Dynamic Response Analysis of Simply Supported Bridge through Experimental and Numerical Modelling Approaches

Abstract In earlier days, bridges were designed with the maximum possible static load on them. In the failure of some bridge structures, it is established that dynamic load often plays a vital role in the failure of bridges. Considering this, it is established that the responses of the bridges under dynamic loading should be evaluated for prior understanding of the bridge condition. This paper reports one such case study carried out on a newly constructed bridge to understand the response of the bridge under dynamic loading. The physical experiments are carried out to monitor the response of the bridge under the dynamic loading from the movement of a 35.5 Metric Tonne (MT) vehicle weight at varying speeds. Numerical simulation of the bridge structure is also carried out using modal analysis and transient analysis methods. The response of the bridge is simulated for varying dynamic load conditions generated through vehicle speed ranging from 30 km/h to 87 km/h and the vehicle weight ranging from 35.5 MT to 106.5 MT. A generic equation for a simply supported bridge for varying speed and vehicle weight is proposed. This study, however, has the limitation of ignoring the influence of uncontrolled environmental factors such as humidity, temperature, and wind effects on bridge dynamic behaviours.