桥梁建设2021年第51卷第2期(总第270期)10Bridge Construction,Vol.51#No.2#2021(Totally No.270)文章编号！003—4722(2021)02—0010—08大跨度铁路悬索桥钢桁加劲梁设计徐伟，李松林，胡文军(中铁大桥勘测设计院集团有限公司，湖北武汉430056)摘要：某大跨度铁路桥位于强震山区，采用主跨1060m的上承式钢桁梁悬索桥，主桁采用华伦式桁架，桁宽30m、桁高12m,节间长10m。
结合强震山区铁路悬索桥的受力特点，加劲梁约束体系采用塔梁分离、塔墩固结的半飘浮体系，桥塔处纵向阻尼器与下平联设置在同一平面，桥塔和桥台处均设置相互协调工作的横向支座与横向阻尼器，并设置地震反压结构，在桥台端横梁中央设置局部受压支座，解决了大跨度铁路悬索桥抗强震、大风作用及轨道局部平顺性问题。
钢桁梁主要构件采用Q370qD钢，局部构件采用Q500qD钢，主桁杆件和联结系杆件分别采用M30和M24高强度螺栓连接。
加劲梁主桁上弦杆采用箱形截面杆件、焊接整体节点，下弦杆主要采用H形截面杆件、拆装式节点；上层通过交叉平联使箱形弦杆与钢桥面组成整体断面共同受力，下层采用H 形弦杆与交叉平联组成镂空层，采用斜杆受拉为主的横联，解决了铁路悬索桥钢梁的疲劳问题，同时具有较好的经济性。
结合场地及运输条件，加劲梁分区段采用顶推、原位拼装、缆索吊结合的方案施工，解决了山区大跨度悬索桥的施工难题。
关键词：铁路桥；悬索桥；强震山区；加劲梁；钢桁梁；约束体系；结构设计；疲劳设计中图分类号：U44&13；U44&25；U442.5文献标志码：ADesign of Truss Stiffening Girder of a Long-SpanRailway Suspension BridgeXU Wei,LI Song-lin,HU Wen-jun(China Railway Major Bridge Reconnaissance&Design Institute Co.Ltd.,Wuhan430056,China) Abstract:A long-span railway bridge,located in the mountainous area with high seismicity,is designed as a deck-type steel truss girder suspension bridge with a main span of1060m.The truss stiffening girder consists of Warren trusses that measure30m wide and12m deep,and a truss panelis10m.Tosui0he mechanical proper0ies of0he railway suspension bridge in moun0ainous areawihhighseismiciy,0he0owersand0hes0i f eninggirderaresepara0ed,and0he0owersand the piers are fixed,which forms a semi-floating system.The longitudinal dampers at the towers and0helowerla0eralbracingsof0hes0i f eninggirderareins0a l edin0hesameplan.A0bo0h0he towers and abutments,the t r ansverse bearings and dampers t h a t can work collaboratively are installed,the back pressure structure that can regulate seismic forces is added,and local compressionbearingsareinsta4edinthecenterofendf4oorbeamsofabutments,toimprovethe intenseseismic and heavy wind resistance ofthe bridge and addresstheissue of4oca4track irregu4arity.The main components of the stee4trusses are made of Q370qD stee4,andcomponents in4oca4partsare madeofQ500qDstee4.The membersofthe maintrussesandtie membersare connectedby M30and M40high strength bo4ts,respective4y.The upper chords of the truss 收稿日期：2021—01—05基金项目：中国国家铁路集团有限公司科技研究幵发计划课题(P2019G002)Project of Science and Technology Research and Development Program of China Railway Corporation(P2019G002)作者简介：徐伟，教授级高工,E-mail：Xuw@&研究方向：公路、铁路大跨度桥梁设计，钢结构设计&大跨度铁路悬索桥钢桁加劲梁设计 徐 伟，李松林,胡文军11stiffening girder are formed of box cross-section members # with integral welding joints # while thelower chords are composed of H cross-section members # with detachable joints. In the upper level # the lateral bracings allow the box cross-section chords and the steel dec[ plates to form an integralcross section and share the acting loads. In the lower level # the H cross-section members and the lateral bracings form a transparent framed structure # with diagonal members in the transverseconnection mainly in tension # which is beneficial to the fatigue resistance of the steel girder ofrailway suspension bridge and has better economic performance. Limited by the construction space and transportation access # the stiffening girder was divided into regions which could be constructedusing tailored methods # including incremental launching # in-situ assembly and cableway crane construction. The proposed methods can facilitate the construction of long-span suspension bridgein mountainousarea.Key words : railway bridge $ suspension bridge $ mountainous area with high seismicity ； stiffening girder $ steel truss girder $ restraint system $ structural design $ fatigue design1工程概况某大跨度铁路桥位于强震山区，桥址处河面宽约130 m,最大水深约10 m,河谷下部狭窄，谷坡陡峻。
