Numerical, experimental and hybrid methods for the prediction of railway-induced ground vibration

摘要

Ground-borne noise and vibration due to railway traffic are important environmental issues in the development of new railway lines and land adjacent to existing lines. Prediction models are indispensable to address properly these issues and to design efficient mitigation measures for both existing and new-build situations. The aim of the present contribution is to provide a comprehensive overview of methods which have been developed for the prediction of railway-induced ground vibration. A distinction is made between numerical models, based on physical or mechanical models, empirical models, derived from measured data, and hybrid models that combine elements from numerical and empirical models. Numerical models are particularly useful in new-build situations. They can be used to assess the environmental impact of new railway lines or to develop and design mitigation measures. Numerical predictions are generally characterized by significant model and parameter uncertainty, however, which need to be considered for robust engineering and design. In engineering practice, empirical metliods are mostly used, which are based on an experimental characterization of the source strength and vibration transmission. These methods have the advantage of accounting for the particularities of the vibration transmission at a given site, but can only be applied in those cases for which suitable data and prior experience are available. In order to overcome the limitations of numerical and empirical metliods, these metliods can be combined in a hybrid or semi-empirical prediction procedure. It is shown how such a hybrid method is obtained by replacing the experimental source strength or vibration transmission term by an equivalent quantity which is computed using numerical simulations.