双坡面临空岩质边坡滑动破坏模式下的稳定性分析

Stability Analysis for Sliding Failure of Double-faced Slope

多数岩质边坡稳定性分析已基本解决了常走向单坡面临空的边坡平面滑动问题。然而,在路堑边坡工程和自然边坡中有很多边坡坡面并不是平面,它包含多个坡面。多坡面边坡包含两个或多个不同走向的坡面。多坡面边坡几何特征不同于单坡面边坡,所以滑动条件也不一样。在赤平投影图上,多坡面的滑动包络线是组成边坡的每个坡面单独投影包络线的组合。为了探讨方便,只讨论了双坡面临空岩质边坡的滑动破坏模式,并将其分为双坡面临空下的平面破坏和楔形体破坏。在赤平投影图上,双坡面滑动区域定义为双坡面边坡滑动包络图中两侧坡面的真倾线之间的面积。如果有一两个节理面真倾向线落在滑动区内,滑动破坏才可能发生。

Most analysis for rock slope stability have dealt with single-faced slopes with a planar surface of a constant strike. However, there are many slopes with non-planar surfaces along road cuts and natural slopes. Multi-faced slopes consist of two or more faces with different strikes. Multi-faced slopes have different sliding conditions compared to single-faced slopes because of their geometrical characteristics. On steregraphic projection, a sliding envelope of a multi-faced slope is a union of envelopes of individual faces formed on the slope surface. For conveniencein discussing, sliding modes of double-faced slope have been discussed and was divided into two modes： plane and wedge sliding. On steregraphic projection, a sliding zone of double-faced slope is defined as the area between the true dip lines of two side-slope faces in the sliding envelope of a double-faces slope. If the true dip line of one or two joint planes plot within a sliding zone of double-faced slope, a double-faced sliding failure can be possible.