金沙江上游某特大型危岩体失稳模式分区与稳定性评价

金沙江上游某水电站坝址区存在特大型危岩体,其稳定性严重影响水电工程布置、施工及安全。因危岩体范围与方量巨大不宜笼统评价,按潜在失稳模式进行分区,并对各分区进行稳定性评价。研究表明,该危岩体范围分为三个区,Ⅰ区为解体崩落型,坡表遍布松动危岩体,浅表部稳定性差;Ⅱ-1区为整体滑移型,Ⅱ-2区为渐进式解体崩落型,受长大张开滑移面及侧边界控制,可能整体滑移破坏,稳定性差;Ⅲ区为局部倾倒或滑移崩落型,基本稳定。根据各分区失稳模式与稳定性差异,有针对性地提出工程处理措施建议。

Unstability Mode Division and Stability Evaluation of a Super Large Dangerous Rock Mass in Upper Jinsha River

Large dangerous rock mass exists in the dam site area of a hydropower station in the upper reaches of Jinsha River,and its stability seriously affects the layout,construction and safety of hydropower projects.Due to the large range and volume of dangerous rock mass,it is not suitable for general evaluation.The zoning is carried out according to the potential instability mode,and the stability of each zoning is evaluated.The study shows that the dangerous rock mass is divided into three areas.Area I is disintegrated and collapsed,loose dangerous rock mass is distributed on the slope surface,and the stability of the shallow part is poor.TheⅡ-1 area is a whole slip type,and theⅡ-2 area is a progressive disintegration type.Controlled by the large open slip surface and the side boundary,the whole slip may be destroyed and the stability is poor.ZoneⅢis local dumping or sliding collapse,basically stable.According to the instability mode and stability difference of each partition,suggestions for engineering treatment measures are put forward.