CALCULATION METHOD FOR SOIL SHEAR DEFORMATION BASED ON STRAIN DISTRIBUTION OF SENSING FIBER

Distributed optical fiber sensing technology, a new type of monitoring technology that emerges in our actual project several years ago, with many advantages for full distribution, real-time, anti-jamming and high durability, is becoming a hot spot in the field of geotechnical engineering. The optical fiber cable is buried in the soil, and the shear deformation of the soil is measured. Based on the correspondence between strain distribution of the optical fiber cable and the soil shear deformation, two strain-deformation conversion models based on arc curve and Logistic growth curve are proposed, and the applicability of the models are preliminarily considered. Then an interior shearing test of soil was designed to verify the accuracy of the models, and finally the models are used for the analysis of the distributed fiber monitoring data of Majiagou landslide in Three Gorges Reservoir. The results show that by using the conversion models, the shear deformation of soil can be figured out with strain distribution of the optical fiber cable.