基于响应面法的土石坝参数随机反演分析

针对常规随机反演过程中需多次进行数值模拟与优化方法耦合存在的计算量过大的问题,提出基于响应面法的土石坝参数反演方法。在有限元分析的基础上,利用中心复合设计进行有限次试验,建立可反映土石坝参数与位移之间非线性隐式关系的响应面方程,以代替有限元计算;结合内点法及Monte-Carlo随机抽样,对响应面方程的目标函数进行迭代寻优,从而实现土石坝参数的随机反演分析。数值算例表明,该方法计算结果误差小,求解效率高;随机反演得到的参数能更准确地反映材料的真实情况,其统计特性还可用于土石坝稳定计算和风险评估。研究成果为实际土石坝工程的参数确定提供了参考。

Stochastic Inversion of Earth Rockfill Dam Parameters Based on Response Surface Method

Given the process of stochastic inversion that needs to repeat the coupling of numerical simulation and optimization will lead to large computation, parameter back analysis of earth rockfill dam is proposed based on the method of response surface. On the basis of FEM analysis, the limited FEM trials are done by means of central composite design. After these trials, response surface equations, which can reflect the non-linear relationship between parameters and displacements of earth rockfill dam, are established to replace the FEM calculation. Then interior point method and Monte-Carlo random sampling are adopted and the objective function of response surface equations is optimized by iterations so that the random inversion of embankment dam parameters is achieved. Numerical simulation example shows that this method has low error and high computational efficiency. Besides, stochastic inversion parameters can reflect the real situation of the material more accurately and the statistical properties of parameters can be used for the stability calculation and risk assessment of earth rockfill dam. The research results provide reference for determination of the parameters in actual earth rockfill dam.