碳化与疲劳耦合作用下铁路桥梁的结构动力响应研究  

Study on Structural Dynamic Response of Railway Bridges Under Coupled Effects of Carbonation and Fatigue

作　　者：肖烨[1] 罗小勇[2] 范亚坤[3] XIAO Ye;LUO Xiaoyong;FAN Yakun(School of Civil and Architectural Engineering,East China University of Technology,Nanchang 330013,China;School of Civil Engineering,Central South University,Changsha 410075,China;School of Civil Engineering and Transportation,Nanchang Hangkong University,Nanchang 330063,China)

机构地区：[1]东华理工大学土木与建筑工程学院,南昌330013 [2]中南大学土木工程学院,长沙410075 [3]南昌航空大学土木与交通学院,南昌330063

出　　处：《铁道标准设计》2024年第11期94-100,共7页Railway Standard Design

基　　金：国家自然科学基金煤炭联合基金项目(U1361204);国家自然科学基金项目(41861058);江西省教育厅基金项目(GJJ210924)。

摘　　要：为研究碳化与疲劳荷载耦合作用对既有铁路桥梁结构动力响应的影响,建立混凝土碳化与疲劳荷载耦合损伤模型;以朔黄铁路线上一典型预应力混凝土简支T梁为例,提出碳化与疲劳荷载耦合作用下主梁的碳化深度影响因素及随年限发展模型,并结合实测桥梁碳化数据,验证耦合损伤模型的准确性;利用有限元软件计算不同服役年限下既有铁路桥梁结构的动力响应,研究碳化与疲劳荷载耦合作用对既有铁路桥梁结构动力响应的影响。结果表明:提出的碳化与疲劳荷载耦合损伤模型计算结果与实测碳化深度吻合较好,表明耦合模型的可靠性。当桥梁服役年限为10年以内时,疲劳荷载对桥梁结构的碳化影响不大;随着服役年限的增长,疲劳荷载对桥梁结构碳化的影响越大;当服役年限为100年时碳化与荷载疲劳耦合作用下的碳化深度为仅碳化时的3倍。桥梁跨中截面竖向位移和动应变峰值随服役年限的增加而减少,加速度响应峰值随服役年限的增加有一定波动,整体趋势将减少。In order to study the coupled effects of carbonation and fatigue load on the dynamic response of existing railway bridge structures,a coupled damage model for concrete carbonation and fatigue load was established.Taking a typical prestressed concrete simply supported T-beam on Shuozhou-Huanghuagang Railway as an example,a model was proposed to identify the influencing factors of the carbonation depth in the main girder under the combined effects of carbonation and fatigue load and its development over time.The coupled damage model was validated using measured carbonation data from the bridge.Finite element software was employed to calculate the dynamic response of the existing railway bridge structure at different service life,and the influence of carbonation and fatigue load coupling on the bridges structural dynamic response was studied.The results showed that the calculated carbonation depth from the proposed coupled damage model closely matched the measured data,confirming the reliability of the coupled model.When the service life of the bridge was less than 10 years,the fatigue load had little influence on the carbonation of the bridge structure.As the service life increased,the influence of fatigue load on carbonation became more significant.At 100 years of service,the carbonation depth under the combined effects of carbonation and fatigue load was three times that of carbonation alone.The vertical displacement and peak dynamic strain of the mid-span section decreased with increasing service life,while the peak acceleration response fluctuated but generally decreased over time.

关 键 词：铁路桥梁 混凝土碳化 疲劳荷载 服役年限 动力响应 

分 类 号：U213.5[交通运输工程—道路与铁道工程] U448.13[建筑科学—桥梁与隧道工程] U441.7