Prestressed soil and rock anchors are widely used in civil engineering to resist the horizontal pressures acting on retaining structures. With time, anchor force may decrease due to relaxation and creep. As a result, anchored elements may displace excessively and eventually fail. Therefore, it is extremely important to have suitable permanent means to measure the residual force and verify that the anchor is functioning properly and according to design.
Advantages:
Low-cost
Although a precision instrument, SAM is conveniently priced and makes monitoring more anchors affordable.
Forms an integral part of the anchor:
In contrast with other measuring instruments, SAM forms an integral part of the anchor and not an extraneous element which is introduced with the sole purpose of monitoring the forces. SAM is built in the form of an anchor head instrumented with Wheatstone Bridge strain gauges and up-to-date electronics.
Simple installation and operation:
When the anchor is initially pre-stressed, the special readout box is connected to the SAM and the initial reading noted. Using the calibration factor supplied with each SAM, subsequent readings are easily converted to differences in residual load values.
The rugged readout box is battery operated and contains just one press-to-test button. It can be easily operated by site personnel.
Easy remote monitoring
Due to their advanced design, any number of SAM devices can be connected by inexpensive cables to a conveniently located remote control box. Thus reading for a large site can be taken in a few minutes eliminating the need for climbing to each anchor separately.
Optionally, the control box can be equipped with a cellular modem which transmits the data to a web-site. thus the engineer can access the real-data anytime, anywhere. In case of a sudden drop in anchor force the system can send an alarm via email or SMS
Sam is available for both multi-tendon and single-bar anchors.
