Inertial interaction in pile-groups: A study of the influence of coupling via an iterative wave-scattering approach

Abstract

The increasing urban population is leading to the exploitation of building sites close to sources of ground-borne vibration, such as railways and busy roads. Piled foundations can provide a significant vibration transmission path into a building, which can then cause disturbance to occupants and sensitive equipment. There is a strong need to develop numerical models that can capture the essential dynamics of a piled foundation, over the frequency range associated with ground-borne vibration, to help practising engineers decide on appropriate countermeasures. In this paper, a piled foundation is modelled as a pile-group embedded in a homogeneous half-space. Previous research has explored the dynamics of pile-groups to inertial loading at relatively low frequencies, over the seismic range. Here, an iterative approach is developed using a source-receiver boundary-element model to account for the wave-scattering effect that becomes more significant at higher frequencies. Predictions of the dynamic interaction factors, which describe the pile-soil-pile interaction, show very good agreement with a standard boundary-element model for a range of geometric and material parameters. The results show that using uncoupled source-receiver models can account effectively for the interaction between piles without resorting to fully coupled models, even at frequencies well above those of previously published results.