循环应力下饱和黏土剪切变形特性试验研究  

Experimental study on shearing deformation behavior of saturated clay under cyclic stress

作　　者：栾茂田[1] 齐剑峰[1] 聂影[1] 张振东[1] 马太雷[1] 

机构地区：[1]大连理工大学海岸和近海工程国家重点实验室

出　　处：《海洋工程》2007年第1期43-49,共7页The Ocean Engineering

基　　金：国家自然科学基金资助项目(50579006);国家自然科学基金重点基金资助项目(50639010;50439010);教育部科学技术研究项目重大项目(305003)

摘　　要：针对饱和重塑黏土,利用土工静力-动力液压三轴-扭转多功能剪切仪,在不固结不排水(UU)条件下进行了应力控制式循环扭剪和竖向-扭转耦合试验,通过对试验结果的对比分析探讨了初始预剪应力和应力反向对应力-应变关系特性的影响,并阐述了不同加荷模式下孔隙水压力发展特性。以此为基础,综合考虑剪切变形和正向偏差变形的共同效应,同时为了能够反映平均残余变形和循环变形的影响,建议了一个综合应变破坏标准的算式。进而通过利用试验数据与目前常用的应变标准比较,表明这种破坏标准具有普遍适用性和较好的稳定性,适用于判定各种应力条件下黏土试样破坏及其强度。The soil static and dynamic universal triaxial and torsional shear apparatus is employed to perform stress-controlled cyclic torsional shear tests and vertical and torsional coupling shear tests under unconsolidated-undrained condition. Through a series of tests on saturated remoulded clay, the effects of initial shear stress and stress reversal on strain-stress behavior are examined, and variation characteristics of pore water pressure are studied. The expression of general strain failure criterion is recommended comprehensively considering the influence of both axial and deviatoric shear deformation as well as the influence of cyclic and accumulative deformation. Moreover, it is verified through comparing experimental data and former criteria of failure that the general strain criterion has characteristics of stability and can be used to distinguish the failures of clay under all types of stress conditions.

关 键 词：循环应力 复杂应力条件 饱和黏土 应力-应变关系 破坏标准 

分 类 号：TU43[建筑科学—岩土工程] TV139.22[建筑科学—土工工程]