含水率和温度对高含冰量冻土力学性质的影响  

Experimental study on influences of water content and temperature on mechanical properties of ice-rich frozen soil

作　　者：霍明[1] 汪双杰[1] 章金钊[1] 金龙[1] 

机构地区：[1]中交第一公路勘察设计研究院有限公司,陕西西安710075

出　　处：《水利学报》2010年第10期1165-1172,共8页Journal of Hydraulic Engineering

基　　金：国家自然科学基金重点资助项目(40730736);中国科学院知识创新工程重要方向项目(KZCX3-SW-351)

摘　　要：对青藏高原黏土在温度为-0.5～-6.0℃,含水率为30.0%～80.0%条件下,进行了一系列的三轴抗压强度试验,分析了不同加载条件下高含冰量冻土的强度随围压、温度和初始含水率的变化规律。研究发现,其力学性质与初始含水率和温度有密切关系,在温度低于-1℃时存在最不利含水率。同时发现相同温度下,强度随围压变化不大,故可以用Mises准则作为其强度准则。给出了随温度、含水率变化时,高含冰量冻土的Mises准则的表达式。采用塑性功作为硬化参数,得到了高含冰量冻土的弹塑性本构模型。与试验值对比表明,该模型能够比较准确地反映高含冰量冻土的应力应变规律。A series of triaxial compression experiments were carried out for frozen clay obtained from Qinghai-Tibet plateau with 30%~80% water content at different temperatures from-0.5℃ to-6℃ to study the variation law of the strength of the ice-rich frozen clay following the change of confining pressure,temperatures and initial water content,under different loading conditions.The results show that the mechanical property of frozen clay was closely related to water content and temperature.It was confirmed that there exist a worst water content when the temperature lower than-1℃.It was also found that the strength of frozen clay remained unchanged when confining pressures changed.So that the Mises criteria can be used as the strength criteria for ice-rich frozen clay.When the plastic work was selected as the hardening parameter.The elasto-plastic constitutive model for ice-rich frozen clay can be deduced.The validity of this model is verified by comparing its calculated results with test results obtained from triaxial test.It is found that,this model can predict the deformation regularity of ice-rich frozen clay exactly.

关 键 词：高含冰量冻土 含水率 温度 强度准则 本构模型 

分 类 号：P642.14[天文地球—工程地质学]