针对土石混合体填筑路堤工后沉降的非线性蠕变特性,提出了一种能考虑材料非线性黏弹性变形的蠕变模型。基于目前对土石混合体蠕变机理研究,将路堤工后的蠕变沉降部分考虑为非线性的衰减蠕变过程,建立了修正的Kelvin模型、广义修正模型,且得到了模型参数的识别方法;通过对修正模型分析表明,非线性常数取值对蠕变曲线变化有较大影响,修正模型的蠕变长期应变值比Kelvin模型要小;结合相关文献中对土石体填料的蠕变试验研究资料,用修正Kelvin模型对试验结果进行拟合,并对参数进行了反演,反演效果良好。修正模型的建立可为编制非线性黏弹性数值计算软件提供理论基础。
According to the nonlinear creep properties of earth-rock aggregate embankment after construction,a modified Kelvin model that can express nonlinear viscoelastic deformation of material is presented.Based on the current research results of the creep mechanism of earth-rock aggregate embankment,the creep settlement after construction is considered to be an attenuation creep process;and the modified Kelvin model,generalized modified model and recognition method of model parameters are presented.Through analyzing the modified Kelvin model,the results show that: the nonlinear constant is an important influencing factor to the model;and long-term strain of the modified Kelvin model is smaller than that of Kelvin model.Based on the creep test data in the related literatures,parameters of modified Kelvin model are fitted;and the fitting effect is well.The modified Kelvin model will distribute theoretical basis for the numerical calculation program of nonlinear viscoelasticity.