Mercury Injection Test and Weathering Microstructure of Weakly Consolidated Coal and Rock Mass of Luxin Coal Mine

Coal and rock before and after weathering of Luxin coal mine was test by SEM test and mercury injection test，the results showed that the micro-structure before weathering in alignment，and more densely of 11# coal，average porosity was 4.78%，some fractures interpenetration after weathering，porosity was 15.1%，more micro pores structure appeared in soft rock surface before weathering，porosity was 24%，water absorption was strong，porosity increased to 28.56% after weathering，gneissoid structure appeared in surface，and micro pore would be formed big pore.The test results showed that sealed surrounding rock supporting technology should be applied in roadway supporting of weakly consolidated soft rock supporting，for example shotcrete support should be applied，then surrounding rock surface weathering could be prevented，soft rock roadway stability would not be influenced.