2×116 m混凝土T型刚构桥主梁设计  

Design of the Main Beam of the 2×116 m Concrete T-frame Bridge

作　　者：朱标 董传芹 李丁立 ZHU Biao;DONG Chuanqin;LI Dingli(North Survey and Design Co.Ltd,of CREEC,Ji’nan,Shandong 250012,China)

机构地区：[1]中铁二院北方勘察设计有限责任公司,济南250012

出　　处：《铁道工程学报》2025年第2期46-50,共5页Journal of Railway Engineering Society

摘　　要：研究目的:随着我国公路和铁路事业的迅速发展,采用预应力混凝土T型刚构桥跨越既有铁路的情况越来越多,且跨度越来越大,而采用成桥后在梁端施加顶升力以加大预应力混凝土T型刚构桥跨越能力的研究相对较少。本文以目前国内最大跨度的某公路上跨铁路2×116 m预应力混凝土T型刚构桥为研究对象,通过建立有限元模型,分析梁端顶升力对大跨度预应力混凝土T型刚构桥主梁梁高和腹板厚度的取值影响,进而探索梁端顶升力对主梁受力的影响规律和取值原则。研究结论:(1)对大跨度预应力混凝土T型刚构桥采用成桥后在梁端施加顶升力的方式可有效降低主梁根部截面负弯矩及剪力设计值;(2)梁端施加顶升力可减小主梁腹板设计厚度,主梁中支点梁高高跨比可取1/10,边支点梁高高跨比可取1/25,使主梁具有良好的技术经济指标;(3)本桥采用成桥后在梁端施加顶升力的方法,各项指标均满足规范要求,设计参数合理,可供以后此类大跨度预应力混凝土T型刚构桥借鉴。Research purposes:With the rapid development of highway and railway in our country,more and more prestressed concrete T-frame bridges are used to cross over existing railways,and the span is getting longer and longer.However,there are relatively few studies on applying the lifting force at the beam end to increase the crossing capacity of prestressed concrete T-frame bridges.In this paper,a 2×116 m prestressed concrete T-frame bridge spanning a railway on a highway with the largest span in China is taken as the research object,by establishing a finite element model,the influence of the lift at the end of the beam on the height of the main beam and the thickness of the web of the long-span prestressed concrete T-frame bridge is analyzed,and then the influence rule and value principle of the lift at the end of the beam on the stress of the main beam are explored.Research conclusions:(1)The design value of negative bending moment and shear force at the root section of the main beam can be effectively reduced by applying the lifting force at the end of the beam of the long-span prestressed concrete T-frame bridge.(2)Applying the top lift force at the end of the beam can reduce the design thickness of the web of the main beam,and the height span ratio of the fulcrum beam in the main beam can be 1/10,and the height span ratio of the side fulcrum beam can be 1/25,so that the main beam has good technical and economic indicators.(3)The bridge adopts the method of applying the lifting force at the end of the beam after the completion of the bridge,and all the indicators meet the requirements of the code and the design parameters are reasonable,which can be used as a reference for this kind of long-span prestressed concrete T-frame bridge in the future.

关 键 词：跨线桥 T型刚构桥 转体施工 梁端顶升 主梁设计 静力计算 

分 类 号：U442.5[建筑科学—桥梁与隧道工程]