山区高墩桥梁的多点激励随机响应  

Random Response of High-rise Pier Bridge Subjected to Multi-excitation in Mountain Area

作　　者：喻梅[1,2] 贾宏宇[1,3] 洪浩[1] 郑史雄[1] 罗楠[1] 

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]重庆交通大学,重庆400074 [3]西南交通大学土木工程系,四川峨眉614202

出　　处：《公路交通科技》2013年第6期27-32,共6页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(51278435);铁道部科技研究开发计划项目(2010-G018-A-4)

摘　　要：为了研究山区高墩桥梁在地震动作用下的特殊抗震性能,基于随机振动理论,研究了场地效应、相干效应及行波效应对高墩桥梁在强地震多点激励下的随机响应规律,及墩高变化对高墩桥梁地震响应规律的影响。研究表明:场地效应对高墩桥梁地震响应影响明显,软场地墩的位移值约为硬场地的12倍,行波效应的影响次之,相干效应的影响最小。场地效应对桥梁的影响大小取决于场地卓越频率是否接近于桥梁自振频率;行波效应是不可忽略的一个重要因素,中场地时桥墩最小的位移值约为最大值的30%,软场地时最小值约为最大值的60%;与场地效应和行波效应相比,部分相干效应对桥墩顺桥向位移影响较小。对于山区高墩桥梁随机地震响应分析,考虑地震动空间效应的多点激励分析是必要的。应对有可能的桥型(不同墩高和墩高差)进行分析,以确定地震力最小的桥型并注意桥梁截面抗力的提升和附加减震措施。In order to research the performance of high-rise pier bridges in mountain area under the action of earthquake, based on the theory of random vibration, the seismic responses of high-rise pier bridges with different pier heights under multi-point random excitation of strong earthquakes are analyzed considering the local site, coherence and traveling wave effects （TWE）. The result indicates that （ 1 ） The influence of local site effect （SE） on the bridge＇s seismic response is obvious, the displacement of pier in soft site is about 12 times in hard site. Compared with SE, TWE causes lower responses and CE causes the lowest. The influence to bridge caused by SE depends on whether predominate frequency of site is close to the natural frequency of bridge or not. The TWE is an important factor which cannot be ignored. The minimum displacement of pier is about 30% of the maximum in medium site, and 60% in soft site. The influence of the partially coherence effect on the longitudinal displacement of pier is much lesser than other effects. For the analysis of stochastic seismic response of high-rise pier bridges in the mountain, it is necessary to consider the multi-excitation of spatial effect of ground motion. Bridge types with different heights of pier and height difference between high pier and low pier should be taken into consideration to confirm the most optimum type. The section resistance of bridge and shock absorption measures should be also noticed.

关 键 词：桥梁工程 高墩桥梁 随机振动 多点激励 地震响应 相干效应 

分 类 号：TU311.3[建筑科学—结构工程] U442.55[建筑科学—桥梁与隧道工程]