非对称刚构-连续组合体系梁桥受力特性研究  

Research on Mechanical Property of Asymmetric Composite Girder Bridge of Combined Rigid Frame and Continuous Girder System

作　　者：杨兴[1] 刘琪[1] 朱玉[1] YANG Xing;LIU Qi;ZHU Yu(CCCC Second Highway Consultants Co.,Ltd.,Wuhan 430056,China)

机构地区：[1]中交第二公路勘察设计研究院有限公司,湖北武汉430056

出　　处：《桥梁建设》2023年第S01期46-53,共8页Bridge Construction

基　　金：重庆市交通行业科学技术项目(KJXM2021-0966)。

摘　　要：为给非对称刚构-连续组合体系梁桥的设计与应用提供理论基础,以渝湘复线高速长头河特大桥主桥为背景,引入非对称比例系数研究不对称程度对非对称刚构-连续组合梁桥力学特性的影响,提出采用在连续墩处设置组合阻尼支承体系改善该体系梁桥连续墩处主梁在横向风荷载作用下受力不利的问题。保持该桥主跨跨径180 m不变,调整刚构侧和连续侧单侧主梁长度在主跨范围内的占比,采用MIDAS Civil软件建立10个不同非对称比例系数的刚构-连续组合体系梁桥有限元模型,分析不同模型在恒载、汽车荷载、温度荷载、收缩徐变等作用下的主梁内力和支座反力,以及组合阻尼支座不同水平等效刚度对主梁受力的影响。结果表明:非对称刚构-连续组合体系梁桥不对称程度对结构内力影响最大的荷载为收缩徐变;非对称比例系数m>0.2时需适当加大连续墩处主梁梁高、延长小边跨长度以减小非对称性的不利影响,m最大限值建议采用0.3;在连续墩处设置组合阻尼支承体系,利用阻尼位移使主梁协调变形,能有效降低横向风荷载引起的主梁弯矩和应力幅。The study focuses on the design and application of the asymmetric composite girder bridge of combined rigid frame and continuous girder system.Based on the Changtouhe River Bridge of the Second Chongqing-Hunan Expressway,the asymmetric proportion coefficient is introduced to study the effect of asymmetric extent on the mechanical property of the asymmetric composite girder bridge of combined rigid frame and continuous girder system.It is proposed to install damping support system at the piers supporting the girders in the continuous spans so as to address the unfavorable load bearing condition of the girders over these piers under lateral wind loads.With main span lengths of 180 m,the portion of the lengths of girders flanked the rigid frame and continuous span is adjusted,and 10 finite element models of composite girder bridges of combined rigid frame and continuous girder system were built up with different asymmetric proportion coefficients,to analyze the internal forces of main girder and reaction forces at supports under the influence of dead loads,vehicle loads,thermal loads and concrete shrinkage and creep.And the impact of horizontal equivalent stiffness of composite damping bearings on the load bearing behavior of the main girder was analyzed as well.The results show that the asymmetric extent of the asymmetric composite girder bridge of combined rigid frame and continuous girder system exerts the most intensive effect on the concrete shrinkage and creep of main girder.To increase the girder depth at piers in the continuous spans and enlarge the lengths of the small side spans are a good way to reduce the adverse impact of asymmetry,the maximum value of the asymmetric proportion coefficient is suggested to be 0.3.To use composite damping bearings at piers in the continuous spans and using damping displacement to adjust the deformation of the main girder can effectively reduce the bending moment and stress range of the main girder induced by lateral wind loads.

关 键 词：非对称刚构-连续组合体系梁桥 非对称比例系数 受力特性 组合阻尼支承体系 横向风荷载 水平等效刚度 有限元法 

分 类 号：U448.21[建筑科学—桥梁与隧道工程] U441.2[交通运输工程—道路与铁道工程]