大跨度下承式刚性系杆拱桥成桥吊杆索力研究

Research on Suspender Cable Force of Long-span Through Rigid Bowstring Arch Bridges

摘要:

随着材料和施工技术的发展，下承式刚性系杆拱桥跨度越来越大，但对于大跨度下承式刚性系杆拱桥的吊杆成桥索力研究还不多，结合工程实例，探讨了刚性吊杆法、刚性支撑连续梁法、最小弯曲应变能法三种常用的成桥索力确定方法，并比较分析了它们在大跨度下承式刚性系杆拱桥的适用性。结果显示三种方法确定的跨度吊杆成桥索力差别不大，但端部短吊杆成桥索力差别较大，对比发现刚性支撑连续梁法对于此类大跨度拱桥得到的成桥索力更均匀，拱肋和主梁弯矩也较小。另外对端部吊杆成桥索力分别采用三种优化方法调整后，得出端部短吊杆采用与跨中吊杆索力接近的优化方法更合适。

Abstract:

With the development of materials and construction technologies, the spans of through rigid bowstring arch bridges have been increasing. However, there is still not much research on the cable force of the suspension rods for long-span though rigid bowstring arch bridges. Combined with the engineering examples, three commonly used methods for determining the cable force of the finished bridges are discussed. These three methods are the rigid suspension rod method, rigid support continuous beam method and minimum bending strain energy method. And the applicability of these methods in large-span through rigid bowstring arch bridges is compared and analyzed. The results show that the bridge cable forces of the span suspension rods determined by the three methods do not differ much. But the bridge cable forces of the short suspension rods at the ends vary greatly. The comparative analysis shows that the rigid support continuous beam method results in a more uniform bridge cable force for such large-span arch bridges, and the bending moments of the arch ribs and girders are also smaller. Furthermore, after three optimization methods are used to adjust the bridge cable forces of suspension rods at the end, it is found that it is more suitable for this project to adopt an optimization method for the short end suspension rods that is close to the cable force of the mid-span suspension rods.