An improved statistical damage constitutive model for warm frozen clay based on Mohr-Coulomb criterion
An improved statistical damage constitutive model for warm frozen clay based on Mohr-Coulomb criterion
复制标题
基于Mohr-Coulomb准则的改进温冻粘土统计损伤本构模型
DOI：
10.1016/j.coldregions.2009.02.010
复制
发表时间：
2009-07-01
影响因子：
4.1
通讯作者：
Liu, Deren
中科院分区：
文献类型：
--
作者：
Li, Shuangyang;Lai, Yuanming;Liu, Deren
冻土中存在许多随机分布的微观缺陷，这会导致外加载荷作用下的力学性能和行为具有很大的不确定性和随机性，因此，用随机方法而不是确定性方法来研究冻土的应力应变关系更为科学。针对温冻土和温富冰冻土，在大量实验数据的基础上，提出了以轴向应变为随机变量的随机损伤本构模型。本文根据-0.5℃、-1.5℃和-2.0℃三种温度条件下的实验数据以及上述研究成果，选择土单元的强度作为随机变量，推导了改进的统计损伤本构模型，并在新模型中还采用莫尔-库仑破坏准则来判断土单元是否发生损伤。最后，与原始模型相比，发现新的改进模型能够更好地描述实验数据并反映变形特征。特别是当应力达到峰值时，实验数据和新的理论曲线相互重叠。 (C) 2009 Elsevier B.V. 保留所有权利。
There are many microdefects distributed randomly in frozen soil, which will lead to great uncertainty and randomness of mechanical properties and behaviors under applied load, therefore, it is more scientific to study stress-strain relationship of frozen soil by stochastic method instead of deterministic way. For the warm frozen clay and warm ice-rich frozen clay, a stochastic damage constitutive model has been proposed on the foundation of a large number of experimental data, in which the axial strain is regarded as random variable. In this paper, according to these experimental data under three temperature conditions (-0.5 degrees C, -1.5 degrees C and -2.0 degrees C) and the above research results, the strength of soil element is selected as random variable and an improved statistical damage constitutive model is deduced, and in this new model, the Mohr-Coulomb failure criterion is also used to judge whether the soil element is damaged. Finally, compared with original model, it is found that the new improved model can better describe the experimental data and reflect deformation characteristics. Especially, when the stress reaches its peak value, the experimental data and new theoretical curves overlap with each other. (C) 2009 Elsevier B.V. All rights reserved.