损伤变量在煤层底板开采破坏深度计算中的应用

Application of Damage Variable in Floor Failure Depth Calculation during Coal Mining

针对煤层底板破坏深度的计算很少考虑实际存在的采动损伤的现状,以某矿A组煤开采为背景,提出一种基于数值模拟与理论计算的底板岩层损伤变量,进而确定底板破坏深度的方法。通过在该矿工作面巷道特定位置施工井下钻孔,采用并行电法探测技术验证该方法的有效性。结果表明:底板应力在推进至断层附近时达到峰值19.70 MPa,底板岩层等效损伤变量D'=0.79;基于损伤变量计算得出的底板岩层的最大破坏深度为20.27 m,对比井下实测结果,其准确率达到93.32%。研究结果为快速准确地确定底板采动破坏深度提供了一个新思路。

In the calculation of the floor failure depth, the existing mining damage is rarely considered. In this paper, by taking the mining of Group A coal seams in a certain mine as the background, the floor damage variable based on the numerical simulation and theoretical calculation was proposed, and then the method for determining the floor failure depth was put forward. Holes were drilled at the specific location of the working face roadway, the validity of this method was then verified with the parallel electric method. The results showed that the floor stress reached the peak of 19. 70 MPa near the fault and the equivalent damage variable of the floor rock was =0. 79; the maximum floor failure depth that was calculated according to the damage variable was 20.27 m, compared with the underground measured results, its accuracy reached 93. 32%. The research results provided a new idea for rapidly and accurately determining the mining-induced floor failure depth.