Experimental and Numerical Investigation of Axial Load Capacity for Box-type Railway Bridges

Abstract

Railway bridges are vital components of transportation infrastructure, exposed to various forces including vertical and horizontal loads. Withstanding increasing axial loads is a critical factor in railway bridge design and operation, and has been the subject of research for many years. Numerous studies have investigated the impact of axial loads on bridge behavior and developed models to forecast their response under different load conditions. This study focused on evaluating the load-carrying capacity of box-type concrete bridges, which were designed to carry a load of 21 MT, to withstand an increased axle load of 25 MT. To achieve this, Operational Modal Analysis (OMA) and finite element analysis were utilized to assess the bridges. Dynamic properties of the system were estimated by recording vibration data using wireless accelerometer sensors, while finite element analysis was developed from Visual Inspection and Non-Destructive Test (NDT) results and then paired with the OMA results. Additionally, the study estimated the maximum load-carrying capacity of the existing through numerical Analysis. To test the methodology, the study was conducted on five real-time bridges at a constant train speed of 10 Kmph. Results showed that all five bridges were capable of withstanding the increased axial load at that speed. Therefore, this study has demonstrated the effectiveness of this technique in predicting the behavior of structures under heightened dynamic loads.