Sondex Settlement System
Applications
The Sondex Settlement System is used to monitor settlement and heave in excavations, foundations, dams, and embankments. It can also be installed behind retaining structures, such as sheet piles and slurry walls, and above underground openings, such as tunnels and shafts. The Sondex system indicates the depths at which settlement has occurred as well as the total amount of settlement.
Operation
The Sondex system consists of a probe, signal cable, a cable reel with a built-in voltmeter, and a number of stainless steel sensing rings that are positioned along the length of an access pipe. A survey tape is typically connected to the probe. In soft ground, sensing rings are fixed to a continuous length of corrugated plastic pipe which slips along the access pipe and allows the rings to move with the surrounding ground. In harder ground, rings can be attached directly to telescoping plastic pipe.
To obtain measurements, the operator draws the probe through the access pipe. The buzzer sounds when the probe is near a ring, and the voltmeter reading peaks when the probe is aligned with a ring. The operator refers to the survey tape and records the depth of the ring. A sensitivity adjustment allows operation adjacent to steel pipes, piles, or other metal objects. Settlement and heave are calculated by comparing the current depth of each ring to its initial depth.
For more information
For further information, please refer to the related document (pdf). These documents can be viewed and printed with Adobe Acrobat Reader.