Mining operations can affect the water resources in the aquifers or on the ground by causing the deformations and cracks of overlying water resisting strata, which will further cause groundwater exhaustion, surface water driving, and other environmental problems. It has been revealed by mining and geological researchers that aquifers above the coal seams is a common mining geological conditions in Shaanxi Province of China. Apart from the environmental issues related to mining under aquifer, water discharging will change the mechanical properties of aquifer, which will further affect the stress concentration, energy dissipation and micro seismicity distribution during mining process. The understanding of water discharging effect on the mechanical properties of aquifer will benefit the mitigation of environmental and safety issues associated with aquifer by providing fundamental water-rock interaction knowledge. This paper investigated the water absorption capacity and water distribution in the sandstone sample by water triaxial saturation tests and X-ray computed tomography observation. Then the uniaxial compression tests were conducted in the lab to understand the water discharging effect on the strength and failure of sandstone with the application of acoustic emission monitoring. It has been found that the water discharging will change the stress concentration and failure mode of sandstone.
 

Auifer,Rock Mechanics,Computed tomography,green mining