断层对顶板稳定性影响相似模拟试验研究

Influence of faults on coal roof stability by physical modeling study

通过相似模拟试验方法分析了不同倾向高角度正断层 ,在采动影响下顶板岩体变形破坏和矿压分布规律。结果表明 ,在采动影响下断层“活化”,断层带及其影响范围内的岩体破碎 ,表现为周期断裂步距小 ,冒落带高 ,尤其是断层下盘 ,顶板稳定性差 ;当工作面开采到离断层面 2 2 .5～ 30 m时 ,直到断层位置的前方煤体中支承压力增大 ,煤体被压碎 ,且随着距断层面距离的缩小 ,支承压力的峰值位置向工作面前方转移 ;通过断层后 ,顶板岩体中支承压力减小 。

Through simulation test of similar materials,the distribution of deformation failure and underground pressure with high angle faults of different dip direction are analyzed during coal mining operation.The results indicate that roof rock mass in fault zone and its influential range is broken and with poor stability by activation of fault after coal mining,so the distance of periodic weighting decreases and the caving zone increases,particularly in the footwall of fault.When working face is mined about 22.5 to 30.0 m to the fault,the abutment stress ahead of working face obviously increases,coal seam is crushed,and the peak value of abutment stress migrates to the inside of rocks(coal)with reduction of distance away from the fault.Compared with non fault,the abutment stress of the foor rock mass decreases after passing the fault.