横向斜坡场地上连续梁桥的地震反应分析  

Seismic Response Analyses of Continuous Beam Bridge in Slope

作　　者：喻泽红[1] 焦志鹏 YU Zehong;JIAO Zhipeng(Central South University,Changsha,Hunan 410076,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410076

出　　处：《公路工程》2021年第4期8-16,22,共10页Highway Engineering

基　　金：国家自然科学基金资助项目(51678573,51778639)。

摘　　要：建立斜坡场地连续梁桥地震反应分析三维有限元模型,计算连续梁桥主要特征点,包括桩中、桩顶,墩中、墩顶,纵梁、横梁跨中等的地震位移和加速度。结果表明,计算点的地震位移和加速度反应与其在斜坡和桥梁结构中的相对位置有关,靠近斜坡上侧和桥梁边桩的地震横向位移及其时程曲线波动幅度较大,其中边桩和边跨尤为明显;靠近坡体上侧的中间桩地震位移比斜坡中、下部桩体位移稍小。不同位置的计算点,其地震加速度反应呈现不同特征,在多数时间点上,靠近斜坡中、下部的桩基地震加速度幅值高于上侧桩基,但加速度最大值不尽如此;墩体加速度计算值离散较大,边部和侧部墩体加速度相差不大,但明显高出中间墩体70%左右;对于上部梁体,某些时间点上,中跨纵梁地震加速度高于次跨和边跨,但边跨纵梁加速度最大,侧跨横梁跨中加速度高于边跨和中间跨横梁,还同时高于侧跨纵梁跨中加速度。A three-dimensional finite element model was established to investigated the dynamic performances of a continuous beam bridge in a slope field,in which the seismic displacement and acceleration responses at representative locations in structural system were analyzed in detail,such as the midpoints and peaks of piles,piers,as well as the midpoints of primary and secondary beam spans.The analyses showed that the seismic displacement and acceleration responses of the calculation points were closely related to their relative positions in slope and structure,those upside the slope or close to the edge piles generally possessed relatively larger seismic lateral displacements,and their displacement time history curves fluctuated relatively violently,especially in the edge piles and beam spans.The seismic displacement of the middle pile upside the slope was smaller than those of the downside.In most of the time points,the earthquake acceleration amplitudes of the pile located in the central and downside slope were larger than those of the upside,while maximum accelerations were not at all.Overall,acceleration responses of those located at edge pile were relatively more powerfully;The calculation values of the pier seismic accelerations appeared discrete comparatively,although there was little difference between the edge and the side piers,they were still larger than those of the middle piers by 70%.At some time,the seismic acceleration response of middle span was greater than those of the edge and side spans,but the acceleration response of edge primary beam was the largest one.In addition,acceleration response of the side secondary beam was larger than those of the middle and the edge secondary spans,even greater than that of the side primary beam.

关 键 词：连续梁桥 边坡 桩土作用 地震反应 时程分析 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]