黄登水电站地下厂房高边墙围岩稳定性分析

The Stability Analysis of the Underground Powerhouse High Slope Wall Surrounding Rocks of Huangdeng Hydropower Plant

黄登水电站;地下厂房在开挖过程中局部出现围岩外鼓开裂、混凝土喷层破裂掉块等现象,这些变形主要因开挖后围岩的应力松弛或集中而导致。采用数值模拟技术,分析开挖过程中厂房围岩位移场、应力场等的分布特征和演化规律,开展了地下厂房开挖完成后围岩稳定性初步预测,为地下厂房的开挖支护设计优化、监测布置等提供数据。

Swelling and cracking of the surrounding rocks,fracture and scaling of shotcrete locally occurred in the course of excavation of the underground powerhouse of Huangdeng hydropower plant,which were mainly caused by stress relaxation or stress concentration after excavation.The paper used the numerical simulation technology to analyze the distribution characteristics and the law of change of deformation field and stress field of the powerhouse surrounding rocks in the course of its excavation and then made preliminary prediction of stability of the surrounding rocks after excavation of the underground powerhouse,thus providing necessary data for optimization of excavation support and monitoring arrangement of the underground powerhouse.The analysis reveals that the main powerhouse enjoys good stability as a whole,however local shallow damage exists,so it is advised to provide pre-stressed tendons for the crown of the powerhouse to improve stability of its surrounding rocks.