A study on factors influencing dynamic response of thin-walled box-girder railway bridge subjected to high-speed train load through regression modeling

Purpose The issue of evaluating the dynamic characteristics of a bridge due to the presence of rapidly moving vehicles has considerable importance. This study aims to conduct a comprehensive study on the variables that influence the dynamic behavior of a thin-walled box-girder bridge exposed to high-speed train loads using regression analysis. Design/methodology/approach The high-speed train is mathematically represented by a system with 38 degrees of freedom (DOF), while the sub-track system uses China’s Railway Track System slab track. The numerical modeling of the bridge is accomplished using computationally efficient finite elements that represent thin-walled box-beams. The rail’s imperfections are also accounted for, and they are represented using a power spectral density function. The dynamic response of the bridge is calculated using the Newmark-beta technique, considering several DOFs and stress resultants. Findings A thorough parametric analysis of the factors affecting the dynamic response of the bridge is conducted and a regression model has been proposed. The regression equation yields an excellent fit for shear force, distortional moment and distortional bimoment, with an R2 value near 1. It has also been observed that the range of the coefficient R2 in case of bending moment, torsion, torsional bimoment and vertical deflection typically falls between 0.82 and 0.9. R2 value near to 1 indicates that it is quite accurate in forecasting the dynamic influence of high-speed trains on the bridge’s response. Originality/value The originality of this research lies in pioneering the regression modeling of dynamic responses in thin-walled box-girder bridges and uniquely modeling high-speed trains with 38 DOF, which has not been previously explored in existing studies.