Abstract

The presence of rigid central clamps (RCCs) minimises the damage potential of short suspenders and expansion joints in in-service long-span suspension bridges. The study presented in this paper evaluated the impact of the presence of RCCs on the longitudinal deformation of a long-span suspension bridge under live load with vehicle braking and random traffic flow excitations. Two finite element (FE) models of the bridge were developed – one with RCCs and the other with a traditional suspender (TS) at mid-span. The impact of RCCs and TS on the structural system response was evaluated by comparing the dynamic characteristics of the models. The exceeding probabilities of longitudinal deformation under different traffic flow levels during the design reference period were obtained. The simulation results show that the RCCs are capable of reducing the longitudinal deformation by 35% to 45%. The unfavourable exceeding probabilities of longitudinal deformation over the design threshold decreased from 1.0 to 0.0002, showing that the RCCs could be an effective measure to enhance the service life of the shortest suspender and expansion joints of long-span suspension bridges.

摘要

刚性中心夹 (RCC) 的存在最大限度地减少了在役大跨度悬索桥中短吊杆和伸缩缝的损坏可能性。本文介绍的研究评估了 RCC 的存在对大跨度悬索桥在车辆制动和随机交通流激励下的活载下的纵向变形的影响。开发了两种桥梁的有限元 (FE) 模型 - 一种使用 RCC，另一种使用中跨传统吊杆 (TS)。通过比较模型的动态特性，评估了 RCC 和 TS 对结构系统响应的影响。获得了设计参考期内不同交通流量水平下纵向变形的超出概率。模拟结果表明，碾压混凝土能够将纵向变形减少 35% 到 45%。纵向变形超过设计阈值的不利超过概率从1.0降低到0.0002，表明RCCs可以成为提高大跨度悬索桥最短吊杆和伸缩缝使用寿命的有效措施。