基于进化多项式回归方法的土体本构关系

Constitutive relationship of soil based on the evolutionary polynomial regression method

进化多项式回归方法是近几年来在国际上引起广泛关注的一种新颖的数据挖掘方法。本文在土样固结排水试验数据的基础上,首次使用该方法建立了土体本构关系。采用上海嘉定区某地软土的固结排水试验结果对模型进行了验证。结果表明,该本构关系能够更精确地描述土体的应力-应变特性,其预测精度比修正剑桥模型高19.6%~57.7%。另外,本文还用切线刚度法,对基于进化多项式回归方法的土体本构关系进行了ABAQUS二次开发,对软土固结排水试验进行了有限元数值模拟。

Evolutionary Polynomial Regression(EPR) is a new method of data mining which attracted much attention in recent years. In this paper, the soil constitutive relation is established by using the data of soil Consolidated Drained(CD) test. The CD test of soft soil from Jiading District of Shanghai City is used to verify the constitutive relationship. The results show that the constitutive relation accurately describes the stress-strain characteristics of soil, and its prediction accuracy is 19.6%~57.7% higher than that of the modified Cambridge model. Using the tangent stiffness method, a constitutive model in ABAQUS is developed by the soil constitutive relationship based on the EPR. Finite element numerical simulation for the CD test of soft soil is conducted via the secondary development constitutive model.