煤层倾角对上覆岩层导水裂隙带的影响

Influence of coal seam dip angle on water conduction fracture zone of overlying strata

为了研究煤层倾角对上覆岩层导水裂隙带的影响,以四明山煤矿工程地质条件为背景,运用UDEC软件分别建立了0、15°、30°、60°煤层倾角条件下的煤层开挖模型,通过分析不同煤层倾角条件下上覆岩层的离层和塑性破坏情况,确定煤层倾角对上覆岩层导水裂隙带的影响规律。结果表明,煤层倾角越大,顶板离层现象最明显区域越靠近采空区倾向高处的边界;在倾斜岩层中,煤层开挖后其上覆岩层塑性破坏区呈现非对称特征,采空区倾向高处的边界附近塑性破坏区高度明显大于另一侧。而且煤层倾角越大,上覆岩层塑性破坏区扩展高度越高;煤层倾角越大,导水裂隙带最发育的区域越靠近采空区倾向高处的边界,导水裂隙带高度也越大。

In order to study the influence of coal seam dip angle on water conduction fracture zone of overlying strata,taking the engineering geological conditions of Simingshan Mine as the background, the UDEC software was used to establish the coal seam excavation models under the conditions of 0°, 15°, 30° and 60° coal seam dip angles.And the influence law of coal seam dip angle on water conduction fracture zone of overlying strata was determined by analyzing the separation layer and plastic failure of overlying strata under different coal seam dip angles. The results showed that the larger dip angle of coal seam, the smaller distance between the most obvious area of separation roof and the boundary of high inclination of goaf. In the inclined strata, the plastic failure zone of overlying strata presented asymmetric characteristics after the coal seam excavation, and the height of the plastic failure zone near the boundary of high inclination of the goaf was significantly greater than that on the other side. Moreover, the larger dip angle of coal seam, the higher the extension height of plastic failure zone of overlying strata;the larger dip angle of coal seam, the smaller distance between the most developed area of water conduction fracture zone and the boundary of high inclination of goaf, and the higher height of water conduction fracture zone.