大倾角煤层协调开采地表移动变形控制

Control of surface movement and deformation during coordinated mining of large dip coal seams

为实现大倾角(倾斜)煤层间协调开采地表减损的目的,以甘肃某矿煤层赋存条件为背景,采用UDEC数值模拟软件,对大倾角(倾斜)煤层间协调开采地表移动变形控制问题进行了探究。结果表明:大倾角(倾斜)煤层开采时,埋深浅的工作面对地表的破坏更严重;随工作面埋深的增大,对地表的影响程度逐步减弱;多煤层开采时,使埋深浅的工作面对应地表不移动或少移动,使煤柱影响范围内的地表进一步下沉,减小地表下沉、移动变形的不均匀变形程度,防止地表出现大的采动裂缝,是煤层间协调开采地表减损的核心问题;地表移动的均匀性、地表张拉程度、地表变形程度可以通过变异系数、张拉区水平移动斜率、地表水平,倾斜,曲率变形分别进行表征;该地质采矿条件下地表移动变形控制的工作面最优错距为80 m,1煤的遗留煤柱距4煤工作面上山边界水平距离约71.9 m,距下山边界39.9 m。

In order to achieve the goal of reducing surface damage during coordinated mining of large dip(inclined)coal seams,taking the occurrence conditions of coal seams in a certain mine in Gansu Province as the background,UDEC numerical simulation software was used to explore the problem of controlling surface movement and deformation during coordinated mining of large dip(inclined)coal seams.The results indicate that during the mining of large dip(inclined)coal seams,the surface damage is more severe when the working face is buried at a shallow depth.As the burial depth of the working face increases,the impact on the surface gradually weakens;in the mining of multiple coal seams,the core problem of surface loss reduction in coordinated mining between coal seams is to make the surface of the working face with shallow buried depth not move or move less,make the surface further sink within the influence range of coal pillar,reduce the uneven deformation degree of surface subsidence and movement deformation,and prevent large mining cracks on the surface;the uniformity of surface movement,the degree of surface tension and the degree of surface deformation can be characterized by the coefficient of variation,the slope of horizontal movement in the tension region,the surface level,inclination and curvature deformation;the optimal fault distance of the working face controlled by surface movement and deformation under this geological mining condition is 80 m,the horizontal distance of the remaining coal pillar of 1~#coal from the uphill boundary of 4~#coal working face is about 71.9 m,and the distance from the downhill boundary is 39.9 m.