大跨径桥梁结构概率地震需求分析中地面运动强度参数的优化选择  

Optimal selection of ground motion intensity measures for probabilistic seismic demand analysis of long-span bridge structures

作　　者：陈亮[1] 李建中[2] 

机构地区：[1]合肥工业大学土木与水利工程学院,合肥230009 [2]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《振动与冲击》2011年第10期91-97,共7页Journal of Vibration and Shock

基　　金：国家自然科学基金项目(90815007);安徽省交通科技进步计划项目(200907001)

摘　　要：对于大跨径桥梁结构,应结合地震工程学和结构抗震两个方面选择合理的地面运动强度参数(IM),进行动力分析。针对一座高速公路双塔斜拉桥采用非线性动力时程分析方法,分析不同的IM对于结构地震需求的影响,可以得到以下结论:对于不同桥向,在累积质量参与系数贡献显著的周期范围内,反应谱对结构地震需求影响显著,且高频区段反应谱的影响大于低频区段。应该采用对结构地震需求影响显著的反应谱区段内质量参与系数较大的短周期谱加速度或PGA作为IM。Intensity measures（IM） should be reasonably selected on the basis of earthquake engineering and earthquake resistance of structures for seismic design and analysis of long-span bridges.The nonlinear dynamic time-history analysis was conducted for a long-span highway cable-stayed bridge with two towers.It was concluded that the influence of response spectra in period range of predominant cumulative modal mass participation on structural seismic demands is significant in different directions of long-span bridges;the effects of response spectra in higher frequency domain on structural seismic demands are larger than those in lower-frequency domain;in general,PGA or short-period spectral accelerations are selected as IMs to conduct dynamic time-history analysis.

关 键 词：桥梁抗震 大跨径桥梁结构 地面运动强度参数 优化选择 概率地震需求分析 

分 类 号：U442.5[建筑科学—桥梁与隧道工程]