采动影响下断层面离层空间产生及其对开采空间传递作用分析

Analysis of fault separation generation and its increasing effect on mining zone

当工作面上覆岩层中含有断层时,地表下沉规律与不含断层时具有显著差别。为了研究断层对开采空间传递的作用,利用空间守恒,通过理论推导发现工作面开采会使断层面产生离层空间,断层对开采空间传递具有增大效应并利用数值模拟进行了验证。研究结果表明:增大的开采沉陷空间主要来自于断层面离层空间;关键层下部软弱岩层在断层面的离层空间主要来自于采空区垮落岩石的再次压缩;关键层及上部岩层在断层面的离层空间主要来自于关键层与下部软弱岩层之间离层空间的减小;影响断层面离层空间大小的因素主要有工作面推进长度、基岩厚度、保护煤柱宽度、煤层厚度、断层倾角等,并且断层倾角与主要影响角的大小关系决定了断层面离层空间的产生。

When fault exists in overburden strata,the earth-surface subsidence laws would be greatly different from the laws without faults.To study the effect of fault on mining zone transferring,the principle of spatial conservation and numerical simulation were utilized to find that there is fault separation space and the earth-surface subsidence zone would be greater based on theoretical derivation.The results showed that the increased subsidence zone is mainly from the fault separation space and the space below key-strata is from broken rocks being compressed again,while the space above key strata was mainly from the decrease of bed-separation.At the same time,the influence factors of fault separation are mining length,bedrock height,protecting coal pillar width,mining height and fault dip.Also,the occurrence of fault separation is decided by the relationship between fault dip and main influence angle.The research result is of significance for studying the earth-surface subsidence laws when there are faults in overburden rock and improving the precision of subsidence prediction.