深部人工冻土黏弹塑损伤耦合本构模型研究及其验证

Study and Verification of Laboratory Prepared Frozen Soil Viscoelastic-Plastic Damage Coupling Constitutive Model

采用改进的Mohr-Coulomb屈服准则(Zienkiewicz-Pande准则),建立了能描述人工冻土3个阶段蠕变特性的黏弹塑损伤耦合本构模型.基于该本构模型建立了模型的柔度矩阵,将本构模型嵌入到ADINA有限元程序中.计算表明:数值模拟得到的人工冻土蠕变特性曲线与实测值吻合良好,最大误差为4.8%,说明基于改进的Mohr-Coulomb准则建立的黏弹塑损伤耦合本构模型能够准确的描述人工冻土剪切特性和3个阶段的蠕变特性.获得的本构模型具有参数少、容易确定等优点.深部人工冻土黏弹塑损伤耦合本构模型的建立,对于人工冻土结构物长期稳定分析和预测具有重大的理论指导意义.

Based on modified Mohr-Coulomb yield criterion （Zienkiewicz-Pande yield criterion）, a viscoelastic-plastic damage coupling constitutive model, which could describe well the three stages of creep of frozen soil, have been established and a flexibility matrix of the model has also been de- veloped. Embedding this constitutive model into a large-scale non-linear limit element procedure, ADINA, a series of curves about creep of frozen soil were obtained. Comparing these curves with measured values found that the simulated values fit pretty to the measured ones, with a maximum er-ror of 4.8. It means that the viscoelastic-plastic damage coupling constitutive model, based on Zienkiewicz-Pande criterion, can accurately de- scribe the shear and three-stage strain properties of frozen soil. What＇s more, lots of shear and strain curves of frozen soil will be got by numerical simulation with a few mechanical parameters of frozen soil. It is believed that this study will be a very important theoretical direction for frozen-soil structure in long time stability analysis and fore- cast.