Investigation on the Responses of Overburden Stress and Water Pressure to Mining under the Reverse Fault

Abstract

This paper focuses on the responses of overburden stress and pore water pressure in confined aquifer to mining under the Ordovician limestone aquifer and the reverse fault. Taking 32 coal seam mining in the first eastern mining area of Qianyingzi coalmine in China as engineering background, on the basis of the mining hydrogeological and engineering geological model of the study area, a numerical calculation model considering the fluid-solid interaction is established. Simulation results indicate that the variation characteristics of pore water pressure in confined aquifer and overburden stress are affected by both mining effect and geological tectonics and are closely related to the shear failure of the reverse fault plane caused by mining effect and the failure characteristics of the overburden strata in the stope. According to the variation of pore water pressure before and after the roof water inrush, the reduction range of pore water pressure can be used as one of the early warning indicators for water inrush accidents. These new understandings are of reference value to the mining water inrush under the combined action of reverse faults and confined aquifers and to the establishment of corresponding forecasting and early warning systems.