Experimental study on sinkhole collapse monitoring based on distributed Brillouin optical fiber sensor

摘要

Sinkhole collapse is a unique geological disaster of the cover soil in karst area, which is very harmful to the safety operation of train and pipeline. In this paper, the distributed Brillouin optical fiber sensing technology was proposed to monitor sinkhole collapse. The Brillouin scat-tering sensing principle and the strain -displacement relation model were studied firstly. And then, sinkhole collapse model was constructed to validate the feasibility of the monitoring method. Under the static load and coupling loads, the man-made sinkholes collapsed gradually, the distributed optical fiber sensor measure the corresponding strain. Test results show that the distributed optical fiber sensors can effectively monitor the collapse strain even if the ambient temperature changes and the corresponding collapse displacement can be calculated with a good accuracy based on the proposed strain-displacement model.