Prediction of Ground Vibration Induced by a High-Speed Train Moving Along a Track Supported by a Pile-Plank Structure

Piles are commonly applied to the construction of high-speed railways at grade for many purposes including controlling train-induced ground vibration. The piles are inserted into the ground periodically in the track direction, making the track/pile/ground system very complicated. The most frequently used method to analyze this kind of structure is to establish a three-dimensional finite element model at a very high computational cost. Based on the fictitious pile method, this paper develops a semi-analytical model, in which the track/pile/ground system is divided into a 2.5D track/ground system and a system of an infinite number of periodically arranged fictitious piles, to investigate the effect of the pile-plank structure on ground vibration. The two systems become equivalent to the original track/pile/ground system when they are coupled using the displacement continuity condition. Making use of the periodicity of the track/pile/ground system, the model works in the Floquet wavenumber domain and only a single cell of the periodic structure is required to analyze. The results show that the pile-plank structure reduces as well as increases, depending on frequency, train-induced ground vibration.