大跨变宽连续梁非对称施工控制研究与应用

Research and Application on Construction Control of Long-Span Variable-Width Continuous Beam under Asymmetric Construction

摘要:

随着公路行业建设发展，互通桥梁跨越既有道路、河道、铁路也越来越广泛，由于预应力混凝土连续梁在行车舒适性、刚度、经济性、耐久性方面的优势，由此不可避免地出现了一些变宽段的大跨径混凝土连续梁，而针对大跨径变宽度预应力混凝土梁的设计和施工目前研究尚有不足。结合实际工程，介绍大跨径变宽度预应力混凝土梁的设计要点，针对这类桥型采用了中跨悬臂浇筑+边跨大节段整体浇筑的非对称施工工艺，并对其施工抗倾覆措施、施工控制方法进行研究，利用实桥测量数据进行验证。验证结果表明，全桥施工过程中节段线形误差控制在规范允许范围内，施工全过程抗倾覆安全系数满足要求，成桥结构状态与设计目标基本一致。大跨变宽连续梁非对称施工工艺和控制技术方案可行，在同类工程中具有参考和推广的价值。

Abstract:

With the development of highway construction, interchanges and bridges increasingly span existing roads, rivers and railways. Prestressed concrete continuous beams have advantages in driving comfort, stiffness, economy and durability, which inevitably leads to the construction of long-span concrete continuous beams with variable-width sections. Current research on the design and construction of long-span variable-width prestressed concrete beams remains insufficient. Combined with a practical engineering project, this paper presents the key design points of long-span variable-width prestressed concrete beams. An asymmetric construction method, consisting of cantilever casting for the middle span and large-segment monolithic casting for the side spans, is adopted for this type of bridge. The anti-overturning measures and construction control methods during construction are investigated and verified by field measurement data from the real bridge. Verification results demonstrate that segmental alignment errors remained within code-specified limits, anti-overturning safety factors satisfied all requirements throughout construction, and the as-built structural state aligned well with design objectives. These findings confirm the feasibility of the asymmetric construction technology and control scheme for large-span variable-width continuous beams, offering valuable insights for similar projects.