对新疆某水电站西域砾岩变形特性的探讨

Discussion on Deformation Characteristics of Western Conglomerate in a Hydropower Station,Xinjiang Province

第四系胶结岩（层）——西域砾岩作为大坝坝基、地下厂房、水工隧洞围岩至今还没有可行的分类评价标准,目前参照软岩进行土体（散体）工程地质评价,与实际的工程特性不符。通过液压枕径向加压测定法及刚性承压板间接计算测定法对该项目区西域砾岩的弹性抗力系数、变形特性进行对比分析,结合试验面下砾岩的颗粒级配、天然含水率、天然密度、渗水试验及相对密度等的各类原位试验结果,对变形特性分析可得：围压在0～3 MPa内,岩体变形模量为1.60～1.67 GPa、单位抗力系数为12.51～13.06MPa/cm。通过试验所得结果与其实际特性不符,西域砾岩为半成岩,因此,现有的岩石试验规范的试验方法对西域砾岩的适用性尚待进一步研究论证。

There is no feasible classification evaluation standard for western conglomerate when it used to be dam foundation, underground powerhouse,the surrounding rock of hydraulic tunnel so far, the reference to engineering geological evaluation of soft rock soil does not match the actual engineering characteristics at present. By comparative analysis on elastic resistance coefficient and deformation characteristics of western conglomerate in the project area with hydraulic pil- low radial pressure assay and rigid bearing plate indirect calculation, combined with the particle size distribution, natural moisture content, natural density, seepage test and many kinds of situ test results of conglomerate under test surface, the paper analyzes the deformation characteristics, explores and discusses the feasibility of existing test specifications for westem conglomerate detection.