Scoping assessment of ground and building vibrations due to railway traffic

Abstract

Chapter 10 2017); Jean et al. (2004)). These models assume the problem is continuous in the track direction and as such not well suited to modelling transition zones, etc.At the earlier stage, when attempting to identify line sections where vibration is likely to cause problems in nearby buildings, simplified scoping models are often used. This is because they are faster running and allow engineers to assess long lengths of track quickly, in absence of detailed design information.Empirical approaches to estimate soil and building vibrations due to a train passage have been proposed by the Federal Railroad Administration (FRA) and the Federal Transit Administration (FTA) of the U.S. Department of Transportation (Hanson et al. (2005, 2006). The simplifications considered in these procedures have been verified by the numerical model presented by Verbraken et al. (2011).Alternatively, some scoping models have been recently proposed. Connolly et al. (2014a,b) presented a scoping tool, called Scoperail, to instantly compute vibrations due to train passages. A machine learning approach to obtain free-field vibrations was developed using numerically records for a wide range of train speeds and soil types. These soil vibrations were coupled with empirical factors in order to predict in-door noise and structural vibrations due to high speed trains. A hybrid model has been proposed by Triepaischajonsak and Thompson (2015), that combined a detailed vehicle-track model formulated in the time domain with a layered ground model operating in the frequency domain, based on the formulation outlined by Kausel and Roësset (1981). Then, forces acting on the ground were obtained from the train-track model and later used to calculate ground free-field vibrations. Kuo et al. (2016) developed a hybrid model where the source and propagation mechanisms were decoupled. The model combined experimental tests and numerical predictions considering the definitions proposed in Hanson et al. (2005Hanson et al. ( , 2006. Kouroussis et al. (2017) developed a hybrid experimental-numerical model to predict vibrations from urban railway traffic. The level of vibration was calculated by combining the force density obtained from a numerical train-track model with the mobility function measured through an experimental approach.Research has also been performed to investigate the propagation of free-field vibration into buildings. Auersch (2010) studied building responses using a simple soil-wall-floor model based on an empirical transfer fuction obtained from the characteristics of the structure. The soil was modelled using a spring and a viscous damper to evaluate the effects of soil-structure interaction. François et al. ( 2007) analysed building induced vibrations by employing simplified methods that ignore soil-structure interaction (SSI), but take into account the relative stiffness between the building and the soil. Later, Hussein et al. (2013) proposed a sub-modelling method to couple a 3D train-track-soil model with a 2D frame building. López-Mend...