铁路空心高墩弹塑性地震反应特征  

Elastic-plastic seismic response characteristics of railway hollow high pier

作　　者：张永亮[1] 孙鹏 黄彦博 刘沛 ZHANG Yongliang;SUN Peng;HUANG Yanbo;LIU Pei(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070

出　　处：《振动与冲击》2024年第9期1-7,17,共8页Journal of Vibration and Shock

基　　金：国家自然科学基金(52168018);甘肃省科技计划(23JRRA848)。

摘　　要：以某铁路高墩大跨简支梁桥的矩形空心截面桥墩为研究对象,构建了4种墩高的计算模型。考虑了纵筋、分段配筋、加强筋截断位置及加强筋设置数量等因素,采用OpenSees软件建立单墩计算模型进行了增量动力分析,总结了铁路高墩弹塑性地震反应特征,对抗震设计提出了建议。结果表明:纵筋配筋率在0.63%~0.89%条件下,当墩高小于42.0 m且纵筋通长布置时,空心墩底截面为薄弱部位;当墩高大于67.0 m且纵筋分段配筋时,则空心墩底截面、纵筋截断处截面以及墩中某一截面均可能为薄弱部位,但空心墩底截面均为首先出现塑性铰的区域;墩中塑性铰需要较大地震动激励才可能产生,纵筋配筋方式的选择应考虑地震动峰值加速度的影响;增加墩底加强纵筋数量总体上对降低墩底截面的塑性程度是有利的,但强震作用下未必能提高桥墩整体的抗震性能;对于高墩,当墩身出现两个或多个塑性铰区时,建议采用曲率延性系数作为评价指标。Here,taking rectangular hollow section pier of a certain railway high-pier long-span simply-supported girder bridge as the study object,4 pier calculation models with different pier heights were constructed considering factors of segmented longitudinal reinforcement,cut-off positions of reinforcement bars and number of reinforcing bars installed.A single pier calculation model was established with the software OpenSees,and the incremental dynamic analysis was performed for it.Elastic-plastic seismic response characteristics of railway high-piers were summarized,and suggestions for aseismic design were proposed.The results showed that when longitudinal reinforcement ratio is 0.63%-0.89%,pier height is less than 42.0 m and longitudinal reinforcement is arranged in full length,the bottom section of hollow pier is weak area;when pier height is larger than 67.0 m and longitudinal reinforcement is segmented,bottom section of hollow pier,section where longitudinal reinforcement is cut off and a certain section in middle of pier may all be weak areas,but bottom section of hollow pier is the area where plastic hinge firstly appears;for plastic hinge to appear on pier body requires larger seismic excitation,and selection of longitudinal reinforcement mode should consider effects of seismic peak acceleration;increasing number of longitudinal reinforcing bars at pier bottom is generally beneficial to reducing plastic degree of pier bottom section,but under strong seismic action,it may not improve aseismic performance of the whole bridge pier;for high-piers,when there are 2 or more plastic hinge zones on pier body,it is suggested to take curvature ductility coefficient as evaluation index.

关 键 词：铁路桥梁 空心墩 地震反应 弹塑性 评价指标 

分 类 号：U448.22[建筑科学—桥梁与隧道工程]