基坑高陡岩质边坡稳定性分析

Stability Analysis of a High and Steep Rock Slope in a Foundation Pit

将赤平极射投影法、有限元强度折减法及极限平衡法相结合,对长沙某矿坑高陡岩质边坡进行分析,采用赤平极射投影法对边坡进行初步分析,利用有限元软件Phase 2对矿坑开挖后的应力变化、破坏模式进行数值模拟,确定边坡支护范围并采取支护措施,结合极限平衡软件Slide计算边坡支护效果。研究表明,开挖后在边坡中上部为应力松弛区,坡脚为应力集中区。该高陡岩质边坡的变形趋势为双平面滑动破坏,采用浅表层刷坡、预应力锚杆十字板深部支护的治理方案,可有效提高边坡的稳定性。

The study analyzes the high and steep rock slope of a mine in Changsha by combining the horizontal polar projection method,the finite element strength reduction method and the limit equilibrium method;does preliminary analysis of the slope by the horizontal polar projection method;uses the finite element software Phase 2 to numerically simulate the stress change and failure mode of the mine after excavation;determines the supporting range of the slope and takes supporting measures;and calculates the support effect of the slope through combining with the limit balance software Slide.The research shows that the stress relaxation zone is in the middle and upper part of the slope after excavation,and the stress concentration zone is at the foot of the slope.The deformation trend of the high and steep rock slope is double-plane sliding failure.The treatment scheme of shallow surface slope brushing and deep support of prestressed anchor cross slab can effectively improve the stability of the slope.