土-结构体系的分枝模态与约束模态混合二步法

Analysis of soil-structure interaction system based on mixed branch mode and constrained mode two-step method

为了在结构设计过程中考虑土-结构非线性相互作用的影响,在线性-非线性混合的约束模态法以及分枝模态法的基础上,提出了适用于土-结构非线性相互作用体系的分枝模态与约束模态的混合方法,该方法既可考虑土体和结构的非线性特性又便于考察土-结构相互作用对上部结构的影响。在分枝模态与约束模态混合方法的基础上,进一步提出了混合二步分析法,并将其应用到地基土-框架结构地震响应分析中,算例结果表明,混合二步分析法在实现上部结构和地基土分开计算的同时,还能够考虑结构与地基土的材料非线性特性,有利于采用专业设计软件仅通过对上部结构进行分析来考虑土-结构相互作用的影响,为实际工程计算考虑土-结构相互作用的影响提供了便利的条件。

In order to introduce the effect of nonlinear soil-structure interaction during the structure design process,based on the branch mode synthesis method and the mixed linear-nonlinear constrained mode synthesis method,the mixed branch mode and constrained mode method suitable for non-linear soil-structure interaction system is proposed.The material nonlinearity of structure and soil could be considered effectively by using this method,and it is easier to inspect the influence of soil-structure interaction on superstructure.Furthermore,a mixed two-step method is also proposed on the basis of the mixed branch mode and constrained mode method and applied to the seismic analysis of soil-frame interaction system.The results indicate that the mixed two-step method could analyze superstructure and soil separately in consideration of material nonlinearity of structure and soil.This method is also beneficial to consider the effect of soil-structure interaction by only analyzing the superstructure model while using the professional design programs.It provides convenient method to consider the effect of soil-structure interaction during practical engineering calculation.