Effect of Train-Induced Ground Vibrations on Liquefiable Soils

Rapid development of railway transportation in recent years has brought attention to the potential problems caused by train-induced vibrations. These problems include damaging the tracks, shaking and cracking the nearby buildings, and damaging the sensitive apparatus and therefore must be addressed when designing the railways. Another potential problem caused by the train-induced vibrations is the increase in the pore water pressures in the loose sandy layers located under the tracks. These excess pore pressures can potentially cause differential settlements in the underlying soil through different mechanisms and damage the railway system. This paper presents the results of finite element modellings developed in PLAXIS software studying this problem. PM4Sand constitutive model is used to capture the response of the loose sandy layer to the train-induced cyclic loads. Different train speeds are considered in the numerical simulations to study the effects of the frequency contents of the dynamic loads on the soil response. Additionally, the effect of the ground profile, including the depth, thickness, and relative density of the loose sand, is also investigated. The results of this study aim to help the researchers and engineers to better understand the problem and design the railway subgrade accordingly to reduce the long-term maintenance costs of the railway system.