Effect of human-induced vibration on the design of steel pedestrian bridges

Abstract

The importance of vibration becomes a dominate criterion for design of footbridges. Modern design and construction techniques produce structures which are competitive in terms of overall cost. To achieve this goal, longer spans and lightweight bridges have been comprised in most of design trends. This leads to lower the natural frequencies of the system which have a great effect on the dynamic performance of bridges subjected to human activities. Although the design of steel footbridges could reach the optimum level of design in terms of strength criterion, it might not reach the acceptance level for vibration condition. This will enforce the designer to choose section profiles with higher inertia to enhance stiffness of the whole system. For such cases, it is required to examine the factors affecting the design of steel structures due to vibration concern. The main goal of this research study is to investigate the range of spans and deck's finish loads of footbridges which are governed by human comfort requirements due to vertical forces induced by pedestrians. The footfall method presented by concrete center "CCIP-016" is adopted in this study to evaluate the response factor and acceleration of pedestrian bridges using a FEA software package "Robot Structural Analysis".