Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
---
title: Geotechnical Instrumentation and Monitoring
…137 unchanged lines
## Instruments shall be installed by personnel experienced in geotechnical instrumentation of the specific types deployed on the project.
+```datasheet
+label: Installer qualification - minimum comparable projects
+type: range
+unit: projects
+min: 1
+max: 10
+step: 1
+setpoints: [1, 3]
+```
+
## Each instrument with a measured output shall be furnished with a current factory calibration certificate traceable to a recognized standard.
…12 unchanged lines
### Instruments installed without verified calibration produce readings that cannot be defended if a threshold exceedance is later disputed. {note}
−```datasheet
−label: Installer qualification - minimum comparable projects
−type: range
−unit: projects
−min: 1
−max: 10
−step: 1
−setpoints: [3]
−```
−
# Geotechnical Instrumentation Plan {toc}
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### Neat cement is too stiff and shrinks: it constrains the soil so the casing understates true movement, and the shrinkage cracks let it move independently. A cement-bentonite mix matched to soil stiffness lets the casing deflect with the ground. {note}
+### The inclinometer casing material shall be specified to suit the anticipated ground movement and installation conditions.
+
```datasheet
label: Inclinometer casing material
…5 unchanged lines
```
+### The inclinometer casing outside diameter shall be specified to match the borehole diameter available for installation.
+
```datasheet
label: Inclinometer casing outside diameter
…6 unchanged lines
```
+### The inclinometer reading system shall be specified, selecting between a portable manual probe and an in-place continuous telemetry string.
+
```datasheet
label: Inclinometer reading system
…12 unchanged lines
max: 60
step: 1
−setpoints: [20]
+setpoints: [5, 20, 60]
drawing_ref: true
```
…15 unchanged lines
max: 9
step: 1
−setpoints: [6]
+setpoints: [3, 6, 9]
```
…5 unchanged lines
max: 0.65
step: 0.05
−setpoints: [0.55]
+setpoints: [0.45, 0.55, 0.65]
```
…4 unchanged lines
## Vibrating-wire piezometers shall be used where pore-pressure response must be tracked in time with active construction or in low-permeability soils.
−### In silts and clays a standpipe lags reality by days to weeks, so by the time the well registers a pressure rise the excavation stage that caused it is long past. A vibrating-wire sensor responds immediately. {note}
−
−## Each piezometer shall be isolated within its monitored zone by a sand pack at the tip and a bentonite seal above to prevent vertical migration of water along the borehole.
−
−### Without an effective seal the borehole short-circuits the natural stratigraphy, and the instrument reads a blended pressure that belongs to no real layer. {note}
−
```datasheet
label: Piezometer type
…5 unchanged lines
```
+### In silts and clays a standpipe lags reality by days to weeks, so by the time the well registers a pressure rise the excavation stage that caused it is long past. A vibrating-wire sensor responds immediately. {note}
+
+## Each piezometer shall be isolated within its monitored zone by a sand pack at the tip and a bentonite seal above to prevent vertical migration of water along the borehole.
+
+### Without an effective seal the borehole short-circuits the natural stratigraphy, and the instrument reads a blended pressure that belongs to no real layer. {note}
+
+### The vibrating-wire piezometer pressure range shall be specified to match the anticipated pore-pressure range at the monitored zone.
+
```datasheet
label: Vibrating-wire piezometer pressure range
…5 unchanged lines
```
+### The vibrating-wire piezometer sensor accuracy, as a percentage of full scale, shall be specified.
+
```datasheet
label: Vibrating-wire sensor accuracy (% full scale)
…3 unchanged lines
max: 0.5
step: 0.1
−setpoints: [0.25]
+setpoints: [0.1, 0.25, 0.5]
```
+### The standpipe piezometer riser diameter shall be specified for the monitoring well construction.
+
```datasheet
label: Standpipe riser diameter
…13 unchanged lines
max: 40
step: 1
−setpoints: [20]
+setpoints: [3, 20, 40]
drawing_ref: true
```
…13 unchanged lines
### Surface-exposed instrument heads are routinely destroyed by construction equipment, which is the leading cause of data gaps. Traffic-rated flush covers in paved areas and protected above-grade pipes elsewhere keep the instrument alive through the work. {note}
+### The settlement monitoring method shall be specified based on site access constraints and the settlement data required for the project.
+
```datasheet
label: Settlement monitoring method
…23 unchanged lines
max: 3
step: 0.5
−setpoints: [1]
+setpoints: [0.5, 1, 3]
```
…5 unchanged lines
max: 8
step: 1
−setpoints: [4]
+setpoints: [2, 4, 8]
```
…71 unchanged lines
max: 240
step: 15
−setpoints: [60]
+setpoints: [15, 60]
```
…5 unchanged lines
max: 30
step: 5
−setpoints: [15]
+setpoints: [5, 15, 30]
```
…14 unchanged lines
max: 5
step: 1
−setpoints: [3]
+setpoints: [1, 3, 5]
```
…18 unchanged lines
## If an instrument malfunctions during a critical excavation stage, the Contractor shall repair or replace it within the response time in the GIP and shall provide redundant coverage where the GIP requires it.
−### A blind spot at a critical stage is as dangerous as a threshold exceedance; the specification must require a defined repair time and redundancy at the highest-risk locations so monitoring is never silently lost. {note}
+### A blind spot at a critical stage is as dangerous as a threshold exceedance; the specification must require a defined repair time and redundancy at the highest-risk locations so monitoring is never silently lost.
```datasheet
…13 unchanged lines
max: 25
step: 1
−setpoints: [12]
+setpoints: [5, 12, 25]
```
…5 unchanged lines
max: 40
step: 1
−setpoints: [25]
+setpoints: [12, 25, 40]
```
…5 unchanged lines
max: 60
step: 1
−setpoints: [38]
+setpoints: [20, 38, 60]
```
…5 unchanged lines
max: 38
step: 1
−setpoints: [19]
+setpoints: [10, 19, 38]
```
…5 unchanged lines
max: 2.0
step: 0.1
−setpoints: [1.0]
+setpoints: [0.5, 1, 2]
```
…67 unchanged lines
## The instrumentation installer shall warrant materials and workmanship of the installed instruments and data acquisition system for the period stated in the datasheet from the date of acceptance.
−### Because a failed instrument below grade cannot simply be reopened and repaired, the warranty must cover replacement of an instrument that fails to perform within its specified accuracy during the monitoring period. {note}
+### Because a failed instrument below grade cannot simply be reopened and repaired, the warranty must cover replacement of an instrument that fails to perform within its specified accuracy during the monitoring period.
## The warranty shall cover replacement of any instrument that drifts outside its specified accuracy or fails to communicate during the monitoring period.
…6 unchanged lines
max: 36
step: 6
−setpoints: [12]
+setpoints: [12, 36]
```
…16 unchanged lines
- Spare cable and connectors
```