The assessment of dynamic performance of large-scale bridges typically relies on the deployment of wired instrumentation systems requiring direct contact with the tested structures. This can obstruct their operation and create unnecessary risks to the involved personnel and equipment. These problems can be readily avoided by using non-contact instrumentation systems. However, the cost of off-the-shelf commercial products often prevents their wide adoption in engineering practice. To this end, the dynamic performance of the biggest one-pylon cable-stayed bridge in Poland is investigated based on data from a consumer-grade digital camera and open access image-processing algorithms. The quality of these data is benchmarked against data obtained from conventional wired accelerometers and a high-end commercial optical motion capture system. Operational modal analysis is conducted to extract modal damping, which has a potential to serve as an indicator of structural health. The dynamic properties of the bridge are evaluated against the results obtained during a proof loading exercise undertaken prior to the bridge opening. It is shown that a vibration monitoring system based on consumer-grade digital camera can indeed provide an economically viable alternative to monitoring the complex time-evolving dynamic behaviour patterns of large-scale bridges.

大型桥梁动态性能的评估通常依赖于部署需要与测试结构直接接触的有线仪器系统。这会阻碍他们的操作，并对相关人员和设备造成不必要的风险。使用非接触式仪器系统可以很容易地避免这些问题。然而，现成的商业产品的成本往往阻碍了它们在工程实践中的广泛采用。为此，根据来自消费级数码相机的数据和开放式图像处理算法，对波兰最大的单塔斜拉桥的动态性能进行了研究。这些数据的质量以从传统有线加速度计和高端商业光学运动捕捉系统获得的数据为基准。进行运行模态分析以提取模态阻尼，它有可能作为结构健康的指标。桥梁的动态特性是根据在桥梁开通前进行的验证加载练习中获得的结果进行评估的。结果表明，基于消费级数码相机的振动监测系统确实可以提供一种经济可行的替代方案来监测大型桥梁随时间变化的复杂动态行为模式。