冻结黏土单轴抗压试验及损伤本构模型分析1)
UNIAXIAL COMPRESSION TEST AND DAMAGE CONSTITUTIVE MODEL FOR ANALYSIS OF FROZEN CLAY 1)
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摘要: 从冻土微元破坏服从Weibull随机分布的特点出发,将Mohr--Coulomb强度准则作为冻土微元统计分布变量,利用应变等价性假说,建立了单轴应力状态下冻结黏土损伤本构模型;在此基础上,讨论了模型参数和弹性模量与冻结温度的关系,对模型参数和弹性模量进行合理修正,建立了温度影响下的冻结黏土损伤本构模型,并与试验结果进行对比。分析结果表明:考虑温度效应的损伤本构模型能很好地模拟冻结黏土应力--应变全过程曲线,具有很好的适应性。Abstract: The Mohr-Coulomb strength criterion is used as the statistical distribution variable in the Weibull random distribution for the frozen soil micro-meter damage. The damage constitutive model of the frozen clay under uniaxial stress state is established by using the strain equivalence hypothesis. On this basis, the relationship between the model parameters and the elastic modulus and the freezing temperature is edetermined. The model parameters and the elastic modulus are corrected reasonably. The damage constitutive model of the frozen clay under the temperature influence is established and the results are compared with the experimental results. The analysis results show that the damage constitutive model with consideration of the temperature effect can be used to simulate the stress-strain full process of the frozen clay well, with a good adaptability.