Dynamic response of a continuous beam bridge supported by nonlinear viscoelastic bearings under earthquake and moving vehicle loads

This paper presents a novel approach for analyzing the transverse vibrations of a continuous beam bridge supported by nonlinear viscoelastic bearings under the combined effects of earthquake and moving vehicle loads. The bridge is modeled as a continuous beam resting on elastic supports, which are extended into the nonlinear domain from the classical Kelvin–Voigt model, with stiffness and damping coefficients defined as nonlinear functions. The moving vehicle loads are represented by axle loads modeled as a double mass-spring-damper system traveling at a constant velocity across the bridge. Earthquake excitations are taken from the PEER Strong Ground Motion Database. The substructure method is employed to derive the governing vibration equations, comprising a partial differential equation coupled with multiple ordinary differential equations. A modal analysis approach is used to transform the mixed equations into a set of ordinary differential equations, from which a numerical simulation program is developed to analyze and evaluate the bridge’s dynamic responses. Numerical examples demonstrate the feasibility and applicability of the proposed approach to real-world bridge engineering problems.