土-筏基钢框架结构动力相互作用试验研究

为了解土-结构动力相互作用,分别在土槽和刚性地基上进行大比例筏板基础-钢框架顶层低频激振,通过改变上部结构刚度而进行了4个工况的试验对比,对采集的信号进行频谱分析和时域分析,得到不同工况下刚框架频率和动力反应,发现土体对结构频率与动力反应的关系呈现出一定的规律,这种规律主要是由上部结构的刚度变化引起的.土槽中的结构比刚性地基结构自振频率有所折减,随着上部结构刚度的增加土槽中的结构自振频率折减增多,试验最大值可达21.63%.结构各层柱的最大剪力、各楼层加速度峰值及位移峰值有明显的变化规律,加速度折减可达30%以上.

Experimental Investigation of the Dynamic Soil-structure Interaction about Steel Frame-raft Foundation Model

In order to understand soil-structure dynamic interaction, tests were done about low frequency vibration exciting a large proportion of raft-foundation-steel frame in trough and on rigid foundation.Changing the stiffness of the superstructure, four contrast tests were conducted.By signal spectrum and time domain analysis, the frequency and dynamic responses of the steel frame were obtained, and it was found that the frequency and dynamic responses had something to do with the soil, which were mainly caused by the change of superstructure stiffness.The natural vibration frequency of structure reduced in trough compared with that on rigid foundation.As the superstructure stiffness increased, the reduction coefficient of frequency increased, which in the test was up to 21.63%.Also, the maximum shear force for columns, peak acceleration and displacement of each floor had obvious variation, and the reduction coefficient of acceleration could be up to 30%.