土体非线性本构模型的修正与土层特性分析

Combining Duncan-Chang Nonlinear Constitutive Model of Soil with ANSYS Software

旨在提出一个合理应用经典土体非线性本构模型进行具体土层分析的方法。依据土体非线性数值模拟的基本理论,通过开发一个适合于大型计算软件ANSYS的Macro文件,采取对邓肯-张非线性本构模型中的参量Et进行逐级荷载作用下的修正方式,建立了一种土体非线性本构模型修正与土层非线性特性分析的方法。一黏性土土样的三轴试验结果表明,对一些常用的土的非线性本构模型,在应用于具体的土层中时所存在的不适应或不适合具体土层特性的部分,采用文中所建立的方法矫正或修正可提高应用这些经典本构模型对具体土层进行非线性特性分析时的合理性和有效性,进而可提高土的变形特性分析和土与其中及相邻结构共同作用分析的计算精度。

Aim. The D-P（Drueker-Prager） model now available in ANSYS software is,in our opinion, inapplicable to nonlinear elastic behavior of soil. We bring in the Duncan-Chang model in order to make ANSYS applicable in such a case. We use Section 1 of our paper to explain in some detail how to combine the Duncan-Chang model with ANSYS software. Essentially Section 1 gives a four-step procedure for making the required comb/nation,including eqs. （3）through（6） in Step 4. Section 2 presents a numerical example of the Duncan-Chang model. The numerical calculation results and their comparison with the three-axis test results,given in table 1,show preliminarily that the error of displacement is less than 10%, indicating that Duncan-Chang model gives much higher calculation precision as compared with that obtainable with D-P model.