黔东南浅变质岩工程地质性质研究

Research on Engineering Geological Properties of Low-grade Metamorphic Rock in Southeast of Guizhou

黔东南多为浅变质岩,其工程地质条件较为复杂。为给隧道施工提供可靠的工程地质参数,通过地质调查、现场试验及室内试验等手段,对隧址区浅变质岩的工程地质性质进行了综合研究。测定了岩石矿物成分和物理水理性质,应用单轴、三轴、点荷载及回弹试验,对岩石在不同风化程度下的力学性质进行分析,并详细调查了隧址区不同规模、不同类型的结构面,分析了结构面的特征。研究结果表明:隧址区浅变质岩抗风化能力较弱,随着风化程度的加剧,其物理力学性质及结构面特征都有显著的变化。

Southeast of Guizhou lies in low-grade metamorphic zone,where the engineering geological conditions are complex.In order to provide reliable engineering geological parameters for tunnel construction,the engineering geological properties of low-grade metamorphic rock in tunnel location were studied through geological investigation,site test and laboratory test.Thus the mineral components and water-physical properties of metamorphic rock were determined.Then the mechanical properties of metamorphic rock under different weathering rates were analyzed using uniaxial test,triaxial test,point load and resilience test;the structural surface of different sizes and different types in tunnel location were surveyed in details to analyze their properties.The results showed that low-grade metamorphic rock in the tunnel location has poor weathering resistance.As weathering rate increased,its physical-mechanical properties and structural surface properties will change significantly.