摘要
云南古水水电站根达坎堆积体已经历了近10 a的勘察,但其斜坡堆积体的演化过程仍有待研究。从堆积体坡表的变形迹象及平硐内部揭示的软弱滑动带结构特征入手,反演推测斜坡堆积体的演化过程,建立数值模型分析堆积体发育过程中的演化机制。模拟结果表明,堆积体的中前缘部位主应力较大,也较为集中,斜坡靠近地表附近的拉应力最大,说明堆积体越靠近江面,其稳定性越差,堆积体的胶结程度越低,越有利于地表雨水入渗及风化作用的深入。数值分析还表明暴雨条件下堆积体饱和状态对斜坡变形有重要影响,暴雨状态下最有可能先发生破坏的部位主要集中在堆积体后缘,从而产生"拉-压-剪"的推移破坏模式,发生连锁的滑移-坠覆-滑移式的链接破坏。
The investigation of Gendakan landslide at Gushui Hydropower Station has being taken for 10 years,but the evolution process of the slope is yet to be studied. Starting with the deformation signs of the slope surface and structural characteristics of weak slip band exposed in the adit,we reversed the evolution process of the landslide and established a numerical model to analyze the evolution mechanism in the development process of the landslide. The simulation results show： the principal stress of mid- leading edge is relatively high and concentrated and the tensile stress of the part near the ground is the maximal which reflects that the closer the landslide is to the river surface,the poorer its stability is and that the lower the cementation degree of the landslide is,the easier it is for ground rainfall to permeate through and weather the landslide. It is also found that the saturated state of the landslide under rainfall condition has great influence on the slope deformation and that the trailing edge is the most likely to fail under rainstorm,which may cause tension- compression- shearing thrust load- induced deformation and the chain deformation of slip- down slope overlapping- slip will occur in turn.
出处
《人民长江》
北大核心
2016年第21期52-56,共5页
Yangtze River
基金
中国地质调查局基金项目"西南深切河谷地区斜坡地质灾害调查评价"(12120113010500)
关键词
变形特征
演化机制
数值模拟
堆积体
landslide
deformation characteristics
evolution mechanism
numerical simulation
accumulative body
