The proposed steel–ultra-high-performance concrete composite truss (SUCT) arch bridge addresses three major technical problems of conventional arch bridges and extends the span to 600–1000 m. An intelligent cyclic construction method and an automated sliding connector are proposed for the SUCT arch ring to reduce construction costs and mitigate stress superposition. This method involves multiple closures of the arch ring from inside to outside. This paper introduces the cyclic construction method, compares it with existing methods, and investigates the mechanical behavior and load distribution of the arch ring through experimental analysis in both slidable and locked states of the sliding connectors. An optimized design for sliding connectors was also developed. The results indicate that the cyclic construction method offers distinct advantages over traditional techniques, ensuring the construction feasibility of SUCT arch bridges. The sliding connectors released most vertical shear forces, and the corresponding bending moments were transferred to the inner arch. Consequently, approximately 10% of the load was transferred to the inner arch, representing approximately 20% of the load in the locked state. However, approximately 25.5% of the negative bending moments were transferred to the inner arch in spring conditions. During the arch ring’s asymmetric loading process, the inner arch’s left spring cracked and crushed before the outer arch due to stress superposition. By optimizing the sliding surface to a vertical orientation (0°) and lubricating the sliding plate and chute, negative bending moments and vertical loads were effectively isolated from the inner arch, eliminating stress superposition and significantly enhancing crack resistance and load-bearing capacity. With the optimized design, the load borne by the innermost arch was reduced to 48% and 85% compared to the non-sliding connector scheme and the original design. Furthermore, the load distribution across all truss arch rows was uniform. These findings advance both the theoretical understanding and practical implementation of innovative arch bridge construction, offering insights for the infrastructure sector.

中文翻译：

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钢结构中的循环结构和荷载再分配 - 使用优化的滑动连接件的超高性能混凝土组合拱

拟议的钢-超高性能混凝土组合桁架 （SUCT） 拱桥解决了传统拱桥的三大技术问题，并将跨度延长至 600-1000 m。为降低施工成本并减轻应力叠加，提出了一种智能循环施工方法和自动滑动连接件。这种方法涉及从内到外对拱环进行多次闭合。本文介绍了循环施工方法，将其与现有方法进行了比较，并通过实验分析研究了拱环在滑动连接件的可滑动和锁定状态下的力学行为和载荷分布。还开发了一种用于滑动连接器的优化设计。结果表明，与传统技术相比，循环施工方法具有明显的优势，保证了 SUCT 拱桥的施工可行性。滑动连接件释放了大部分垂直剪力，相应的弯矩传递到内拱。因此，大约 10% 的负载被转移到内拱，占锁定状态下负载的约 20%。然而，在弹簧条件下，大约 25.5% 的负弯矩转移到内拱。在拱环的不对称加载过程中，由于应力叠加，内拱的左弹簧在外拱之前开裂和压碎。通过将滑动面优化为垂直方向 （0°） 并润滑滑板和滑槽，有效地将负弯矩和垂直载荷与内拱隔离，消除应力叠加，显著提高抗裂性和承载能力。 与非滑动连接方案和原始设计相比，优化后的设计使最内侧拱形所承受的载荷分别降低到 48% 和 85%。此外，所有桁架拱行的荷载分布是均匀的。这些发现促进了对创新拱桥建设的理论理解和实际实施，为基础设施领域提供了见解。