The significance of source-receiver interaction in the response of piled foundations to ground-borne vibration from underground railways

Abstract

The numerical prediction of vibration in buildings due to underground railways involves modelling many physical phenomena. Not least of these is the dynamic soil-structure interaction that exists between the various elements of the system. The majority of existing models assume that the interaction between the railway tunnel and the building’s foundation is negligible, with the two sub-systems behaving as though they are uncoupled. This paper presents some initial results from a three-dimensional model that accounts for the through-soil coupling between a tunnel and a piled foundation. The model is based on the pipe-in-pipe model, of a circular, longitudinally invariant tunnel excited by wheel-rail roughness, coupled to a boundary-element model of the foundation using an iterative wave-scattering approach. Initial test cases, involving single piles and pile-groups, highlight new details of tunnel-pile and pile-pile interaction, as well as predicting the effect of piles on ground vibration levels.