Study of the validity of a rectangular strip track/soil coupling in railway semi-analytical prediction models

Semi-analytical prediction models for railway-induced vibration problems consider a two-dimensional track coupled with a three-dimensional soil. The semi-analytical models found in the literature assume a simplified model of force distribution for representing track/soil interactions. based on a rectangular strip load that acts on the soil surface. Because an accurate modelling of the track/soil interface forces is a key factor to obtain reliable prediction results of the vibration levels on the ground or on the surrounding buildings, this paper is intended to study the validity of consideringa rectangular strip track/soil coupling load. The results associated to consider a rectangular strip track/soil coupling load are compared with the ones obtained from a two-and-a-half dimensional coupled finite element-boundary element model of the track/soil system, which is considered an accurate numerical model. For the presen t study, the soil is assumed as a homogeneous halfspace. Some proposals to enhance the accuracy of the rectangular strip modelling are also presented.