Abstract: Both the main cable of the bridge cable hoisting system and the stay cable passing through diverting pulleys in the arch bridge cable-stayed buckling system belong to sliding cables, and their cable force and deformation calculations are relatively complex. Firstly, a single pulley was simplified as a rigid link, and the formula for calculating the direction angle of the link of the sliding cable under the static equilibrium state was derived, proving that the link located at the angle bisector of the sliding cable was a necessary and sufficient condition for ensuring equal cable forces. A solution procedure for the sliding cable structure was proposed, and the correctness and efficiency of the proposed method were verified through two numerical examples and one engineering case study. The research results show that the maximum error between the theoretical cable force obtained by the proposed method and the actual tension force is only 3.9%, while the maximum error of the cable forces calculated by the reverse extension method and the elastic modulus reduction method is up to 12.8%. Furthermore, the inherent reasons that cause the larger errors in the latter two methods are revealed.

Key words: bridge engineering; sliding cable; pulley; angle bisector; rigid link; continuous cable; cable force

摘要： 桥梁缆索吊装系统主索与拱桥斜拉扣挂系统中经转向滑轮的扣索均属于滑移索，其索力与变形计算较为复杂。将单个滑轮简化为刚性链杆，推导了滑移索静力平衡时链杆方向角的计算公式，证明链杆位于滑移索角平分线是保证索力相等的充要条件；提出了滑移索结构的求解流程，并通过两个算例与一个工程实例验证了该方法的正确性与高效性。研究结果表明：采用该方法所得理论扣索力与实际张拉力最大误差仅为3.9%，而反向延伸法和弹性模量折减法所得索力最大误差达12.8%，并进一步揭示了导致后两种方法误差偏大的内在原因。

关键词: 桥梁工程； 滑移索； 滑轮； 角平分线； 刚性链杆； 连续索； 扣索力