Comparison of Various Walking Load Models in Predicting the Dynamic Behavior of Lightweight Pedestrian Bridges

With the growing use of high-strength and lightweight materials for sustainable constructions, vibration serviceability often governs the design of such structures, specifically for pedestrian bridges under human-induced walking excitations. To better design lightweight pedestrian bridges, it is necessary to accurately predict human-induced excitations. To this end, the periodic moving force model has been highly accepted by the existing design codes around the world because of its simplicity of calculation. However, the capability of this modeling approach to realistically predict the vibration response of lightweight pedestrian bridges is debatable. More accurate modeling approaches have also been proposed in the literature based on human walking dynamics such as the mass–spring–damper and bi-pedal models that can capture the human–structure interaction phenomena. However, none of such models has been validated for lightweight pedestrian bridges. This study aims at evaluating these models for their capability in predicting the vibration response of lightweight bridges. In particular, the numerical responses have been estimated for the mass–spring–damper and the moving force models and compared with experimental observations from an aluminum pedestrian bridge under single-person walking loads. A comparison study between the performances of these two modeling approaches has also been undertaken to identify the better load model for lightweight pedestrian bridges. In the future, this study will be extended to other modern modeling approaches of walking loads as well as for crowd excitations including the human–structure interaction phenomena.