The carbonaceous shale exposed during the excavation of the Xianglushan Tunnel of Central Yunnan Water Diversion Project was taken as the research object.Point load test,uniaxial compression test,and Brazilian splitting test were conducted to obtain several strengths and strength conversion coefficients.Failure modes of specimens and micro-scopic morphology were analyzed.The results show that the strength parallel to bedding planes is lower than that perpen-dicular to bedding planes,indicating strength anisotropy.The tensile strength conversion coefficients for parallel and per-pendicular to bedding planes are 1.40 and 0.90,respectively,which are close to the theoretical value.The uniaxial com-pressive strength conversion coefficients for parallel and perpendicular to bedding planes are 7.19 and 8.03,respectively.The converted uniaxial compressive strength is lower than the results of empirical formulas of the ISRM and specifica-tions,and the reason is that the uniaxial compressive strength of carbonaceous shale is low due to the microscopic defects in weak layer and matrix body.The research results can provide reference for the rapid and accurate evaluation of the strength of carbonaceous shale in the Xianglushan Tunnel of Water Diversion Project in Central Yunnan.
关键词
滇中引水/香炉山隧洞/炭质页岩/强度/转换系数
Key words
Central Yunnan Water Diversion/Xianglushan Tunnel/carbonaceous shale/strength/conversion coefficient
维普
万方数据