Analysis of Influence of Lithological Characteristics on Mechanical Properties of Concrete Dam-Body-Bedrock In-situ Direct Shear Test
Taking the Poyue Reservoir Project in Bama County,Guangxi Province as the research object,the in-situ direct shear test of concrete dam body-bedrock under different normal stresses(0.4 MPa,0.8 MPa,1.2 MPa,1.6 MPa,2.0 MPa)was carried out by flat thrust method,and the influence of lithological characteristics on the mechanical charac-teristics of concrete dam-bedrock was explored.The results show that the shear stress-displacement curves of the speci-men under different normal stresses show three stages:the stable expansion stage of microcrack propagation of the initial defect inside the specimen,the unstable propagation stage of microcrack gradually propagation to form macroscopic frac-ture,and the cracking stage of separation of concrete and rock mass;Normal stress and lithology of rock mass have signif-icant effects on the fracture energy of the specimen.Under different normal stresses,the range of fracture energy of the specimen is 16.65 N/m-177.28 N/m,and the fracture energy increases with the increase of normal stress or gray sand-stone content,and decreases with the increase of argillaceous siltstone content or weathering degree;The shear strength of concrete dam-bedrock increases with the increase of gray sandstone content in bedrock,and decreases with the increase of argillaceous siltstone content or weathering degree of bedrock.The research results can provide a reference for similar studies.
concrete dam body-bedrockin-situ direct shear testmechanical propertieslithological characteristicsinfluencing factors
万方数据
维普
