下坂地水利枢纽工程坝基砂层透镜体的动力特性试验研究  

Research on dynamic characteristic of sand lens for the foundation of Xiabandi key water control project

作　　者：陈存礼[1] 胡再强[1] 谢定义[1] 冯志炎[1] 

机构地区：[1]西安理工大学岩土工程研究所,陕西西安710048

出　　处：《地震工程与工程振动》2006年第5期264-270,共7页Earthquake Engineering and Engineering Dynamics

摘　　要：在不同固结状态(σ3 c和kc)下对下坂地水利枢纽工程坝基砂层透镜体的砂土进行了动三轴试验。结果表明:不能用Hard in公式确定偏压固结时的起始动剪切模量G0,G0和τy(最大动应力)均与σ3 c.kc之间有良好的幂函数关系,且对不同固结状态可以归一;动强度dτ/σm′受固结围压σ3 c的影响很小,但随固结比kc的增大而增大;动孔压比ud/σ′m与振次比N/Nf关系曲线为下凹型,不符合Seed提出的孔压模型,可用指数关系来拟合。动应力σd值变化对ud/σm′-N/Nf和ud/σm′-εdr关系影响很小,固结比kc变化对它们有显著的影响;界限残余应变εdr,t受kc的影响较小,但它随σ3 c的增大而增大,当εdr大于εdr,t时呈先快速增长后趋于平缓的变化。Dynamic triaxial tests are conducted for sand in sand lens of dam foundation of Xiabandi key water control project in different consolidation conditions. It is indicated that from test results the maximum dynamic shear modulus Go cannot obtained by Hardin formula under anisotropic consolidation. The relations between both G0and τy （the maximum dynamic shear stress） and σ3c · kcare power functions, and they are irrelative to different consolidation conditions. The dynamic intensity τd/σ＇m increases with the increase of ko, but it is not affected by the variation of σ3c. The sunken curve of Ud/σ＇m - N/Nf can be fitted by exponential which does not accord with the Seed model. It is relative to consolidation ratio but is undependent to consolidation confining stress σ3cand dynamic stress σd. The variation of σd has no effect on the relations of Ud/σ＇m - N/Nf andu/σ＇m - εdr· The critical residual strain εdr,t increases with the increase of σ3c but keep invariable with the increase of kc. Dynamic pore water pressure almost rapidly increases when εdr is large than εdr,t ·

关 键 词：砂土 动三轴试验 动模量 动强度 动孔压 

分 类 号：P315.983[天文地球—地震学]