层状软岩力学特性现场试验研究

In-Situ Test on Mechanical Chara Cteristics of Soft Layer Rock Mass

水布垭水电站地下厂房薄层页岩、粉砂岩互层岩体及层间剪切带属于层状软岩,针对其进行原位承压板法变形试验、直剪试验及三轴试验,对通过不同试验得到的力学参数进行了对比分析,结果表明:变形模量的围压效应明显,通过三轴试验得到的变形模量大于承压板法变形试验的变形模量,且随围压的增加而变大;三轴试验有整体拉裂破坏和较软层首先拉裂而导致破坏两种破坏方式;通过三轴试验求出的抗剪强度参数明显大于以层面为剪切面的直剪试验抗剪强度参数。

The interbedded thin shale and sandstone layers and shear zone in Shuibuya underground power house zone is a kind of soft layer rock mass. In-situ bearing plate deformation test, shear test and tfi-axial test are carried out on it and the mechanical parameters gained from different tests are compared and analyzed. The result indicates： The deformation modulus gained from tri-axial test is larger than that from beating plate deformation test and the larger the confining pressure, the more the deformation modulus is, indicating significant compressing-effect ; there＇re two failure styles in tri-axial test ,one due to weaker layer＇s splitting failure and the other due to whole sample＇s splitting failure; The shear strength parameters gained from tri-axial test is larger than that from shear test with bedding surface as shear front.