Bridge Weigh-in-Motion (B-WIM) systems use the bridge response under a traversing vehicle to estimate its axle weights. The information obtained from B-WIM systems has been used for a wide range of applications such as pre-selection for weight enforcement, traffic management/planning and for bridge and pavement design. However, it is less often used for bridge condition assessment purposes which is the main focus of this study. This paper presents a bridge damage detection concept using information provided by B-WIM systems. However, conventional B-WIM systems use strain measurements which are not sensitive to local damage. In this paper the authors present a B-WIM formulation that uses rotation measurements obtained at the bridge supports. There is a linear relationship between support rotation and axle weight and, unlike strain, rotation is sensitive to damage anywhere in the bridge. Initially, the sensitivity of rotation to damage is investigated using a hypothetical simply supported bridge model. Having seen that rotation is damage-sensitive, the influence of bridge damage on weight predictions is analysed. It is shown that if damage occurs, a rotation-based B-WIM system will continuously overestimate the weight of traversing vehicles. Finally, the statistical repeatability of ambient traffic is studied using real traffic data obtained from a Weigh-in-Motion site in the U.S. under the Federal Highway Administration’s Long-Term Pavement Performance programme and a damage indicator is proposed as the change in the mean weights of ambient traffic data. To test the robustness of the proposed damage detection methodology numerical analysis are carried out on a simply supported bridge model and results are presented within the scope of this study.

动桥称重（B-WIM）系统使用横越车辆下的桥响应来估计其轴重。从B-WIM系统获得的信息已被广泛用于各种应用中，例如预选重量执行，交通管理/规划以及桥梁和人行道设计。但是，它很少用于桥梁状况评估，这是本研究的主要重点。本文使用B-WIM系统提供的信息提出了桥梁损伤检测的概念。但是，常规的B-WIM系统使用的应变测量对局部损伤不敏感。在本文中，作者提出了一种B-WIM公式，该公式使用了在桥梁支架处获得的旋转测量值。支撑架旋转与轴重之间存在线性关系，与应变不同，旋转对桥梁中任何地方的损坏都很敏感。最初，使用假设的简单支撑桥模型研究了旋转对损伤的敏感性。看到旋转对损伤很敏感后，就分析了桥梁损伤对重量预测的影响。结果表明，如果发生损坏，基于旋转的B-WIM系统将不断高估行进车辆的重量。最后，根据联邦公路管理局的“长期路面性能”计划，使用从美国Weigh-in-Motion站点获得的实际交通数据研究环境交通的统计可重复性，并提出了损坏指标作为平均权重的变化的周围交通数据。