考虑物态变化的六参数砂土本构模型

Six-parameter constitutive model of sand with physical state changes

以往的大多数砂土本构模型仅采用相对密度作指标,把初始密度不同的砂土当作不同的材料,需采用多组不同的材料参数。本文基于状态参数概念,提出了一个数学描述简单、仅有6个材料参数的砂土本构模型。该模型能够同时考虑相对密度和有效围压两个因素对材料物态变化的影响,并只用一组材料参数即可描述较大的围压和密度范围内砂土的排水应力应变响应。通过不同围压和初始密度条件下的三轴排水试验结果与数值模拟结果的对比,初步验证了模型的有效性。

Most constitutive models for sands use the relative density as an index, so that a sand with different initial densities is treated as different materials. These models result in multiple sets of model parameters for a single material. This paper presents a simple constitutive model with only six material parameters based on the state parameter concept. The model takes into account the physical state changes due to changes in the relative density and the effective pressure to represent the constitutive response of sand during drained shearing over a wide range of densities and pressures using a unique set of parameters. Simulations with this constitutive model agree well with triaxial drained test results.