采用基于塑性极限理论的弹塑性极限平衡法研究三峡升船机上闸首———基岩的整体稳定性 ,该方法以逐渐降低材料强度来逼近系统的极限平衡状态 ,以塑性区的贯通表示系统的临界失稳状态 ,无需事先确定滑裂面 ,适合于复杂基岩的稳定性分析。研究中模拟施工过程 ,把开挖卸载后的基岩应力作为再加载时的初应力 ,并考虑到基础固结灌浆等加固措施 ,假定基岩从弹性状态开始再加载。结果表明 ,上闸首———基岩系统的整体稳定安全系数为 3 .3 ,具有足够的安全度 The elasto-plastic limit equilibrium method based on the plastic limit theory is used to study the overall stability of the head-rock bedrock of the Three Gorges ship lift. This method approximates the limit equilibrium state of the system by gradually decreasing the material strength. The critical instability state, without prior determination of the sliding surface, is suitable for the stability analysis of complex bedrock. In the study, the construction process was simulated, and the bedrock stress after unloading was taken as the initial stress when reloading. Considering the reinforcement measures such as foundation consolidation grouting, the bedrock was assumed to be reloaded from the elastic state. The result shows that the overall stability safety factor of the head-head rock system is 3.3, with sufficient safety