Derailment of a train moving on bridge during earthquake considering soil liquefaction

Abstract

Abstract Soil liquefaction may occur due to frequent earthquakes in regions characterized by sandy soil. When liquefaction occurs, the strength of the soil decreases, which may cause trains to derail during earthquakes. This study establishes a three-dimensional two-stage finite element procedure to analyze train derailment behavior during earthquakes under soil liquefaction conditions. In the first stage, a cuboid soil profile is used to simulate the displacement and water pressure fields. Then, the train derailment model using p-y, t-z, and Q-z curves for soil is analyzed, and the displacements obtained from the first stage are added into the p-y, t-z, and Q-z elements to simulate the earthquake motion. The capacities of the p-y, t-z, and Q-z elements are reduced due to excess pore water pressure. Thus, the derailment coefficient of each wheel of the train can be obtained appropriately. Finally, the finite element results indicate that the wheel derailment coefficients with soil liquefaction are greater than those without soil liquefaction for the most of the seismic load time periods.