1 Scope

NOTE This standard covers the materials, fabrication, installation, monitoring, and testing of deep foundation elements that transfer structure loads through weak or compressible strata to competent bearing soil or rock. (1.1)

NOTE Deep foundation elements covered are driven piles, cast-in-place drilled shafts and piers, continuous flight auger (CFA) piles, micropiles, and helical piles. (1.2)

NOTE A deep foundation is required where the geotechnical report determines that a shallow foundation cannot satisfy bearing capacity or settlement criteria. Common drivers include weak near-surface soils, high concentrated column loads, uplift from wind or buoyancy, expansive or collapsible soils, liquefaction, and scour. The geotechnical report — not this standard — establishes the design loads, resistance, and target bearing stratum. (1.3)

1.4 The Contractor shall furnish all deep foundation elements and accessories, perform installation and field monitoring, and execute the specified load and integrity testing program.

1.5 The Contractor shall not deviate from the foundation type, tip elevation, or minimum penetration shown on the Contract Documents without the written approval of the Engineer of Record.

NOTE Items excluded from this standard (1.6)

NOTE The following are governed by other standards or are owner/engineer deliverables, and are not specified here: (1.7)

Shallow spread footings, mat foundations, and grade beam design — general structural concrete design.
Concrete mix design, formwork, and placement for pile caps and grade beams — Cast In Place ConcreteCast-in-Place ConcreteResolves to the current edition.sync/cast-in-place-concrete.
Mild and prestressed reinforcement detailing within pile caps and pile/shaft cages — Concrete ReinforcementConcrete ReinforcementResolves to the current edition.sync/concrete-reinforcement.
Excavation, shoring, and dewatering of foundation pits — EarthworkEarthworkResolves to the current edition.sync/earthwork.
Permanent earth-retention and retaining wall systems — Retaining WallsSite Retaining WallsResolves to the current edition.sync/retaining-walls.
Soil borings, laboratory testing, and the geotechnical report — geotechnical engineering deliverables that precede and govern this work.

2 Referenced Standards

2.1 Materials, fabrication, installation, and testing shall comply with the latest adopted edition of each of the following unless a specific edition is cited on the Contract Documents.

2.2 Where referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.

2.3 Where the locally adopted building code differs from a referenced industry standard, the building code as adopted by the Authority Having Jurisdiction shall govern.

Standard	Title
IBC 2021 Section 1810	International Building Code, Chapter 18 — Deep Foundation Elements
ASTM D1143/D1143M	Deep Foundations Under Static Axial Compressive Load
ASTM D3689/D3689M	Deep Foundations Under Static Axial Tensile Load
ASTM D4945	High-Strain Dynamic Testing of Deep Foundations
ASTM D6760	Integrity Testing of Concrete Deep Foundations by Ultrasonic Crosshole Testing
ASTM D5882	Low Strain Impact Integrity Testing of Deep Foundations
ASTM D8169/D8169M	Deep Foundations Under Bi-Directional Static Axial Compressive Load
ASTM A252/A252M	Welded and Seamless Steel Pipe Piles
ASTM A36/A36M	Carbon Structural Steel
ASTM A572/A572M	High-Strength Low-Alloy Columbium-Vanadium Structural Steel
ACI 318	Building Code Requirements for Structural Concrete
ACI 336.3R	Report on Design and Construction of Drilled Piers
FHWA NHI-16-009	Drilled Shafts: Construction Procedures and LRFD Design Methods

NOTE ACI 336.3R and FHWA NHI-16-009 are guidance and design references, not enforceable codes; where they are invoked, the enforceable structural requirements are those of ACI 318 and the adopted building code. (2.4)

3 System Selection

NOTE Deep foundation type is a design decision made by the Engineer of Record from the geotechnical report; it is recorded here so the field requirements that follow are scoped to the selected system. (3.1)

3.2 The selected deep foundation system shall be as shown on the Contract Documents and shall not be substituted without written approval of the Engineer of Record.

NOTE Each deep foundation type carries distinct trade-offs in capacity, soil suitability, vibration and noise, site access, and schedule. The notes below summarize the basis for selection so that field substitution requests can be evaluated against the original intent. (3.3)

NOTE Selection considerations by type (3.4)

Driven piles (steel H, steel pipe, precast prestressed concrete, timber) suit sites with a reachable competent stratum and tolerance for driving vibration and noise; installation provides a real-time driving record.
Drilled shafts/piers (straight or belled) suit high single-element loads and rock sockets; they are low-vibration but sensitive to caving soils and groundwater.
CFA / auger-cast piles are fast and low-vibration but require continuous grout/concrete monitoring and are difficult to verify after installation.
Micropiles suit restricted-access sites, underpinning, and hard or obstructed ground; they develop capacity primarily in grout-to-ground bond.
Helical piles suit lighter loads, fast installation, and immediate loading, with installation torque used as a real-time capacity indicator.

3.5 The deep foundation system type shall be specified as shown on the Contract Documents, selected based on the load transfer mechanism given in the geotechnical report.

Deep foundation system typeradio

○ Steel H-pile (driven)

○ Steel pipe pile (driven)

○ Precast prestressed concrete pile (driven)

○ Timber pile (driven)

● Drilled shaft / pier (cast-in-place)

○ Continuous flight auger (CFA / auger-cast)

○ Micropile

○ Helical pile

3.6 The load transfer mechanism (end bearing, skin friction, or combined) shall be as determined by the geotechnical report and shall govern the required tip elevation and embedment depth.

Primary load transfer mechanismradio

○ End bearing

○ Skin friction

● Combined end bearing and skin friction

4 Design Loads and Capacity

NOTE Required capacities are established by the structural and geotechnical engineers; this section captures them as datasheet fields so the field can confirm the installation criteria against the design intent. (4.1)

4.2 The basis of design — allowable stress design (ASD) or load and resistance factor design (LRFD) — shall be stated on the Contract Documents and shall be consistent between the geotechnical report and the structural drawings.

NOTE Mixing ASD allowable capacities with LRFD factored resistances between the geotechnical report and the structural drawings is a frequent source of sizing errors; both documents shall use the same basis, and the basis shall be confirmed before fabrication. (4.3)

4.4 Each deep foundation element shall develop the design axial compression capacity shown on the Contract Documents.

4.5 Where uplift is shown, each element shall develop the design tension (uplift) capacity shown on the Contract Documents.

4.6 Where lateral load is shown, each element shall develop the design lateral capacity at the head deflection limit shown on the Contract Documents.

Design basisradio

○ Allowable stress design (ASD)

● Load and resistance factor design (LRFD)

Design axial compression capacity per elementrange

kips

204000

Per drawings

Design uplift (tension) capacity per elementrange

kips

01500

Per drawings (deferred by default)

Design lateral capacity per elementrange

kips

0200

Per drawings (deferred by default)

4.7 In cohesive soils the capacity of a closely spaced pile group is less than the sum of the individual pile capacities; the pile cap design shall use the group capacity, applying the group efficiency factor from the geotechnical report.

NOTE Group efficiency in clays can reduce group capacity 20 to 40 percent below the sum of individual capacities; designing the cap on individual capacities can overload the group. The geotechnical report establishes the applicable efficiency. (4.8)

5 Tip Elevation and Penetration

NOTE Specifying tip elevation and minimum penetration separately is the single most important field control for deep foundations; conflating them is a common and expensive error. (5.1)

5.2 The required minimum tip elevation for each element shall be shown on the Contract Documents foundation plan and pile schedule.

5.3 The required minimum penetration into the bearing stratum for each element shall be shown on the Contract Documents.

5.4 Tip elevation fixes where the element must reach; minimum penetration fixes how far it must embed into competent material. An element that reaches the nominal tip elevation but has not penetrated the bearing stratum (for example, stopping on a boulder or a lens of dense fill) has not achieved capacity and shall not be accepted.

5.5 An element that achieves design resistance above the specified tip elevation shall not be accepted as final without the written approval of the Engineer of Record, because premature refusal may indicate an obstruction rather than the bearing stratum.

5.6 An element that reaches the specified tip elevation without achieving the required driving resistance or torque shall be reported to the Engineer of Record, who shall determine whether additional penetration, a longer element, or a redesign is required.

5.7 The pile head cutoff elevation shall be shown on the Contract Documents foundation sections.

5.8 Cutoff lengths and drilled shaft overcast generate spoil; the Contractor shall include cutoff and spoil removal and disposal in the work and shall not leave concrete or steel spoil at grade.

6 Driven Pile Materials

NOTE Driven piles develop capacity through displacement and end bearing, and provide a driving record that documents capacity in real time. Material grade governs the allowable driving stress and the structural capacity of the section. (6.1)

6.2 Steel H-Piles

6.2.1 Steel H-piles shall conform to ASTM A572 Grade 50, or to ASTM A36 where shown on the Contract Documents.

6.2.2 H-pile sections (HP shapes) shall be rolled, not built up from plate, unless built-up sections are specifically shown and detailed.

6.2.3 H-piles shall be furnished in the shape designation shown on the Contract Documents.

H-pile section (HP shape)select

HP10x42

HP10x57

HP12x53

HP12x63

HP12x74

HP12x84

HP14x73

HP14x89

HP14x102

HP14x117

HP16x141

HP18x204

Structural steel grade (H-pile)radio

○ ASTM A36 (Fy = 36 ksi)

● ASTM A572 Grade 50 (Fy = 50 ksi)

6.2.4 Where hard driving or end bearing on rock is anticipated, H-piles shall be furnished with a cast-steel driving point (pile tip reinforcement) at the toe.

6.3 Steel Pipe Piles

6.3.1 Steel pipe piles shall conform to ASTM A252, of the grade shown on the Contract Documents.

NOTE ASTM A252 Grade 3 provides the highest minimum yield (45 ksi) and is the default for new permanent construction; Grade 2 (35 ksi) may be used where driving stresses and capacity demands permit. (6.3.2)

6.3.3 Pipe piles shall be furnished open-end or closed-end as shown on the Contract Documents.

6.3.4 Closed-end pipe piles shall be fitted with a flat or conical steel plate closure plate fully welded to the pile toe.

6.3.5 The pile wall thickness shall be not less than the value shown on the Contract Documents, exclusive of any sacrificial corrosion allowance.

Pipe pile outside diameterselect

10.75 in

12.75 in

14 in

16 in

18 in

20 in

24 in

30 in

36 in

Pipe pile wall thicknessrange

in

0.251

Default: 0.5 in

Pipe pile grade (ASTM A252)radio

○ Grade 2 (Fy = 35 ksi)

● Grade 3 (Fy = 45 ksi)

Pipe pile end conditionradio

○ Open-end

● Closed-end with welded plate

6.3.6 Where pipe piles are to be filled with concrete, the concrete shall conform to Cast In Place ConcreteCast-in-Place ConcreteResolves to the current edition.sync/cast-in-place-concrete and shall be placed only after the pile interior has been inspected and dewatered.

6.4 Precast Prestressed Concrete Piles

6.4.1 Precast prestressed concrete piles shall be manufactured under plant quality control with concrete and prestressing strand conforming to the Contract Documents and to ACI 318.

6.4.2 Precast concrete piles shall be furnished in the cross-section (square or octagonal) and size shown on the Contract Documents.

6.4.3 Precast concrete piles shall not be handled, transported, or driven until the concrete has reached the release and driving strengths shown on the Contract Documents.

Precast concrete pile cross-sectionradio

● Square

○ Octagonal

Precast concrete pile sizeselect

10 in

12 in

14 in

16 in

18 in

20 in

24 in

Precast pile concrete strength (f'c) at 28 daysrange

psi

50008000

Default: 6000 psi

6.5 Timber Piles

6.5.1 Timber piles shall be furnished only where shown on the Contract Documents, shall be of the species and grade specified, and shall be pressure-treated with preservative to the retention shown for the site exposure.

NOTE Timber piles shall be straight, free of decay and large knots, and shall not be driven where the cutoff is permanently above the lowest expected groundwater level unless treated for that exposure. (6.5.2)

7 Cast-in-Place Drilled Shafts

NOTE Drilled shafts (also called drilled piers or caissons) carry high single-element loads with low vibration, but they are constructed in the ground and cannot be inspected end-to-end after placement; success depends on disciplined hole stabilization, cleaning, and concrete placement. (7.1)

7.2 Drilled shafts shall be constructed to the diameter, tip elevation, and rock socket (where shown) on the Contract Documents shaft schedule.

Drilled shaft diameterrange

in

18120

Default: 36 in

7.3 Belled (underreamed) shafts shall be constructed only in cohesive soils capable of standing during belling, with the bell diameter and geometry shown on the Contract Documents.

Shaft base typeradio

● Straight shaft

○ Belled (underreamed)

○ Rock socket

NOTE A belled shaft enlarges the base to increase end bearing in stiff clay; bells are not used in sands, in caving soils, or in rock. The bell diameter is commonly limited to about three times the shaft diameter. (7.4)

7.5 Hole Stabilization

7.5.1 The method of hole stabilization — open hole (dry), temporary casing, permanent casing, or slurry — shall be shown on the Contract Documents or shall be submitted by the Contractor for approval before drilling.

7.5.2 Temporary or permanent steel casing shall be provided wherever the bore passes through caving soils, soft near-surface zones, or where groundwater is above the bearing stratum.

7.5.3 Failure to specify casing in caving sands or high groundwater leads contractors to assume open-hole drilling, which can cause the shaft to collapse and contaminate the concrete; casing requirements shall be explicit in the Contract Documents.

7.5.4 Where slurry is used to stabilize the bore, the slurry type (mineral/bentonite, polymer, or water) and its control properties shall be submitted and maintained throughout drilling and concrete placement.

7.5.5 Permanent casing, where shown, shall not be considered in the structural capacity of the shaft unless it is specifically designed and detailed as a composite section.

Drilled shaft hole stabilization methodradio

○ Open hole (dry)

● Temporary steel casing

○ Permanent steel casing

○ Mineral (bentonite) slurry

○ Polymer slurry

7.6 Base Cleaning and Inspection

7.6.1 Before placing reinforcement and concrete, the base of each shaft shall be cleaned of loose, disturbed, or softened material.

7.6.2 For shafts designed for end bearing, the cumulative loose sediment at the base shall not exceed the depth shown on the Contract Documents, and shall be verified by the Inspector before concrete placement.

7.6.3 The base condition shall be documented for each shaft before concrete placement, by direct observation in dry holes or by an approved sounding or weighted-tape method in wet or slurry holes.

7.7 Concrete for Drilled Shafts

7.7.1 Concrete for drilled shafts shall conform to Cast In Place ConcreteCast-in-Place ConcreteResolves to the current edition.sync/cast-in-place-concrete for the strength shown, and shall be proportioned for the placement method (free-fall in dry holes, or tremie/pump in wet or cased holes).

7.7.2 Concrete placed by tremie or pump shall be a self-consolidating or high-slump-flow mix proportioned to flow through and around the reinforcing cage without vibration and without segregation.

7.7.3 Specifying only a slump for drilled shaft concrete, rather than a slump flow and a placement-specific mix design, produces stiff mixes that bridge across the cage and leave honeycombing and voids; the mix shall be specified for the actual placement method.

7.7.4 Concrete shall be placed continuously and shall be raised at a rate that keeps the tremie or pump line embedded in fresh concrete at all times, so that no soil, water, or slurry is trapped within the shaft.

7.7.5 Where temporary casing is withdrawn during placement, a positive head of fluid concrete shall be maintained above the bottom of the casing at all times to prevent inflow of soil or groundwater.

Drilled shaft concrete strength (f'c) at 28 daysrange

psi

40006000

Default: 4000 psi

Concrete placement method (drilled shaft)radio

○ Free-fall (dry hole)

● Tremie

○ Pump

Concrete consistency (tremie / pump placement)range

in

711

Default: 9 in

8 Continuous Flight Auger (CFA) Piles

NOTE CFA (auger-cast) piles are installed by drilling a continuous hollow-stem auger to depth, then pumping grout or concrete under pressure through the stem as the auger is withdrawn. They are fast and low-vibration, but because the soil is never fully open the process must be monitored continuously to confirm a sound shaft. (8.1)

8.2 CFA piles shall be installed to the diameter and tip elevation shown on the Contract Documents.

8.3 Grout or concrete shall be pumped continuously under positive pressure as the auger is withdrawn, so that the head of grout at the auger tip exceeds the surrounding soil and groundwater pressure at all times.

8.4 The auger shall be withdrawn at a controlled rate matched to the grout pumping rate, so that the volume of grout placed at each increment of withdrawal equals or exceeds the theoretical volume of the hole.

8.5 Each CFA pile shall be monitored with an automated recording system logging depth, grout pressure, grout volume, and auger rotation and withdrawal rate versus depth.

8.6 A grout-volume ratio (placed volume divided by theoretical volume) below the specified minimum at any depth indicates necking or soil inflow and shall be reported to the Engineer of Record.

CFA pile diameterselect

12 in

14 in

16 in

18 in

24 in

30 in

36 in

CFA grout/concrete strength (f'c) at 28 daysrange

psi

40006000

Default: 4000 psi

Minimum acceptable grout-volume ratiorange

%

100150

Default: 115 %

8.7 Reinforcement, where shown, shall be placed into the fluid grout column immediately after the pile is cast, before initial set, to the depth shown on the Contract Documents.

9 Micropiles

NOTE Micropiles are small-diameter (typically 5 to 12 in.) drilled and grouted elements that develop capacity primarily through grout-to-ground bond along the bond zone. They are used for underpinning, restricted-access sites, and hard or obstructed ground where conventional drilling or driving is impractical. (9.1)

9.2 Micropiles shall be installed to the diameter, bond zone length, and tip elevation shown on the Contract Documents.

9.3 The micropile shall be reinforced with the steel casing, all-thread bar, or combination shown on the Contract Documents, with corrosion protection appropriate to the soil exposure.

9.4 Grout shall be a neat cement grout proportioned to the water-cement ratio and minimum compressive strength shown, and shall be placed to fill the drilled hole from the bottom up.

9.5 The bond zone is the portion of the micropile that transfers load to the ground; its length and the grouting method (gravity, pressure, or post-grouting) are the primary capacity controls and shall be as shown on the Contract Documents.

Micropile drill-hole diameterrange

in

512

Default: 8 in

Micropile reinforcement typeradio

○ Steel casing

○ All-thread bar

● Steel casing with all-thread bar

Micropile grout methodradio

○ Gravity (Type A)

● Pressure grouted through casing (Type B)

○ Post-grouted (Type C/D)

Micropile grout compressive strength at 28 daysrange

psi

40006000

Default: 5000 psi

10 Helical Piles

NOTE Helical piles are steel shafts with one or more helical bearing plates that are screwed into the ground with a hydraulic torque motor. Installation torque correlates to capacity, giving a real-time capacity indicator, and the pile can be loaded immediately after installation. (10.1)

10.2 Helical piles shall be installed to the shaft size, helix configuration, and minimum effective torque shown on the Contract Documents.

10.3 Helical piles shall be advanced until the specified minimum effective installation torque is achieved over the final shaft length, or until the specified termination depth is reached, whichever the Contract Documents make governing.

10.4 The torque-to-capacity correlation factor (Kt) shall be project-verified against a load test, and shall not be taken solely from the manufacturer's generic published value.

10.5 Using a generic torque-to-capacity factor without a site-specific load-test correlation leads to systematic over- or under-installation; the Kt factor shall be confirmed by the project load test before it is applied to production acceptance.

Helical pile shaft typeradio

○ Round shaft (2-7/8 in)

● Round shaft (3-1/2 in)

○ Round shaft (4-1/2 in)

○ Round shaft (10-3/4 in)

○ Square shaft (1-1/2 in)

○ Square shaft (1-3/4 in)

○ Square shaft (2-1/4 in)

Helix configurationradio

○ Single helix

● Double helix

○ Triple helix

○ Multi-helix (4 or more)

Minimum effective installation torquerange

ft·lb

100020000

Per drawings

11 Corrosion Protection

11.1 Steel deep foundation elements in aggressive soils lose section over the service life; the protection method shall match the soil aggressiveness established by the geotechnical report (resistivity, pH, chlorides, sulfates) and the required service life.

11.2 The corrosion protection method for steel elements shall be as shown on the Contract Documents, based on the soil resistivity, pH, and chloride content reported in the geotechnical report.

11.3 Where a sacrificial corrosion allowance is used, the design section thickness shall exclude the sacrificial thickness, and the as-furnished thickness shall include it.

Corrosion protection method (steel elements)radio

● Bare steel with sacrificial thickness allowance

○ Coal-tar epoxy / fusion-bonded epoxy coating

○ Concrete encasement

○ Cathodic protection

Sacrificial corrosion thickness allowancerange

in

00.25

Default: 0.0625 in

12 Splices

12.1 Deep foundation elements are spliced where the required length exceeds the mill, plant, or handling length; the splice must transfer the full design force and survive driving where the element is driven.

12.2 Pile and shaft splices shall be of the type shown on the Contract Documents and shall develop the full design axial, tension, and bending capacity of the spliced section.

12.3 Steel pile field splices shall be full-penetration welded splices or approved mechanical couplers, made by qualified welders to a qualified procedure.

Field splice type (steel elements)radio

● Full-penetration welded splice

○ Mechanical coupler

12.4 Precast concrete pile splices shall be the approved dowel or mechanical splice detailed for the pile section, and shall be cured or set before driving resumes.

NOTE Splice locations shall be staggered between adjacent elements where shown, and shall not be located within the bond or bearing zone, to avoid concentrating splices at a single plane in the group. (12.5)

13 Submittals

13.1 Action Submittals

13.1.1 The Contractor shall submit the following action submittals for review and approval before fabricating or installing any deep foundation element:

Installation work plan describing equipment, sequence, and methods for the selected system.
Shop drawings for piles, shafts, casings, reinforcing cages, and splices, including the pile/shaft schedule.
Pile or shaft installation/driving criteria, including the wave equation (WEAP) analysis for driven piles.
Concrete and grout mix designs, including slump flow for tremie/pump placement.
Material certifications (steel mill certificates, ASTM A252/A572 conformance, prestressing strand, preservative treatment).
Welder qualifications and welding procedure specifications for field splices.
Load and integrity testing plan, including test locations, methods, and acceptance criteria.

Action submittalscheckbox

☑ Installation work plan

☑ Shop drawings and pile/shaft schedule

☑ Installation/driving criteria (WEAP for driven piles)

☐ Concrete and grout mix designs (with slump flow)

☑ Material certifications

☐ Welder qualifications and WPS

☑ Load and integrity testing plan

13.2 Informational Submittals

13.2.1 The Contractor shall submit the following informational submittals during and after installation:

Pile driving records (blow counts, set, and final resistance) for each driven pile.
Drilled shaft and CFA installation logs (depth, base condition, concrete/grout volume, and pressure where applicable).
Helical pile installation torque logs for each pile.
Concrete and grout test results (cylinders/cubes, slump, slump flow).
Load and integrity test reports.
As-built pile/shaft locations, tip elevations, and cutoff elevations.

Informational submittalscheckbox

☑ Pile driving records

☑ Drilled shaft / CFA installation logs

☑ Helical pile torque logs

☑ Concrete and grout test results

☑ Load and integrity test reports

☑ As-built locations and elevations

13.3 Closeout Submittals

13.3.1 The Contractor shall submit the following closeout submittals before final acceptance:

Final as-built foundation plan with all element locations, tip elevations, and cutoff elevations.
Reconciliation of installed elements against the design schedule, including any deviations and their approved dispositions.
Complete record set of installation logs and test reports.

Closeout submittalscheckbox

☑ Final as-built foundation plan

☑ Deviation reconciliation against design schedule

☑ Complete installation logs and test reports

14 Quality Assurance

14.1 The installing contractor shall be a specialty deep foundation contractor with documented experience installing the selected system at comparable scale, and shall employ a competent superintendent on site during all installation.

14.2 Field installation shall be observed and recorded by a qualified geotechnical Inspector engaged by the Owner, independent of the installing Contractor.

NOTE Independent field inspection is essential because most of a deep foundation element is in the ground and cannot be inspected after completion; the installation record made during construction is the primary evidence of conformance. (14.3)

14.4 Welders performing field splices shall be qualified to the applicable welding code for the procedure and position used.

15 Installation Monitoring

NOTE The monitoring requirements below convert each installation method into a recorded, acceptance-grade dataset; without them, acceptance rests on assumptions rather than evidence. (15.1)

15.2 Driven Pile Monitoring

15.2.1 A wave equation analysis (WEAP) shall be performed for each pile type and hammer combination before production driving, to establish the relationship between blow count, driving stress, and capacity.

15.2.2 Driving criteria established without a wave equation analysis or dynamic testing are arbitrary and lead contractors to drive to refusal on obstructions or to under-drive in variable fill; the WEAP analysis shall set the driving criteria.

15.2.3 The Contractor shall record, for each driven pile, the hammer energy, blow count per foot, final set, and any interruptions or splices.

15.2.4 Each pile shall be driven to the final set criterion (blows per inch or set) established by the wave equation analysis and confirmed by dynamic testing, in addition to reaching the specified tip elevation and minimum penetration.

15.3 Drilled Shaft and CFA Monitoring

15.3.1 The Inspector shall log, for each drilled shaft, the drilled depth, soil/rock conditions, base cleanliness, casing or slurry use, and concrete placement volume versus theoretical volume.

15.3.2 A plot of placed concrete volume versus depth shall be maintained for each shaft; an over-volume or under-volume relative to theoretical indicates overbreak or necking and shall be reported to the Engineer of Record.

15.3.3 For CFA piles, the automated grout pressure and volume record shall be reviewed against the acceptance criteria immediately after each pile, and any deficient pile shall be flagged before the rig leaves the location.

15.4 Vibration Monitoring

15.4.1 Where driven piles or vibratory installation occur near existing structures, utilities, or sensitive equipment, the Contractor shall monitor ground vibration and shall not exceed the peak particle velocity (PPV) limit shown on the Contract Documents.

Peak particle velocity (PPV) limit at nearest sensitive receptorrange

in/s

0.12

Default: 0.5 in/s

NOTE Driven-pile vibration in built-up areas can damage adjacent buildings and buried utilities; a PPV limit and monitoring requirement protect those assets and are a frequent omission in urban specifications. (15.4.2)

16 Testing

NOTE Load and integrity testing verifies that installed elements actually achieve the design capacity and are structurally sound; the program is selected for the system, the load magnitude, and the consequence of failure. (16.1)

16.2 Pre-Production Test Program

16.2.1 A pre-production test pile or test shaft program shall be performed before production installation where shown on the Contract Documents, to confirm the installation criteria and capacity at the project soil conditions.

NOTE Omitting a pre-production test program risks driving or drilling the entire job to incorrect criteria when site soils differ from the boring locations, with capacity shortfalls discovered only after mass production; a pre-production test confirms the criteria first. (16.2.2)

16.3 Static Load Testing

16.3.1 Static axial compression load tests shall be performed to ASTM D1143 on the number of elements shown on the Contract Documents.

16.3.2 Where uplift capacity is required, static axial tension load tests shall be performed to ASTM D3689.

16.3.3 For large-diameter drilled shafts where a top-down test is impractical, bi-directional (O-cell) static load testing to ASTM D8169 shall be used where shown.

16.3.4 Each load test shall be carried to the maximum test load shown on the Contract Documents, and the element shall be judged against the acceptance criterion (typically a settlement or displacement limit) stated in the geotechnical report.

Static load test methodradio

● Static axial compression (ASTM D1143)

○ Static axial tension / uplift (ASTM D3689)

○ Bi-directional / O-cell (ASTM D8169)

Maximum static test load (multiple of design load)range

×

1.53

Default: 2 ×

16.4 Dynamic and Integrity Testing

16.4.1 High-strain dynamic testing (Pile Driving Analyzer) to ASTM D4945 shall be performed on driven piles where shown, with signal-matching analysis to evaluate capacity and driving stresses.

16.4.2 Low-strain integrity testing to ASTM D5882 (sonic echo / impulse response) shall be performed on cast-in-place elements where shown, to screen for major defects, necking, or breaks.

16.4.3 Crosshole sonic logging (CSL) to ASTM D6760 shall be performed on drilled shafts where shown, to verify concrete integrity between pre-installed access tubes.

16.4.4 Where crosshole sonic logging is required, access tubes shall be tied to the reinforcing cage and shown on the structural drawings; if the tubes are omitted, integrity verification reverts to coring, which is far more expensive and disruptive.

16.4.5 The number of CSL access tubes per shaft shall be as shown on the Contract Documents, based on the shaft diameter.

Dynamic / integrity testing methods requiredcheckbox

☑ High-strain dynamic / PDA (ASTM D4945)

☐ Low-strain integrity (ASTM D5882)

☐ Crosshole sonic logging (ASTM D6760)

CSL access tubes per shaftrange

tubes

28

Default: 4 tubes

16.5 Acceptance

16.5.1 An element shall be accepted only when it satisfies the tip elevation, minimum penetration, installation criteria, and the applicable load and integrity test acceptance criteria.

16.5.2 An element that fails a load or integrity test, or that cannot be reconciled to the installation record, shall be evaluated by the Engineer of Record, who shall direct repair, replacement, supplemental elements, or acceptance with reduced capacity.

17 Pile Cap Interface

NOTE The transition from the deep foundation element into the pile cap or grade beam is a recurring source of field RFIs when the embedment and dowel detail is left off the drawings. (17.1)

17.2 Each element shall be embedded into the pile cap, or connected by dowels, as detailed on the Contract Documents pile-cap connection detail, in accordance with ACI 318.

17.3 Pile cap and grade beam concrete and reinforcement shall conform to Cast In Place ConcreteCast-in-Place ConcreteResolves to the current edition.sync/cast-in-place-concrete and Concrete ReinforcementConcrete ReinforcementResolves to the current edition.sync/concrete-reinforcement.

17.4 The connection detail shall account for installation position tolerance, so that an element installed within the specified location tolerance still develops the required load path into the cap.

17.5 Installation Tolerances

17.5.1 Each element shall be installed within the plan location tolerance shown on the Contract Documents, measured at the cutoff elevation.

17.5.2 Each element shall be installed within the plumbness (out-of-vertical) tolerance shown on the Contract Documents.

17.5.3 An element installed outside the specified location or plumbness tolerance shall be reported to the Engineer of Record for evaluation of the eccentric load on the cap before it is incorporated.

Plan location tolerance at cutoffrange

in

16

Default: 3 in

Plumbness tolerance (out-of-vertical)range

%

14

Default: 2 %

18 Delivery, Storage, and Handling

18.1 Steel and precast elements shall be delivered, stored, and handled to prevent damage, distortion, and excessive bending stress.

18.2 Precast prestressed concrete piles shall be supported at the designed pick-up and storage points shown on the shop drawings, and shall not be lifted or supported at other points.

NOTE Precast concrete piles are most vulnerable to cracking from improper handling before they reach driving strength; storing and lifting only at the marked support points prevents handling cracks that reduce driving durability. (18.3)

18.4 Steel elements shall be stored off the ground and protected from conditions that would compromise any applied corrosion-protection coating.

19 Warranty

19.1 The Contractor shall warrant that all deep foundation elements are installed in conformance with the Contract Documents and the approved installation work plan, free of defects in materials and workmanship, for the warranty period shown on the Contract Documents.

19.2 Warranty coverage shall not relieve the Contractor of responsibility for elements that fail acceptance testing or that are shown by the installation record to have been installed outside the approved criteria.