公铁合建钢混板-桁斜拉桥悬挑式钢锚箱受力特性及结构优化  

Mechanical Characteristics and Structure Optimization of Cantilevered Steel Anchor Box of Rail-cum-Road Steel-Concrete Slab-Truss Cable-Stayed Bridge

作　　者：施洲[1] 周勇聪 江峰[1] 刘振标[2] 夏正春[2] 印涛[2] SHI Zhou;ZHOU Yongcong;JIANG Feng;LIU Zhenbiao;XIA Zhengchun;YIN Tao(School of Civil Engineering,Southwest Jiaotong University,Chengdu Sichuan 610031,China;China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan Hubei 430063,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]中铁第四勘察设计院集团有限公司,湖北武汉430063

出　　处：《中国铁道科学》2024年第3期50-60,共11页China Railway Science

基　　金：中国国家铁路集团有限公司科技研究开发计划课题(N2021G034);中铁第四勘察设计院集团有限公司科技研发项目(2021K015)。

摘　　要：为研究大跨度公铁合建钢混板-桁斜拉桥主梁悬挑式索梁钢锚箱结构的受力特性及结构优化,以主跨808 m的洪奇沥特大桥钢锚箱为背景,采用仿真分析方法,研究钢锚箱3个设计方案主要板件应力、焊缝应力以及推荐方案锚箱节点的传力特性和锚箱参数对钢锚箱受力的影响。结果表明:锚箱尺寸较大、顶底板加肋方案的主要板件应力最大为300 MPa,小于其他2种方案,且6条焊缝的最大应力和应力不均匀系数较优,因此确定该方案为最终设计方案;索力首先由锚垫板直接向钢锚箱顶、底板和内外腹板较为均匀传递,最终边弦杆底板、内腹板和外腹板分别承担了22.2%,46.4%和31.4%的索力;节点处副桁斜杆、近桥塔侧和远桥塔侧边弦杆、混凝土桥面、节点横梁分别传递约66.71%,9.72%,9.32%,9.68%和4.56%的斜拉索竖向分力;板件应力随顶底板厚度增加而减小,顶底板深入边弦杆长度增加可以降低底板-内腹板焊缝峰值应力,顶底板间距减小可降低内外腹板和顶底板与锚垫板接触区域应力;顶底板厚44 mm、锚箱顶底板深入边弦杆长度1800 mm、顶底板间距660 mm时较为合理。To investigate the mechanical characteristics and structure optimization of the cantilever steel anchor box structure of the main girder of the long span rail-cum-road steel-concrete slab-truss cable-stayed bridge,taking the steel anchor box of the Hongqili Grand Bridge with a span of 808 m as the engineering background,the stress analyses on the main plates and welds for the three design schemes,force transferring characteristics of the anchor box joints of the recommended scheme,and the parametric analysis on the forces of the steel anchor box were carried out based on the simulation analysis.The results show that the maximum stress of main plates in the scheme with larger anchor box size and stiffeners on the top and bottom plates is 300 MPa,which is less than the other two schemes.And the maximum stress and stress non-uniformity coefficient of the six welds are better,so it is determined as the final design scheme.The cable force is firstly transmitted evenly from the anchor pad plate directly to the top plate,bottom plate,inner web and outer web of the steel anchor box.Finally,the bottom plate,inner web,and outer web of the side chord bear 22.2%,46.4%,and 31.4%of the cable force,respectively.About 66.71%,9.72%,9.32%,9.68%,and 4.56%of the vertical component of cable force are transferred through the tilted belly poles of auxiliary truss,the side chords of the near pylons,the side chords of the far pylons,the concrete deck,and the node crossbeam,respectively.The stresses of the plates decrease with the increasing thickness of the top and bottom plates.The increase of the length of the top and bottom plates deep into the side chords can reduce the peak stress of the welds between the bottom plate and the inner web.The decrease of the distance between the top and bottom plates reduces the stress of the contact area between the inner and outer webs and the top and bottom plates and the anchor pad plate.It is reasonable for the thickness of top and bottom plates selecting 44 mm,the length of anchor box top and bot

关 键 词：公铁合建斜拉桥 索梁钢锚箱 受力特性 传力特性 结构优化 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]