空心型框架桥地震动力响应分析

摘要

为探讨空心结构框架桥的地震动力响应,以一下穿框架桥项目为工程背景,通过有限元软件分别建立空心型框架桥和原型框架桥三维模型,对比了空心结构框架桥和实际框架桥的自振频率、振型和时程曲线.分析结果表明:2种结构在整体刚度方面基本保持一致,横向刚度较小,纵向刚度较大,保证了结构的稳定性.通过时程响应分析法对结构的特征点进行分析,对比了2种结构在最不利时刻的第1、第3主应力,发现二者时程曲线变化趋于一致,抗震性能几乎相同.%The seismic dynamic response of the hollow structure frame bridge was studied in this paper and the background was an undercrossing frame bridge.Finite element analysis was conducted for two types of bridges.One was a hollow-type frame bridge and the other was a prototype frame bridge.The natural frequency,vibration mode and time history curves of the hollow-type frame bridge and the real frame bridge were compared.The analysis results show that the integrated stiffness of the two structures are the same.The lateral stiffness is relatively low while the longitudinal stiffness is relatively high,ensuring the stability.Time history analysis was used for its dynamic feature points.The first and the third principle stresses of the two structures at the worst moment were compared.It shows that the time history curves tend to be the same and the seismic resistance abilities are close.