How to Monitor Building Settlement?

Building settlement often occurs as a result of adjacent construction activities and may result in damage to a structure.

There are several ways to monitor building settlement. These include:

  • Tilt Beam Sensors
  • Optical Surveys
  • Liquid Level Sensors
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1. Tilt Beam Sensors

Beams with tilt sensors (tiltmeters) can be installed end-to-end along a wall to form a continuous string. This allows you to build a settlement profile between the string end points. In order to do this, one end of the beam string must be located in a stable area (settlement movement is not expected). The tilt sensors can transmit data wirelessly or can be wired into a central datalogger to allow for automated data acquisition.

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2. Optical Survey

A total station may be used to monitor building settlement by shooting survey targets, like optical prisms. This may be done manually by a surveyor who uses a total station set up on a tripod or in an automated fashion by installing an automated motorized total station (AMTS) and programming it to shoot prisms automatically. Once the AMTS collects data, it can send the data back to a central server for processing into engineering units. The remote data acquisition system often results in more frequent and higher quality data since the AMTS is left in a fixed position.

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3. Liquid Level Sensors

In this method, a series of hydrostatic pressure sensors are installed along a building wall or floor and connected by an air and water line to make a string of sensors. At one end of the string is a water reservoir and a sensor that is in an area where no movement is expected. Any change in settlement at a sensor location results in a change in water pressure due to the change in hydrostatic head. To automate the collection of data, liquid level sensors may be wired into a central datalogger.