Study on the deformation and migration law of overburden rock of coal seam mining in Sunjiagou coal mine

Aiming at the water damage problem caused by the overburden rock instability and deformation to the roof plate after mining in the deep coal seam of Sunjiagou Coal Mine, according to its geological conditions, we study the deformation evolution law of the overburden rock during mining, and set up the overburden rock deformation and stress observation system based on the Distributed Optical Fiber Sensing and Testing (DOFS) ground drilling technology. The Brillouin Optical Time Domain Reflectometer (BOTDR) was used to analyze the "light" evolution law of overburden rock during the mining process, and to determine the deformation evolution characteristics of overburden rock, as well as the heights of the fallout zone and fissure zone. The results show that after mining, the development height of the fallout zone is about 75 m, and the development height of the fissure zone is about 205 m. The influence distance of the early mining shear stress is about 92.7 m.