三峡库区反倾岩质滑坡防治措施研究

选取巫峡段茅草坡一典型反倾岩质滑坡为研究对象,阐述了库岸滑坡防治措施的分阶段设计流程(原则、思路和方法):首先基于已有的地质勘察资料和现阶段岸坡变形破坏特征分析岸坡变形破坏过程及现阶段所处的变形阶段,确定其相应的失稳模式和主控因素,提出滑坡防治比选方案;其次对于滑坡不同变形破坏阶段进行合理划分,运用数值模拟对滑坡防治各比选方案的治理效果开展岸坡不同变形破坏阶段的全过程评价,对比分析制定较合理的防治措施。研究结论主要有:(1)对同一岸坡而言,当其处于不同变形阶段时,其变形破坏模式和主控因素不完全相同,且同一防治方案的治理效果差别较大;(2)就茅草坡现阶段而言,滑坡处于变形破坏过程的坡脚弱化滑移阶段,此阶段变形破坏的主控因素为消落带岩体的弱化和滑移,格构护坡方案的造价低且防治效果最好,而锚杆锚固方案造价高且效果低。

STUDY ON CONTROL MEASURES OF COUNTER-TILT ROCK LANDSLIDE IN THREE GORGES RESERVOIR REGION

In this paper, Maocaopo in the Wu Gorge section, a typical anti-dip rock landslide, was taken as the research object to describe the phased design process of prevention and control measures for this type of landslide (principle, idea and method):First, the deformation failure process and the current deformation stage of the bank slope were analyzed on the basis of existing geological survey data and the characteristics of bank slope deformation failure at the current stage, so as to determine the corresponding instability mode and main control factors, then propose alternative schemes for landslide prevention and control. Second, different deformation failure stages of the landslide were reasonably divided. Numerical simulation was applied to carry out whole-process evaluation of the outcome of each alternative scheme for landslide prevention and control at different deformation failure stages of the bank slope. Reasonable prevention and control measures were established through comparative analysis. Main conclusions of the research include the followings:(1) For the same bank slopes, their deformation failure mode and main control factors are not exactly the same at different deformation stages, and the same prevention and control scheme renders significantly different outcomes. (2) For the current stage of Maocaopo, the landslide is at the slope toe weakening and slipping stage of the deformation failure process. The main control factor of deformation failure at this stage is the weakening and slipping of rock mass in the hydro-fluctuation belt. The scheme of slope protection with lattice needs a lower construction cost and produces a better prevention and control effect, while the scheme of bolt anchoring needs a higher construction cost but has a poorer effect.