烧变岩边坡渗流特征及采动稳定分析研究

Study on seepage characteristics and mining stability of burnt rock slope

对富水烧变岩露天煤矿边坡渗透特征及稳定性分析方法展开研究,通过现场水文勘查分析,确定边坡地下水渗流水力坡降的坡降角为5.0°~12.8°。建立边坡渗流模型,对边坡地下水渗流场进行模拟分析,考虑地下水动水压力对边坡稳定性的影响,采用应力场与渗流场耦合分析的方法,研究了边坡的稳定性。研究结果表明,渗透力主要作用在25号煤层以上泥岩层中,边坡在烧变岩体及边坡坡脚变形明显;采动影响下,边坡稳定性呈加速下降趋势。动水压力随采深近似呈线性增加,火烧区地下水向原岩区渗透量随采深增加增速逐渐下降,采深增加对边坡稳定性影响呈增加趋势。

The seepage characteristics and stability analysis method of slope in water rich burnt rock open-pit coal mine were studied.Through on-site hydrological exploration and analysis,it was determined that the hydraulic gradient of slope groundwater seepage was 5.0°~12.8°.The slope seepage model was established to simulate and analyze the slope groundwater seepage field.Considering the influence of groundwater hydrodynamic pressure on slope stability,the slope stability was studied by the coupling analysis method of stress field and seepage field.The results showed that the seepage force mainly acted in the mudstone layer above No.25 coal seam,and the deformation of the slope was obvious in the burnt rock mass and the slope toe;under the influence of mining,the slope stability showed an accelerated downward trend.The hydrodynamic pressure increased approximately linearly with the mining depth,and the speed increase of groundwater infiltration into the original rock area in the fire area decreased gradually with the increase of mining depth,and the influence of mining depth on slope stability increased.