Nonlinear analysis of the ballast influence on the train-bridge resonance of a simply supported railway bridge

Abstract In the present work, the influence of the ballast-deck interface on the dynamic response of single ballasted track, simply supported high speed railway bridges is investigated. The ballasted track railway bridge is modelled by a composite Euler-Bernoulli beam with two layers connected between them through longitudinal springs and dampers representing the nonlinear friction behavior occurring at their interface. A constant moving load model termed (HSLM-A) is utilized to simulate the moving trains. The governing nonlinear transverse vibration equation of the system has been derived by using the Hamilton’s principle. By applying the Galerkin method and using the Differential Quadrature Method (DQM) and the Integral Quadrature Method (IQM), the time history of the studied beam is numerically solved by the Runge-Kutta scheme. Considering two railway bridges having different lengths, the obtained results have shown that the dynamics of the system is governed essentially by a Duffing like oscillator, where the ballast superstructure contributes through both additional nonlinear stiffness and damping. The ballast-bridge interface was found to affect largely the dynamic response at resonance of short-span bridge than that of lengthier structures. In this last case the ballast influence can be reduced to just an additional mass.