Settlement Cells
Applications
Settlement
cells are used to monitor settlement and heave in soils. Typical
applications include:
- Monitoring settlement or heave in embankments
and embankment foundations.
- Monitoring subsidence due to
tunneling and mining.
- Monitoring consolidation under storage
tanks.
- Monitoring settlement due to dewatering or preloading.
- Monitoring
settlement in fills.
Operation
 A
settlement cell consists of a liquid reservoir, liquid-filled
tubing, and the settlement cell, which contains a pressure transducer.
One end of the tubing is connected to the settlement cell, which
is embedded in fill or installed in a borehole. The other end
of the tubing is connected to the reservoir, which is located
away from the construction area.
The transducer measures the pressure created by the column of
liquid in the tubing. As the transducer settles with the surrounding
ground, the height of the column is increased and the settlement
cell measures higher pressure. Settlement is calculated by converting
the change in pressure to millimeters or inches of liquid head.
Advantages
- The reservoir and readout station can be located away from
the construction area. The cell and tubing are buried and
do not interfere with construction activities.
- Vibrating wire cells can be automated. The vented version
is the most precise settlement cell and automatically compensates
for changes in barometric pressure. Tubing lengths of up
to 300 m (1000 feet) are permissible with VW cells.
- Pneumatic cells are less expensive and a good choice in lightning-prone
regions.
Limitations
- Temperature
changes in reservoirs and above ground tubing can affect
the repeatability of readings.
- Non-vented VW cells require corrections for barometric pressure
(vented VW cells do not).
- Pneumatic cells take longer to read and generally should
not be used with tubing lengths longer than 100 m (300 feet).
For more information
Please download the datasheets and manuals
listed below. These can be viewed and printed with Adobe
Acrobat Reader.
VW Settlement
Cell Datasheet
Vented VW Settlement Cell Manual
Non-Vented VW Settlement Cell Manual
Pneumatic
Settlement Cell Datasheet
Pneumatic Settlement Cell Manual
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