Abstract：Optical fiber sensing can be applied to monitoring sliding damage of terrain interface，for which the general monitoring means can¢t do. Based on microbending loss mechanism of optical fiber and optical time- domain reflectormetry (OTDR) technique，the monitoring system of optical fiber sliding sensing and data collection system are constructed. Triaxial shear test of soil is firstly used to construct monitoring system and data collection. The difficulty of optical-mechanical data collection for instantaneous brittle fracture of the solid material is solved. The relation data and curve of sliding distance versus loss are obtained. The embedding mode of optical fiber applied to high rock slope for sliding monitoring is presented. It shows that the optical fiber sensing system is high sensitive，light loss is 30 to 50 dB and the dynamic range of optical fiber sliding monitoring reaches 3.0 to 3.5 mm.
