ABSTRACT
Engineers need to assess the effects that underground excavations can have on existing structures. Experimental and field data on the tunnel-building interaction problem that accurately consider building characteristics are rarely reported. This paper aims to address this shortcoming by providing results from geotechnical centrifuge tests where tunnel volume loss was simulated beneath model frame buildings with either raft or separate footing foundations. The paper investigates the influence of the foundation configuration on the soil-structure interactions by comparing the displacements and deformation mechanisms of the geotechnical and structural domains (including the soil, the foundation, and the superstructure). A plane-strain experimental package was used, comprising a 2-storey aluminium framed building model and a flexible membrane model tunnel buried within dense sand. During tunnelling, displacements were measured at the front wall of the centrifuge container using digital image analysis. Three centrifuge tests are reported including a greenfield case and two scenarios of tunnelling centrally beneath a framed building; one with a raft foundation and another with separate footings. Insights into the effects of the structure on the soil movements and deformation mechanisms along with a description of the building displacement and distortions are provided to illustrate how the foundation type alters the soil-structure interaction.
