大跨度单箱双室连续刚构桥施工阶段的主梁顶板正应力分布规律研究  

Study on Normal Stress Distribution of Main Girder Roof in Construction Stage of Long-span Single-box-double-chamber Continuous Rigid Frame Bridge

作　　者：曾勇[1,2] 冉久黉 刘新[1,2] 谭红梅[1,2] Zeng Yong;Ran Jiuhong;Liu Xin;Tan Hongmei(State Key Laboratory of Mountain Bridge and Tunnel Engineering(Chongqing Jiaotong University),400074,China;Engineering Research Center of Mountain Bridge and Materials(Chongqing Jiaotong University),Ministry of Education,400074,China)

机构地区：[1]山区桥梁及隧道工程国家重点实验室(重庆交通大学),400074 [2]山区桥梁结构与材料教育部工程研究中心(重庆交通大学),400074

出　　处：《特种结构》2022年第5期82-88,共7页Special Structures

基　　金：重庆市留学人员回国创业创新支持基金(cx2018113,CX2020117);山区桥梁及隧道工程国家重点实验室开放基金(CQSLBF-Y14-3,CQSLBF-Y16-10)。

摘　　要：国内外对箱梁的正应力分布规律进行了较多研究,而对于大跨度单箱双室连续刚构桥施工阶段主梁的正应力分布规律研究较少。通过三维实体有限元分析模型的建立,研究并得到了大跨度单箱双室连续刚构桥施工阶段的主梁正应力分布规律与特征,在施工过程中主梁顶板截面有着非常显著的正应力分布不均匀现象,在预应力钢束锚固位置处有显著的应力集中现象,施工阶段主梁顶板正应力大小的主要影响因素是混凝土的湿重和张拉钢束的预应力大小,每一个箱梁梁段中心截面的正应力在浇筑混凝土后会减小,而在张拉预应力钢束后会增大。为同类桥梁的设计与施工提供参考。More studies have been carried out on the positive stress distribution law of the box girder at home and abroad,while the normal stress distribution law of the main girder during the construction stage of the large-span single-box and double-chamber continuous rigid bridge has been less studied.Through the three-dimensional solid finite element analysis model,the normal stress distribution law and characteristics of the main girder roof in the construction stage of the large-span single-box and double-chamber continuous rigid-frame bridge were obtained.The main influencing factors of the normal stress of the main girder roof during the construction stage are the wet weight of the concrete and the prestress of the tensile steel beam,and the compressive stress of the central section of each box girder section decreases after pouring the concrete,and increases after the tensile prestressed steel beam.These conclusions would provide reference for the design and construction of similar bridges.

关 键 词：箱梁 正应力 分布规律 单箱双室 挂篮 悬臂施工 

分 类 号：U448.23[建筑科学—桥梁与隧道工程] U445.4[交通运输工程—道路与铁道工程]