Simulating test on the subsidence law of subsurface water resisting layer upon shallow coalbed mining

The subsidence movement law of overburden and subsurface water resisting layer of Yushuwan coal field in northwestern China are studied by simulating model test.Through the specific simulating study on the simulating material of real clay of water resisting layer,the physical simulating model is made to simulate the stress-strain capacity of clay layer under mining conditions.Based on the simulating test,it is found that the movement of soft clay water-resisting layer is followed the movement of under hard layer.And the key parameter to control the stability of water resisting layer is to reduce the subsiding grade T_s,and the basic caving law of overburden roof strata is given as well.