库水位变动速率对某水电站坝前倾倒变形体稳定性的影响

发布时间：2018-12-11 02:47

【摘要】：澜沧江上游某电站坝前大面积发育倾倒变形体,边坡中的地下水对其稳定性有重大影响。为此,运用二维饱和—非饱和渗流有限元分析程序SEEP/W,并联合极限平衡法分析库水位变动期间库水位变动速率对倾倒变形体边坡渗流场及其稳定性的影响机理及规律。结果表明,水位变动速率对倾倒变形体的瞬时渗流场有较大影响,坡体表面形态在水位变动期间,对其水力梯度影响较为明显;水位上升阶段,水位变动速率与倾倒变形体稳定性呈现正相关关系,水位上升速率由0.5 m/d增大至5 m/d,稳定性系数上升了0.7%~2.0%,而水位下降阶段,水位变动速率与其呈现负相关关系,堆积体稳定性系数降低0.6%~1.6%,且其存在临界速率(2.0m/d)、水位(死水位以上3/8坡高处),速率、水位超过其临界值之后,稳定性变幅明显放缓甚至出现回升。
[Abstract]:A large area of toppling deformation is developed in front of a power station dam in the upper reaches of Lancang River, and the groundwater in the slope has a great influence on its stability. For this reason, the finite element analysis program SEEP/W, and the limit equilibrium method are used to analyze the influence mechanism and law of reservoir water level change rate on seepage field and stability of toppling deformable slope during the period of reservoir water level change. The results show that the rate of water level change has a great influence on the instantaneous seepage field of toppling deformation body, and the surface morphology of slope body has obvious influence on its hydraulic gradient during the period of water level change. In the stage of rising water level, the change rate of water level is positively correlated with the stability of toppling deformation body. The water level rising rate increases from 0.5 m / d to 5 m / d, and the coefficient of stability increases by 0.72.0%, while at the stage of water level decreasing, The change rate of water level is negatively correlated with it, the stability coefficient of accumulation body is reduced by 0.6% and 1.6%, and there is critical rate (2.0m/d), water level (3 / 8 slope height above dead water level), rate, After the water level exceeds its critical value, the fluctuation of stability obviously slows down and even rises.
【作者单位】：成都理工大学地质灾害防治与地质环境保护国家重点实验室;
【基金】：中国地质调查局西南深切河谷地区斜坡地质灾害调查评价工作(12120113010500) 国家自然科学基金项目(41272332)
【分类号】：TV223;TV697.21

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