超长大跨度公铁合建桥梁结构体系研究  

Research on Structural System for Super Long-Span Rail-cum-Road Bridge

作　　者：王小飞[1,2] WANG Xiaofei(China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430063,China;China Railway Construction Laboratory of Bridge Engineering,Wuhan 430063,China)

机构地区：[1]中铁第四勘察设计院集团有限公司,武汉430063 [2]中国铁建股份有限公司桥梁工程实验室,武汉430063

出　　处：《铁道标准设计》2024年第1期87-95,共9页Railway Standard Design

基　　金：中国铁建股份有限公司科技重大专项(2020-A01);中铁第四勘察设计院集团有限公司科技研发项目(2021K012)。

摘　　要：新建甬舟铁路西堠门公铁两用大桥连接金塘岛和册子岛,桥位处海域宽2.7 km,最大水深93 m,地形复杂,桥梁设计难度大。为研究超长大跨度公铁合建桥梁合理结构体系,结合地形地质条件,选取主跨1500 m悬索桥、斜拉桥及斜拉悬索协作体系3种桥型方案,对上部结构设计进行详细介绍,并从静力性能、动力性能、经济性能等方面对不同结构体系进行对比分析。研究表明:(1)与斜拉体系相比,协作体系桥可减小30%~50%的主梁内力和60%的桥塔内力,一定程度上解决了加劲梁承受巨大轴压力造成屈曲问题,并有效减小了桥塔规模;(2)与悬索桥相比,协作体系可减小50%的主缆内力,主缆钢丝和锚碇的工程量相应减小,施工难度得以降低,同时协作体系扭转频率更高,降低了结构在较低风速下发生涡激振动的可能性;(3)斜拉悬索协作体系能够充分发挥斜拉结构和悬索结构的组合优势,实现超大跨度的同时具有较大的纵向刚度和竖向刚度,满足铁路行车对结构刚度的要求;(4)对于主跨1500 m级超长大跨度公铁合建桥梁,斜拉悬索协作体系经济性更好。The newly-built Xihoumen Rail-cum-Road Bridge on Ningbo-Zhoushan Railway is connected to Jintang Island and Cezi Island.The sea area at the bridge site is 2.7 km wide and the maximum water depth is 93 m.The topography is complex and bridge design is difficult.In order to find a reasonable structural system for super long span rail-cum-road bridge,three bridge types of suspension bridge,cable-stayed bridge and combined cable-stayed and suspension system with main span of 1500 m are selected according to the topographic and geological conditions.The design of superstructure is introduced,and different structural systems are compared and analyzed from the aspects of static performance,dynamic performance and economic performance.The research shows that:(1)Compared with the cable-stayed bridge,the combined cable-stayed and suspension system can reduce the internal force of the main girder by 30%~50%and the internal force of the bridge tower by 60%.(2)Compared with the suspension bridge,the combined cable-stayed and suspension system can reduce the internal force of the main cable by about 50%,the engineering quantity of main cable steel wire and anchorage are correspondingly reduced,the construction difficulty is reduced.The torsional frequency of the cooperative system is higher,which reduces the possibility of vortex-induced vibration of the structure at low wind speed.(3)The combined cable-stayed and suspension system can give full play to the advantages of the cable-stayed bridge and the suspension bridge.It can realize super long span with large longitudinal stiffness and vertical stiffness,which can meet the requirements of the stiffness of the railway traffic.(4)For the super long-span rail-cum-road bridge with main span of 1500 m,the combined cable-stayed and suspension system bridge is more economical.

关 键 词：超长大跨度公铁合建桥 斜拉悬索协作体系 斜拉桥 悬索桥 桥梁结构体系 

分 类 号：U24[交通运输工程—道路与铁道工程] U448.27[建筑科学—桥梁与隧道工程] U442.5