初始剪应力和循环应力方向对饱和密砂液化特性的影响

Effect of initial static shear stress and cyclic loading direction on liquefaction characteristics of saturated dense sand

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摘要边坡土单元体在地震荷载作用期间同时受到初始剪应力和循环应力的作用,且初始剪应力和循环应力作用方向往往不同。为探究初始剪应力和循环应力作用方向对饱和密砂液化特性的影响,对饱和密砂进行了一系列固结不排水多向循环单剪试验。试验结果表明:饱和密砂的破坏模式主要包括循环活动性和累积塑性应变两种,破坏模式受初始剪应力大小的影响;初始剪应力的存在会降低饱和密砂的抗液化强度,但垂直加载模式下饱和密砂的抗液化强度比平行加载模式下高约5%~7%;不同加载模式下均表现出损耗能的累积速率随初始剪应力的增加而增大的现象,初始剪应力作用下饱和密砂的损耗能累积速率加快是导致其抗液化强度降低的内在原因;饱和密砂的残余孔压和损耗能的归一化曲线在对数坐标下呈现出线性关系。 Soil elements of slope are subjected to both initial shear stress and cyclic stress during seismic loading,and the directions of initial shear stress and cyclic stress are often different.In order to investigate the effects of initial shear stress and cyclic stress direction on the liquefaction characteristics of saturated dense sand,a series of consolidated undrained multi-directional cyclic simple shear tests are carried out on saturated dense sand.The test results show that the failure modes of saturated dense sand mainly include cyclic activity and cumulative plastic strain,and the failure modes are affected by the initial shear stress.The existence of initial shear stress will reduce the liquefaction resistance of saturated dense sand,but the liquefaction resistance of saturated dense sand under vertical loading mode is about 5%~7%higher than that under parallel loading mode。It is found that the cumulative rate of energy loss increases with the increase of initial shear stress,which is the internal reason for the decrease of liquefaction resistance of saturated dense sand.The normalized curves of residual pore pressure and energy loss of saturated dense sand show a linear relationship in the logarithmic coordinate.

作者张迎宾覃一巧张世豪魏江涛熊亦翔刘永航 ZHANG Yingbin;QIN Yiqiao;ZHANG Shihao;WEI Jiangtao;XIONG Yixiang;LIU Yonghang(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区西南交通大学土木工程学院

出处《岩土工程学报》北大核心 2025年第11期2246-2254,共9页 Chinese Journal of Geotechnical Engineering

基金国家自然科学基金项目(U2468214,52378370,52278372,52478362) 国家重点研发计划项目(2024YFE0111900)。

关键词初始剪应力抗液化强度能量法孔压模型多向循环单剪试验 initial static shear stress liquefaction resistance energy-based method pore pressure model multidirectional cyclic simple shear test

分类号 TU411 [建筑科学—岩土工程]