Simulation study of fiber optic monitoring technology of surrounding rock deformation under deep mining conditions

Abstract

Characteristic parameters of the surrounding rock deformation under deep mining conditions are crucial data, which require the relevant test generally. In this study, a simulation model with the length 400 cm, the width 40 cm, and the height 144.5 cm was created in laboratory, and multi-group optical fiber sensors were set in the simulated rock stratum. Strained condition and characteristics of surrounding rock of the working face under mining conditions were dynamically analyzed in terms of distributed optical strain measuring technique of PPP-BOTDA with high-resolution. The test results indicate that the distributed optical monitoring technology can show varying strain tendencies relating to the deformation processes of surrounding rocks. Therefore, strain characteristics of different measuring points can be synthesized to effectively determine the development height of the caving and fissure zones in the roof. In the laboratory, fiber optical strain distribution characteristics fit relatively the practical location and depth of developed fractures. This study lays a foundation for detection of deformation at working face advances in the mine.