Load models for flexible pedestrian bridges

加拿大佩德尔塔有兴趣与滑铁卢的研究人员合作，为用碳纤维和铝等轻质材料建造的人行天桥开发更好的荷载模型。该项目将评估适用于人行天桥的现有荷载模型，特别是适用于单个行人荷载的加拿大桥梁规范标准，并开发修改后的模型，以更好地预测实验观测。目前，该判据是建立在简谐稳态条件下的，对于行人激励频率的非共振范围内的桥梁，其结果过于保守。作为该项目的一部分，将为这类情况制定更合适的负荷率。此外，公路规范中的动力放大曲线仅适用于阻尼比小于1%的情况。在需要减振器的情况下，这些曲线需要扩展到更高的范围(例如，3-5%)。这样的曲线将被生成并作为该项目的一部分提供。该项目的主要成果是一个软件设计辅助工具，它将使Pedelta Canada能够更好地预测轻型人行天桥对个别行人负载和行人群体的反应。

Pedelta Canada is interested in collaborating with researchers at Waterloo in developing better load models for pedestrian bridges constructed out of light-weight materials such as carbon fibre and aluminum. This project will evaluate existing load models applicable to pedestrian bridges, especially the Canadian Bridge Code criteria for individual pedestrian loads, and develop a modified model to better predict experimental observations. Currently, the criterion is based on harmonic steady-state condition, which produces overly conservative results for bridges in the non-resonant range of pedestrian excitation frequencies. More appropriate load factors for such cases will be produced as a part of this project. Furthermore, dynamic amplification curves in the highway code are available only for damping ratios less than 1%. In cases where vibration absorbers are required, these curves need to be extended to higher ranges (e.g., 3-5%). Such curves will be generated and provided as a part of this project. The main deliverable in this project is a software design aid tool that will allow Pedelta Canada to better predict the response of lightweight pedestrian bridges to individual pedestrian loads and groups of pedestrians.