Study on overburden damage and prevention of runoff disaster in multiseam mining of gully region
LIU Yilong;YANG Tianhong;MA Kai;YE Qiang;ZHAO Yong;ZHAO Qianbai
沟谷地形下多煤层开采带来了严重且复杂的“裂隙发育—山体滑坡—河道堵塞—涌水加剧”链式灾害。探究沟谷地形与煤层重复采动耦合作用下的覆岩破坏特征与规律是滑坡、涌水灾害防治的关键。以西曲矿沟谷地形下多煤层开采为研究对象,综合采用集地表勘察、InSAR动态观测、降雨-径流分析和数值模拟为一体的“覆岩移动−地表变形−径流积水”分析方法,分析了沟谷区多煤层下行开采引发覆岩破坏与地表沉降的空间扩展全过程。结果表明:沟谷区下组煤充分采动后,煤层间关键层以下岩层移动范围无明显外扩特征,竖向裂隙发育,以张拉开裂为主。关键层上方岩层剪切裂隙占比明显增加,采动沉降效应与重力作用下的沟谷坡体易产生剪切滑移,甚至发生坡体下行裂隙与覆岩上行裂隙的贯通现象。重复采动造成山体滑坡形成的堆积体若阻塞河道并在汛期形成堰塞湖,则具有井下涌水风险。基于无人机倾斜摄影测量合成的高精度地形,通过降雨−径流模拟再现了山西“百年一遇”暴雨期间矾石沟流域不同历时降雨淹没范围与时间百分比,为矾石沟小流域的沟谷水灾害防范和风险评估提供了支撑,并提出了基于裂隙发育与地表淹没范围的地表径流水害综合防治方法。研究可为沟谷区多煤层开采条件下地表地质灾害防治与水资源保护提供有益参考。
Multi-seam mining in gully region has resulted in serious and complex chain disasters, including fissure development, mountain landslides, river blockage, and intensified water inflow. To prevent and control landslides and water inrush disasters, it is crucial to explore the characteristics and laws of overlying strata failure under the coupling effect of gully terrain and repeated mining in coal seams. This study focuses on the mining of multiseam in the gully terrain of Xiqu Coal Mine. The comprehensive analysis method, integrating surface exploration, InSAR dynamic observation, rainfall-runoff analysis, and numerical simulation, is used to analyze the entire process of spatial expansion of overlying strata failure and surface subsidence caused by downward mining of multiseam in the gully region. The results reveal that after the critical mining of the lower coal seam in the gully region, the lower strata beneath the key stratum in interlayered formations are prone to develop cutting failure and vertical fissure, with tensile cracking being the dominant mode of failure. The proportion of shear fractures in the overburden above the key stratum increases significantly, and the gully slope is prone to shear slip under the effects of mining subsidence and gravity. The connection phenomenon between the downward fractures of the slope and the upward fractures of the overburden can even occur. In addition, if the accumulation formed by mountain landslides due to repeated mining blocks the river channel and forms a barrier lake during the flood season, there is a risk of underground water inflow. To prevent such disasters, high-precision terrain synthesized by UAV tilt photogrammetry is used to simulate the rainfall inundation range and time percentage of different durations in Fanshigou watershed during the “100-year return period” rainstorm in Shanxi Province. The research proposes a comprehensive prevention and control method of surface runoff water disaster based on fissure development and surface inundation range, which provides support for gully water disaster prevention and risk assessment in Fanshigou small watershed. This study can serve as a useful reference for the prevention and control of surface geological disasters and the protection of water resources under the condition of multiseam mining in gully regions.
gully terrain;multiseam mining;strata movement;surface subsidence;runoff disaster
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会