摘要
土与结构动力相互作用(简称SSI)存在于大多数的建筑物,在普通结构设计中,并没有考虑SSI,这和缺少一种简单有效的计算方法有关.通过调整结构的自振周期,可以很好地考虑SSI,实际情况是,一般的计算方法都偏于保守,计算结果与实测结果的误差离散性比较大.土是非线性很强的材料,结构振动过大,土容易进入非线性状态,使得计算变得复杂.找出由于土的非线性导致结构自振周期的增大的规律,对于实际工程很有意义.本文通过对刚性基础与土槽中柔性地基上的钢框架模型进行激振,分别测得上部结构在不同刚度以及不同激振加速度时的结构自振周期.并根据实验结果,拟合结构自振周期与激振加速度、上部结构与地基相对刚度比的关系.通过拟合后的公式对两个文献中的试验模型的自振周期进行计算,结果显示,本文拟合的公式能很好的考虑土的非线性,有效地减少简化模型计算与实测的差别.
Abstract
Soil and structure dynamic interaction (SSI) exists in most buildings, while we rarely consider it in normal design because of lacking an efficient method of calculation.We used to adjust the natural period of structure when considering SSI in actual design.This frequently leads to conservative results.Soil is a highly nonlinear material, so the calculation of the structure considering the nonlinearity of soil is too complex to get accurate results.Finding out a way to simplify the calculation is significant to real engineering.In this article, a steel frame model is excited on the rigid foundation and the soil-trough indoor respectively under different working conditions, and the natural period under different accelerations in each condition can be gotten.We derive a formula for the period changing with the acceleration and relative stiffness ratio between superstructure and ground soil and use the formula to calculate the natural period of the model in two references.The results indicate that the difference between experiment natural period and estimated natural period can be effectively eliminated for applying the fitted formula.
基金项目
国家"十二五"科技支撑计划项目(2011BAJ08B02)
湖南省科技重点项目(064SK4057)
NETL
NSTL
维普
万方数据