Liu Zengwu, Zhao Kunpeng, Xiong Yuanshun, Wang Baoqun
School of Transportation and Civil Engineering, Shandong Jiaotong University, Changqing District, Jinan, 250357, China.
China Railway 14th Bureau Group Co., Ltd, Lixia District, Jinan, 250357, China.
Sci Rep. 2024 Sep 4;14(1):20635. doi: 10.1038/s41598-024-71725-4.
The Fenshui River Bridge is a steel-concrete composite girder bridge with a main span of 90 m. Due to the topographical constraints, the steel box girder was constructed without the use of auxiliary piers, employing incremental launching techniques. This article focuses on the construction technology used for the steel box girder of the Fenshui River Bridge. Firstly, using the influence matrix method, the cable force is determined based on the maximum cantilever state of the structure, with the vertical deformation of the front end of the guide beam and the horizontal deformation of the top of the tower as the control objectives. The unstressed cable length is then calculated based on the mechanical relationship between cable deformation and cable force. A calculation method for adaptive cable force is proposed, which is based on the variation of the stress-free cable length within the adaptive structural system. Next, the finite element analysis method was employed to determine the optimal layout position for the tower. The results indicate that during the incremental launching construction of the steel box girder, the calculated cable forces using the method proposed in this paper are in close agreement with the measured cable forces. At the maximum cantilever state of the structure, the calculated and measured values of the cable force resulted in a percentage difference of 3.96%. The calculated values of deformation and stress in key sections showed a percentage difference of 6.4% for deformation and 6.6% for stress. To maximize the effectiveness of the tower and cable, the tower should be positioned above the bridge pier when the guide beam crosses the maximum span. The findings of this paper can serve as a reference for the construction of similar types of bridges.
分水河大桥是一座主跨为90米的钢混组合梁桥。由于地形限制，钢箱梁施工未使用辅助墩，采用了顶推施工技术。本文重点介绍分水河大桥钢箱梁的施工技术。首先，采用影响矩阵法，以导梁前端竖向变形和塔顶水平变形为控制目标，基于结构最大悬臂状态确定索力。然后根据索变形与索力的力学关系计算无应力索长。提出了一种基于自适应结构体系内无应力索长变化的自适应索力计算方法。其次，采用有限元分析方法确定塔的最优布置位置。结果表明，在钢箱梁顶推施工过程中，本文提出的方法计算得到的索力与实测索力吻合较好。在结构最大悬臂状态下，索力计算值与实测值的百分比差值为3.96%。关键截面变形和应力的计算值与实测值的百分比差值分别为6.4%和6.6%。为使塔和索的效能最大化，当导梁跨越最大跨度时，塔应位于桥墩上方。本文的研究结果可为同类桥梁的施工提供参考。
