预应力锚索对岩质边坡加固效应的数值模拟

Numerical simulation of reinforcement of rock slopes by prestressed anchor cables

针对预应力锚索加固岩质边坡稳定性分析与评价问题,应用FLAC 3D建立了双滑面楔形体边坡模型,模拟了边坡边开挖、边锚固的施工过程及室内模型的超载破坏试验,分析了锚固岩体的位移和应力、节理裂隙面位移随工况的变化以及锚索预应力损失等问题.研究结果表明:预应力锚索加固作用提高了边坡整体的稳定性;分析边坡的整个破坏过程可知边坡的变化过程为柔性变化,而不是刚性变化;从锚索预应力变化情况可知锚索自上而下进入屈服状态,不同部位的锚索受力有先后、大小之分,呈不均匀分布;对锚固后边坡安全系数进行计算,计算结果与模型试验得出的结果相近.

Based on the conclusion of research present state of the reinforcement mechanism of the prestressed anchorage cables for slope, a dual-sliding surface wedge slope model was established with help of FLAC 3D to analyze and evaluate the stability of the rock slope. The construction process of anchoring while excavating and the overloading damage of indoor model test were simulated. As to verify and comply analysis for the indoor model test, the displacement and stress of anchorage rock mass and joints crack surface with the case changes were obtained, meanwhile, some issues such as the cable pre-stress loss were analyzed. The results show that： the pre-stressed cables can improve the overall stability of the slope; the whole process of changes are flexible through analysis of the slope failure process, not rigid change; through pre-stress changes from anchorage cable, it can be seen that the anchorage cables get into the yield condition from top to down, and the force values of cable are different within different parts, which is shown uneven distribution. The calculated results are similar to that of model test among the calculation of slope safety factor.