普速铁路单线独塔斜拉桥总体设计及创新

潜江铁路支线属于江汉平原货运系统的重要组成部分,岳口汉江特大桥是潜江铁路支线跨越汉江的控制性重点工程。为提高结构通航安全性,更好地满足防洪要求,主桥采用(32.7+50+93.7+260+38.2) m的独塔双索面混合梁斜拉形式,实现大跨独塔结构体系在国内铁路桥梁上的跨度突破。考虑到建造铁路大跨度独塔混合梁斜拉桥面临着疲劳活载大、动力指标及刚度要求高等诸多难题,且非对称铁路独塔斜拉桥具有设计技术复杂、建设标准高等特点,对主桥的桥型方案选取、桥梁设计难点、桥塔、主梁形式、钢混结合段、索塔索梁锚固形式等进行详细介绍,给出相关结构刚度、应力强度、疲劳应力幅、风车桥耦合等计算结果,并阐述主桥设计时所采用的创新性技术构思。

Overall Design and Innovation of Single Tower Cable-stayed Bridge on Conventional Railway

The Qianjiang railway branch line is an important part of the freight transportation system in the Jianghan plain. The Yuekou Hanjiang bridge is a key control project for the Qianjiang railway branch line to cross the Hanjiang river. In order to improve the navigation safety of the structure and better meet the requirements of flood control, the main bridge adopts cable-stayed single tower and double cable-plane composite beam(32.7+50+93.7+260+38.2) m, which realizes the span breakthrough of the long-span single tower structure system on domestic railway bridges. Considering the difficulties in the construction of long-span single-pylon hybrid girder cable-stayed bridge, such as heavy live fatigue load, high dynamic index and rigidity requirements, and such characteristics as complex design technology and high construction standard of the asymmetric single-pylon cable-stayed bridge, this paper addresses the selection of bridge type scheme, difficulties in bridge design, bridge tower, main girder form, steel-concrete composite section and cable-pylon girder anchorage form. The calculation results of structural stiffness, stress intensity, fatigue stress amplitude and windmill-bridge coupling are provided in detail, and the innovative technical ideas adopted in the design of the main bridge are elaborated.