Assessing the impact of building foundations located in the transmission path on train-induced ground vibration using a hybrid computational model

Abstract Train-induced ground vibration impacts the environment and has attracted increased attention. Prediction of this vibration is subject to considerable uncertainty and is affected by many factors, particularly when building foundations are situated within the transmission path between the vibration source and the target building. A hybrid computational model for predicting ground vibration has been developed to assess the impact of building foundations of various types located in the transmission path. The model is used to investigate four types of foundations: raft, strip, pile, and box. The ground responses are determined by combining the semi-analytical model ‘modelling of train-induced vibration’ (MOTIV) for train-induced vibration with a finite element model of the ground including the building. MOTIV is used to determine the excitation in terms of the force density for a train running either on a surface railway or in a tunnel. The finite element model is used to determine line source transfer mobilities in the presence of the building foundations by applying a set of incoherent unit loads to the ground. The results indicate that building foundations in the transmission path can mitigate ground vibration, particularly for excitation at the ground surface, for which reductions in overall vibration level of between 4 and 8 dB are found. Deep foundations provide greater vibration reduction than shallow foundations, notably in cases involving surface railways. The underground railway case demonstrates less significant insertion loss than the surface railway case, with values based on overall velocity level between −2 and 2 dB, rising to 4 dB for the box foundation. Furthermore, it is observed that ground vibration mitigation is more pronounced in the near field than in areas further from the building.