双箱多室混凝土曲线异形箱梁横截面正应力分布研究  

Research on Normal Stress Distribution in Cross Section of Double-box Multi-room Concrete Curved Special-shaped Box Girder

作　　者：康俊涛[1] 邹立 贾贤盛 KANG Juntao;ZOU Li;JIA Xiansheng(School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan 430070, China;CITIC EngineeringDesign & Construction Co. Ltd., Wuhan 430070, China)

机构地区：[1]武汉理工大学土木工程与建筑学院,武汉430070 [2]中信工程设计建设有限公司,武汉430070

出　　处：《武汉理工大学学报（交通科学与工程版）》2020年第2期222-227,共6页Journal of Wuhan University of Technology（Transportation Science & Engineering）

基　　金：国家自然科学基金项目资助(51708436)。

摘　　要：双箱多室预应力混凝土异形箱梁结构受力较为复杂,当腹板间距较大时,薄壁箱梁截面的剪力滞效应成为工程设计中不可忽视的因素之一.为研究该类型桥梁在典型荷载类型作用下关键截面正应力的分布特点及变化规律,本文以某28 m+36 m+28 m预应力混凝土双箱多室分叉连续箱梁为工程背景,采用Midas/FEA 3.7建立空间实体有限元模型,计算并分析了该桥在恒载、纵向预应力、汽车荷载、横向预应力及温度荷载作用下关键控制截面的顶底板正应力分布特点及变化规律.结果表明:恒载作用下曲线内外侧顶底板正应力呈非对称分布,且箱室较多一侧应力沿横向变化较缓;纵向预应力对曲线内侧正截面应力影响较大;活载效应约为恒载效应的60%~80%,局部位置活载效应大于恒载效应;横向预应力对主梁正应力影响较小,所以桥梁纵向计算可不考虑横向预应力作用,且越靠近横梁,横向预应力钢束对横截面正应力影响越显著,横向预应力对支座反力有一定影响;底板温度应力受支座、横梁约束影响较大.The stress of double-box multi-room prestressed concrete special-shaped box girder structure is relatively complex.When the web spacing is large,the shear lag effect of thin-wall box girder section becomes one of the factors that cannot be ignored in engineering design.In order to study the distribution characteristics and variation rules of normal stress in key sections of this type of bridge under the action of typical load types,taking a 28 m+36 m+28 m prestressed concrete double-box multi-room bifurcated continuous box girder as the engineering background,Midas/FEA 3.7 was adopted to establish a spatial solid finite element model,and the distribution characteristics and variation rules of normal stress in top and bottom plates of key control sections of the bridge under the action of dead load,longitudinal prestress,automobile load,transverse prestress and temperature load were calculated and analyzed.The results show that under constant load,the normal stress of the top and bottom plates on the inner and outer sides of the curve is asymmetrically distributed,and the stress on the side with more compartments changes slowly along the transverse direction.The longitudinal prestress has a great influence on the stress of the normal section inside the curve.The live load effect is about 60%~80%of the dead load effect,and the local live load effect is greater than the dead load effect.Moreover,the transverse prestress has little influence on the normal stress of the girder,so the transverse prestress cannot be considered in the longitudinal calculation of the bridge.And the closer to the beam,the more significant the influence of the transverse prestressed steel bundle on the cross-sectional normal stress,and the transverse prestress has certain influence on the bearing reaction force.Meanwhile,the temperature stress of the bottom plate is greatly influenced by the constraints of the support and the cross beam.

关 键 词：双箱多室 曲线异形箱梁 正应力 有限元 

分 类 号：U448.21[建筑科学—桥梁与隧道工程]