Dynamic Behaviour of RC Bridges Under Moving Loads: A Simplified Numerical and Analytical Approach

Abstract

Using numerical and analytical modelling of the dynamic behaviour of concrete bridges subjected to moving loads is essential for ensuring their structural safety and durability. This topic aims to investigate the impact of moving loads on the dynamic behaviour of concrete bridges and to identify simplified methods for accurately evaluating their response. This research addresses the practical necessity for simple, reliable and efficient methods for monitoring the structural integrity of concrete bridges under traffic loading conditions. A range of research methodologies can be utilised to evaluate the dynamic behaviour of concrete bridges under the influence of moving loads. These may encompass numerical modelling techniques such as Vehicle-Bridge-Interaction (VBI) and analytical techniques such as Response Surface Methodology (RSM). VBI entails simulating the interaction between moving vehicles and bridge structures to assess their dynamic response. RSM involves creating a meta-model for predicting the response of bridge structures subjected to various parameters of interest, including bridge span, pavement condition, the velocity of moving vehicles, their trajectory, and the weight and number of axles of vehicles. Sensitivity analysis can subsequently be employed to identify the most critical parameter that influences the response. One of the possible responses for evaluating the dynamic behaviour of bridge structures is the Dynamic Amplification Factor (DAF). This factor indicates the increase in effects caused by the dynamic action of the load. In other words, it shows how many times the static effects are amplified due to dynamic behaviour. A crucial finding of this research is that many interrelated factors influence the dynamic response of concrete bridges to moving loads. These may encompass the bridge's design and its properties, material properties, condition, and the moving loads' characteristics. Hence there is need for a combination of numerical and analytical modelling. Each methodology has advantages and limitations, and a comprehensive assessment of a bridge's dynamic behaviour requires multiple approaches. Evaluating the dynamic behaviour of concrete bridges under the influence of moving loads is a complex undertaking that necessitates a multi-dimensional approach. By integrating numerical and analytical modelling techniques such as VBI and RSM, it is possible to accurately determine the impact of moving loads on bridge structures and ensure their structural safety and durability.