Furnish and install Settlement Gauges as shown in the plans at locations designated in the plans. Place the base on a level surface near the natural ground as shown in the plans. Extend the metal pipe by adding pipe sections at threaded couplings as the embankment is progressed.
Full Answer
How can I measure the settlement of a site?
Measurements can also be taken automatic and remote by using special displacement transducers. If a multipoint settlement monitoring is requested, three different models of magnet settlement gauge are available: The BRS extensometer, the T-REX extensometer and the DEX in-place extensometer.
What types of magnet settlement gauges are available?
If a multipoint settlement monitoring is requested, three different models of magnet settlement gauge are available: The BRS extensometer, the T-REX extensometer and the DEX in-place extensometer.
How are embankment settlement gauges measured?
Measurement and Payment. Embankment Settlement Gauges will be measured as the actual number that have been incorporated into the completed and accepted work and will be paid for at the contract unit price per each.
When do I abandon a settlement gauge or rod?
All settlement gages and rods shall be abandoned after termination of the construction waiting period, unless the Geotechnical Engineering Bureau requests in writing that installations be retained for future readings. Procedures for abandonment are as follows:
How do I install settlement plates?
A. The base plate shall be installed at least 6 inches (150 mm) below natural ground, firmly seated on a level surface. The PVC casing shall be placed on the base plate, centered on the steel bar attached to the base plate.
How do I monitor my settlement markers?
The settlement marker is used to measure a localised settlement or heave of roads, slopes, embankments, utility pipes and cables. The monitoring of settlement marker is carried out by leveling survey and readings are taken at regular intervals to check any settlement or heave.
What is a settlement gauge?
The settlement gauge is a pressure transducer with vibrating wire or capacitive technology, mounted on a plate with a protective cover. Depending on the requirement, the settlement system can be installed with just a single gauge or with multiple gauges.
How do you monitor ground settlement?
Monitoring SettlementCracks in floor slabs and walls are monitored with crackmeters.Misalignment or separation of incoming utilities or expansion joints can be monitored with jointmeters.Differential settlement of floors and walls can be monitored with hydrostatic level cells.More items...
How do Settlement markers work?
Structure settlement marker is used to monitor the movement of the existing buildings/ structures which may be affected by the works. Featuring a spherical head and a plated body that minimize damage to the building, the wall-mounted marker is installed around the external facade of the building.
What is Rod settlement gauge?
Rod Settlement Gauge Rod Settlement Gauge/Settlement Plate is typically installed during initial phase of construction and designed to monitor the immediate vertical ground settlement as well as long term.
What is a settlement plate?
Settlement plates are typically installed in areas where significant settlement is predicted. They can be used to examine if predicted settlement: 1) is occurring. 2) is occurring at predicted rates and magnitudes. 3) has occurred to a magnitude of interest (or over a time of interest)
What is a standpipe piezometer?
Standpipe Piezometers offer a simple and economic method for measuring water pressures in soil and rock. The Standpipe Piezometer (also known as a Casagrande Piezometer) is used to monitor piezometric water levels in vertical boreholes.
How is building settlement measured?
There are several ways to monitor building settlement. These include:Tilt Beam Sensors.Optical Surveys.Liquid Level Sensors.
How do you monitor movement in a building?
One of the most commonly used methods is crack monitoring to establish if there is ongoing movement in the building. Small metal studs are inserted either side of the cracks, and regular readings taken to ascertain whether the cracks are opening or closing. Typically, as little as 1mm movements can be detected.
How is soil settlement calculated?
1. Calculation of stresses. Structures with their loads generate a stress change in the soil. In order to be able to calculate settlements in the soil due to this change in stress, it is necessary to know the spreading and distribution of the stresses in the foundation soil.
What is ground settlement in construction?
Introduction. Settlement is the downward movement of the ground caused by a load consolidating the soil below it or causing displacement of the soil. Settlement often refers to the downward movement of the ground around an excavated space, such as that for tunnels, shafts, or basements.
How can we reduce the settlement of soil?
Compacting the soil. Draining the soil, in case of cohesive types. Compacting the soil, in case of cohesion less soils. Confining the soil, increasing stiffness.
What is settlement analysis?
Soils consolidate under the application of loads from buildings. All foundations settle as the soil around and beneath the foundation adjust to the loading. Buildings with light loads or built on rock may experience negligible settlement.
What is a pipe surface settlement gage?
A pipe surface settlement gage indicates total foundation settlement behavior during and after embankment construction.
How does a manometer surface settlement gage work?
The manometer gage works on the principle that a fluid seeks its own level. The fluid line reflects any change in elevation between the base and readout box. The air line maintains the same atmospheric pressure at the base that exists at the readout box. The distance between the readout box and base should not exceed 230 ft. (70 m).
What is the settlement rod manual?
This manual establishes uniform statewide procedures for fabrication, installation, documentation, maintenance and disposal of settlement gages and settlement rods.
How to install a gage on a foundation?
These gages shall be installed at locations designated on the plans by driving or pressing the anchor post, using the outside casing (NPS 1) , from the surface of the embankment foundation to the elevation specified in the plans (see Figure 7). The anchors post shall then be expanded by tapping, with a small sledge hammer, the inside pipe (NPS ¼) while the outside casing is held in a fixed position. A 3 ft. (1 m) piece of pipe is now added to the inside pipe, wit the inside pipe held in a fixed position, the outside casing shall be detached at the left-hand threaded connection and retracted about 3 ft. (1 m) (see Figure 6).
How often are geotechnical readings recorded?
Readings for each installation are to be recorded weekly for one month commencing with the date of installation. Readings thereafter are recorded monthly until termination of the construction waiting period or otherwise for a period of time specified n the contract or by the Engineer. All readings are to be recorded, on Form GE 436, (see Figure 2), in triplicate, with one copy immediately forwarded to the Geotechnical Engineering Bureau, one to the Regional Geotechnical Engineer, and one to the project files.
When are settlement gages and rods abandoned?
All settlement gages and rods shall be abandoned after termination of the construction waiting period, unless the Geotechnical Engineering Bureau requests in writing that installations be retained for future readings. Procedures for abandonment are as follows:
How accurate is a pipe reference mark?
The pipe shall be scribed to an accuracy of ¼ in. (6.3 mm) at maximum intervals of 3 ft. (1 m) measured from the initial mark. Immediately after each pipe is scribed, the graduations shall be numbered to reflect the distance in feet (meters) from the initial scribe, in a durable paint of a color contrasting with that of the rod. Any additional extensions shall be scribed as stated above.
Why is settlement monitoring important?
Settlement monitoring is essential to evaluate the possible problems and for risk management related to ground displacement on surface or underground constructions.
What is multipoint settlement?
The multipoint settlement system is an hydraulic system that can be used to monitor embankments or earth fill dams. The system consists of a number of pressure transducer hydraulically connected to an external reference vessel. This pressure transducers, equipped with a base plate are installed within the embankment.
What is a hydrostatic profile gauge?
The manual operated hydrostatic profile gauge is used for measuring vertical displacement in and below embankment. This easy to operate instrument of limited accuracy provides settlement profiles. Therefore a probe is pulled through a pipe previously installed in the embankment. The probe consists of a high precise pressure transducer that is interconnected to a reference vessel. The reference vessel is mounted on a electric hydraulic cable winch. The readings are taken with on the digital display at regular intervals by pulling the probe through the pipe.
What is a fixed extensometer?
Fixed extensometers are basically columns used to monitor the settlement between two points. The lower point is a platform installed within an embankment or an anchor installed in a borehole. At the top head usually settlement is measured by topographic surveying.
Is the BRS extensometer accurate?
The BRS extensometer being not a very accurate settlement gauge, but is inexpensive and allows measurement of many reference settlement points within one column. The T-REX incremental extensometer able to detect meter by meter ground settlement with high accuracy.
What is a settlement marker?
The settlement marker is used to measure a localised settlement or heave of roads, slopes, embankments, utility pipes and cables.
How to measure ground water level?
Ground water level is measured by using water level indicator. The probe of water level indicator is lowered down into the water standpipe until light or buzzer indicates contact with the water. Depth to water level is measured from the measuring tape attached to the indicator.
Why is the inclinometer capped?
After the installation of inclinometer casing in the hole, the casing top is capped to prevent the entry of foreign particles.
Why is casing capped?
Installed casing is capped and kept in a protective metal box to prevent damage & disturbance
How to measure depth of spider magnet?
Depth of the magnet is measured from the measuring tape attached to the probe.
Where is the ground water pressure reading stored?
The vibrating wire piezometer is connected to the read out unit and the ground water pressure readings are recorded and stored in the data logger
Why is a piezometer kept in a protective box?
The borehole with vibratingwire piezometer installed is kept in a protective metal box to prevent damage & disturbance to the instrument.
