安哥拉KK水电站高混凝土重力坝坝基综合勘察技术及建基岩体选择

High concrete gravity dam of Angola KK Hydropower Station Dam foundation comprehensive investigation technology and construction foundation rock selection

本文以安哥拉KK水电站为例,通过在坝址区开展工程地质测绘、物探、勘探、试验测试等综合勘察,对坝基地质条件进行复核评价,新发现主坝区顺河流右岸及河床发育的碎裂岩带,并查明碎裂岩带及带内fb1、fb2断层的产状、规模及性状;同时结合综合勘察技术成果,分析碎裂岩及片麻岩各风化带岩体性质,根据岩体性质将坝基岩体共分为六个带,对每个带(亚带)进行RMR评分,提出各带力学性质参数;根据带内岩体性状及力学性质的不同,对不同坝高对应的建基岩体进行选择,减少坝基开挖,提供安全经济的工程设计。此研究成果可供类似工程参考。

Angola KK Hydropower Station is adopted as an example in the paper.The geological conditions of dam foundation is reviewed and evaluated through engineering geological mapping,geophysical prospecting,exploration,test and other comprehensive exploration in the dam site area.The calving,scale and character of cataclasite belt as well as fb1 and fb2 faults in the belt are investigated.Meanwhile,the comprehensive investigation results are combined,the rock mass properties of cataclastic and gneiss weathering zones are analyzed,and the dam foundation rock mass is divided into six zones based on rock mass properties.Each zone(sub-zone)undergoes RMR scoring.The mechanical property parameters of each zone are proposed.The foundation rock mass corresponding to different dam heights is selected to reduce the excavation of dam foundation and provide safe and economic engineering design according to the characteristics and mechanical properties of rock mass in the belt.The research results can be used as reference for similar projects.