安太堡露天矿边坡蠕滑区滑动机理与稳定性分析

针对安太堡露天矿西北帮边坡出现的蠕滑现象，介绍了边坡的工程背景和滑坡现状，结合位移监测数据，研究了边坡蠕滑区滑坡的主要形成因素和滑动机理，简述了蠕滑边坡的失稳预测方法。结果表明：露天矿边坡蠕滑区滑坡机理为前缘沿红黏土顺层持续蠕滑，后缘产生大量拉裂带，中部阻滑段最终被剪断导致边坡产生陡倾切层滑动；持续的强降雨是造成边坡滑坡的主要外在因素，不利的地形与地貌和地质特征与构造是导致边坡蠕滑变形的内在因素；可以通过判定边坡后缘拉裂带的裂缝深度对边坡失稳进行预测。运用基于有限单元法的MIDAS-GTS软件构建了边坡蠕滑区三维地质模型，采用强度折减法计算了边坡稳定系数，并进行了边坡的变形破坏分析和稳定性评价。结果表明：边坡天然状态下稳定系数为1.06，整个边坡蠕滑区处于临界破坏状态；边坡蠕滑区位移自上而下逐渐减小，坡顶最大位移达到0.43 m，位移变化最显著的区域分布于红黏土层，说明其发生了蠕滑变形，并形成了剪切破坏带，与坡顶拉裂带有贯通的趋势，滑坡的可能性较大，应该采取必要的工程防治措施。

Analysis of sliding mechanism and stability of creep area of Antaibao Open-Pit Mine slope

According to the northwest creep area of Antaibao Open-Pit Mine slope，the engineering background and the slide status were introduced.The main influence factors and sliding mechanism of creep area were researched combined with the data of displacement monitoring，and the instability prediction method of creep slope was described.At the same time，the sliding mechanism of creep area of open-pit mine slope was got.Firstly，the leading edge creeps along the red clay continuously，then a large amount of cracks are produced on the back edge，and the central resistance area is sheared to failure，thus steep slicing sliding is brought out.The strong rainfall is the main external factor of the sliding while the adverse geological conditions are thought to be the internal factors，and the slope instability can be predicted through judging the crack depth of the back edge.3D geological model of creep area was constructed by the software MIDAS-GTS，which is based on finite element method，and the strength reduction method was adopted to calculate slope stability coefficient，then deformation and destruction analysis and stability evaluation of creep area were induced.The results show that the slope stability coefficient is 1.06，and the slope is at a critical state.Displacement of creep area decreases from high to low，with a biggest displacement of 0.43 m on the top.Displacement change significantly in the red clay layer，and it indicates that creep deformation develops continuously in red clay layer，and shear failure belt is formed，and there is a trend for it to link with the tensile zone on the top.Thus，the possibility of landslide is larger，and necessary engineering prevention and control measures should be taken.