3D STABILITY ANALYSIS OF THREE GORGES DAM FOUNDATION NEAR LEFT ABUTMENT
三峡左岸坝段三维抗滑稳定性分析

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.