三峡左岸坝段三维抗滑稳定性分析

三峡大坝左岸由于建基面抬高，大坝建于一个边坡之上，同时边坡内部存在定位的长大裂隙，其抗滑稳定受到普遍关注。目前大多数的工作均局限于二维领域。基于三峡工程的极端重要性。采用边坡稳定三维上限解分析方法对三峡左岸坝段进行三维稳定分析，研究三维效应对安全系数的影响。该方法具有理论基础严格，计算简捷的优点，它是二维的Sarma法在三维条件下的扩展。计算结果表明，三维安全系数比二维安全系数有明显的提高。

3D STABILITY ANALYSIS OF THREE GORGES DAM FOUNDATION NEAR LEFT ABUTMENT

Because there exists a set of long persistent joints in the bed rock near the left abutment of the Three Gorges dam,a general attention is paied to the problem of stability. Most of the former study employed 2D analysis methods. As this issue is related to an extremely important dam,the 3D upper-bound method is used to evaluate the factors of safety and find how much additional help is needed if 3D effect is accounted for. The presented method makes feature of its rigorous theoretical background and simple numerical procedures,and it is an extension of the Sarmas 2D method. The study result shows that the 3D safety factor is much larger than 2D one.