哈拉沟矿工业广场东侧滑坡地质条件与成因研究

Investigation of geological conditions and causes of landslide at the east side of the industrial site of Halagou Mine

为了查明哈拉沟煤矿工业广场东侧滑坡成因,通过现场地质调查、水文地质钻探、地表位移监测等技术手段研究了滑坡地质条件、渗流与变形特征,采用数值模拟方法分析了滑坡的成因机制。结果表明,在滑坡区东部第四系松散层底部发育一条近东西向的古冲沟,上游有两条支沟;地表神东湖水渗漏和日常生态灌溉水大量补给古冲沟流域,导致地下水位上升,在滑坡坡脚处形成排泄区;使得坡脚处地下水渗流速度和孔隙水压力升高,基质吸力和坡体抗剪强度降低,导致抗滑力降低;滑坡大量渗水,坡体重量增加,并产生动水压力,导致下滑力增加,进而诱发该滑坡;随着水温的升高,滑坡稳定性系数降低。在坡脚施工三口排水井,经过抽水降低坡体地下水位,并治理了上部沟渠渗漏点,目前该滑坡得到了有效控制。

In order to find out the causes of the landslide at the east side of the industrial site of Halagou Coal Mine,the geological conditions,seepage,and deformation characteristics of the landslide were investigated with field geological survey,hydrogeological drilling and surface displacement monitoring,and the mechanical mechanism of the landslide was analyzed with numerical simulation.The results show that,a nearly transmeridional ancient gully is developed at the bottom of the Quaternary loose layer on the east of the landslide with two branches in the upstream.The surface water of Shendong Lake and the daily ecological irrigation water supplies the ancient gully basin in large quantities,resulting in a rise of groundwater level and the formation of a discharge area at the foot of the landslide slope;due to the leakage of a large amount of surface water,the groundwater seepage velocity increases,the water level rises,and the pore water pressure increases,and therefore the matrix suction decreases and the shear strength of the landslide soil decreases,resulting in the reduction of the anti-sliding force.A large amount of water seepage at the slope increases the weight of the slope and generates downward osmotic pressure,resulting in the increase of sliding force.And therefore,the landslide was induced.As the water temperature increases,the landslide stability coefficient decreases.Three drainage wells were constructed at the foot of the slope.After pumping,the groundwater level of the slope was reduced,and the leakage point of the upper ditch was treated,and the landslide was controlled.