K_0固结条件下土石坝坝基砂卵砾石料强度与变形分析

Analysis of Strength and Deformation of Sand-grained Materials of Earth Dam Foundation under K_0-consolidation Condition

选取级配相同的双江口土石坝、长河坝土石坝坝基覆盖层砂卵砾石料,分别进行4种不同围压下的静止土侧压力系数K_0固结排水剪切大型三轴试验,分析了K_0条件下砂卵砾石料的强度与变形特性。结果表明,K_0条件下的砂卵砾石料在低围压下表现出较强的剪胀特性;不同围压下,砂卵砾石料的峰值强度与围压之间近似呈线性关系;两种砂卵砾石料的初始弹性模量Ei、初始泊松比νi与围压之间均存在良好的幂函数关系。结果为土石坝坝基覆盖层砂卵砾石料的强度与变形特性研究提供了参考。

Using large-scale shearing device,K_0 consolidated-drained triaxial test under different confining pressures were performed for overburden materials of Shuangjiangkou earth dam and Changheba earth dam which own the same size grading curve.The strength and deformation properties of sand grained materials were analyzed under K_0-consolidation condition.The test results show that the sand grained materials under K_0-consolidation condition are characterized by volumetric dilatancy.The relationship between the peak strength of K_0 consolidated-drained sand grained materials and confining pressure are approximate linear.The initial Young＇s modulus Eiand Poisson＇s ratio vimaterial of sand grained materials and confining pressure show good power function relationship.The results provides reference for study on the strength and deformation properties of overburden sand grained materials of earth dam.