带压开采煤层底板破坏深度研究

底板破坏深度影响底板注浆改造层位的选择，采取钻孔压水试验、声波测试、钻孔窥视3种实测技术手段，选择桑树坪煤矿下组煤3105工作面进行底板破坏深度综合测试。研究结果表明，钻孔压水试验测试显示底板破坏深度为14.9 m，声波测试显示底板破坏深度为14.7 m，钻孔窥视显示底板破坏深度为15 m，声波测试结果真实合理地反应了工作面回采过程中底板岩层应力、应变变化规律，最终综合评价3105工作面底板破坏深度为15 m，可应用于同一采区其他工作面，为底板注浆加固层位选择提供了技术参数。

Study on floor failure depth of coal seam mining under pressure

The factors of failure depth of floor affected the selection of floor grouting reinforcement horizon.By means of borehole water pressure test，acoustic test and borehole peeping，No. 3105 working face of lower coal group in Sangshuping coal mine was selected to comprehensively test the failure depth of floor.The research results showed that the borehole water pressure test showed that the failure depth of floor was 14.9 m；acoustic test showed that the failure depth of floor was 14.7 m，borehole peeping showed that the floor failure depth was 15 m. Acoustic test results truly and reasonably reflected the variation law of stress and strain of floor strata in the process of mining.The comprehensive evaluation of the failure depth of floor of No.3105 working face was 15 m.It can be applied to other working faces in the same mining area，which provided technical parameters for the selection of floor grouting reinforcement layers.