三峡水库碳酸盐岩区岩溶作用与斜坡破坏

三峡水库峡谷区矗立着大量岩溶不稳定库岸，危及长江黄金水道安全。采用野外勘查和力学分析，对三峡库区碳酸盐岩区岩溶作用与斜坡破坏关系进行深入研究。野外勘查发现，三峡库区碳酸盐岩库岸存在许多与溶洞、溶隙、溶蚀带、溶槽、溶沟等表层岩溶作用有关的斜坡不稳定现象。巫峡段库岸内共发育岩溶地质灾害及隐患点186处，其中滑坡隐患点37处，大型以上危岩体6个。岩体力学分析表明:强降雨、蓄水和岩体劣化会因为有效应力减少、强度下降而造成破裂的节理/裂隙逐渐扩大。同时，水位变动带岩体劣化的裂缝扩展速率比三峡的平均溶蚀率高出约1 300倍，极大地加快了已经进入屈服状态的不稳定岩体的演化进程。溶蚀作用是岩溶岸坡中最基本的作用，库水长期波动加快了岩溶岸坡演化。本次研究将为三峡库区峡谷段不稳定库岸识别和防灾减灾提供技术支撑。 

Karstification and slope failure in carbonate areas of Three Gorges Reservoir

A large number of karst unstable banks in the gorge area of the Three Gorges Reservoir stand on both sides of the main stream of the Yangtze River， endangering the safety of the golden waterway. Based on field survey， exploration and mechanical analysis， this work analyzes the relationship between karstification and slope failure in the carbonate areas of the Three Gorges Reservoir. The field survey shows that there are many unstable slope phenomena related to karst caves， dissolution fissures， dissolution zones， dissolution troughs， dissolution ditches and other surface karstification on the carbonate bank slope. There are 186 karst potential geo-hazards in Wu Gorge， including 37 potential landslides and 6 large-scale dangerous rock masses. The mechanical analysis of rock mass indicates that the joints / cracks will gradually expand due to the decrease of effective stress and strength under heavy rainfall， impounding and rock mass degradation. At the same time， the crack growth rate of rock mass deterioration in the water level fluctuation zone is about 1，300 times higher than the average dissolution rate in the Three Gorges， which greatly accelerates the evolution process of unstable rock mass which has entered the yield state. Dissolution is the most basic action of karst bank slopes， and the long-term fluctuation of reservoir water accelerates the evolution of karst bank slopes. This study provides technical support for the identification and disaster prevention and mitigation of unstable banks in the gorge section of the Three Gorges Reservoir area.