An efficient simplified model for high-speed railway simply supported bridge under earthquakes

Abstract

An efficient model of high-speed railway simply supported bridge with China Railway Track Structure II (CRTS II) ballastless track structure, setup on ANSYS platform, is proposed in this article. The goal is to improve the low computational efficiency and reduce the high computer memory consumption caused by complex bridge models of numerous spans. Programming language and modeling procedures are utilized to ensure that all spans in the proposed model of a large multispan simply supported railway bridge have consistent boundary conditions. Hence, only the middle span is simulated. The comparison of the first longitudinal vibration modes and first natural frequencies of the proposed model and the conventional simply supported bridge model preliminarily validates the feasibility of the model. It also confirms the range of the span number that the proposed model can simulate with accuracy. Taking into account eight different seismic excitations, the results further prove that the proposed model can significantly improve the computational efficiency of the seismic analyses, and can decrease the modeling complexity and calculation time cost without loss of accuracy. The design verification of three different heights of pier groups and the consideration of nonlinear springs enables the proposed model to be utilized in a wide range of applications. As a conclusion, for seismic simulation of high-speed railway simply supported bridges, the proposed model is a reliable alternative for practical engineering simulation.