大跨度铁路单索面预应力混凝土斜拉桥设计关键技术及创新——以隆叙铁路沱江特大桥主桥设计为例  

Key Technology and Innovation in Design of Long-Span Railway Prestressed Concrete Cable-Stayed Bridge With Single Cable Plane—Taking the design of the main bridge of Tuojiang Super Bridge on Longchang-Xuyong Railway as an example

作　　者：高策 刘永锋 时代 刘远长 GAO Ce;LIU Yongfeng;SHI Dai;LIU Yuanchang(China Railway Engineering Design and Consulting Group Co.,Ltd.,Beijing 100055,China;Track Structure Construction Technology Sub Research Center of National Engineering Research Center of High-speed Railway Construction Technology,Beijing 100055,China)

机构地区：[1]中铁工程设计咨询集团有限公司,北京100055 [2]高速铁路建造技术国家工程研究中心轨道结构建造技术分研究中心,北京100055

出　　处：《铁道标准设计》2023年第12期97-102,120,共7页Railway Standard Design

基　　金：中国中铁股份有限公司科技研究开发计划项目(2021-重大专项-02);中铁工程设计咨询集团科技研究课题(研2021-25)。

摘　　要：隆叙铁路沱江特大桥是隆叙铁路的控制性工程,为满足行洪、通航及一跨跨越珍稀、特有鱼类国家级自然保护区需求,结合本线新建单线预留双线条件的情况,采用主跨292 m单索面矮塔斜拉桥结构形式。为避免长期偏载,预留线二期恒载同步实施。通过对单箱三室截面、单箱双室贯通锚固截面、单箱单室大隔板截面、W形截面进行比较,优选传力路径直接、受力合理、施工方便的W形截面。针对变梁高时连续内腹板构造复杂、不便于施工的特点,在传统W形截面基础上提出纵向间隔布置预应力混凝土斜杆的W形截面主梁结构形式。通过对钢斜杆及预应力混凝土斜杆两种方案对比,分析斜杆内的预应力钢筋可主动承受拉索竖向分力、预压应力可有效避免较大变形和顶板开裂的特点。梁部采用挂篮悬臂浇筑施工。根据拉索布置及受力需要,结合泸州地方经济文化特色,提出束腰酒尊造型的桥塔结构。下部结构采用双薄壁墩、钻孔灌注桩基础,根据防洪、通航及两个主墩均衡受力的需求,对主墩岸坡进行刷坡防护。Tuojiang bridge is a controlling project of Longchang-Xuyong Railway.In order to meet the needs of flood discharge,navigation and one span crossing National Nature Reserve,and in combination with the conditions of reserving double lines,the structural form of single cable plane low tower cable-stayed bridge with a main span of 292m is adopted.In order to avoid long-term eccentric load,the phaseⅡdead load of the reserved line is implemented synchronously.By comparing the single box three chamber section,the single box double chamber through anchorage section,the single box single chamber large diaphragm section and the W-shaped section,the W-shaped section with direct force transmission path,reasonable stress and convenient construction is optimized.In view of the complex structure of the continuous inner web when the beam height is changed and it is not convenient for construction,a W-shaped section main beam structure with longitudinal spacing prestressed concrete diagonal bars is proposed on the basis of the traditional W-shaped section.By comparing the two schemes of steel inclined rod and prestressed concrete inclined rod,the characteristics that the prestressed reinforcement in the inclined rod can actively resist the vertical component of the cable,and the preloading stress can effectively avoid large deformation and roof cracking are analyzed.The cantilever pouring construction is adopted for the beam.According to the cable layout and stress needs,combined with the local economic and cultural characteristics of Luzhou,a bridge tower structure with waist tied wine statue shape is proposed.The substructure adopts double thin-wall piers and cast-in-place bored pile foundation.According to the requirements of flood control and navigation and the demand of balanced stress of the two main piers,the bank slope of the main pier is protected.

关 键 词：铁路桥 单索面斜拉桥 矮塔斜拉桥 预应力混凝土 W形截面 斜杆 景观造型 结构设计 

分 类 号：U24[交通运输工程—道路与铁道工程] U448.13[建筑科学—桥梁与隧道工程] U448.27