摘要
金沙江某水电站引水洞出口边坡为千枚岩类软岩边坡,其地质条件复杂、结构面发育。由于边坡特殊的岩体结构及其重要性,其稳定发展趋势便成为工程技术人员关心的主要问题。本文在地质调查的基础上,分析了边坡岩体结构特征,建立边坡地质模型,并采用3D-FLAC模拟边坡-洞室组合开挖后的应力、变形分布特征及破坏区范围。结果表明,洞室开挖主要影响6倍洞径范围内围岩应力分布状态,对边坡整体稳定性影响不大;但边坡开挖会使得坡面产生不同程度的受拉区域,对边坡稳定性影响较大。另外,在此基础上选取典型的边坡进行稳定性分析,分析表明,天然状态下,边坡开挖后局部岩体稳定性较差,存在块体失稳的可能,但整体稳定性较好;暴雨、地震条件下,边坡稳定性较差,边坡顶部岩土体有沿结晶灰岩与千枚岩的地层分界面发生失稳的可能。
The slope of water diversion tunnel of a hydropower station at the Jinsha rever is of the soft rock phylitte,where the geological conditions were complex and structural surface developed.As the slope of the rock mass structure and its special importance,the stability trend of the slope had became the major problems,which engineering and technical personnel concerned.In this paper,based on the analysis of structural features of rock slope,the authors established the geological model of slope,and simulated the stress and deformation and damage of the slop after excavation chamber using 3D-FLAC.The results showed that the main impact of the stress distribution by underground excavation would be on the range of 6 times of the diameter of the chamber in the surrounding rock,and that there would be little effect on the overall stability of the slope.But slope excavation would make different degrees of tension in the slopes,which would be put greater impact on slope stability.
出处
《地质灾害与环境保护》
2010年第1期58-62,共5页
Journal of Geological Hazards and Environment Preservation
