考虑初始各向异性的砂土弹塑性本构模型及试验验证

基于复杂应力条件下的试验结果,就针对不同主应力方向对应力–应变关系的影响进行了试验研究,并在此基础上结合状态概念提出了基于应力–剪胀关系和应力–应变拟双曲线关系的弹塑性本构模型。利用应力–应变拟双曲线关系描述了主应力方向对有效应力路径、应力–应变发展模式的影响,并通过常规三轴试验测定了试验参数,同时与试验结果进行对比,说明基于状态概念,引入状态参数,利用主应力方向对塑性模量的影响,能够同时描述初始物理状态及初始各向异性对砂土应力–应变关系的影响。

Elasto-plastic constitutive model of sand considering initial anisotropy and its verification through experiments

Based on the results of test under complex stress, the relationship of stress-strain under the principal stress with different directions is studied through experiments, and according to this, combined with the concept of state, an elasto-plastic constitutive model based on relationship of stress-dilatancy and simulated hyperbolic relationship of stress-strain is put forward. The effect of direction of the principal stress on the effective stress path and the evolution mode of stress-strain is described by use of simulated hyperbolic relationship of stress-strain. The experimental parameters are determined by conventional triaxial tests. It is shown by comparison between the calculated and measured results that introducing the state parameters based on the concept of state and using the effect of the direction of principal stress on the plastic modulus, the effect of the initial physical state and initial anisotropy on the stress-strain relationship of sand can be described.