}
−
−### Structural excavation is excavation performed to create space for foundations, pits, grade beams, retaining walls, and similar structures. {note}
−
−### Structural excavation shall be performed to the neat lines and grades shown on the structural drawings, plus working space required for forming and waterproofing.
−
−### Final trimming of the bearing surface at the bottom of structural excavation shall be performed by hand or by a smooth-bucket excavator, removing no more than necessary to achieve a clean, undisturbed bearing surface at the design elevation.
−
−### Over-excavation of foundation bearing surfaces is a common and costly error — once the bearing stratum is loosened or saturated, it cannot be simply re-compacted to the same condition. {note}
−
−### If the bearing surface is inadvertently over-excavated, or if soft, loose, or otherwise unsuitable material is encountered at the bearing elevation, the geotechnical engineer shall be consulted before proceeding, and remedial options may include further over-excavation and replacement with lean concrete or compacted structural fill, subgrade improvement, or foundation redesign.
−
−```datasheet
−label: Over-Excavation Remediation — Foundation Bearing
−type: select
−options:
− - "Lean concrete fill to design grade (minimum 2,000 psi)"
− - "Compacted structural fill to design grade (geotechnical engineer approval required)"
− - "Geotechnical engineer to evaluate and direct — case by case"
−default: "Geotechnical engineer to evaluate and direct — case by case"
−```
−
−### The bearing surface at the bottom of structural excavation shall be proof-rolled or probed by the geotechnical engineer before any concrete or fill is placed.
−
−### Soft, yielding, or pumping areas shall be undercut and replaced.
−
−### The Contractor shall provide the geotechnical engineer at least 24 hours notice before each bearing surface will be ready for observation.
−
−## Trench Excavation {toc}
−
−### Trench excavation serves utility installation, including water supply, sanitary sewer, storm drainage, electrical conduit, gas, and communications. {note}
−
−### Trench excavation shall conform to the alignment, depth, grade, and bedding requirements shown on the utility drawings.
−
−```datasheet
−label: Trench Bottom Preparation — Pipe Bedding
−type: select
−drawing_ref: "utility drawings"
−options:
− - "Undisturbed native soil shaped to pipe O.D."
− - "Granular bedding material — minimum 4 in. depth below pipe"
− - "Concrete cradle"
−default: "Granular bedding material — minimum 4 in. depth below pipe"
−```
−
−### Trench width shall be the minimum necessary for safe worker access and utility installation and bedding placement, but not less than the pipe outside diameter plus 12 inches on each side for pipes up to 24 inches in diameter.
−
−### Unnecessarily wide trenches increase the volume of backfill and the potential for consolidation settlement. {note}
−
−### Trenches shall be excavated to stable, undisturbed material.
−
−### Where unstable trench bottom conditions are encountered, the geotechnical engineer shall evaluate the need for over-excavation and replacement with crushed stone or other suitable material.
−
−### Trench sidewalls shall be stable during the time workers are in the trench.
−
−### Every trench 5 feet or deeper shall have a protective system as required by OSHA 29 CFR 1926 Subpart P.
−
−### The Contractor shall not permit workers in an unprotected trench 5 feet or deeper for any reason, including hand trimming, pipe laying, or inspection.
−
−## Excavation Beneath Groundwater {toc}
−
−### Where excavation extends below the groundwater table, the Contractor shall manage groundwater by dewatering as described in the dewatering section of this specification.
−
−### Excavation into groundwater without effective dewatering causes piping, boiling, and bottom heave that destroys the integrity of the bearing surface and is an immediate safety hazard. {note}
−
−### The Contractor shall not allow workers in an excavation where active groundwater inflow is occurring and the bottom is not stable.
−
−## Stockpile Management {toc}
−
−### Stockpiles of excavated material shall be located at least 2 feet from the edge of any excavation for stockpiles less than 5 feet high, and farther for taller stockpiles, to prevent surcharge-induced slope failure into the excavation.
−
−### Stockpile heights shall not exceed the maximum for the soil type unless the geotechnical engineer approves a higher stockpile with appropriate side slopes.
−
−### Stockpiles shall be protected from excessive drying, wetting, or freezing that would render the material unsuitable for its intended reuse.
−
−# Excavation Support and Dewatering {toc}
−
−## Excavation Support — General {toc}
−
−```datasheet
−label: Excavation Protective System Type
−type: select
−options:
− - "Sloping and benching per OSHA Appendix B"
− - "Aluminum hydraulic shoring (tabulated data)"
− - "Steel sheet piling"
− - "Soldier beams and wood lagging"
− - "Secant or tangent pile wall"
− - "Trench box / shield"
− - "Designed system — PE-stamped drawings required"
−default: "Sloping and benching per OSHA Appendix B"
−```
−
−### All excavations 5 feet or deeper shall be protected by a sloping/benching system or a support system designed to prevent cave-in, as required by OSHA 29 CFR 1926 Subpart P.
−
−### Protective systems shall be selected from the OSHA-tabulated options (sloping per Appendix B, timber shoring per Appendix C, aluminum hydraulic shoring per Appendix D) or shall be designed by a registered professional engineer.
−
−### The competent person shall evaluate soil conditions and select or confirm the appropriate protective system for each excavation.
−
−### Selection of a protective system is the responsibility of the Contractor; the Engineer of Record's review of the excavation safety plan does not constitute approval of the protective system design.
−
−### Where excavation support is designed by the Contractor's engineer, the design shall account for soil type and stratification based on the project geotechnical report, groundwater level and hydrostatic pressure, surcharge loads from stockpiles, equipment, and adjacent structures, and any restrictions on ground movement that protect adjacent foundations, utilities, or improvements.
−
−### The Owner's Engineer of Record shall be consulted before any designed support system is installed that affects permanent structures or existing improvements.
−
−## Temporary Shoring Adjacent to Existing Structures {toc}
−
−```datasheet
−label: Excavation Within 10 ft of Existing Foundation — Protection Method
−type: select
−options:
− - "Engineered shoring system — PE-stamped drawings required"
− - "Underpinning of existing foundation"
− - "Not applicable — no excavation within 10 ft of existing foundations"
−default: "Engineered shoring system — PE-stamped drawings required"
−```
−
−### When excavating adjacent to existing buildings, foundations, pavements, or utilities, the Contractor shall evaluate whether the excavation will undermine the support of adjacent improvements.
−
−### No excavation that removes lateral or vertical support from an existing foundation shall be performed without either underpinning the existing foundation or designing and installing a temporary support system adequate to prevent movement.
−
−### IBC Chapter 18 requires that excavation near any foundation not reduce vertical or lateral support without prior protection of the affected foundation.
−
−### The Contractor shall monitor any existing structures adjacent to deep excavations for signs of movement or distress.
−
−### Pre-construction condition surveys shall be performed on adjacent structures within a distance equal to the depth of excavation, and the Contractor shall maintain records sufficient to defend against claims of damage.
−
−## Dewatering {toc}
−
−### Dewatering removes groundwater from excavations to maintain dry working conditions, prevent bottom heave and piping, and allow compaction of fill to meet density requirements. {note}
−
−### The Contractor shall provide dewatering systems capable of maintaining the water level at least 2 feet below the working level in every excavation, unless the geotechnical report indicates that a lower drawdown is required.
−
−```datasheet
−label: Dewatering Method
−type: select
−options:
− - "Sump pumping with open ditches"
− - "Submersible pumps in gravel sumps"
− - "Wellpoints"
− - "Deep wells (submersible turbine pumps)"
− - "Eductor / vacuum wellpoints"
− - "Not required — groundwater below excavation depth"
−default: "Not required — groundwater below excavation depth"
−```
−
−### The Contractor shall maintain dewatering continuously during all excavation and fill operations until the fill or structure has progressed to a height where groundwater no longer affects compaction or bearing capacity.
−
−### Dewatering shall not be discontinued abruptly.
−
−### If dewatering equipment fails, the Contractor shall immediately notify the Engineer of Record and take emergency measures to prevent flooding of the excavation.
−
−### Groundwater shall not be discharged in a manner that causes erosion, flooding, or contamination of adjacent properties; all dewatering discharge shall comply with applicable NPDES permit conditions and local stormwater regulations.
−
−```datasheet
−label: Dewatering Discharge Management
−type: select
−options:
− - "Discharge to sanitary sewer with utility owner approval"
− - "Discharge to storm system with permit and sediment settling"
− - "Discharge to vegetated buffer on site"
− - "Sediment basin before off-site discharge"
−default: "Sediment basin before off-site discharge"
−```
−
−### Where dewatering causes settlement of adjacent soils or structures, the Contractor shall stop dewatering, notify the Owner and Engineer of Record, and not resume until a revised dewatering plan is approved.
−
−### Fine-grained soils are susceptible to consolidation settlement when groundwater is permanently lowered; the effect on adjacent improvements shall be evaluated by the geotechnical engineer before dewatering begins in such soils.
−
−# Fill and Backfill Materials {toc}
−
−## Material Categories {toc}
−
−### Fill materials shall be free of organic material, frozen lumps, ice, snow, debris, and other deleterious matter.
−
−### All fill material sources — whether excavated from the site or imported — shall be evaluated and approved by the geotechnical engineer before placement.
−
−### The Contractor shall not change material sources without re-evaluation and approval.
−
−### Structural Fill {toc}
−
−#### Structural fill is used beneath foundations, floor slabs, pavements, and other load-bearing applications where settlement or inadequate bearing capacity would cause structural damage. {note}
−
−#### Structural fill shall be granular or low-plasticity cohesive material with USCS classification GW, GP, GM, GC, SW, SP, SM, or SC unless the geotechnical report specifies otherwise.
−
−```datasheet
−label: Structural Fill Material — USCS Classification
−type: checkbox
−options:
− - "GW — Well-graded gravel"
− - "GP — Poorly graded gravel"
− - "GM — Silty gravel"
− - "GC — Clayey gravel"
− - "SW — Well-graded sand"
− - "SP — Poorly graded sand"
− - "SM — Silty sand"
− - "SC — Clayey sand"
− - "CL — Low-plasticity clay (with geotechnical engineer approval)"
−default: "SM — Silty sand"
−```
−
−#### Structural fill maximum particle size shall be 3 inches for lifts up to 8 inches and 6 inches for lifts up to 12 inches, and no particle shall exceed two-thirds of the compacted lift thickness.
−
−```datasheet
−label: Structural Fill — Maximum Particle Size
−type: radio
−unit: inches
−options:
− - "3 in. (lifts up to 8 in.)"
− - "6 in. (lifts up to 12 in.)"
− - "Per geotechnical engineer"
−default: "3 in. (lifts up to 8 in.)"
−```
−
−#### Structural fill liquid limit shall not be greater than 40.
−
−#### Structural fill plasticity index shall not be greater than 15.
−
−#### Structural fill shall be free of organics and deleterious material.
−
−#### Where the geotechnical report indicates that on-site soils are not suitable as structural fill, or where the volume of suitable material is insufficient, the Contractor shall import approved granular fill.
−
−#### Imported structural fill shall be certified by a qualified laboratory prior to delivery, and certification shall include gradation analysis per ASTM C136/C136M and ASTM D7928, Atterberg limits per ASTM D4318, and Proctor test per ASTM D1557, performed on a sample representative of the import source.
−
−### Select Granular Fill {toc}
−
−#### Select granular fill is a high-quality, free-draining material used for pipe bedding, drainage layers under slabs, and applications where low compressibility and positive drainage are required. {note}
−
−#### Select granular fill shall have USCS classification GW, GP, SW, or SP.
−
−#### Select granular fill maximum particle size shall be 1.5 inches unless otherwise specified.
−
−#### Select granular fill shall be non-plastic (liquid limit).
−
−#### Select granular fill fines content (material passing the No. 200 sieve) shall not be greater than 5 percent.
−
−```datasheet
−label: Select Granular Fill — Fines Content Maximum
−type: radio
−unit: percent passing No. 200 sieve
−options:
− - "5 percent"
− - "8 percent"
− - "12 percent (engineering judgment required)"
−default: "5 percent"
−```
−
−### Controlled Low-Strength Material (CLSM) {toc}
−
−#### Controlled Low-Strength Material (CLSM), also known as flowable fill, is a self-compacting cementitious fill that may be used as an alternative to compacted fill in confined spaces, around complex structures, or where compaction is not feasible.
−
−```datasheet
−label: CLSM — Allowed
−type: radio
−options:
− - "Not permitted — all backfill shall be compacted granular or cohesive fill"
− - "Permitted in designated locations only — Engineer of Record approval required"
− - "Permitted at Contractor's option in inaccessible locations"
−default: "Permitted in designated locations only — Engineer of Record approval required"
−```
−
−#### CLSM shall be used only where approved by the Engineer of Record.
−
−#### CLSM mix design shall achieve a 28-day compressive strength of 30 to 200 psi where future excavation may be required, or up to 1,200 psi where re-excavation is not anticipated.
−
−### General Site Fill {toc}
−
−#### General site fill is used in areas remote from structures where settlement over time is acceptable, such as landscaped areas and non-traffic areas beyond the building footprint. {note}
−
−#### General site fill may include cohesive soils with higher plasticity than structural fill, provided the material is free of organics and debris.
−
−#### General site fill shall have USCS classification GW, GP, GM, GC, SW, SP, SM, SC, ML, CL, or ML-CL.
−
−#### General site fill maximum particle size shall be 3 inches.
−
−#### General site fill plasticity index shall not be greater than 30.
−
−#### General site fill shall be free of organics and deleterious material.
−
−#### General site fill shall not be used within 10 feet of building foundations or within any utility trench or pavement subgrade zone unless specifically approved by the geotechnical engineer.
−
−### Unsuitable Material — Use Prohibited {toc}
−
−#### The following materials shall not be used as fill in any application: organic soils, topsoil, peat, or muck; frozen material; high-plasticity material; debris-laden or contaminated material; and combustible material.
−
−```datasheet
−label: Unsuitable Material Disposal
−type: radio
−options:
− - "Remove from site and dispose legally"
− - "Stockpile on site at designated location — Owner approval required"
−default: "Remove from site and dispose legally"
−```
−
−#### Organic soils, topsoil, peat, or muck (any material with organic content greater than 3 percent by mass) shall not be used as fill in any application.
−
−#### Frozen material shall not be used as fill in any application.
−
−#### Material with liquid limit greater than 50 or plasticity index greater than 25 shall not be used as fill in any application, unless specifically approved by the geotechnical engineer for a stated application.
−
−#### Material containing construction debris, chemical contamination, or deleterious substances shall not be used as fill in any application.
−
−#### Trash, wood, and combustible material shall not be used as fill in any application.
−
−## Fill Material Testing Before Placement {toc}
−
−### The Contractor shall submit laboratory test results for each fill source — both on-site stockpiles and import sources — before that material is placed, including USCS classification, gradation, Atterberg limits, and Proctor compaction curve.
−
−### If the source material changes in character during production (e.g., a stockpile contains zones of different material), additional testing shall be performed.
−
−### The geotechnical engineer shall be notified of any material change that may affect suitability.
−
−# Compaction {toc}
−
−## General Compaction Requirements {toc}
−
−### Compaction is the densification of soil by mechanical energy that reduces void space, increases dry density, and reduces future settlement potential. {note}
−### The energy is delivered by compaction equipment — vibratory rollers, tamping foot rollers, plate compactors, and pneumatic rollers — and the effectiveness depends on equipment type, lift thickness, number of passes, and most critically, on the moisture content of the soil relative to its optimum. {note}
−
−### Compaction shall be performed in uniform horizontal lifts of the thickness specified herein, using equipment appropriate for the soil type and application.
−
−```datasheet
−label: Maximum Compacted Lift Thickness — Structural Fill
−type: select
−unit: inches
−options:
− - "6 in."
− - "8 in."
− - "12 in. (where vibratory roller equipment is used and geotechnical engineer verifies)"
−default: "8 in."
−```
−
−```datasheet
−label: Maximum Compacted Lift Thickness — Trench Backfill
−type: select
−unit: inches
−options:
− - "6 in."
− - "8 in."
−default: "6 in."
−```
−
−### No fill shall be placed on frozen subgrade, and no compaction shall be performed on material that is frozen.
−
−### Lift thickness shall not exceed the capability of the compaction equipment to achieve uniform density through the full lift depth.
−
−### A common compaction error is placing lifts that are thicker than the equipment can penetrate, producing a dense top crust that passes density testing while the lower portion remains loose. {note}
−
−### The geotechnical engineer may require proof of uniform compaction by performing density tests at mid-lift depth where there is reason to suspect layering.
−
−## Moisture Conditioning {toc}
−
−### Soil compaction achieves its maximum density at optimum moisture content, as determined by the Proctor test. {note}
−
−### The moisture content range for compaction shall be specified relative to the Proctor optimum, appropriate to the fill soil type.
−
−```datasheet
−label: Moisture Content Range for Compaction
−type: select
−options:
− - "Within -2% to +2% of optimum (cohesive fine-grained soils)"
− - "Within -3% to +1% of optimum (granular soils — prevent collapse on wetting)"
− - "Within -2% to +3% of optimum (less critical fill areas)"
− - "Per geotechnical engineer — site-specific recommendation"
−default: "Per geotechnical engineer — site-specific recommendation"
−```
−
−### Soil that is too dry will not compact fully regardless of roller passes, and soil that is too wet will pump under roller traffic and cannot achieve the required density without drying; both conditions are common causes of compaction failures. {note}
−
−### The Contractor shall measure soil moisture before compaction using a nuclear gauge per ASTM D6938 or by laboratory determination per ASTM D2216.
−
−### If fill is too dry, it shall be wetted uniformly using water trucks or sprinklers and allowed to condition before compaction begins.
−
−### Surface wetting without adequate mixing does not bring the full lift to optimum moisture. {note}
−
−### If fill is too wet, it shall be aerated by discing, blading, or windrowing until moisture falls within the acceptable range.
−
−### The Contractor shall not attempt to compact overly wet material in the expectation that density testing will pass.
−
−### Highly plastic clays are particularly difficult to moisture-condition because they absorb and release water slowly, and such soils may require extended conditioning periods or should be replaced with more workable material.
−
−## Compaction Requirements by Application {toc}
−
−### Structural Fill Under Foundations and Grade Beams {toc}
−
−```datasheet
−label: Compaction — Structural Fill Under Foundations
−type: range
−unit: percent of Modified Proctor (ASTM D1557) maximum dry density
−options:
− min: 92
− max: 100
− setpoints: [92, 95, 97, 98, 100]
−default: 95
−```
−
−#### Structural fill placed beneath footings, grade beams, mat foundations, and foundation walls shall be compacted to a minimum of 95 percent of Modified Proctor maximum dry density (ASTM D1557) unless the geotechnical report specifies a higher value.
−
−#### The geotechnical engineer shall determine the required bearing capacity from the project report and shall direct the compaction criterion accordingly.
−
−#### For highly loaded foundations or expansive soil conditions, compaction to 98 or 100 percent of Modified Proctor may be required.
−
−### Structural Fill Under Floor Slabs and Pavements {toc}
−
−```datasheet
−label: Compaction — Structural Fill Under Slabs on Grade
−type: range
−unit: percent of Modified Proctor (ASTM D1557) maximum dry density
−options:
− min: 90
− max: 100
− setpoints: [90, 92, 95, 98, 100]
−default: 95
−```
−
−#### Fill beneath floor slabs, concrete pavements, and asphalt pavements shall be compacted to a minimum of 95 percent of Modified Proctor maximum dry density unless the structural drawings specify a higher value.
−
−#### The top 6 inches of subgrade immediately beneath the slab or base course shall be compacted to not less than 95 percent of Modified Proctor.
−
−### Trench Backfill {toc}
−
−```datasheet
−label: Compaction — Trench Backfill (Within Structure or Pavement Zone)
−type: range
−unit: percent of Modified Proctor (ASTM D1557) maximum dry density
−options:
− min: 90
− max: 100
− setpoints: [90, 92, 95, 98, 100]
−default: 95
−```
−
−```datasheet
−label: Compaction — Trench Backfill (Outside Structure and Pavement Zone)
−type: range
−unit: percent of Modified Proctor (ASTM D1557) maximum dry density
−options:
− min: 85
− max: 98
− setpoints: [85, 90, 92, 95, 98]
−default: 90
−```
−
−#### Trench backfill within the footprint of any structure, within 5 feet of any foundation, or within any pavement area shall be compacted to a minimum of 95 percent of Modified Proctor maximum dry density.
−
−#### Trench backfill in unpaved areas remote from structures shall be compacted to a minimum of 90 percent.
−
−#### Initial backfill directly over pipe shall be hand-tamped or lightly compacted with small equipment to avoid pipe damage, and after the initial backfill covers the pipe crown by 12 inches, heavier equipment may be used.
−
−### General Site Grading {toc}
−
−```datasheet
−label: Compaction — General Site Fill (Non-Structural Areas)
−type: range
−unit: percent of Standard Proctor (ASTM D698) maximum dry density
−options:
− min: 85
− max: 95
− setpoints: [85, 90, 92, 95]
−default: 90
−```
−
−#### Fill in landscaped areas, turf areas, and other non-traffic, non-structural areas shall be compacted to a minimum of 90 percent of Standard Proctor (ASTM D698) maximum dry density.
−
−#### This value provides adequate stability for surface drainage and vehicle access without over-compacting areas that will be planted. {note}
−
−## Compaction Equipment {toc}
−
−### Compaction equipment shall be selected based on soil type and application.
−
−```datasheet
−label: Compaction Equipment Type
−type: checkbox
−options:
− - "Vibratory smooth-drum roller"
− - "Tamping foot (sheepsfoot) roller"
− - "Pneumatic-tired roller"
− - "Plate compactor"
− - "Jumping jack (vibratory rammer)"
− - "Hand tamper — adjacent to structures only"
−default: "Vibratory smooth-drum roller"
−```
−### Vibratory smooth-drum rollers are effective for granular materials. {note}
−### Tamping foot (sheepsfoot) rollers are effective for cohesive fine-grained soils. {note}
−### Plate compactors and jumping jack tampers are used in confined areas and around utilities where large rollers cannot operate. {note}
−
−### The compaction equipment shall be of adequate size to achieve the required density in the specified lift thickness.
−
−### Light equipment used on heavy lifts will not achieve required compaction regardless of passes. {note}
−
−## Compaction Adjacent to Structures {toc}
−
−```datasheet
−label: Compaction — Minimum Setback from Foundation for Heavy Equipment
−type: radio
−unit: ft
−options:
− - "3 ft"
− - "5 ft"
− - "8 ft (near sensitive structures)"
−default: "5 ft"
−```
−
−### Compaction equipment shall not operate within 5 feet of any foundation wall, retaining wall, buried structure, or buried utility without the approval of the Engineer of Record.
−
−### Heavy vibratory equipment transmits dynamic loads that can crack concrete, displace reinforcement, or damage flexible pipe. {note}
−
−### In the zone within 5 feet of any structure, compaction shall be performed with hand-operated vibratory plate compactors or jumping jack tampers in lifts not exceeding 6 inches.
−
−### The Contractor shall verify that the approved compaction equipment achieves the required density in confined zones by performing test strips before committing to full production.
−
−## Verification of Compaction — Failing Tests {toc}
−
−### When a field density test fails to achieve the required percent compaction, the Contractor shall immediately cease filling the affected area, scarify and rework the failing lift, adjust moisture content if needed, re-compact, and request re-testing at the same location before proceeding.
−
−### A single passing test after a failure does not eliminate the need to understand why the failure occurred. {note}
−
−### The geotechnical engineer shall evaluate patterns of repeated failure, which may indicate that the material is unsuitable, the moisture is persistently out of range, or the equipment is inadequate, and shall direct corrective action.
−
−### The Contractor shall not hide failed test results or attempt to proceed past a failing test based on verbal assurances.
−
−### All test results, including failures, shall be documented, and the corrective action shall be recorded before the next test in the same area.
−
−# Subgrade Preparation {toc}
−
−## Foundation Bearing Subgrade {toc}
−
−```datasheet
−label: Foundation Subgrade Observation — Timing
−type: radio
−options:
− - "Geotechnical engineer present for all foundation excavation bottoms"
− - "Geotechnical engineer called for observation — minimum 24-hour advance notice"
−default: "Geotechnical engineer called for observation — minimum 24-hour advance notice"
−```
−
−### The bearing surface for every spread footing, strip footing, mat foundation, and grade beam shall be observed by the geotechnical engineer of record before any concrete, lean fill, or other material is placed.
−
−### The observation shall confirm that the bearing elevation matches the design, that the material is the bearing stratum identified in the geotechnical report, and that there are no soft spots, disturbed zones, or groundwater that would compromise bearing capacity.
−
−### Loose material, disturbed soil, and standing water shall be removed before observation.
−
−### If the bearing stratum is exposed more than 2 hours in advance of concrete placement, the top 2 to 3 inches shall be re-trimmed immediately before placement to remove desiccated crust in fine-grained soils or disturbed material in granular soils.
−
−### In freezing weather, bearing surfaces shall be protected from frost and shall be confirmed unfrozen by the geotechnical engineer before concrete is placed.
−
−## Proof Rolling {toc}
−
−### Proof rolling consists of driving a fully loaded, rubber-tired vehicle over the prepared subgrade surface to identify soft, pumping, or yielding areas that indicate inadequate bearing or insufficient compaction. {note}
−
−### The proof rolling vehicle shall be specified, loaded sufficiently to reveal soft, pumping, or yielding subgrade areas.
−
−```datasheet
−label: Proof Rolling Vehicle
−type: select
−options:
− - "Fully loaded tandem-axle dump truck (minimum 20-ton loaded weight)"
− - "Fully loaded tri-axle dump truck (minimum 25-ton loaded weight)"
− - "As directed by geotechnical engineer"
−default: "Fully loaded tandem-axle dump truck (minimum 20-ton loaded weight)"
−```
−
−### Proof rolling shall be performed on all areas to receive structural fill under foundations or slabs, on all subgrades to receive base course under pavements, and at any location where the geotechnical engineer suspects inconsistent subgrade conditions.
−
−```datasheet
−label: Proof Rolling Required
−type: radio
−options:
− - "Required — all areas under structural fill, slabs, and pavements"
− - "Required — areas as directed by geotechnical engineer"
− - "Not required on this project"
−default: "Required — all areas under structural fill, slabs, and pavements"
−```
−
−### The geotechnical engineer shall observe all proof rolling.
−
−### Areas that exhibit more than 0.5 inch of deformation, rut, or pumping shall be undercut to competent material and replaced with approved structural fill or otherwise stabilized as directed by the geotechnical engineer.
−
−### The Contractor shall not proceed with fill placement or base course until all failing areas have been remediated and re-proof-rolled.
−
−## Subgrade Stabilization {toc}
−
−### Where the subgrade is soft, wet, or otherwise unable to support compaction equipment or proof-rolling, the geotechnical engineer shall evaluate stabilization options, which include mechanical stabilization, geosynthetic stabilization, chemical treatment, or undercutting and replacement.
−
−```datasheet
−label: Subgrade Stabilization Method (where required)
−type: select
−options:
− - "Crushed stone working layer — per geotechnical engineer"
− - "Geotextile separator with granular fill — per geotechnical engineer"
− - "Lime treatment — per geotechnical engineer (mix design required)"
− - "Cement treatment — per geotechnical engineer (mix design required)"
− - "Undercut and replace with structural fill — per geotechnical engineer"
− - "Not required — subgrade confirmed competent by geotechnical engineer"
−default: "Not required — subgrade confirmed competent by geotechnical engineer"
−```
−
−### Mechanical stabilization may be provided by placing and compacting a layer of clean crushed stone (12 to 24 inches) that bridges the soft zone.
−
−### Geosynthetic stabilization may be provided using a geotextile separator over the soft zone, followed by granular fill.
−
−### Lime or cement treatment of cohesive fine-grained soils may be used to improve workability and bearing capacity.
−
−### Undercutting and replacement with approved granular fill may be used to stabilize a soft, wet, or unstable subgrade.
−
−### Lime and cement treatment requires a mix design developed by a qualified laboratory, field application with calibrated equipment, and curing before the treated layer is loaded.
−
−### Treated layers shall be re-tested before being loaded to confirm achievement of the target unconfined compressive strength.
−
−## Slab-on-Grade Subgrade — Granular Capillary Break {toc}
−
−```datasheet
−label: Capillary Break Layer Under Slab on Grade
−type: radio
−options:
− - "Provided — 4 in. clean crushed stone per drawings"
− - "Provided — 6 in. clean crushed stone per drawings"
− - "Not required — vapor retarder placed directly on compacted subgrade"
−default: "Provided — 4 in. clean crushed stone per drawings"
−```
−
−### Where slabs on grade are designed with a capillary break layer, the layer shall consist of clean crushed stone with less than 5 percent fines (USCS SP or GP), placed and compacted in a single layer of the thickness shown on the drawings.
−
−### The capillary break layer shall be placed after the subgrade has been proof-rolled and accepted by the geotechnical engineer.
−
−### The capillary break layer shall be compacted with a vibratory plate compactor to a stable surface and shall not be over-compacted to the point of crushing aggregate.
−
−### The capillary break layer shall not be contaminated with fines from traffic before the vapor retarder and concrete are placed.
−
−# Erosion and Sediment Control {toc}
−
−## Regulatory Framework and SWPPP {toc}
−
−### Construction activities that disturb 1 acre or more of land — or less if part of a common plan of development that totals 1 acre or more — require coverage under the EPA Construction General Permit (CGP) or the applicable state NPDES stormwater permit before grading begins.
−
−```datasheet
−label: NPDES Stormwater Permit Coverage Required
−type: radio
−options:
− - "Yes — land disturbance 1 acre or greater; SWPPP required before grading"
− - "Yes — part of common plan of development totaling 1 acre or greater"
− - "No — land disturbance less than 1 acre; verify with local authority"
−default: "Yes — land disturbance 1 acre or greater; SWPPP required before grading"
−```
−
−### The Contractor shall obtain all required stormwater permits, prepare a Stormwater Pollution Prevention Plan (SWPPP) in accordance with the permit requirements, and maintain the SWPPP on site at all times for inspection.
−
−### The SWPPP shall describe every Best Management Practice (BMP) to be used, the location of each BMP shown on a site map, the sequence of installation relative to grading operations, the maintenance and inspection protocol, and the basis for determining when the permit can be terminated at project completion.
−
−### The SWPPP shall be updated when conditions change, when BMPs prove ineffective, or when new areas of disturbance are added.
−
−## Sediment Control at Site Perimeter {toc}
−
−### The perimeter of the site shall be protected by sediment controls installed before grading begins, to intercept sediment-laden runoff before it leaves the site.
−
−```datasheet
−label: Perimeter Sediment Control — Primary Method
−type: select
−drawing_ref: "SWPPP site plan"
−options:
− - "Silt fence (slopes not exceeding 2:1, drainage area not exceeding 0.25 acre per 100 ft)"
− - "Fiber wattle / compost sock"
− - "Rock check dams (swales and channels)"
− - "Sediment basin (drainage areas exceeding 5 acres)"
−default: "Silt fence (slopes not exceeding 2:1, drainage area not exceeding 0.25 acre per 100 ft)"
−```
−
−### Silt fence shall be installed by slicing the fabric into the soil using a mechanical device or by digging a 6-inch trench, inserting the fabric, and backfilling.
−
−### Fabric simply staked to the surface without embedment will fail in the first rain event. {note}
−
−### Silt fence shall be inspected after every rain event and repaired or replaced when sediment accumulation reaches one-third of the exposed fabric height.
−
−## Stabilized Construction Entrance {toc}
−
−### A stabilized construction entrance shall be provided at every point where construction vehicles enter or exit the site onto a public road, to remove mud and sediment from tires before vehicles reach the pavement.
−
−```datasheet
−label: Stabilized Entrance — Aggregate Depth
−type: radio
−unit: inches
−options:
− - "6 in."
− - "8 in."
− - "12 in."
−default: "6 in."
−```
−
−```datasheet
−label: Stabilized Entrance — Aggregate Size
−type: radio
−options:
− - "1.5 in. to 3 in. crushed stone"
− - "2 in. to 4 in. crushed stone"
− - "Recycled concrete aggregate"
−default: "1.5 in. to 3 in. crushed stone"
−```
−
−### The stabilized entrance shall extend from the public road into the site at least 50 feet, or the full length of the ingress/egress zone if shorter.
−
−### Where vehicles track mud onto public roads despite the stabilized entrance, the Contractor shall arrange for street sweeping at a frequency that prevents sediment buildup.
−
−## Temporary Slope Protection {toc}
−
−### Temporary seeding with fast-germinating annual grasses provides cost-effective erosion protection for exposed slopes during construction. {note}
−
−### Disturbed slopes shall be protected from erosion by temporary seeding, erosion control blankets, compost applications, or other approved methods when the slope will be exposed for more than 7 days on slopes steeper than 3:1 or more than 14 days on slopes 3:1 or flatter.
−
−```datasheet
−label: Temporary Slope Erosion Protection Method
−type: select
−options:
− - "Temporary seeding — slopes 3:1 or flatter"
− - "Erosion control blanket (straw, wood fiber, or coconut) — slopes steeper than 3:1"
− - "Hydraulic mulch / hydroseed"
− - "Compost blanket"
− - "Combination per SWPPP"
−default: "Temporary seeding — slopes 3:1 or flatter"
−```
−
−## Storm Inlet Protection {toc}
−
−### All storm drain inlets within or immediately downslope of the construction area shall be protected with inlet protection devices to prevent sediment from entering the storm drainage system.
−
−```datasheet
−label: Storm Inlet Protection Device
−type: select
−options:
− - "Silt fence with stakes around inlet"
− - "Prefabricated inlet protection device"
− - "Rock filter dike around inlet"
− - "Drop inlet sediment trap"
−default: "Prefabricated inlet protection device"
−```
−
−### Inlet protection shall be installed before grading begins in the contributing drainage area.
−
−### Inlet protection devices shall be inspected after every rain event and cleaned when sediment accumulates to one-half the device capacity.
−
−### Clogged inlet protection that blocks drainage and causes ponding presents a flooding risk and shall be cleaned immediately.
−
−## Erosion Control Maintenance and Inspection {toc}
−
−```datasheet
−label: BMP Inspection Frequency
−type: radio
−options:
− - "Weekly and within 24 hours after rain events of 0.5 inch or greater"
− - "Every 7 days (regardless of rain events)"
− - "Per permit requirements — check applicable CGP conditions"
−default: "Weekly and within 24 hours after rain events of 0.5 inch or greater"
−```
−
−### All erosion and sediment control BMPs shall be inspected by the Contractor's designated responsible party at least weekly and within 24 hours after any rain event of 0.5 inch or greater.
−
−### Inspection records shall document the condition of each BMP, any deficiencies noted, and corrective actions taken.
−
−### Corrective actions shall be completed within 24 hours of inspection unless weather prevents it, in which case they shall be completed as soon as practicable.
−
−### At project completion, all temporary erosion and sediment control BMPs shall be removed and disturbed areas stabilized with permanent vegetation or hardscape.
−
−### Temporary BMPs shall not be removed until the areas they protect have achieved permanent stabilization.
−
−### Silt fence fabric and other synthetic materials shall be collected and disposed of properly and shall not be buried in place.
−
−# Field Testing and Quality Control {toc}
−
−## Compaction Testing Program {toc}
−
−### Field compaction testing shall be performed by the Owner-retained special inspection or geotechnical firm.
−
−```datasheet
−label: Compaction Testing — Owner Retains Testing Agency
−type: radio
−options:
− - "Yes — testing agency retained by Owner, independent of Contractor"
− - "No — project below threshold requiring special inspection (verify with AHJ)"
−default: "Yes — testing agency retained by Owner, independent of Contractor"
−```
−
−### Testing is Owner-retained because the testing entity must be independent of the Contractor — Contractor-retained testing for compaction acceptance is not acceptable for structural applications. {note}
−
−### The Contractor shall cooperate fully with the testing agency, provide access to all fill areas, and provide information about lift locations, material types, and moisture conditioning operations.
−
−### The testing agency shall use nuclear density gauge testing per ASTM D6938 as the primary production method, with sand cone tests per ASTM D1556/D1556M for verification or calibration.
−
−### The nuclear gauge shall be standardized at the beginning and end of each shift.
−
−### Gauge count standard results shall be recorded and compared to the reference standards.
−
−### If count ratios fall outside acceptable limits, the gauge shall be recalibrated before testing continues.
−
−## Testing Frequency Requirements {toc}
−
−### Minimum testing frequencies, in the absence of project-specific geotechnical recommendations, shall be one test per 2,500 sf of fill surface per lift under foundations and grade beams; one test per 2,500 sf of fill surface per lift under floor slabs and pavements; one test per 100 lf of trench per lift for utility trench backfill within structures or pavement; one test per 250 lf of trench per lift for utility trench backfill in open areas; one test per 5,000 sf of fill surface per lift for general site grading; and additional tests wherever the geotechnical engineer identifies variable conditions or failing results.
−
−```datasheet
−label: Testing Frequency — Under Foundation/Slab (per lift)
−type: select
−options:
− - "1 test per 2,500 sf"
− - "1 test per 1,500 sf (higher-risk or variable conditions)"
− - "1 test per 500 sf (special inspection continuous observation)"
− - "Per geotechnical engineer"
−default: "1 test per 2,500 sf"
−```
−
−### Testing shall be performed at one test per 2,500 sf of fill surface per lift under foundations and grade beams.
−
−### Testing shall be performed at one test per 2,500 sf of fill surface per lift under floor slabs and pavements.
−
−### Testing shall be performed at one test per 100 lf of trench per lift for utility trench backfill within structures or pavement.
−
−### Testing shall be performed at one test per 250 lf of trench per lift for utility trench backfill in open areas.
−
−### Testing shall be performed at one test per 5,000 sf of fill surface per lift for general site grading.
−
−### Additional tests shall be performed wherever the geotechnical engineer identifies variable conditions or failing results.
−
−## Proctor Reference Curves {toc}
−
−```datasheet
−label: Proctor Reference Curves Required
−type: radio
−options:
− - "One per on-site material type placed as structural fill"
− - "One per import source"
− - "Both — on-site and import sources"
−default: "Both — on-site and import sources"
−```
−
−### For each distinct fill material on the project, a Proctor reference curve (maximum dry density vs. moisture content) shall be established by laboratory testing before that material is placed in the field.
−
−### Field density results are meaningless without an accurate reference Proctor. {note}
−
−### If visual observation by the geotechnical engineer suggests that the material being placed has changed from the material on which the reference Proctor was performed, the geotechnical engineer shall direct verification testing on the new material before compaction acceptance continues.
−
−## Foundation Bearing Pressure Verification {toc}
−
−### Where the structural design is based on a minimum allowable bearing pressure, the geotechnical engineer of record shall confirm that the bearing material at the foundation bearing elevation is consistent with the material on which the design bearing pressure is based.
−
−### Consistency is established by visual observation, standard penetration test blow counts from boring logs, hand penetrometer readings, or dynamic cone penetrometer testing in the bearing surface, as appropriate to the material type.
−
−### The geotechnical engineer's written observation report for each foundation bearing elevation shall be provided to the Owner and Engineer of Record and retained in the project file.
−
−## Gradation and Plasticity Testing of Fill Materials {toc}
−
−### In addition to Proctor and density testing, the geotechnical engineer may direct gradation and Atterberg limits tests on fill materials at any time during construction to confirm continued conformance to the approved material description.
−
−### Gradation and plasticity testing shall be performed when material appearance changes, when a new stockpile or import delivery is initiated, or when compaction testing shows unexplained variability that may indicate a material change.
−
−### Gradation and plasticity test frequency shall be as directed by the geotechnical engineer.
−
−## Documentation and Reporting {toc}
−
−```datasheet
−label: Test Report Delivery Time
−type: radio
−options:
− - "Within 24 hours of test"
− - "Same day (digital submittal)"
− - "Weekly batch — not acceptable for structural applications"
−default: "Within 24 hours of test"
−```
−
−### All field testing data shall be recorded on forms that include project name, test date, test location (plan coordinates or station and offset, plus depth or lift number), material description, moisture content, wet density, dry density, percent compaction relative to the applicable Proctor, and pass/fail determination.
−
−### The testing agency shall provide results to the Owner and Contractor within 24 hours of testing.
−
−### Failing tests shall be flagged immediately and shall not be buried in a batch report delivered days later.
−
−### The Contractor must have immediate notice to stop work and address the failure.
−
−# Warranty {toc}
−
−## The Contractor shall warrant earthwork operations for the project warranty period beginning at substantial completion.
−
−```datasheet
−label: Earthwork Warranty Period
−type: select
−options:
− - "1 year from substantial completion"
− - "2 years from substantial completion"
−default: "1 year from substantial completion"
−```
−
−```datasheet
−label: Settlement Monitoring — Required
−type: radio
−options:
− - "Yes — install monuments per geotechnical engineer direction"
− - "No — not required on this project"
−default: "No — not required on this project"
−```
−
−## The Contractor shall warrant earthwork operations, including achievement of specified grades, compaction of all fill and backfill, and the performance of erosion and sediment control measures, for the project warranty period beginning at substantial completion.
−
−## Warranty obligations include correction of settlement, heaving, erosion, or other defects attributable to non-conforming earthwork operations.
−
−## The warranty does not relieve the Contractor of liability for concealed non-conforming work discovered after the warranty period expires, nor does it limit the Owner's remedies for latent defects.
−
−## Settlement or structural distress discovered after the warranty period that is attributable to inadequate compaction or non-conforming fill materials shall be evaluated by the geotechnical engineer and may constitute a latent defect extending beyond the warranty term.
−
−## Settlement monitoring pins or monuments shall be installed where directed by the geotechnical engineer to provide objective data on fill performance during the warranty period.
−
−## Readings shall be taken at the intervals specified by the geotechnical engineer and reported to the Owner.
−
−## Accelerated settlement that exceeds the predicted range shall be reported immediately.
+---
+title: Earthwork
+category: Sitework
+description: >
+ When to use: Mass and structural earthwork for commercial, institutional, industrial, and multi-family building sites, from the cleared and demolished condition through placement of fill and acceptance of the subgrade. Covers excavation to the lines and grades of the grading and foundation drawings, classification of excavated material and rock removal, removal and replacement of unsuitable material, foundation and trench excavation, protection of workers and of adjacent structures in ordinary excavations, routine groundwater control by sump pumping, the fill classes (structural fill, free-draining granular fill, general site fill, recycled concrete aggregate, controlled low-strength material) and their sources, lift placement, moisture conditioning, compaction targets by use, backfill against structures and walls, trench backfill above the pipe zone, backfill of cavities and voids, proof rolling and subgrade acceptance, subgrade stabilization where proof rolling fails, field density testing and acceptance, frozen-ground and wet-weather restrictions, and the disposition of surplus and the sourcing of borrow. Read alongside the geotechnical investigation report and the civil grading drawings, which carry the project-specific values this standard defers to them.
+ Not intended for: highway and roadway embankments built to state DOT specifications, and earthen dams and levees; contaminated soil and hazardous material excavation, which requires a project-specific remediation specification; clearing, grubbing, topsoil stripping and stockpiling, and protection of trees to remain (see [[sync/site-clearing]]); demolition of structures and their foundations (see [[sync/building-demolition]]) and selective removal within a retained structure (see [[sync/selective-demolition]]); finish grading of site surfaces to the tolerances of the trade that follows (see [[sync/site-rough-grading]]); engineered excavation support systems, underpinning, and designed dewatering systems for deep excavations, with their instrumentation and monitoring (see [[sync/excavation-support-and-dewatering]]); construction-phase erosion prevention, sediment control, and the SWPPP (see [[sync/erosion-and-sediment-control]]); aggregate base course beneath pavements, slabs, and pads (see [[sync/aggregate-base-course]]); the granular subbase and vapor retarder directly beneath a building slab (see [[sync/slab-on-grade]] and [[sync/vapor-barriers-under-slab]]); chemical treatment of subgrade with lime, cement, or fly ash (see [[sync/soil-stabilization]]); geotextile and geogrid materials and their installation (see [[sync/geosynthetics]]); aggregate piers, deep mixing, and jet grouting (see [[sync/ground-improvement]]); deep foundation installation, including driven piles, drilled shafts, auger-cast piles, micropiles, and helical piles (see [[sync/deep-foundations]]); spread and strip foundation forming, reinforcement, and concrete (see [[sync/shallow-foundations]]); below-grade waterproofing and dampproofing of foundation walls (see [[sync/below-grade-waterproofing]]); perimeter footing drains and sub-slab drainage layers (see [[sync/foundation-drainage]]); pavement edge drains, underslab relief drains, and other subsurface drainage (see [[sync/subdrainage]]); storm sewer mains, inlets, manholes, and their embedment (see [[sync/storm-drainage]]); water, sanitary sewer, and electrical and telecommunications duct banks outside the building (see [[sync/site-utilities]]); and permanent site retaining walls (see [[sync/retaining-walls]]).
+---
+
+# Scope {toc}
+
+## This standard governs the excavation, fill, backfill, compaction, and subgrade acceptance that shape the site and prepare it to carry foundations, slabs, pavements, utilities, and landscape. {note}
+
+## The work begins at the cleared, grubbed, and demolished condition delivered by the clearing and demolition scopes and ends at an accepted subgrade or bearing surface on which the following trade builds. {note}
+
+## Earthwork is the one scope every later scope inherits, and its defects surface as someone else's problem: a footing settles because the fill beneath it was placed in lifts the roller could not reach, a pavement dishes along a utility trench because the upper backfill was never tested, and a slab cracks because the subgrade was proof-rolled on a dry day and placed on a wet one. {note}
+
+## The geotechnical investigation report is the primary governing document for the soil-specific values in this standard: fill suitability, compaction targets, lift thickness, moisture windows, over-excavation and replacement rules, and allowable bearing. Where this standard carries a value in a datasheet field that defers to the geotechnical report, the report's value governs and the fallback stated here applies only where the report is silent. {note}
+
+## This standard ends at the completion of mass earthwork; [[sync/site-rough-grading]] takes over from that point through delivery of an accepted subgrade and fine-graded surface, and it applies the proof-rolling procedure and acceptance criteria stated in this standard rather than restating them. {note}
+
+## Proof rolling and subgrade acceptance beneath foundations, slabs, pavements, and structural fill are stated once, in this standard, because the standards for those surfaces cite them here. {note}
+
+## The pipe zone of a utility trench, from the trench bottom through the bedding, haunch, and initial backfill to 12 in. above the pipe crown, belongs to the standard for the utility installed: [[sync/site-utilities]], [[sync/storm-drainage]], [[sync/sanitary-sewer-systems]], [[sync/water-distribution-piping]], [[sync/underground-fire-service-mains]], [[sync/foundation-drainage]], [[sync/subdrainage]], [[sync/landscape-irrigation]], and [[sync/packaged-pump-stations]]. This standard resumes above the pipe zone, and it supplies a default pipe-zone material only where the utility standard states none. {note}
+
+## Worker protection in ordinary excavations and trenches, by sloping, benching, trench shields, and tabulated shoring, is within this standard. An excavation that needs an engineered support system, underpinning of an adjacent foundation, or a designed dewatering system is the work of [[sync/excavation-support-and-dewatering]], and this standard states where that threshold is crossed. {note}
+
+## The following are outside this standard: {note}
+
+- Clearing, grubbing, topsoil stripping, and tree protection, which precede this work under [[sync/site-clearing]]
+- Demolition of structures and their foundations under [[sync/building-demolition]], and selective removal within a retained structure under [[sync/selective-demolition]]
+- Finish grading of site surfaces to trade tolerances under [[sync/site-rough-grading]]
+- Erosion prevention, sediment control, and the SWPPP under [[sync/erosion-and-sediment-control]]
+- Aggregate base course under [[sync/aggregate-base-course]], and the granular subbase and vapor retarder directly beneath a building slab under [[sync/slab-on-grade]] and [[sync/vapor-barriers-under-slab]]
+- Chemical treatment of subgrade under [[sync/soil-stabilization]], geotextiles and geogrids under [[sync/geosynthetics]], and aggregate piers, deep mixing, and jet grouting under [[sync/ground-improvement]]
+- Deep foundations under [[sync/deep-foundations]], footings under [[sync/shallow-foundations]], waterproofing under [[sync/below-grade-waterproofing]], and permanent site retaining walls under [[sync/retaining-walls]]
+
+## All earthwork shall conform to the recommendations of the geotechnical investigation report prepared for the project.
+
+## Where this standard and the geotechnical report conflict, the geotechnical report shall govern for soil-specific criteria and this standard shall govern for procedure, testing, and submittal requirements, unless the Engineer of Record directs otherwise in writing.
+
+## The Contractor shall perform excavation and fill to the lines, grades, and limits shown on [[drawing: the grading plan and sections]].
+
+## The Contractor shall coordinate work under this standard with [[sync/erosion-and-sediment-control]] for the grading sequence, stockpile protection, and sediment control on dewatering discharge; with [[sync/site-clearing]] and [[sync/building-demolition]] for the condition of the site at handover; with [[sync/excavation-support-and-dewatering]] for every excavation that needs an engineered system; with the utility standards for the pipe zone of each trench; and with [[sync/aggregate-base-course]], [[sync/slab-on-grade]], [[sync/shallow-foundations]], and [[sync/retaining-walls]] for the surfaces this standard delivers to them.
+
+# Referenced Standards {toc}
+
+## Materials, testing, and execution shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
+
+## Where referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
+
+| Standard | Title |
+|----------|-------|
+| ASTM D698 | Laboratory Compaction Characteristics of Soil Using Standard Effort |
+| ASTM D1557 | Laboratory Compaction Characteristics of Soil Using Modified Effort |
+| ASTM D1140 | Determining the Amount of Material Finer than 75-µm (No. 200) Sieve in Soils by Washing |
+| ASTM D1556/D1556M | Density and Unit Weight of Soil in Place by Sand-Cone Method |
+| ASTM D2167 | Density and Unit Weight of Soil in Place by the Rubber Balloon Method |
+| ASTM D2216 | Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass |
+| ASTM D2321 | Underground Installation of Thermoplastic Pipe for Sewers and Other Gravity-Flow Applications |
+| ASTM D2487 | Classification of Soils for Engineering Purposes (Unified Soil Classification System) |
+| ASTM D2488 | Description and Identification of Soils (Visual-Manual Procedures) |
+| ASTM D2937 | Density of Soil in Place by the Drive-Cylinder Method |
+| ASTM D2974 | Determining the Water (Moisture) Content, Ash Content, and Organic Material of Peat and Other Organic Soils |
+| ASTM D4253 | Maximum Index Density and Unit Weight of Soils Using a Vibratory Table |
+| ASTM D4254 | Minimum Index Density and Unit Weight of Soils and Calculation of Relative Density |
+| ASTM D4318 | Liquid Limit, Plastic Limit, and Plasticity Index of Soils |
+| ASTM D4832 | Preparation and Testing of Controlled Low Strength Material (CLSM) Test Cylinders |
+| ASTM D6103 | Flow Consistency of Controlled Low Strength Material (CLSM) |
+| ASTM D6938 | In-Place Density and Water Content of Soil and Soil-Aggregate by Nuclear Methods (Shallow Depth) |
+| ASTM D7928 | Particle-Size Distribution (Gradation) of Fine-Grained Soils Using the Sedimentation (Hydrometer) Analysis |
+| ASTM C136/C136M | Sieve Analysis of Fine and Coarse Aggregates |
+| AASHTO T 99 | Moisture-Density Relations of Soils Using a 2.5-kg Rammer and a 305-mm Drop |
+| AASHTO T 180 | Moisture-Density Relations of Soils Using a 4.54-kg Rammer and a 457-mm Drop |
+| ACI 229R | Report on Controlled Low-Strength Materials |
+| IBC Chapter 17 | Special Inspections and Tests (International Building Code) |
+| IBC Chapter 18 | Soils and Foundations (International Building Code) |
+| 29 CFR 1926 Subpart P | Excavations (OSHA Safety and Health Regulations for Construction) |
+
+# Submittals {toc}
+
+## Action Submittals {toc}
+
+### The Contractor shall submit the following for review by the Engineer of Record before the earthwork they describe begins:
+
+- Fill source report for each on-site stockpile and each import source proposed as fill: USCS classification per ASTM D2487, gradation per ASTM C136/C136M and ASTM D7928, Atterberg limits per ASTM D4318, organic content per ASTM D2974 where the material is suspected of containing organics, and the laboratory compaction curve by the reference method selected in the datasheet
+- Environmental source documentation for imported fill, where the datasheet requires it
+- Recycled concrete aggregate source report, where the datasheet permits its use as fill
+- Controlled low-strength material mix design with flow per ASTM D6103 and strength per ASTM D4832, where the datasheet permits its use
+- Excavation safety plan prepared or reviewed by the competent person, describing the soil classification method, the protective systems to be used for each excavation 5 ft or deeper, and the means of access and egress
+- Groundwater control plan where sump pumping is anticipated, describing sump locations, pump capacity, the discharge route, and the sediment control it discharges through
+- Earthwork sequence showing the order of mass cut and fill, stockpile locations, and haul routes, coordinated with the sequence in the SWPPP
+
+```datasheet
+label: Action Submittals Required
+type: checkbox
+options:
+ - "Fill source report for each on-site and imported source"
+ - "Environmental source documentation for imported fill"
+ - "Recycled concrete aggregate source report"
+ - "CLSM mix design"
+ - "Excavation safety plan"
+ - "Groundwater control plan for sump pumping"
+ - "Earthwork sequence and stockpile plan"
+default: ["Fill source report for each on-site and imported source", "Excavation safety plan", "Earthwork sequence and stockpile plan"]
+```
+
+### Fill shall not be placed from any source until the fill source report for that source has been reviewed and the source accepted by the geotechnical engineer of record.
+
+### Review of a submittal does not relieve the Contractor of responsibility for compliance with the Contract Documents.
+
+## Closeout Submittals {toc}
+
+### The Contractor shall deliver the following before the subgrade or bearing surface is turned over to the following trade, and shall deliver the compiled set before substantial completion:
+
+- Field density test reports for every test taken, passing and failing, with the location, lift, material, reference curve, dry density, moisture content, percent compaction, and disposition of each
+- Proof-rolling records for each area proof-rolled, with the date, the vehicle and its loaded weight, the areas that failed, and the stabilization applied
+- Geotechnical engineer of record's written observation report for each foundation bearing surface
+- As-built grading survey showing the finished earthwork surface against the design grades
+- Record of each differing site condition encountered, the direction received, and the work performed under it
+- Record of each over-excavation and replacement, with its location, depth, and replacement material
+
+```datasheet
+label: Closeout Submittals Required
+type: checkbox
+options:
+ - "Field density test reports, passing and failing"
+ - "Proof-rolling records"
+ - "Foundation bearing surface observation reports"
+ - "As-built grading survey"
+ - "Differing site condition record"
+ - "Over-excavation and replacement record"
+default: ["Field density test reports, passing and failing", "Proof-rolling records", "Foundation bearing surface observation reports", "As-built grading survey", "Differing site condition record", "Over-excavation and replacement record"]
+```
+
+# Quality Assurance {toc}
+
+## Geotechnical Engineer of Record {toc}
+
+### The Owner shall retain a licensed geotechnical engineer of record to observe earthwork and to interpret the geotechnical report in light of the conditions actually encountered.
+
+### The geotechnical engineer of record shall observe every foundation bearing surface before concrete, lean concrete, or fill is placed on it.
+
+### The geotechnical engineer of record shall observe every proof-rolling operation.
+
+### The geotechnical engineer of record shall accept or reject each proposed fill source on the basis of the fill source report and the requirements of this standard.
+
+### The geotechnical engineer of record shall evaluate each differing site condition reported by the Contractor and shall direct the response in writing.
+
+### The geotechnical engineer of record may stop earthwork that does not conform to the geotechnical report or to this standard, and the Contractor shall comply with that direction.
+
+### The Contractor shall give the geotechnical engineer of record not less than 24 hours notice before each bearing surface, proof-rolling operation, or fill lift is ready for observation.
+
+### The geotechnical engineer's observation is a hold point rather than a courtesy: the bearing stratum identified in the report from a handful of borings is confirmed or contradicted at every footing, and the only person positioned to make that call is the one who wrote the report. {note}
+
+## Testing Agency and Special Inspection {toc}
+
+### Field density testing and fill material testing shall be performed by the testing agency retained as indicated in the datasheet.
+
+```datasheet
+label: Earthwork Testing Agency Retained By
+type: radio
+options:
+ - "Owner"
+ - "Contractor, with results reported directly to the Owner"
+default: "Owner"
+```
+
+### Owner retention keeps the testing agency independent of the party whose work it accepts, which is the arrangement IBC Chapter 17 requires where special inspection applies; Contractor retention with direct reporting to the Owner is used on projects below the special inspection threshold and on design-build work where the Owner has no separate testing contract, and it depends on the reporting path being enforced. {note}
+
+### Where the statement of special inspections on the structural drawings requires special inspection of fill placement under [[parameter: adopted-building-code]] Chapter 17, the special inspector shall perform the periodic or continuous inspection that statement requires and shall report each nonconformance to the Owner and the Engineer of Record.
+
+```datasheet
+label: Special Inspection of Fill Placement
+type: radio
+options:
+ - "Required"
+ - "Not required"
+derived: "the statement of special inspections on the structural drawings under [[parameter: adopted-building-code]] Chapter 17"
+default: derived
+```
+
+### Special inspection does not relieve the geotechnical engineer of record of the separate observation obligations stated in this standard.
+
+### The testing agency shall standardize each nuclear gauge at the start and end of every testing day in accordance with ASTM D6938 and shall record the standard counts.
+
+### The testing agency shall verify nuclear gauge results against the sand-cone method of ASTM D1556/D1556M at a frequency of not less than one verification test per 20 nuclear tests on each material.
+
+## Excavation Competent Person {toc}
+
+### The Contractor shall designate a competent person, as defined in 29 CFR 1926 Subpart P, for every excavation 5 ft or deeper and for every excavation in which a cave-in hazard exists regardless of depth.
+
+### The competent person shall classify the soil of each excavation by the visual and manual tests of 29 CFR 1926 Subpart P Appendix A, shall select or confirm the protective system, and shall inspect the excavation daily before work begins and after every rain, thaw, vibration event, or change in loading.
+
+### The Contractor shall remove workers from any excavation the competent person finds unsafe until the hazard is corrected.
+
+### The Contractor shall not replace the designated competent person with a person who does not meet the same qualification.
+
+## Pre-Earthwork Conference {toc}
+
+### Before mass excavation or fill placement begins, the Contractor shall convene a conference attended by the Contractor's earthwork superintendent, the competent person, the geotechnical engineer of record, the testing agency, the special inspector where one is required, and the Engineer of Record.
+
+### The conference shall review the geotechnical report recommendations, the accepted fill sources, the compaction targets and reference method, the testing frequency and reporting path, the excavation safety plan, the groundwater control plan, the earthwork sequence, and the procedure for reporting differing site conditions.
+
+## Differing Site Conditions {toc}
+
+### The geotechnical report characterizes the subsurface from a limited number of borings and test pits, and the conditions encountered between them differ from the report on most sites in some respect; the procedure below exists so the difference is recorded and resolved rather than argued about after the fill is in place. {note}
+
+### The Contractor shall notify the Engineer of Record and the geotechnical engineer of record in writing within one working day of encountering groundwater, rock, soft or organic soil, buried structures or utilities, or suspected contamination that the geotechnical report and the Contract Documents do not identify at that location.
+
+### The Contractor shall suspend work in the affected area, except work required for immediate safety, until the geotechnical engineer of record directs the response in writing.
+
+### The Contractor shall not remove, cover, or backfill over a differing condition before the geotechnical engineer of record has observed it, except where immediate safety requires it.
+
+### Where the parties disagree whether a condition differs materially from the geotechnical report, the Engineer of Record shall make the initial determination.
+
+# Site and Weather Conditions {toc}
+
+## Groundwater Basis {toc}
+
+### The groundwater condition for earthwork planning shall be [[parameter: seasonal-high-groundwater-elevation]] as established by the geotechnical report, and not the water level observed in the borings on the day they were drilled.
+
+### Excavations whose bottom lies below [[parameter: seasonal-high-groundwater-elevation]] shall be planned for groundwater control before excavation begins, as indicated in the datasheet.
+
+```datasheet
+label: Groundwater Control Anticipated
+type: radio
+options:
+ - "Not anticipated"
+ - "Sump pumping within the excavation"
+ - "Engineered dewatering system"
+derived: "[[parameter: seasonal-high-groundwater-elevation]] and the lowest excavation elevation shown on the grading and foundation drawings"
+default: derived
+```
+
+### Sump pumping handles seepage that enters an excavation through its walls and bottom and can be collected at a low point; it is adequate where the excavation bottom is not far below the water table and the soil is not so fine that pumping draws the bottom up with the water. An engineered system, under [[sync/excavation-support-and-dewatering]], lowers the water table before the excavation reaches it and is the answer where the bottom lies well below the water table, where the soil is a silt or fine sand that will boil or pipe, or where the drawdown reaches adjacent structures. {note}
+
+## Frost and Freezing Weather {toc}
+
+### Fill shall not be placed on a frozen surface.
+
+### Fill placed during freezing weather shall be compacted and tested before it freezes, and a lift that freezes before it is tested shall be removed or thawed, moisture-conditioned, and recompacted before the next lift is placed.
+
+### Foundation bearing surfaces exposed during freezing weather shall be protected from frost by insulation, heated enclosure, or a covering of loose fill, and the geotechnical engineer of record shall confirm the bearing surface unfrozen before concrete is placed.
+
+### Frost-susceptible soil shall not be placed as fill within [[parameter: frost-depth]] of the finished surface beneath pavements, exterior slabs, and footings, unless the geotechnical report permits it for that location.
+
+### A frozen lift looks compacted and tests dense, and then thaws into the loose material it always was; the settlement arrives in the spring, beneath whatever was built on it over the winter. {note}
+
+## Wet Weather {toc}
+
+### The Contractor shall grade every exposed subgrade and fill surface to drain, and shall seal the surface with a smooth-drum roller before leaving it at the end of each working day and ahead of forecast rain.
+
+### Fill operations shall stop when rain raises the moisture content of the fill or the receiving surface above the upper limit of the moisture window in the datasheet.
+
+### After rain, the Contractor shall remove or dry back the wetted material to within the moisture window before placing the next lift, and shall not blend wet material into a thicker lift to average the moisture.
+
+### Fill shall not be placed on a surface with standing water, mud, or a pumping condition, and the surface shall be restored and re-accepted before placement resumes.
+
+# Fill Materials {toc}
+
+## Fill Classes and Sources {toc}
+
+### This standard uses five fill classes, each defined by the properties the use demands rather than by where the material came from: structural fill beneath foundations, slabs, and pavements; free-draining granular fill where water must pass or capillary rise must be stopped; general site fill in landscape and other areas where some long-term settlement is tolerable; recycled concrete aggregate as a processed substitute for either of the first two where the datasheet permits it; and controlled low-strength material where a flowable, self-compacting fill replaces compaction. {note}
+
+### Every fill material, whether excavated on the site or imported, shall be classified per ASTM D2487 and described per ASTM D2488, and shall be identified in the fill source report by its USCS group symbol.
+
+### Every fill material shall be free of organic matter, frozen lumps, ice, snow, debris, and other deleterious material.
+
+### The Contractor shall not change a fill source, and shall not blend sources, without submitting a fill source report for the new or blended material and receiving the geotechnical engineer's acceptance of it.
+
+### The Contractor shall stockpile fill of different classes separately and shall protect each stockpile from contamination, saturation, and drying beyond the moisture window.
+
+### The limits of structural fill beneath the building and beneath pavements shall be as shown on [[drawing: the building pad and pavement limits on the grading plan]].
+
+## Structural Fill {toc}
+
+### Structural fill shall be placed beneath footings, slabs on grade, grade beams, pavements, equipment pads, and site concrete structures, and wherever the drawings call for engineered or compacted fill.
+
+### The USCS groups permitted as structural fill shall be as indicated in the datasheet.
+
+```datasheet
+label: Structural Fill Permitted USCS Groups
+type: checkbox
+options:
+ - "GW"
+ - "GP"
+ - "GM"
+ - "GC"
+ - "SW"
+ - "SP"
+ - "SM"
+ - "SC"
+ - "CL"
+ - "ML"
+drawing_ref: "the geotechnical report fill recommendations"
+default: deferred
+```
+
+### Where the geotechnical report does not state which groups are permitted, structural fill shall be a GW, GP, GM, GC, SW, SP, SM, or SC material.
+
+### The clean gravels and sands (GW, GP, SW, SP) compact readily over a wide moisture range and are the least sensitive to weather, at the cost of import price where the site has none; the silty and clayey sands and gravels (GM, GC, SM, SC) are what most sites yield and compact well inside a narrower moisture window; a low-plasticity clay or silt (CL, ML) can serve as structural fill where the geotechnical engineer has evaluated it for the loads involved, and it is admitted where the alternative is importing everything beneath a large pad, at the cost of a moisture window a wet week can close. {note}
+
+### The maximum particle size in structural fill shall be as indicated in the datasheet.
+
+```datasheet
+label: Structural Fill Maximum Particle Size
+type: range
+unit: in
+min: 1
+max: 6
+setpoints: [1, 1.5, 2, 3, 4, 6]
+default: 3
+```
+
+### No particle in any fill lift shall exceed two-thirds of the compacted thickness of that lift.
+
+### The maximum liquid limit of structural fill shall be as indicated in the datasheet.
+
+```datasheet
+label: Structural Fill Maximum Liquid Limit
+type: range
+min: 20
+max: 50
+step: 1
+default: 40
+```
+
+### The maximum plasticity index of structural fill shall be as indicated in the datasheet.
+
+```datasheet
+label: Structural Fill Maximum Plasticity Index
+type: range
+min: 0
+max: 25
+step: 1
+default: 15
+```
+
+### Where the geotechnical report sets a liquid limit, plasticity index, or particle size limit for structural fill, the report's limit shall govern over the datasheet value.
+
+### Structural fill shall contain not more than 3 percent organic material by mass when tested per ASTM D2974.
+
+## Free-Draining Granular Fill {toc}
+
+### Free-draining granular fill shall be a GW, GP, SW, or SP material, or a clean crushed stone, wherever the drawings call for drainage fill, free-draining backfill, or a capillary break outside the building slab.
+
+### The maximum fines content of free-draining granular fill, as the percentage passing the No. 200 sieve when tested per ASTM D1140, shall be as indicated in the datasheet.
+
+```datasheet
+label: Free-Draining Granular Fill Maximum Fines Content
+type: range
+unit: '% passing No. 200'
+min: 0
+max: 15
+step: 1
+default: 5
+```
+
+### A fines content at or below 5 percent keeps the material permeable and non-frost-susceptible after it has been handled and compacted; a limit of 8 to 12 percent admits a wider range of pit-run sources at the cost of permeability that drops sharply as the fines fill the voids, and it suits locations where the material is a working platform first and a drain second. {note}
+
+### Free-draining granular fill shall be non-plastic.
+
+### The maximum particle size of free-draining granular fill shall not exceed the structural fill maximum particle size in the datasheet, and shall not exceed 2 in. within 24 in. of a waterproofed or dampproofed surface.
+
+## General Site Fill {toc}
+
+### General site fill shall be placed in landscape areas, berms, and other areas that carry no foundation, slab, pavement, or utility, and shall not be placed within 10 ft of a building foundation, beneath any pavement, or in any utility trench unless the geotechnical engineer of record accepts it for that location in writing.
+
+### General site fill shall be a GW, GP, GM, GC, SW, SP, SM, SC, ML, CL, or CL-ML material.
+
+### The maximum plasticity index of general site fill shall be as indicated in the datasheet.
+
+```datasheet
+label: General Site Fill Maximum Plasticity Index
+type: range
+min: 0
+max: 40
+step: 1
+drawing_ref: "the geotechnical report fill recommendations"
+default: deferred
+```
+
+### Where the geotechnical report does not state a plasticity limit for general site fill, the maximum plasticity index shall be 30.
+
+### A higher plasticity limit lets the site's own clay be used as landscape fill instead of being hauled off, at the cost of shrink-swell movement in the finished surface and a moisture window that is slow to recover after rain; a lower limit costs import or disposal and buys a surface that stays where it was graded. {note}
+
+## Recycled Concrete Aggregate {toc}
+
+### Recycled concrete aggregate from demolition on the site or from an off-site processor shall be used as fill only as permitted in the datasheet.
+
+```datasheet
+label: Recycled Concrete Aggregate as Fill
+type: radio
+options:
+ - "Not permitted"
+ - "Permitted as general site fill"
+ - "Permitted as structural fill and as general site fill"
+```
+
+### Crushed concrete from the demolition scopes is a sound, well-graded, free-draining fill when it is processed to a gradation and freed of reinforcing steel, wood, and soil, and using it on the site avoids both a disposal haul and an import haul; it carries a high pH leachate that can harm vegetation and corrode aluminum and galvanized steel in contact with it, it can contain gypsum or other contaminants from the structure it came from, and as structural fill it depends on a processor who can hold a gradation. Prohibiting it is the position where the source cannot be verified; permitting it as general site fill keeps it away from foundations and buried metal; permitting it as structural fill is the position where the source is a controlled processor with gradation and contaminant data. {note}
+
+### Where permitted, recycled concrete aggregate shall be crushed and screened to a maximum particle size not exceeding the structural fill maximum particle size in the datasheet, shall be free of reinforcing steel, wood, gypsum, asphalt, and soil, and shall be reported in the fill source report with gradation per ASTM C136/C136M and a description of the source structure.
+
+### Recycled concrete aggregate shall not be placed within 24 in. of aluminum, galvanized steel, or copper that remains in service, and shall not be placed as general site fill within the root zone of planting shown on the landscape drawings.
+
+### Compaction of recycled concrete aggregate shall be accepted by the method stated in this standard for crushed stone where the material has no usable laboratory compaction curve.
+
+## Controlled Low-Strength Material {toc}
+
+### Controlled low-strength material, a flowable mixture of cement, fly ash or other fine aggregate, water, and admixtures that consolidates without compaction, shall be used as fill or backfill only as permitted in the datasheet.
+
+```datasheet
+label: Controlled Low-Strength Material as Backfill
+type: radio
+options:
+ - "Not permitted"
+ - "Permitted at designated locations"
+ - "Permitted at the Contractor's option in confined locations"
+default: "Permitted at designated locations"
+```
+
+### CLSM fills a space no compactor can reach, under a pipe haunch, around a tank, in a narrow trench against a wall, and it does so without the lift-by-lift testing that compacted fill requires; it costs several times the price of compacted fill by volume, it floats an empty pipe or tank it is placed around, and once it has hardened it is excavated with a breaker rather than a shovel. Restricting it to designated locations keeps the choice with the designer; permitting it at the Contractor's option in confined locations lets the field substitute it wherever compaction cannot be achieved or tested, at the Contractor's cost. {note}
+
+### Where CLSM is used, it shall be proportioned per ACI 229R, shall have a flow of 8 in. or greater per ASTM D6103 at placement, and shall be tested for strength per ASTM D4832.
+
+### The excavatability of CLSM shall be as indicated in the datasheet.
+
+```datasheet
+label: CLSM Excavatability
+type: radio
+options:
+ - "Excavatable"
+ - "Non-excavatable"
+default: "Excavatable"
+```
+
+### Excavatable CLSM shall have a 28-day compressive strength of 50 to 150 psi and a long-term strength not exceeding 300 psi.
+
+### Non-excavatable CLSM shall have a 28-day compressive strength of 300 to 1,200 psi.
+
+### CLSM placed around a pipe, tank, or vault shall be placed in lifts whose height does not float or displace the element, and the element shall be ballasted or restrained during placement.
+
+## Unsuitable Material {toc}
+
+### The following shall not be used as fill in any class: topsoil, peat, muck, and other soil with more than 3 percent organic material by mass per ASTM D2974; frozen material; soil with a liquid limit above 50 or a plasticity index above 25, unless the geotechnical engineer of record accepts it in writing for a stated location; construction debris, trash, wood, and combustible material; and contaminated material.
+
+### Unsuitable material encountered within the limits of a footing, slab, pavement, or structural fill zone shall be removed to the depth directed by the geotechnical engineer of record and replaced with structural fill or as directed under the over-excavation provisions of this standard.
+
+### Unsuitable material shall be disposed of as indicated in the datasheet.
+
+```datasheet
+label: Unsuitable Material Disposition
+type: radio
+options:
+ - "Removed from the site and legally disposed"
+ - "Placed in a designated on-site disposal area"
+default: "Removed from the site and legally disposed"
+```
+
+### Removal is the certain disposition; an on-site disposal area, used where the site has a landscape berm or a non-structural area that can absorb organic or high-plasticity spoil, saves the haul at the cost of a location that can never carry a structure and has to be recorded as such. {note}
+
+## Imported Fill Certification {toc}
+
+### Imported fill shall be certified by a fill source report, tested on a sample representative of the material to be delivered, before the first load is accepted on the site.
+
+### Environmental documentation for imported fill shall be as indicated in the datasheet.
+
+```datasheet
+label: Imported Fill Environmental Documentation
+type: radio
+options:
+ - "Not required"
+ - "Source documentation of origin as clean fill"
+ - "Source documentation and laboratory analysis for contaminants"
+```
+
+### Fill that arrives from an unknown excavation can carry petroleum, metals, or asbestos from the site it left, and the party that accepts it owns the problem thereafter; source documentation names the site and use the material came from, which is enough where the origin is a known construction excavation, while laboratory analysis is the position on a site with a sensitive use, a regulatory clean-fill program, or an import source that is a soil broker rather than a known excavation. {note}
+
+### The testing agency shall sample each import source at the frequency the geotechnical engineer of record directs, and not less than once per 2,000 cubic yards delivered, and shall report any change in classification, gradation, or plasticity from the fill source report.
+
+# Excavation {toc}
+
+## Lines, Grades, and Classification {toc}
+
+### Excavation shall be performed to the lines, grades, and dimensions shown on the drawings, with unformed excavation finished within ±0.1 ft of the design elevation.
+
+### Excavated material that meets a fill class in this standard shall be stockpiled for reuse in that class, and material that meets no fill class shall be handled as unsuitable material or as surplus.
+
+### Excavation shall be classified for measurement and payment as indicated in the datasheet.
+
+```datasheet
+label: Excavation Classification Basis
+type: radio
+options:
+ - "Unclassified"
+ - "Classified, with rock excavation measured separately"
+default: "Unclassified"
+```
+
+### Unclassified excavation puts the whole subsurface at the Contractor's risk and price, which is the usual position on a building site with a geotechnical report and no rock in the borings; classified excavation pays rock separately at a unit price, which moves that risk to the Owner and is the position where the borings show rock within the excavation depth and the quantity cannot be estimated closely enough to price. {note}
+
+### Where excavation is classified, rock shall be defined as material that cannot be excavated with a hydraulic excavator of the class the Contractor has on the site, and the geotechnical engineer of record shall confirm the classification of each occurrence before it is measured.
+
+## Rock Excavation {toc}
+
+### Rock encountered within the excavation shall be removed by a method permitted in the datasheet.
+
+```datasheet
+label: Rock Removal Methods Permitted
+type: checkbox
+options:
+ - "Mechanical ripping"
+ - "Hydraulic breaker"
+ - "Drilling and blasting"
+ - "Expansive chemical agents"
+default: ["Mechanical ripping", "Hydraulic breaker"]
+```
+
+### Ripping and hydraulic breaking remove weathered, fractured, and soft rock with the equipment already on the site and are limited by the hardness and continuity of the rock; blasting removes sound rock at a fraction of the cost per cubic yard but needs a licensed blaster, a permit, a vibration and air-blast monitoring program, and distance from structures the jurisdiction and the neighbors will tolerate; expansive chemical agents break rock without vibration or flyrock, at a slow rate and a high cost per cubic yard, and are the method next to a structure that blasting could not be brought near. {note}
+
+### Where blasting is permitted, the Contractor shall obtain the permits the jurisdiction requires, shall conduct a pre-blast condition survey of every structure within the distance the permit or the Engineer of Record specifies, and shall monitor ground vibration and air overpressure at the nearest structure for every blast.
+
+### Rock excavated beneath a footing or slab shall be removed to the elevation directed by the geotechnical engineer of record, and the void shall be filled with lean concrete or compacted crushed stone to the design bearing elevation.
+
+### Rock excavated in a trench shall be removed to not less than 6 in. below the pipe invert, and the trench bottom shall be brought back to grade with the bedding material the utility standard requires.
+
+### A pipe laid on a rock trench bottom bears on a point that never moves while the soil on either side of it settles, and the pipe shears at that point; the bedding course over rock exists to spread that reaction. {note}
+
+## Unsuitable Material Removal {toc}
+
+### Where soft, organic, loose, or otherwise unsuitable material is encountered at the design excavation bottom beneath a footing, slab, or structural fill zone, the Contractor shall notify the geotechnical engineer of record and shall over-excavate to the depth and lateral extent the geotechnical engineer directs.
+
+### The over-excavation beneath a footing shall extend laterally beyond each footing edge a distance not less than the depth of over-excavation, unless the geotechnical engineer of record directs otherwise.
+
+### Over-excavation beneath a footing or slab shall be replaced with the material indicated in the datasheet.
+
+```datasheet
+label: Over-Excavation Replacement Beneath Footings and Slabs
+type: select
+options:
+ - "Lean concrete"
+ - "Compacted structural fill"
+ - "Compacted crushed stone"
+ - "Controlled low-strength material"
+```
+
+### Lean concrete restores the bearing elevation in one pour with no compaction testing and no dependence on the weather, at a material cost that governs where the over-excavation is deep or wide; compacted structural fill is the economical replacement for a large area where the replacement can be placed in lifts and tested; compacted crushed stone is the replacement where the bottom is wet, because it can be placed and worked into a soft bottom without a moisture window; CLSM behaves like lean concrete in a narrow or irregular hole where a concrete truck chute cannot reach the bottom. {note}
+
+### Over-excavation and replacement directed by the geotechnical engineer of record for a condition the geotechnical report did not identify shall be paid as a change; over-excavation to correct the Contractor's own over-digging or disturbance shall be at the Contractor's expense.
+
+### The Contractor shall record the location, depth, lateral extent, and replacement material of each over-excavation and shall include the record in the closeout submittals.
+
+## Foundation Excavation {toc}
+
+### Foundation excavation shall be performed to the neat lines and bearing elevations shown on [[drawing: the foundation plan and footing schedule]], plus the working space required for forming, waterproofing, and drainage.
+
+### The final 6 in. of excavation to a bearing surface shall be removed by a smooth-edged bucket or by hand immediately before the geotechnical engineer's observation, so the bearing surface is undisturbed and has not been exposed to drying or wetting.
+
+### A bearing surface exposed for more than two hours before concrete placement, or exposed to rain, shall be trimmed to fresh material before concrete is placed.
+
+### The bearing surface shall be level, free of loose material and standing water, and at the elevation shown, and the geotechnical engineer of record shall confirm in writing that the material exposed is the bearing stratum on which the design bearing pressure is based.
+
+### Where the material exposed is not the bearing stratum identified in the geotechnical report, the geotechnical engineer of record shall direct over-excavation and replacement under this standard, or shall direct a change to the foundation under the Engineer of Record's authority.
+
+### A footing excavation that is dug too deep is not fixed by throwing the spoil back in: the loosened material beneath the footing compresses under the first load it sees, and the footing follows it down. {note}
+
+## Trench Excavation {toc}
+
+### Trenches for utilities shall be excavated to the alignment, depth, and grade shown on [[drawing: the utility plan and profiles]].
+
+### Trench width at the pipe springline shall be as required by the standard for the utility installed, and where that standard states none, not less than the pipe outside diameter plus 16 in. and not less than the width needed to place and compact the embedment on each side of the pipe.
+
+### The trench bottom shall be excavated to undisturbed material at the grade required by the utility standard, and shall not be brought back to grade with loose spoil where it is over-excavated.
+
+### Where the trench bottom is soft, pumping, or otherwise unable to support the pipe and its embedment, the trench bottom shall be stabilized by over-excavation and replacement with compacted crushed stone, with a separation geotextile under [[sync/geosynthetics]] where the stone is placed against fine-grained soil, to the depth the geotechnical engineer of record directs at each occurrence.
+
+### The pipe zone of each trench shall be constructed under the standard for the utility installed, and where that standard states no pipe-zone material, the pipe-zone material shall be as indicated in the datasheet.
+
+```datasheet
+label: Default Pipe-Zone Material Where the Utility Standard States None
+type: select
+options:
+ - "ASTM D2321 Class I crushed stone"
+ - "ASTM D2321 Class II clean sand and gravel"
+ - "Native soil free of stones larger than 1 in."
+ - "Controlled low-strength material"
+```
+
+### Crushed stone gives a flexible pipe its haunch support on placement, with no compaction effort in the one place a compactor cannot reach, and is the material where the trench is wet; clean sand is the material for small-diameter irrigation and conduit where stone would abrade the pipe and a shovel-placed sand envelope is all the support the pipe needs; screened native soil is the least-cost envelope for a rigid pipe or a conduit in a dry trench in sandy soil, and it is the material a wet or clayey trench cannot use; CLSM encases the pipe without compaction where the trench is too narrow to work in, at the cost of floating the pipe unless it is restrained. {note}
+
+### Where the utility standard and this standard both state a pipe-zone requirement, the more stringent shall govern.
+
+### Excavated material shall not be stockpiled within 2 ft of the edge of a trench, and the setback shall increase to the height of the stockpile where the stockpile is more than 2 ft high.
+
+### Trenches shall not be left open overnight within 50 ft of an occupied building or a public way without barricades and lighting, and no trench shall be left open longer than the time needed to install, test, and backfill the utility in it.
+
+## Excavation Adjacent to Existing Structures {toc}
+
+### Before excavating within a horizontal distance from an existing foundation, pavement, or utility equal to the depth of the excavation below it, the Contractor shall survey and document the condition of that structure and shall deliver the survey to the Owner and the Engineer of Record.
+
+### Excavation shall not remove lateral or vertical support from an existing foundation, as required by IBC Chapter 18, by excavating below a plane rising at 1H:1V from the bottom edge of that foundation, unless the foundation is first underpinned or supported by an engineered system designed and installed under [[sync/excavation-support-and-dewatering]].
+
+### The Contractor shall monitor each existing structure within the surveyed distance for movement or distress for the duration of the excavation adjacent to it, and shall report any change from the condition survey to the Engineer of Record within one working day.
+
+### Existing structures and utilities adjacent to the excavation shall be as shown on [[drawing: the existing conditions and demolition plans]], and the Contractor shall locate every underground utility in the area of work by the one-call service and by hand digging within the tolerance zone the utility owner specifies before excavating with equipment.
+
+### A footing undermined by an adjacent excavation does not fail during the excavation; it fails later, after the backfill has been placed and nobody is watching, because the soil beneath its edge moved toward the open face and the footing rotated to follow it. {note}
+
+## Worker Protection in Excavations {toc}
+
+### Every excavation 5 ft or deeper, and every shallower excavation in which the competent person finds a cave-in hazard, shall be protected by sloping, benching, a trench shield, or a shoring system that conforms to 29 CFR 1926 Subpart P.
+
+### Sloping and benching shall conform to the maximum allowable slopes of 29 CFR 1926 Subpart P Appendix B for the soil type the competent person has classified, and timber and aluminum hydraulic shoring shall conform to the tabulated data of Appendices C and D.
+
+### An excavation deeper than 20 ft, an excavation whose protective system cannot be selected from the tabulated appendices, and an excavation whose support restrains movement of an adjacent structure shall be protected by a system designed under [[sync/excavation-support-and-dewatering]].
+
+### Selection of the protective system is the Contractor's responsibility, and the Engineer of Record's review of the excavation safety plan does not approve or warrant the protective system.
+
+### The Contractor shall provide a ladder, ramp, or other means of egress within 25 ft of lateral travel of every worker in an excavation 4 ft or deeper.
+
+### No worker shall enter an unprotected excavation 5 ft or deeper for any purpose, including hand trimming, pipe laying, grade checking, or inspection.
+
+### A worker shall not work beneath a load suspended over an excavation, beneath the raised bucket of an excavator, or on the downhill side of a stockpile that can slide into the excavation.
+
+### Permanent cut slopes shall be finished to the slopes shown on the grading drawings and shall not be steeper than the maximum the geotechnical report permits for the soil at that location.
+
+## Stockpiles, Surplus, and Borrow {toc}
+
+### Stockpiles shall be located as shown on [[drawing: the staging and stockpile areas on the site plan]], outside the limits of structural fill, foundations, and pavements, and outside the drip line of trees to remain.
+
+### Each stockpile shall be surrounded by the sediment controls required by [[sync/erosion-and-sediment-control]] and shall be shaped to shed water.
+
+### The surcharge of a stockpile shall not be placed within a horizontal distance of any excavation, retaining wall, or buried structure equal to the height of the stockpile.
+
+### Excavated material in excess of the fill needed on the site shall be disposed of as indicated in the datasheet.
+
+```datasheet
+label: Surplus Excavated Material Disposition
+type: radio
+options:
+ - "Removed from the site and legally disposed"
+ - "Placed as general site fill in designated areas"
+ - "Stockpiled on the site for the Owner's use"
+default: "Removed from the site and legally disposed"
+```
+
+### Removal is the clean closeout and the position on a tight site; placing surplus as general site fill in a berm or a landscape area avoids the haul where the grading plan has room for it and the material meets the general site fill class; stockpiling for the Owner suits a campus or industrial site that will use the material on later work, at the cost of a stockpile the Owner then owns and has to protect. {note}
+
+### Where the fill needed on the site exceeds the suitable material excavated, the Contractor shall furnish borrow from an off-site source that has been accepted on a fill source report, or from an on-site borrow area where one is designated on the grading drawings.
+
+### An on-site borrow area shall be excavated to the limits and finished slopes the grading drawings show for it and shall be left draining, and material shall not be borrowed from any area that will carry a foundation, slab, or pavement.
+
+### Cut and fill quantities are the Contractor's to estimate from the grading drawings and the geotechnical report, and the Contractor shall not claim a change for a shortfall or surplus of on-site material unless it results from a differing site condition recorded under this standard.
+
+# Groundwater Control {toc}
+
+## Routine groundwater control within this standard is the collection and removal of seepage by sumps and pumps inside the excavation; the design and operation of wellpoint, deep well, eductor, and cutoff systems are the work of [[sync/excavation-support-and-dewatering]], and this standard requires that work wherever sump pumping cannot hold the condition stated below. {note}
+
+## The Contractor shall keep every excavation free of standing water from the time it is opened until the fill, concrete, or utility in it has been placed to the height stated below.
+
+## The groundwater level within an excavation shall be held below the working surface by not less than the drawdown indicated in the datasheet throughout excavation, bearing surface preparation, fill placement, and compaction.
+
+```datasheet
+label: Minimum Drawdown Below the Working Surface
+type: range
+unit: ft
+min: 1
+max: 5
+setpoints: [1, 2, 3, 4, 5]
+default: 2
+```
+
+## Sumps shall be located outside the footprint of any footing and outside the pipe zone of any trench, and a sump excavated below the bearing elevation shall be backfilled with compacted crushed stone or lean concrete when it is abandoned.
+
+## Where sump pumping draws fines out of the excavation bottom or walls, causes the bottom to heave or boil, or cannot hold the groundwater at the required drawdown, the Contractor shall stop excavation, notify the geotechnical engineer of record, and provide an engineered dewatering system under [[sync/excavation-support-and-dewatering]] before resuming.
+
+## Groundwater control shall continue without interruption until the structure or fill in the excavation has reached a height at which the groundwater no longer affects its bearing, compaction, or stability, and shall not be discontinued abruptly where the geotechnical engineer of record has identified adjacent soils subject to consolidation on recharge.
+
+## A pipe, tank, vault, or basin placed in a trench or pit below the groundwater level shall be backfilled to a cover sufficient to resist flotation, or ballasted as its manufacturer requires, before groundwater control is discontinued.
+
+## Dewatering discharge shall pass through the sediment controls required by [[sync/erosion-and-sediment-control]] and shall be routed to the destination indicated in the datasheet.
+
+```datasheet
+label: Dewatering Discharge Destination
+type: select
+options:
+ - "Storm drainage system through a sediment control device"
+ - "Sanitary sewer with the utility owner's written approval"
+ - "Vegetated area or infiltration basin on the site"
+ - "Surface water under a discharge permit"
+drawing_ref: "the SWPPP"
+default: deferred
+```
+
+## Discharge to the storm system is the usual route and depends on the sediment control being sized for the pump rate rather than for runoff; discharge to the sanitary sewer is available only where the utility owner agrees and charges for it, and is the route where the groundwater is contaminated; land application on the site is the route where the site has room and the soil can take the flow; a surface-water discharge needs its own permit and its own monitoring and is the route where no other is available. {note}
+
+## Dewatering discharge shall not be routed into a storm or sanitary line that has not yet been tested and accepted, and shall not cause erosion, flooding, or sediment deposition on adjacent property.
+
+## Where groundwater control causes settlement of adjacent ground or structures, the Contractor shall stop pumping, notify the Owner and the Engineer of Record, and resume only under a revised plan the geotechnical engineer of record has accepted.
+
+# Fill and Backfill Placement {toc}
+
+## Preparation of the Surface to Receive Fill {toc}
+
+### Before fill is placed on any surface, that surface shall be stripped of topsoil, vegetation, and unsuitable material, and shall be proof-rolled and accepted under this standard where it will carry structural fill.
+
+### Where fill is placed on a slope steeper than 5H:1V, the slope shall be benched into firm material in steps not less than 2 ft high and wide enough for the compaction equipment, so each lift of fill is keyed into the slope.
+
+### Where the surface to receive fill is scarified, moisture-conditioned, and recompacted, the top 8 in. of that surface shall be compacted to the target for the fill above it before the first lift is placed.
+
+### Fill placed on an unbenched slope is a lift sitting on a ramp, and it moves down the ramp as a unit the first time the slope is saturated. {note}
+
+## Lift Placement {toc}
+
+### Fill shall be placed in horizontal lifts of uniform thickness across the full width of the fill area, and each lift shall be compacted and accepted before the next lift is placed.
+
+### The maximum loose lift thickness for fill compacted by rollers shall be as indicated in the datasheet.
+
+```datasheet
+label: Maximum Loose Lift Thickness, Roller-Compacted Fill
+type: range
+unit: in
+min: 4
+max: 12
+setpoints: [4, 6, 8, 10, 12]
+drawing_ref: "the geotechnical report compaction recommendations"
+default: deferred
+```
+
+### Where the geotechnical report does not state a lift thickness, the maximum loose lift thickness for roller-compacted fill shall be 8 in.
+
+### The maximum loose lift thickness for fill compacted by hand-operated plate compactors or rammers, in trenches above the pipe zone, against structures, and wherever rollers cannot operate, shall be as indicated in the datasheet.
+
+```datasheet
+label: Maximum Loose Lift Thickness, Hand-Compacted Fill
+type: range
+unit: in
+min: 3
+max: 8
+setpoints: [3, 4, 6, 8]
+default: 6
+```
+
+### A thick lift compacts at the top and stays loose at the bottom, and a density test taken in the top 6 in. passes it; the lift limit is set by the depth the compactor actually densifies, which is why the hand-compactor limit is lower than the roller limit and why a heavier roller can earn a thicker lift from the geotechnical engineer and a lighter one cannot. {note}
+
+### The Contractor shall select compaction equipment suited to the material: vibratory smooth-drum rollers for granular fill, padfoot or sheepsfoot rollers for cohesive fill, and plate compactors or rammers in confined zones.
+
+### Where the Contractor proposes a lift thickness greater than the datasheet value for a specific roller, the Contractor shall demonstrate it on a test strip of not less than 100 ft by 20 ft, with density tests at the top, middle, and bottom of the lift, and the geotechnical engineer of record shall accept or reject the thicker lift in writing for that roller and that material.
+
+## Moisture Conditioning {toc}
+
+### Fill shall be compacted at a moisture content within the window below and above the optimum moisture content of the reference compaction curve, as indicated in the datasheet.
+
+```datasheet
+label: Moisture Window Below Optimum
+type: range
+unit: percentage points
+min: 0
+max: 5
+step: 1
+drawing_ref: "the geotechnical report compaction recommendations"
+default: deferred
+```
+
+### The upper limit of the moisture window above optimum shall be as indicated in the datasheet.
+
+```datasheet
+label: Moisture Window Above Optimum
+type: range
+unit: percentage points
+min: 0
+max: 5
+step: 1
+drawing_ref: "the geotechnical report compaction recommendations"
+default: deferred
+```
+
+### Where the geotechnical report does not state a moisture window, fill shall be compacted at a moisture content within 2 percentage points below and 2 percentage points above optimum.
+
+### A window set dry of optimum, such as 3 below to 1 above, suits a clean granular fill that collapses on wetting if it is compacted dry and loose; a window set wet of optimum, such as 0 below to 4 above, suits an expansive clay that swells less when it is compacted wet and close to its final moisture; a symmetrical window is the general-purpose setting for the silty and clayey sands that make up most structural fill. The geotechnical report sets the window for the site's soil, and the fallback here is the symmetrical one. {note}
+
+### The Contractor shall measure the moisture content of each lift before compaction, by nuclear gauge per ASTM D6938 or by oven drying per ASTM D2216, and shall add water by distributor truck and mix it through the lift, or shall dry the lift by discing and aeration, until the moisture content is within the window.
+
+### Water sprayed on the surface of a lift and not mixed through it does not condition the lift, and a lift that is wet on top and dry below will not reach density at any number of passes. {note}
+
+### The Contractor shall not attempt to compact material outside the moisture window on the expectation that the density test will pass.
+
+## Compaction Targets by Use {toc}
+
+### Compaction targets in this standard are expressed as a percentage of the maximum dry density from the reference compaction curve selected under the field density testing provisions, and each target is tied to the surface the fill supports rather than to the material placed. {note}
+
+### Structural fill beneath footings, grade beams, slabs on grade, and equipment pads, and the upper 12 in. of native subgrade beneath them, shall be compacted to not less than the percentage of maximum dry density indicated in the datasheet.
+
+```datasheet
+label: Compaction Target, Fill Beneath Foundations and Slabs
+type: range
+unit: '% of maximum dry density'
+min: 90
+max: 100
+setpoints: [90, 92, 95, 98, 100]
+drawing_ref: "the geotechnical report compaction recommendations"
+default: deferred
+```
+
+### Where the geotechnical report does not state a target for fill beneath foundations and slabs, the target shall be 95 percent of maximum dry density.
+
+### Fill beneath pavements and the upper 12 in. of native subgrade beneath them shall be compacted to not less than the percentage of maximum dry density indicated in the datasheet.
+
+```datasheet
+label: Compaction Target, Fill Beneath Pavements
+type: range
+unit: '% of maximum dry density'
+min: 90
+max: 100
+setpoints: [90, 92, 95, 98, 100]
+drawing_ref: "the geotechnical report compaction recommendations"
+default: deferred
+```
+
+### Where the geotechnical report does not state a target for fill beneath pavements, the target shall be 95 percent of maximum dry density.
+
+### General site fill in landscape areas, berms, and other areas that carry no structure, pavement, or utility shall be compacted to not less than the percentage of maximum dry density indicated in the datasheet.
+
+```datasheet
+label: Compaction Target, General Site Fill
+type: range
+unit: '% of maximum dry density'
+min: 85
+max: 95
+setpoints: [85, 88, 90, 92, 95]
+drawing_ref: "the geotechnical report compaction recommendations"
+default: deferred
+```
+
+### Where the geotechnical report does not state a target for general site fill, the target shall be 90 percent of maximum dry density.
+
+### A higher target buys less settlement and a stiffer subgrade at the cost of more passes, a narrower moisture window, and more failed tests on a wet day; the 95 percent fallback is the figure beneath which footings and slabs are designed on most sites, a 98 or 100 percent target is set where the geotechnical report has a settlement-sensitive structure or a heavily loaded floor, and the general site fill target is set lower so landscape areas are not compacted to a density roots cannot penetrate. {note}
+
+### Where the geotechnical report states a compaction target for a use not listed above, that target shall govern for that use.
+
+### Where the fill is a clean crushed stone or a recycled concrete aggregate with no usable laboratory compaction curve, the geotechnical engineer of record shall accept compaction by relative density per ASTM D4253 and ASTM D4254 at not less than 70 percent, or by a method specification of lift thickness and roller passes demonstrated on a test strip, and the datasheet target shall not be applied to that material.
+
+## Backfill Adjacent to Structures and Walls {toc}
+
+### Backfill against foundation walls, retaining walls, and buried structures shall not be placed until the structure has reached the strength its standard requires for backfilling, until waterproofing and drainage against it have been installed and accepted, and until the wall is braced or its supporting floor is in place where the wall design depends on that support.
+
+### Backfill material against below-grade walls, beyond the drainage envelope required by [[sync/foundation-drainage]], shall be as indicated in the datasheet.
+
+```datasheet
+label: Backfill Material Against Below-Grade Walls
+type: select
+options:
+ - "Free-draining granular fill"
+ - "Structural fill"
+ - "General site fill"
+ - "Controlled low-strength material"
+```
+
+### Free-draining fill behind a wall keeps hydrostatic pressure off the wall and the waterproofing and is the material where no drainage composite is installed on the wall face; structural fill is the material where the backfill also carries a slab, pavement, or footing above it; general site fill is the economical backfill where a drainage composite handles the water and the surface above is landscape, at the cost of a clay that swells against the wall if the window is not held; CLSM backfills a narrow space between a wall and a shored excavation face where nothing else can be compacted, and loads the wall as a fluid while it sets. {note}
+
+### Backfill against a structure shall be placed in lifts on both sides of the structure at the same time, with the difference in fill height across a wall not exceeding 2 ft unless the wall is designed for the unbalanced load.
+
+### The maximum particle size in backfill within 24 in. of a structure, a waterproofed or dampproofed surface, or a drainage composite shall be as indicated in the datasheet.
+
+```datasheet
+label: Maximum Particle Size in Backfill Adjacent to Structures
+type: range
+unit: in
+min: 0.75
+max: 4
+setpoints: [0.75, 1, 1.5, 2, 3, 4]
+default: 2
+```
+
+### Heavy compaction equipment shall not operate within the setback from a wall, buried structure, or waterproofed surface indicated in the datasheet, and backfill within that setback shall be compacted with hand-operated plate compactors or rammers in lifts not exceeding the hand-compacted lift thickness in the datasheet.
+
+```datasheet
+label: Heavy Equipment Setback From Walls and Buried Structures
+type: range
+unit: ft
+min: 2
+max: 10
+setpoints: [2, 3, 4, 5, 6, 8, 10]
+default: 5
+```
+
+### A roller against a wall delivers a lateral load the wall was not designed for and a vibration that cracks the waterproofing and dislodges the drainage composite, while hand equipment in thin lifts reaches the same density without either; the setback is set wider where the wall is tall, cantilevered, or carries a brittle coating, and narrower where it is a short wall with a membrane that tolerates it, and the particle size limit keeps the stone that would puncture a membrane out of the zone where it would be pressed against one. {note}
+
+### Backfill against a structure shall be compacted to the target for the surface it supports, and not less than the general site fill target.
+
+### Backfill against waterproofed surfaces shall also conform to the lift and equipment limits of [[sync/below-grade-waterproofing]], and the more stringent limit shall govern.
+
+## Trench Backfill Above the Pipe Zone {toc}
+
+### Trench backfill above the pipe zone shall be placed in lifts not exceeding the hand-compacted lift thickness in the datasheet until 24 in. of compacted cover is in place over the pipe crown, and in roller-compacted lifts thereafter.
+
+### Trench backfill above the pipe zone shall be compacted to the target in this standard for the area in which the trench falls: the foundation and slab target within the building footprint and within 5 ft of any footing, the pavement target beneath pavements and within 5 ft of the pavement edge, and the general site fill target elsewhere.
+
+### Trench backfill above the pipe zone shall be structural fill wherever the trench falls within the building footprint, beneath a pavement, or within 5 ft of a footing or pavement edge, and shall be general site fill or structural fill elsewhere.
+
+### Compaction equipment shall not be operated over a pipe until the cover the utility standard requires for construction loading is in place.
+
+### Water jetting and flooding shall not be used to consolidate trench backfill.
+
+### Jetting consolidates a clean sand and does nothing to anything else, and the trench it is used in is rarely clean sand all the way up; the pavement over a jetted trench settles into the voids the water left behind. {note}
+
+### Where a trench crosses a pavement or a slab that is already in place, the Contractor shall saw-cut the edges, shall backfill the trench with structural fill or CLSM to the subgrade, and shall restore the aggregate base and the surface under the standards for those materials.
+
+## Backfill of Cavities and Voids {toc}
+
+### Cavities left by grubbing, by removal of foundations, basements, tanks, utilities, and other buried structures, and by extraction of sheet piles, soldier piles, and wellpoints, shall be backfilled under this standard after the removal has been verified by the party responsible for it.
+
+### A cavity within the building footprint, beneath a pavement, or within the structural fill zone shall be backfilled with structural fill compacted to the target for the surface above it, after the sides of the cavity have been benched or the loose material removed so the fill keys into firm ground.
+
+### A cavity below the groundwater level, a cavity too narrow to compact in, and a cavity beneath a structure that cannot be undermined shall be backfilled with CLSM or compacted crushed stone placed through the water or into the void, as the geotechnical engineer of record directs.
+
+### Where a basement or foundation wall is left in place below grade under the demolition scope, the Contractor shall breach the floor and walls at the intervals the demolition standard requires before backfilling, so the backfilled cavity drains.
+
+### An intact basement slab left under a new building is a bathtub, and the fill placed in it stays saturated and soft no matter how it was compacted. {note}
+
+# Subgrade Acceptance and Proof Rolling {toc}
+
+## Proof Rolling Procedure {toc}
+
+### Every subgrade that will carry structural fill, a slab, a pavement, or an aggregate base course, and every structural fill surface on which a slab, pavement, or base course will be placed, shall be proof-rolled in the presence of the geotechnical engineer of record and accepted in writing before the next material is placed on it.
+
+### Proof rolling shall be performed with a loaded rubber-tired vehicle, a tandem-axle or tri-axle dump truck or a pneumatic-tired roller, with a gross loaded weight not less than that indicated in the datasheet.
+
+```datasheet
+label: Proof-Rolling Vehicle Minimum Gross Weight
+type: range
+unit: tons
+min: 10
+max: 40
+setpoints: [10, 15, 20, 25, 30, 40]
+default: 20
+```
+
+### Proof rolling shall cover the entire area in overlapping passes in two perpendicular directions, at a speed not exceeding 3 mph, and the geotechnical engineer of record shall mark every area that ruts, pumps, deflects, or rebounds.
+
+### An area that deflects or ruts more than the limit indicated in the datasheet under the proof-rolling vehicle, or that pumps or rebounds visibly, shall be rejected and stabilized under this standard before it is re-proof-rolled.
+
+```datasheet
+label: Proof-Rolling Deflection Limit
+type: range
+unit: in
+min: 0.5
+max: 2
+setpoints: [0.5, 1, 1.5, 2]
+default: 1
+```
+
+### A heavier vehicle and a tighter deflection limit find the soft spots that a slab or a pavement would find later, at the cost of rejecting a subgrade that a lighter check would have passed and of a rejected area the Contractor has to stabilize; the 20-ton tandem and a 1 in. limit are the usual pairing beneath pavements and building pads, a 25 to 30 ton tri-axle and a 0.5 in. limit are set where the pavement carries heavy truck traffic or the floor carries racking, and a lighter vehicle and a looser limit are set over a utility corridor where a heavy truck would damage the pipes beneath. {note}
+
+### Proof rolling shall not be performed on a subgrade that is frozen, that has standing water on it, or that was wetted by rain within the previous 24 hours unless the geotechnical engineer of record directs that it proceed.
+
+### A subgrade accepted by proof rolling shall be re-proof-rolled if it is exposed to rain, freezing, or construction traffic after acceptance and before the next material is placed, and the Contractor shall protect an accepted subgrade from each of these.
+
+### Proof rolling is the test the density test cannot replace: a density test proves the top 6 in. of one spot, while a loaded truck proves the whole area to the depth its load reaches, and it is the soft lens 18 in. down beneath a passing density test that a proof roll finds. {note}
+
+## Subgrade Stabilization Where Proof Rolling Fails {toc}
+
+### An area rejected by proof rolling shall be stabilized by the method indicated in the datasheet, to the depth and extent the geotechnical engineer of record directs at each occurrence, and shall be re-proof-rolled and accepted before the next material is placed.
+
+```datasheet
+label: Subgrade Stabilization Method Where Proof Rolling Fails
+type: select
+options:
+ - "Scarify, moisture-condition, and recompact"
+ - "Undercut and replace with structural fill"
+ - "Undercut and replace with crushed stone"
+ - "Undercut, separation geotextile, and crushed stone"
+ - "Geogrid-reinforced crushed stone platform"
+ - "Chemical treatment"
+```
+
+### Scarifying and recompacting corrects a surface that is wet or loose but sound below, and does nothing for a soft stratum beneath it; undercutting and replacing with structural fill corrects a shallow soft zone where the replacement can be compacted in lifts and tested; crushed stone replaces fill where the undercut bottom is wet and nothing with a Proctor curve could be compacted on it; a separation geotextile beneath the stone, under [[sync/geosynthetics]], keeps the stone from being pushed into a fine-grained bottom and lets a thinner stone layer do the work; a geogrid platform bridges a deep soft zone with the least stone where undercutting to firm material is not practical; chemical treatment under [[sync/soil-stabilization]] dries and strengthens a wet clay in place over a large area where undercutting would move too much material. {note}
+
+### Where the rejected area results from a soft or wet condition the geotechnical report identified at that location, or from the Contractor's own traffic, exposure, or failure to protect an accepted subgrade, stabilization shall be at the Contractor's expense; where it results from a condition the geotechnical report did not identify, stabilization shall be paid as a change.
+
+### The Contractor shall record each stabilized area, its extent and depth, and the method used, and shall include the record in the proof-rolling records.
+
+# Field Density Testing and Acceptance {toc}
+
+## Compaction Reference and Test Methods {toc}
+
+### The laboratory compaction curve against which field density is compared shall be developed for each fill material by the reference method indicated in the datasheet, which shall be the method on which the geotechnical report's compaction recommendations are based.
+
+```datasheet
+label: Laboratory Compaction Reference Method
+type: radio
+options:
+ - "ASTM D698 standard effort"
+ - "ASTM D1557 modified effort"
+derived: "the compaction test method on which the geotechnical report states its compaction recommendations"
+default: derived
+```
+
+### Modified effort produces a maximum dry density several pounds per cubic foot higher and an optimum moisture several points lower than standard effort on the same soil, so 95 percent of one is not 95 percent of the other, and a target stated against the wrong curve is either unachievable or meaningless; the method follows the geotechnical report because the report's bearing and settlement analysis assumed one of them, and the field cannot choose the other. {note}
+
+### A new laboratory compaction curve shall be developed whenever the fill material changes in classification, gradation, or plasticity from the material on which the current curve was run, and the geotechnical engineer of record shall direct a one-point check per ASTM D698 or ASTM D1557 whenever field results suggest the curve no longer represents the material.
+
+### Field density and moisture shall be measured by the method indicated in the datasheet.
+
+```datasheet
+label: Field Density Test Method
+type: select
+options:
+ - "Nuclear gauge, ASTM D6938"
+ - "Sand cone, ASTM D1556/D1556M"
+ - "Rubber balloon, ASTM D2167"
+ - "Drive cylinder, ASTM D2937"
+default: "Nuclear gauge, ASTM D6938"
+```
+
+### The nuclear gauge tests a spot in a few minutes without disturbing it, which lets the same spot be retested after more passes and lets a technician keep pace with the fill; the sand cone is the reference method that the gauge is checked against and the method where a gauge cannot be licensed or carried; the rubber balloon serves the same role in a fine-grained soil where the sand cone's hole will not hold; the drive cylinder tests a cohesive soil where a sample can be taken intact, and cannot test gravel or stone. {note}
+
+### Field density tests shall be taken in the full depth of the lift being tested, with the gauge probe set to the depth of the lift, and not in the surface crust.
+
+## Testing Frequency {toc}
+
+### Field density tests on fill and backfill beneath foundations, slabs, pavements, and within the structural fill zone shall be taken at not less than one test per lift for each area of fill surface indicated in the datasheet, and not less than one test per lift in any such area.
+
+```datasheet
+label: Fill Area Per Density Test, Structural Fill Zones
+type: range
+unit: sq ft per test per lift
+min: 500
+max: 5000
+setpoints: [500, 1000, 1500, 2000, 2500, 3000, 5000]
+default: 2500
+```
+
+### Field density tests on general site fill shall be taken at not less than one test per lift for each area of fill surface indicated in the datasheet, and not less than one test per lift in any such area.
+
+```datasheet
+label: Fill Area Per Density Test, General Site Fill
+type: range
+unit: sq ft per test per lift
+min: 1000
+max: 10000
+setpoints: [1000, 2500, 5000, 7500, 10000]
+default: 5000
+```
+
+### Field density tests on trench backfill above the pipe zone shall be taken at not less than one test per lift for each length of trench indicated in the datasheet, and not less than one test per lift in any trench.
+
+```datasheet
+label: Trench Length Per Density Test
+type: range
+unit: linear ft per test per lift
+min: 50
+max: 300
+setpoints: [50, 100, 150, 200, 300]
+default: 100
+```
+
+### A denser testing grid catches a thin lift or a dry zone before the next lift buries it, at the cost of a technician who cannot keep pace with a large fill; the 2,500 sq ft grid beneath structures and the 100 ft trench interval are the usual settings, a 500 to 1,000 sq ft grid is set beneath a mat foundation or a heavily loaded floor, and the general site fill grid is opened up because the consequence of a soft spot in a lawn is a depression rather than a crack. {note}
+
+### Where the geotechnical report states a testing frequency, the report's frequency shall govern, and the geotechnical engineer of record may increase the frequency in any area that shows variable material, variable moisture, or failing tests.
+
+### The testing agency shall take not less than one field density test on each day on which fill is placed, in each distinct fill area, regardless of the area placed.
+
+## Failing Tests and Retesting {toc}
+
+### Where a field density test fails the target, the Contractor shall scarify the lift, adjust its moisture to within the window, recompact it, and request a retest at the same location before placing the next lift.
+
+### Where the retest also fails, the Contractor shall remove the lift to the previously accepted surface, or shall rework the lift with the material, moisture, equipment, or lift thickness changed as the geotechnical engineer of record directs, and shall retest.
+
+### The cost of retesting after a failed test, and of the rework, shall be borne by the Contractor.
+
+### Where tests in an area fail repeatedly, the geotechnical engineer of record shall determine whether the material, the moisture, the equipment, or the lift thickness is the cause and shall direct the change in writing.
+
+### A failed test reported after the next lift is placed cannot be retested at the same location, and the lift above it has to come off to reach it; the reporting requirement below exists so the failure is known before that happens. {note}
+
+### Fill placed over a failed lift before the retest has passed shall be removed at the Contractor's expense.
+
+## Test Records {toc}
+
+### Each field density test shall be recorded with the project, date, test number, location by coordinates or by station and offset, lift number and elevation, material and its reference curve, wet density, moisture content, dry density, percent of maximum dry density, the target, and the pass or fail result.
+
+### The testing agency shall report each failing test to the Contractor's superintendent and to the geotechnical engineer of record on the day the test is taken, before the next lift is placed over it.
+
+### The testing agency shall deliver the written report of each day's tests to the Owner, the Engineer of Record, the geotechnical engineer of record, and the Contractor within 24 hours of the tests.
+
+### Failing tests shall appear in the written reports with their retests, and a report that omits a failing test shall be corrected and reissued.
+
+# Warranty {toc}
+
+## The Contractor shall warrant the earthwork against settlement, heave, and loss of grade attributable to nonconforming fill material, placement, moisture, or compaction for the period indicated in the datasheet, beginning at substantial completion.
+
+```datasheet
+label: Earthwork Warranty Period
+type: range
+unit: years
+min: 1
+max: 5
+setpoints: [1, 2, 3, 5]
+default: 1
+```
+
+## A one-year correction period matches the general warranty of most construction contracts and catches the settlement that appears through the first wet season and the first freeze; a longer period is set where the fill is deep, where the structure above it is settlement-sensitive, or where the Owner has had fill settle on earlier work and wants the exposure to last past the second winter. {note}
+
+## Warranty correction shall include removal and replacement of the nonconforming fill, restoration of the surface and of the structure, pavement, utility, or landscape above it, and the repair of damage to adjacent work caused by the settlement or by the correction, at the Contractor's expense.
+
+## Where the parties disagree whether settlement is attributable to nonconforming earthwork or to a cause outside the Contractor's control, the geotechnical engineer of record shall make the initial determination.
+
+## The warranty does not limit the Owner's remedies for a latent defect in fill or compaction discovered after the warranty period.