深水库区铁路多塔矮塔斜拉桥设计施工关键技术研究

Research on Key Technology of Design and Construction of Railway Multi and Low Tower Cable-Stayed Bridge in Deep Reservoir

近年来矮塔斜拉桥凭借其刚度大、经济性好、施工方便、景观效果好等特点在铁路桥梁建设中得到了广泛的应用。本文以池黄铁路太平湖特大桥主桥为工程背景,对矮塔斜拉桥索力参数敏感性、主梁局部应力状态进行分析研究;同时,对位于深水库区的基础施工和主梁悬臂浇筑施工技术进行探讨。研究表明:主梁徐变变形和恒载挠度受斜拉索索力影响明显;塔墩梁锚固区、索梁锚固区应力状态复杂,需在对应区域设预应力或加强钢筋配置改善结构受力;主梁悬臂施工除了可以采用常规挂篮方案,也可以采用大节段浇筑的造桥机方案;深水库区中采用钻孔桩平台与围堰一体化施工方案可有效缩短基础施工工期。

In recent years,cable-stayed bridges with low towers has been widely used in railway bridge construction due to its large stiffness,good economy,convenient construction and good landscape effects.In this paper,taking the main bridge of Taiping Lake Bridge on Chizhou-Huangshan Railway as an example,the important engineering properties such as the sensitivity of cable force parameters and the local stress state of the main beam of the low-tower cable-stayed bridge are analyzed and studied.At the same time,the foundation construction and the main beam cantilever pouring construction technology in the deep reservoir area are discussed.The research shows that the creep deformation and dead load deflection of the main beam are obviously affected by the cable force of the stay cable.The stress state of the tower pier beam anchorage area and the cable beam anchorage area is complex,and it is necessary to set prestressed or reinforced steel bars in the corresponding areas to improve the structural stress.In addition to the conventional hanging basket scheme,the cantilever construction of the main girder can also use the bridge-building machine scheme that can perform large-section pouring.In reservoir area,the integrated construction scheme of the bored pile platform and the cofferdam can effectively shorten the construction period of the foundation,etc.The research results can provide engineering reference for the optimization design and construction of related projects.