Study on the Impact Coefficient Calculation of Long-Span Curved Continuous Rigid Frame Bridge Based on Principal Component–Stepwise Regression

Abstract

In order to determine the calculation formula of the impact coefficient of a long-span curved continuous rigid frame bridge, based on the mechanism of structural dynamics and vehicle-bridge coupling, the vibration equation of vehicles and bridges is established. The vehicle–bridge interaction is determined through the wheel–bridge displacement coordination relationship, and the vehicle–bridge coupling analysis module of the long-span curved continuous rigid frame bridge is compiled by using MATLAB software. The dimensionality of multiple parameters is reduced by using the principal component analysis method. Comprehensively considering the target parameters with the eigenvalue greater than one and the cumulative contribution rate of variance greater than 90%, the bridge deck roughness, radius of curvature, and pier height are determined as the main sensitive parameters. The calculation formulas of bridge deflection, bending moment, and torque impact coefficient are fitted and regressed by a stepwise regression method. The result shows that: (1) the impact coefficient of bridge deflection is significantly affected by the bridge deck roughness and pier height, while the curvature radius has little influence on it; (2) the impact coefficient of the bridge bending moment is significantly affected by the bridge deck roughness, while the pier height and curvature radius have little influence on it; and (3) the bridge torque impact coefficient is greatly affected by the bridge deck roughness and curvature radius, while the pier height has little influence on it. The correlation coefficients of the bridge impact coefficient calculation formula fitted by regression are greater than 0.94, the correlation is good, and the standardized correlation coefficients of bridge deck roughness in all impact coefficient calculation formulas are more than 0.9, indicating that this factor has a great influence on the impact coefficient of the long-span curved continuous rigid frame bridge. It is suggested that this factor should be considered in subsequent specification revisions.