提出的钢-UHPC组合桁式拱桥有望解决传统拱桥的三大技术难题，将跨径增加至600m~1000m。针对钢-UHPC组合主拱，提出了更智能的循环施工方法和自动化的滑动连接器以降低施工费用并解决应力叠加问题。主拱由内到外分多次合龙。本文简要介绍了循环施工方法，并与现有施工方法进行了对比。通过试验研究重点关注了滑动连接器分别处于可滑动和锁定状态下主拱在循环施工时的力学响应以及荷载分配关系，并对滑动连接器进行了优化设计。结果表明，与现有的施工方法相比，循环施工方法均有一定的优势，确保了新型拱桥的施工可行性。滑动连接器释放了绝大部分传递给内拱的竖向剪力和对应的弯矩，使得只有大约10%的荷载传递给内拱，仅约为锁定状态时的20%。然而，拱脚处大约有25.5%的负弯矩传递给内拱。主拱在后期的非对称加载过程中，叠加效应使得内拱的左侧拱脚率先出现裂缝，并且也先于外拱压溃。将滑动面优化设计为竖直状态（0°）并对滑动板和滑槽进行润滑，可实现几乎不传递竖向荷载和拱脚处的负弯矩给内拱，不存在应力叠加，从而进一步提高主拱的抗裂性能和承载力。采用优化设计时，最内拱承担的荷载仅分别为不采用滑动连接器方案和当前设计的48%、85%，并且各排桁架拱承担的荷载趋于均匀。这些发现深化了创新拱桥施工的理论认识，并推动了其实践应用，可为基础设施领域提供有益借鉴。

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.