NUMERICAL STUDY ON WATER INRUSH ABOVE ACONFINED AQUIFER IN COAL MINING USING HYDRO-FRACTURING

s:It is a big diffusion for the mechanics of water inrush in coal mining that is above a confined aquifer. because there are many influencing factors. The situation differs greatly in various coal mining districts,and it is difficult to find a uniform model to solve the problem. In this paper,based on rock hydraulic fracture mechanism and its penetrability alteration,the base plate′s stress state changing was studied. All of those would increase the possibility of water inrush. Aimed at a case of study,a water inrush danger location was presented and the concept was introduced. Damage parameters are used to describe the degree of rock damage,i.e.,the rock structure evolution. The rock damage would induce the change of the penetrability. It was important for water inrush forecasting in mining works because the changes of base plate penetrability would make ways for the water form confined aquifer. Based on perpendicular anisotropic rock to upbuild the relation function between permeability coefficient and damage parameter,which was used to deduce the permeability change with base plate damage,the results of the numerical computing show that it agrees well with the real case.