有限元模拟土-箱基-框架结构大比例模型动力相互作用研究

FEM study on dynamic interaction of soil-box foundation-frame structure

通过野外大比例模型试验,对土-箱形基础-框架结构体系进行动力测试,研究在土-结构相互作用影响下,不同质量分布情况下,结构体系的动力特性变化规律以及其在顶部稳态激振试验中的动力反应;此外,通过有限元软件MSC.Marc建模计算与试验对比分析。研究结果表明:考虑土-结构相互作用影响后,结构的自振频率减小,周期延长;通过堆载改变结构楼层质量分布后,基频减小,结构的动力特性变化规律满足动力相似关系。有限元计算与现场试验吻合较好,为研究如何利用土-结构共同作用指导结构设计提供了参考。

This paper presents the analysis on the dynamic characteristics of soil - structure system in different mass distribution, which based on outdoor large - scale model experiment for soil - box foundation - superstructure system. The dynamic characteristics were also tested in the forced vibration test （FVT） at the superstructure. The FEM （finite element method） software MSC. Marc was used to estabilish a numerical model considering SSI for comparison to real experiment. It presented that the comparisons of results using FEM analysis to the experiment show a good agreement. Considering the SSI, the frequency of motion reduces and the period of motion protracts, the dynamic properties change in rule of relationship of dynamic similitude when the mass distribution changes. So it presents a reference for structure design by the use of characteristics of SSI.