Compared with traditional two-tower suspension bridges, three-tower suspension bridges have to face challenges caused by the mid-tower effect, which requires the stiffness of the mid-tower satisfying two contradictory parameters, the deflection-to-span and the saddle sliding resistance coefficient, simultaneously. Meanwhile, the central buckles are often utilized to reduce the live load deflection and the torsional vibration caused by wind in two-tower suspension bridges. This study proposes an analytical model for predicting the structural responses of three-tower suspension bridges with central buckle under vehicle loads and examines the effect of the central buckle on suppressing the mid-tower effect. The analytical model simplifies the bridge as a series of cables with horizontal spring constraints. The validation analysis based on the structural parameters of the Yingwuzhou Yangtze River Bridge using the nonlinear finite element method demonstrates that the error of the proposed model does not exceed 5%. The parametric investigations show that the central buckle can significantly improve the performance of three-tower suspension bridges by enhancing their stiffness and reducing the unbalanced tension of the main cable on both sides of the mid-tower. Three-tower suspension bridge with central buckle has a much wider feasible mid-tower stiffness range than that of the traditional three-tower suspension bridges, and the critical dead-to-live load ratio for the feasible dimensionless stiffness range has decreased from 6.7 to 4.4.

与传统的两塔悬索桥相比，三塔悬索桥面临着中塔效应带来的挑战，这就要求中塔的刚度满足两个相互矛盾的参数——挠度跨度和鞍座滑移。阻力系数，同时。同时，中心扣常用于减少两塔悬索桥的活载挠度和风引起的扭振。本研究提出了一种用于预测在车辆载荷下具有中央扣的三塔悬索桥的结构响应的分析模型，并检验了中央扣对抑制中塔效应的影响。分析模型将桥梁简化为一系列具有水平弹簧约束的缆索。应用非线性有限元方法对鹰五洲长江大桥结构参数进行验证分析，表明该模型的误差不超过5%。参数研究表明，中心扣可以通过增强三塔悬索桥的刚度和减少中塔两侧主索的不平衡张力，显着提高三塔悬索桥的性能。与传统三塔悬索桥相比，带中心扣的三塔悬索桥具有更宽的中塔刚度范围，可行无因次刚度范围的临界死活荷载比从6.7降低到4.4.