土体小应变刚度特征是准确分析土与结构相互作用的重要因素。土体刚度的衰减速率宜由带有小应变量测装置的高等三轴实验确定,这制约了土的小应变刚度模型的应用。另外,虽然该类实验在国外已对典型土体进行了较系统的研究,但是在国内还鲜有报道。该文结合小应变理论,提出了加载为正弦函数和卸载为双曲线形式的弹塑性模型,并且针对多种土体将模型的计算结果与实验值进行对比,二者的基本符合证明了模型的合理性。
It is important to consider the small-strain stiffness of soil in analyzing the interaction between soil and structures.The attenuation rate of soil stiffness should be determined through advanced triaxial test with local strain measurement device,which restricts the application of small strain model.Although systematic study of typical soils has been carried out abroad through such experiments,it is rarely reported in China.This paper proposes an elasto-plastic constitutive model with sine function and hyperbolic function to simulate the stress-strain relations during loading and unloading respectively.The calculated results using the proposed model for a variety of soils are compared with experimental data and good agreement is found,which proves the model is reasonable.