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 marine 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.

Settlement cells are available with vibrating wire or pneumatic pressure transducers. The vibrating wire version is easier to read, can be automated, and provides a wider range. The pneumatic version is less expensive.

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.

The vibrating wire version can be automated.

Limitations

The system must be corrected for changes in temperature and barometric pressure. Careful installation can minimize these effects.

For more information

Please visit the Slope Indicator website to download a data sheet and a manual. These documents can be viewed and printed with Adobe Acrobat Reader.