红黏土损伤特性及损伤演化规律试验

发布时间：2018-07-06 07:39

本文选题：红黏土 + 三轴试验　；参考：《桂林理工大学学报》2016年04期

【摘要】：基于原状红黏土三轴不排水试验,得出桂林红黏土应力-应变关系,分析了原状红黏土结构损伤特性,确定损伤变量D,并对红黏土的损伤演化规律进行分析,验证其损伤本构关系。研究结果表明:桂林原状红黏土的应力-应变关系曲线表现出理想塑性的特点;不同围区条件下,轴向应变1.36%处可视作红黏土应变的门槛阈值,对应的应力作为应力门槛阈值;初始弹性模量和割线模量有关的变量D可作为损伤变量;损伤变量随主应力差的增大而增大,基本呈线性关系,损伤变量与轴向应变基本呈指数函数关系,表明红黏土损伤过程是不可逆的特点;本文提出的损伤本构方程能够较好地拟合红黏土的应力-应变曲线关系,反映不同围压条件下的红黏土结构性损伤变化规律。
[Abstract]:Based on the undrained triaxial test of red clay, the stress-strain relationship of red clay in Guilin is obtained. The damage characteristics of red clay structure are analyzed, the damage variable D is determined, and the damage evolution law of red clay is analyzed. The damage constitutive relation was verified. The results show that the stress-strain relationship curve of the red clay in Guilin shows the characteristic of ideal plasticity, the axial strain of 1.36% can be regarded as the threshold of the strain of red clay under different confining conditions, and the corresponding stress is the threshold of stress. The initial elastic modulus and Secant modulus variable D can be regarded as damage variable, and the damage variable increases with the increase of principal stress difference, and the damage variable and axial strain show exponential function relationship, and the damage variable increases linearly with the increase of principal stress difference. It is shown that the damage process of red clay is irreversible and the damage constitutive equation presented in this paper can fit the stress-strain curve of red clay well and reflect the structural damage of red clay under different confining pressure.
【作者单位】：桂林理工大学广西岩土力学与工程重点实验室;
【基金】：国家自然科学基金项目(41262011,41262011,51369010) 广西重点实验室基金项目(11-kf-02,11-CX-01,12-A-01-02) 广西高校科学技术研究项目(KY2015YB119)
【分类号】：TU446

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