Detection Research on Weak Stress Wave in Rock-soil Based on Quasi Distributed Optical Fiber Sensing Technology

To detect low-pressure dynamic loading in rock-soil, optical fiber Michelson interferometer was adopted to set up the sensing system. Polyurethane package was used to enhance stress sensitivity of optical fiber sensors that composed quasi distributed optical fiber detection system. The sensitivity of optical fiber senor reached -170dB, and met the measurement requirement of low pressure dynamic loading at 0.001MPa-0.01MPa. The results proved that it was feasible to detect low-pressure dynamic loading using the designed optical fiber sensors. It provides a new experiment method for research on response of low-pressure dynamic loading in geotechnical engineering.