摘要
在车辆荷载作用下钢结构桥梁的关键构件会受到循环荷载作用而产生疲劳,疲劳的不断积累可能会导致构件发生疲劳损伤甚至断裂。疲劳冲击系数是车辆荷载对桥梁疲劳性能影响的重要参数,随着桥梁运营年限的增加,桥面不平整度会发生劣化,使得桥梁的疲劳冲击系数发生改变。改进型波形钢腹板组合箱梁桥(ICBGBCSW)是一种新型的桥梁结构,其构造细节的受力复杂,研究ICBGBCSW构造细节的疲劳性能至关重要。因此,考虑桥面不平整度劣化,对ICBGBCSW构造细节的疲劳应力进行了研究。首先,利用有限元模型计算静荷载作用下ICBGBCSW的静应力,以确定ICBGBCSW构造细节的疲劳应力分布规律;然后,研究了不同车速和桥面不平整度对ICBGBCSW构造细节的疲劳应力和疲劳应力冲击系数的影响;最后,基于桥面不平整度劣化模型,提出了ICBGBCSW疲劳冲击系数的设计值。结果表明:波形钢腹板(CSW)的波折处容易出现应力集中现象,且桥面不平整度劣化为差和非常差时,其应力和应力幅冲击系数超过AASHTO桥梁规范中规定的0.15;当桥面不平整度为一般且车速小于60 km·h^(-1)时,应力和应力幅冲击系数也超过了AASHTO桥梁规范值。研究成果可为考虑桥面不平整度劣化的ICBGBCSW疲劳应力和疲劳冲击系数分析提供参考。
The key components of steel bridges under vehicle loading are subjected to cyclic loading,causing fatigue;the continuous accumulation of fatigue may lead to fatigue damage or even fracture of the components.The fatigue impact coefficient is an important parameter for evaluating the influence of vehicle load on the fatigue performance of bridges.With an increase in the operating life of a bridge,the bridge deck roughness deteriorates,affecting the fatigue impact coefficient of the bridge.An improved composite box girder bridge with corrugated steel webs(ICBGBCSW)is a new type of bridge structure.However,the forces acting on its structural details are complex,making it crucial to study the fatigue performance of the ICBGBCSW structural details.Therefore,this study investigated the fatigue stress of the ICBGBCSW structural details,considering the deterioration of the bridge deck roughness.First,finite element software was used to calculate the static stress of the ICBGBCSW under the action of a static load to determine the fatigue stress distribution of the structural details of the ICBGBCSW.Subsequently,the effects of different vehicle speeds and bridge deck roughness levels on the fatigue stress and fatigue stress impact coefficients of the ICBGBCSW structural details were investigated.Finally,based on the bridge deck roughness degradation model,the design value of the fatigue impact coefficient of the ICBGBCSW was proposed.The results show that the stress easily concentrates at the corrugated folds of corrugated steel webs(CSW).When the bridge deck unevenness deteriorates to poor or very poor,its stress and stress amplitude impact coefficients exceed 0.15,as specified in the AASHTO Bridge Code.The stress and stress amplitude impact coefficients exceeded the values in the AASHTO Bridge Code when the bridge deck roughness is average and the vehicle speed is less than 60 km·h^(-1).The research results can provide a reference for analyzing the fatigue stress and fatigue impact factor of ICBGBCSW,considering the deterioration of the bridge deck roughness.
作者
罗奎
邵天彦
冀伟
孔烜
邓露
李捷奇
LUO Kui;SHAO Tian-yan;JI Wei;KONG Xuan;DENG Lu;LI Jie-qi(College of Civil Engineering,Hunan University,Changsha 410082,Hunan,China;Zhejiang Infinite Element Composite Structure Bridge Design Co.Ltd.,Hangzhou 310000,Zhejiang,China;College of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,Gansu,China)
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2024年第8期98-110,共13页
China Journal of Highway and Transport
基金
国家自然科学基金项目(52168019)
中央高校基本科研业务费专项资金项目(541109030099)
甘肃省重点研发计划-工业类项目(23YFGA0043)
湖南省自然科学基金项目(2024JJ5084)
关键词
桥梁工程
疲劳应力
车桥耦合
组合箱梁
冲击系数
桥面不平整度
bridge engineering
fatigue stress
vehicle-bridge coupling
composite box girder
impact factor
bridge roughness
作者简介
罗奎(1991-),男,陕西汉中人,工学博士研究生,E-mail:luokui@hnu.edu.cn;通讯作者:冀伟(1982-),男,山西阳泉人,教授,博士研究生导师,工学博士,E-mail:jiwei@hnu.edu.cn。
