岩土工程非线性优化反演模型在ABAQUS中的应用

Nonlinear Optimum Inversion Model of Geotechnical Engineering and Its Application in ABAQUS

目的针对常规反演方法应用于岩土工程参数反演时搜索效率低、计算量大的缺点,提出了基于改进Nelder-Mead算法的有限元优化反分析法,为工程所需的计算参数提供参考.方法基于混合罚函数法,以测点的实测值与计算值建立误差函数,将有限元程序ABAQUS作为一个单独模块嵌入到改进的Nelder-Mead算法中,编制了优化反演分析程序.结果给出了具体的应用实例,结果表明,改进Nelder-Mead算法提高了参数的搜索效率,用较少的迭代次数就能得到满足精度要求的结果,是一种可行的参数反演方法.结论笔者提出的优化反演方法具有很强的实用性,可应用于实际工程中复杂岩土体初始应力场反演、渗流场以及位移反分析.

In order to offset the disadvantage of low search efficiency and large amount of calculation by the traditional methods of back analysis in geotechnical engineering, the back analysis method combining the Nelder-Mead algorithm and finite element method is studied. Based on the mixed penalty function method, a penalty function model of error is established between the actual measures and corresponding calculated results. The back analysis code is developed by the software MATLAB, in which the finite element code of ABAQUS is embedded as a module in the modified Nelder-Mead algorithm. This approach is applied to two engineering examples. The results show that the parameter searching efficiency and the convergence precision of the proposed method have an obvious improvement and the inverse results meeting accuracy requirements can be obtained with less iteration. So the proposed method is a feasible method for back analysis of stress, seepage and displacement in geotechnical engineering.