Characteristics of damage of confining beds and surface water infiltration under mining conditions in karst mountains

This paper discusses the characteristics of surface water infiltration in the influence area of goal and coal mining subsidence and outside influence boundary area. Data of seepage test, hydrogeological investigation and observation of water table are used. Comparison of the water table and surface water infiltration in 1955 and 2011, respectively, indicate that (1) The surface rock above the minedout area is broken, causing the surface impermeable layers to lose confining effect; (2) In the coal mining subsidence area, water table decreases up to 86.3 m, and surface infiltration capacity is 31.61 times the value of experience; (3) Outside the mining influence boundary area, surface infiltration capacity and water table do not have not change significantly.