1. School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, China; 2. Wanbei Coal-Electricity Group Co., Ltd., Suzhou 234000, China; 3. Huainan Ming Group Corp. Ltd., Huainan 232001, China
Abstract：The grouting reinforcement of the coal seam floor and the construction of aquifers are effective methods in preventing and controlling of karstic water disaster in the coal seam floor above the confined aquifer during safe mining.In order to evaluate the effect of grouting reinforcement in the coal seam floor, the authors set the Ⅱ615 working face of the Hengyuan coal mine in northern Anhui Province as the study object and selected normal regions as well as abnormal regions.In addition,wave velocity detection was conducted for floor rocks before and after grouting in each region respectively by logging with seismic wave in drill holes.The results show that there is a considerable difference in wave velocity between the normal and abnormal regions before grouting,and the wave velocities in the two regions are basically the same after grouting.The wave velocity of floor sandstone strata rises obviously after grouting and it is 1.2 times the wave velocity before grouting.However,the wave velocities of marine mudstone change only insignificantly before and after grouting, which is in accordance with the completeness of rock core and non-guide rise exposed by drill holes.All this fully indicates that grouting could play a good role in the reinforcement of crack rocks.
