砾岩层控制覆岩和地表移动机理分析

Analysis of the Mechanism of Conglomerate Layer Controlling Overlying Strata and Surface Movement

本文针对砾岩层下3煤开采地表移动与变形值偏小的机理问题,运用关键层理论确定了山东某煤矿3煤开采厚110 m砾岩层为高位主关键层,采用UDEC软件模拟计算了含有砾岩层3煤开采地表下沉和水平移动值,及砾岩层厚度分别为50 m、100 m、150 m、200 m时不同高度处的岩层下沉值;分析了位于砾岩层上和砾岩层下及砾岩层内部不同高度岩层下沉值变化规律。又根据砾岩层受开采影响内部岩块能量运移过程,建立了砾岩层内部能量与体应变、tanβ间函数模型。研究表明:砾岩层内部岩块运动过程中体积不断扩展,阻止了岩层移动向地表移动传播;开采区域上覆岩体存在多个离层空间,这些离层空间承担了地表变形当量,使地表变形值偏小。

This paper focuses on the mechanism of small surface movement and deformation of coal mining under conglomerate stratum 3. Based on the critical stratum theory, the 110 m thick conglomerate stratum of no. 3 coal mining in Shandong is determined as the high key stratum. UDEC software is used to simulate and calculate the surface subsidence and horizontal movement values of coal mining with conglomerate layer 3, and the strata subsidence values at different heights when conglomerate layer thickness is 50 m, 100 m, 150 m and 200 m respectively. The subsidence values of strata at different heights above and below the conglomerate layer and in the conglomerate layer are analyzed. According to the process of energy migration in conglomerate strata affected by mining, the function models of energy, bulk strain and tanβ in conglomerate strata are established. The results show that the volume of rock blocks in the conglomerate layer expands continuously during the movement process, which prevents the movement of rock strata from moving to the surface. There are multiple separation spaces in the overlying rock mass in the mining area, which bear the equivalent surface deformation and make the surface deformation value smaller.