古贤水利枢纽坝址区基岩剪切带抗剪强度参数确定

Study on Shear Strength Parameters of Dam Shear Zone at Guxian Hydro-junction

古贤水利枢纽坝址区剪切带具有地质形成历史长、岩体组合结构复杂、延展规模大等特点,根据颗粒分析试验结果,剪切带软弱结构面由岩屑夹泥和泥夹岩屑两种类型组成,采用室内直剪和原位剪切两种试验方法研究其抗剪强度参数。结果表明,综合对比两种试验条件下获得的抗剪强度指标,发现直剪试验结果较高;剪切试验的破坏过程与充填物性质密切相关,且应考虑平硐开挖扰动对抗剪强度指标的影响。

Shear zone of Guxian hydro-junction has some typical characteristics, such as long geological history, complex rock mass multiplex structure, large scale spread. Based on test results of particle analysis, the weak structural plane of shear zone was classified into mud with debris and debris with mud. Two kinds of test methods including indoor direct shear test and in-situ shear test were used to study parameters of shear strength. Compared with the shear strength indexes under two experimental conditions, the results of direct shear test were higher. Then, the paper discussed the relationship damage process of shear test with property of fillings, and the impact of excavation disturbance on the shear strength index should be considered.