含粉粒砂土循环及循环后液化特性研究  

Cyclic and Post-Cyclic Liquefaction Behavior of Silty Sand

作　　者：施周桓 孙宏磊 孙淼军 潘坤 Shi Zhouhuan;Sun Honglei;Sun Miaojun;Pan Kun(College of Civil Engineering,Zhejiang University of Technology,Hangzhou 310014,China;POWERCHINA Huadong Engineering Corporation Limited,Hangzhou 311122,China)

机构地区：[1]浙江工业大学土木工程学院,杭州310014 [2]中国电建集团华东勘测设计研究院有限公司,杭州311122

出　　处：《地下空间与工程学报》2025年第2期490-496,516,共8页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(52178362)。

摘　　要：利用GDS标准型动态三轴仪,对含粉粒砂土进行了不同固结应力条件下的循环剪切试验,研究了粉粒含量和固结条件对土体循环及循环后液化特性的影响。结果表明:(1)不同固结应力条件下粉砂呈现出3种响应模式,即流动液化、循环活动性以及残余变形累积;(2)相同的初始状态参数条件下,粉砂土的抗液化动强度随着粉粒含量的增加先增大后减小,而非等向固结条件对土体动强度的影响也具有非单调性,与初始静偏应力的方向和大小有关;(3)对发生循环液化破坏的试样进行了再循环加载,发现在初次循环中表现为流动液化或循环活动性的试样,其循环后抗液化强度下降较为明显;(4)而当试样破坏由残余变形累积导致时,其循环后动强度有一定程度的增大。A series of cyclic triaxial tests on anisotropically consolidated sand samples were conducted to explore the effects of silt contents and consolidation stress conditions on the cyclic and post-cyclic liquefaction characteristics.The test results show that the silty sand exhibits three distinct response patterns:flow liquefaction,cyclic mobility,and residual deformation accumulation.Under the same initial state parameters,the cyclic liquefaction resistance of silty sand firstly increases and then decreases with the increase in silt content.The influence of anisotropic consolidation on the cyclic resistance is also nonmonotonic,depending on the direction and magnitude of the initial static deviator stress.Reliquefaction tests were performed on samples that are failed during the first cyclic stage,and it is found that the liquefaction resistance of samples exhibiting flow liquefaction or cyclic mobility decrease significantly in the post-cyclic tests.However,for the samples that are failed due to the residual deformation accumulation,the post-cyclic liquefaction resistance has an increasing tendency.

关 键 词：非等向固结 抗液化强度 粉砂 循环后 响应模式 

分 类 号：TU441[建筑科学—岩土工程]