三轴循环加卸载条件下砂性土变形特性研究  

Experimental study on deformation behaviors of sandy soil under triaxial cyclic loading

作　　者：孙益振[1] 邵龙潭[1] 

机构地区：[1]大连理工大学工程力学系工业装备结构分析国家重点实验室,辽宁大连116024

出　　处：《岩土工程学报》2005年第11期1353-1357,共5页Chinese Journal of Geotechnical Engineering

基　　金：教育部高等学校骨干教师资助计划项目(2000-65);留学回国人员科研启动基金资助项目(2001-345)

摘　　要：利用基于局部变形数字图像测量的三轴试验系统和可提供循环加卸载的试验机,设计了砂性材料的三轴循环加卸载试验,研究了砂性散体材料在不同状态下的轴向、径向和体积变形特性以及泊松比的变化。加载体胀和卸载体缩是砂性材料颗粒结构性的具体表现,在多次加卸载循环后,颗粒的滑移、滚动和破碎等结构性变形最终完全消除,结构变形达到稳定状态。泊松比的变化与试样的体积变形密切相关,从体积变化趋势中可以分析出泊松比的变化范围。By means of digital image measuring technique of local deformation and the cyclic loading test machine, the triaxial cyclic loading test of sandy soil was devised, and the variation of axial, radial and volumetric deformations and Poisson＇s ratio of sandy soils in different states were investigated. Expansion in loading and contraction in unloading were the behaviors of sandy soils. After many cycles of loading and unloading, the structural deformation of particles, such as slipping, rotating and crushing, would fade away in the end, and the structural deformation would arrive at a stabilization point. The variation of Poisson＇s ratio was related closely with the change of volume of specimen. The range of variation for Poisson＇s ratio could be analyzed from the change of volume.

关 键 词：三轴试验 循环荷载 卸载体积收缩 变形 泊松比 砂性土 

分 类 号：TU411.99[建筑科学—岩土工程]