Studies on safety criteria for trains running on floating railway bridges

Abstract

When subjected to internal and external dynamic factors, the train wheels move laterally, which can cause a derailment accident. When new external factors are introduced, derailment prevention measures must be established accordingly. For the expansion of railway application, this study aims to develop a fundamental technology for trains to run on the floating bridges on coasts. First, the vibration characteristics of ocean waves were statistically investigated so that simple equations could be proposed for estimating wave heights in terms of frequencies. It was found that ocean waves vibrate at low frequencies. Derailment criteria were derived for wheels on a vibrating track of a floating railway bridge. In addition, results were verified by conducting a shaking table test using a model bogie. A procedure for assessing the running safety of a train on a floating railway bridge subjected to ocean waves was then proposed. Based on this procedure, a model test was performed in a two-dimensional water tank to determine the motion response of the bridge. The running safety of a train on the vibrating track of the bridge was assessed under the influence of actual ocean waves, and measures for safe operation were suggested.