Experimental Study of Water Storage Soaking of Coal Mine Underground Reservoir to Coal Pillar Dam Body Strength

In order to study influence of coal mine underground reservoir water storage soaking to coal pillar dam strength parameters,field coal samples were collected in Lijiahao coal mine,UCS and Brazil Split Experiment were proceeded under different soaking time,the results showed that unidirection compressive strength and extension strength all decreased with soaking time increased,without appeared regularity decreased trend,elasticity modulus variation in small range and influence was small,the mechanical property of coal sample appeared obviously anisotropy as bedding plane.When bedding vertical to axial direction,uniaxial compressive strength was 2-4 times of bedding parallel axial direction,to uniaxial extension strength,reached the largest value as bedding vertical to axial direction,secondly was bedding parallel to axial direction and loading direction vertical bedding,the minimum was bedding parallel to axial direction and loading direction parallel to bedding situation.