三轴循环加卸载条件下高含冰冻结砂土变形特性试验研究

发布时间：2018-01-02 09:33

本文关键词：三轴循环加卸载条件下高含冰冻结砂土变形特性试验研究　出处：《岩土力学》2017年06期 　论文类型：期刊论文

【摘要】：基于一系列同一温度、同一应变率、不同含水率和围压条件下的高含冰冻结粉质砂土的三轴循环加、卸载试验,开展了高含冰量冻结粉质砂土的能量耗散与剪切模量特性研究。试验结果表明:随着含水率的增加,冻土的塑性先增加,然后减小,并且30.6%的含水率可以作为一个塑性破坏点;随着剪应变的增加,偏应力的变化主导着能量耗散的变化,并且在试样变形过程中克服冰颗粒之间的作用所耗散的能量值很小;随着剪应变的增加,冻土的剪切模量一直减小,且小含水率条件下减小的速率会有一个明显的转折点,并且含水率对剪切模量的影响可分为3类。该研究结果可为高含冰冻土区工程设计中参数的选择提供重要的依据。
[Abstract]:Triaxial cyclic loading and unloading test of frozen silty sand with high ice content under the same temperature, same strain rate, different moisture content and confining pressure. The characteristics of energy dissipation and shear modulus of frozen silty sand with high ice content are studied. The experimental results show that the plasticity of frozen sand increases first and then decreases with the increase of moisture content. And the moisture content of 30.6% can be used as a plastic failure point. With the increase of shear strain, the variation of deflection stress dominates the change of energy dissipation, and the energy value of overcoming the action of ice particles in the process of specimen deformation is very small. With the increase of shear strain, the shear modulus of frozen soil decreases all the time, and there is an obvious turning point in the decreasing rate of frozen soil under the condition of low moisture content. The effect of moisture content on shear modulus can be divided into three categories. The results of the study can provide important basis for the selection of parameters in engineering design of high ice frozen soil regions.
【作者单位】：中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室;
【基金】：国家重点基础研究发展计划(973)项目(No.2012CB026106) 冻土工程国家重点实验室自主课题(No.SKLFSE-ZT-07);冻土工程国家重点实验室开放基金(No.SKLFSE201605)~~
【分类号】：TU41
【正文快照】： This work was supported by the National Program on Key Basic Research Project of China(973 Program)(2012CB026106),the Independent Program for StateKey Laboratory of Frozen Soil Engineering(SKLFSE-ZT-07)and the Open Project Program of the State Key Labora

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