SUBSOIL MODELLING FOR RAILWAY INDUCED VIBRATIONS

摘要

Nuisance due to railway induced vibrations has been receiving increased attention in the Netherlands, as a recent study has found that a significant part of the population living in the vicinity of railway tracks in the Netherlands, experiences excessive vibrations levels. As a result, the Dutch government has commissioned the design and implementation of a screening model for the estimation of railway induced vibrations at a network level. Within this screening model, attention has been paid to the characterisation of the subsoil. This paper focuses on the methodology developed to perform a semi-stochastic subsoil characterisation, based on publicly available datasets for the Netherlands. The method uses a countrywide cone penetration test database and the Dutch geomorphological map to define, at a specific location, a set of possible subsoil schematisations, their likelihood of occurrence, and the corresponding subsoil parameters. The effect of soil variability on the vibration levels is assessed by computing the transfer function at different distances from the source. The transfer functions are computed with a newly developed finite element model kernel. The kernel is optimised to specifically compute layered half-spaces. The results show that the subsoil schematisation plays a significant role on the vibration level, which shows that it is paramount to perform a correct characterisation of the subsoil when trying to estimate induced vibration.