STABILITY EVALUATION OF LEFTMOST POWER-UNIT MONOLITHS OF THE THREE GORGES DAM

摘要

This paper summarizes stability analyses and evaluation of the leftmost power-stationmonoliths of the Three Gorges Dam. Those monoliths are constructed immediatelyupstream of the power station atop of a high and steep foundation cut slope which dips ina downstream direction. Problematic discontinuities dipping downstream at low angleswithin the cut slope pose a threat to the monolith stability against deep-seated sliding.This became one of the top issues among many challenges of the project. TheDepartment of Hydraulic Engineering at Tsinghua University in Beijing, China wasretained to perform stability analyses and evaluations of the monoliths. By employing theconventional limit equilibrium method and advanced finite element analysis, significantefforts were made to conduct the analyses and evaluate the stability of the monolithsagainst a deep-seated sliding potential failure. Efforts also were made to study the effectof the counter force from the cut slope on the powerhouse.