基于系数折减的行波效应对连续曲线箱梁桥的影响  

Influence of Traveling Wave Effect Based on Coefficient Reduction on Continuous Curve Box-girder Bridge

作　　者：吴多[1] 李青宁[1] 

机构地区：[1]西安建筑科技大学,陕西西安710055

出　　处：《水利与建筑工程学报》2014年第2期15-20,共6页Journal of Water Resources and Architectural Engineering

基　　金：国家自然科学基金(51078306);高等学校博士学科点专项科研基金(20106120110004);西安建筑科技大学重大科技项目创新基金(ZX0901);陕西省重点学科建设专项资金资助项目(E01004)

摘　　要：行波效应是目前大跨结构中考虑多点激励的一种主要影响因素。特别是针对受力复杂的曲线桥,不考虑地震动的行波效应已经不能满足工程抗震的需求。目前常用大质量模型进行行波效应的分析,然后利用位移差动的方法求出结构的相对位移。对于多支撑的大跨结构来说位移差动的方法经常会导致位移的"漂移"和失真。以一座五跨曲线箱梁桥为例,提出了一种基于基底系数折减的行波处理方法,采用不同视波速进行了地震时程响应分析。结果表明在地震作用下,行波效应对于结构位移上是有利的;并且考虑折减系数的行波可以很好的修正地震作用下的实际位移。最后在考虑行波效应时,视波速、墩高等变参量对曲线桥的地震反应影响较大。因此,在对曲线桥进行抗震分析时,应根据工程具体要求进行对比验算,以保证设计的安全。Traveling wave effect is a main influence factor for the multi-support excitation of large-span structures .It has been unable to meet the needs of engineering earthquake-resistance without considering the traveling wave effect of earth -quake ground-motion ,especially for the curve bridges by complex loading .Large mass model is currently used for the analysis of the traveling wave effect ,then the displacement differential method is used to calculate the relative displace-ment of the structure .However ,the displacement differential method often can lead to displacement “drift” and distortion for more support of large-span structures .Taking a five cross curve box girder bridge as an example ,a traveling wave processing method based on the basal coefficient reduction is proposed ,and the different apparent-wave velocity is used for seismic time-history response analysis .The results show that under the seismic action ,the traveling wave effect is fa-vorable for structural displacement ,and considering the traveling wave of reduction factor can better fix the actual dis -placement under the action of earthquake .Finally when considering the traveling wave effect ,the variable parameters such as the apparent-wave velocity and high pier have a greater influence on the seismic response of curve bridge .There-fore ,in the seismic analysis of curve bridge ,the specific requirements of engineering should be considered for contrast calculation so as to ensure the safety of the design .

关 键 词：曲线桥 行波效应 系数折减 地震反应 

分 类 号：U448.215[建筑科学—桥梁与隧道工程]