In-situ testing and model updating of a long-span cable-stayed railway bridge with hybrid girders subjected to a running train

Abstract

This study investigates the dynamic responses of a long-span cable-stayed railway bridge with steel–concrete hybrid girders in different train load scenarios. The investigated scenarios included driving and braking of running trains. The bridge was instrumented with different types of sensors to measure strains, displacements, and accelerations during train load testing. Based on the measurement results, this study evaluated the effects of train speed on the vertical and transverse accelerations, impact factor, derailment coefficient, and wheel unloading rate, which are critical parameters that affect safety and riding comfort. Assessment results revealed that the bridge had adequate dynamic behavior to ensure safe operation and riding comfort of the train. Based on test data, a finite element model was developed, and a finite element model updating framework was proposed to improve the prediction accuracy. This study provides real-life test data and an assessment tool for promoting design and evaluation of cable-stayed railway bridges.