京藏高速拉萨段高边坡稳定性分析

Analysis on Stability of High Slope in Lhasa Section of Beijing—Tibet Expressway

针对京藏高速拉萨段高边坡加固前后稳定性问题,概化高边坡典型数值计算模型,基于不同失稳判据的有限元强度折减分析方法对该高边坡稳定性进行数值模拟。结果表明:不同失稳判据下,经锚杆、锚索加固后的高边坡安全系数提高约30%;锚杆、锚索所承受的轴力沿其长度方向不均匀分布,未达到屈服状态;加固前后高边坡失稳破坏时的塑性区扩展路径具有一致性,锚固作用很好地抑制了边坡内部塑性区的扩展延伸。

In order to deal with the reinforcement effect of high and steep slope of Beijing--Tibet Expressway, the typical numerical calculation model of the high slope is generalized, the finite element strength reduction method based on different instability criterion was used to carry out numerical simulation of the high slope stability before and after reinforcement. The results show that the safety factor of high slope strengthened by anchors rod and anchor cables is increased by about 30 % under different instability criteria. The axial force of anchor rod and anchor cable is unevenly distributed along its length and does not reach the yield state. The plastic zone expansion path is consistent before and after reinforcement for the instability failure of high slope and the anchorage greatly inhibits the expansion and extension of the plastic zone inside the slope.