In-flight simulation of a multi-propped excavation de-stabilised by an underlying aquifer

摘要

Base instability due to hydraulic uplift can be a major concern for deep excavations in soft soilswith an underlying aquifer. To understand the failure mechanism of an excavation subjected to hydraulic uplift,an in-flight simulation of a multi-propped excavation in soft clay with an underlying aquifer was carriedout in centrifuge. Digital cameras are used to capture images of soil deformation during the in-flight test.Based on the captured digital images, soil displacements developed during excavation and hydraulic uplift arededuced by using a Particle Image Velocimetry (PIV) technique coupled with a close-range photogrammetrycorrection. In order to verify the observed failure mechanism, a three-dimensional, elasto-plastic, coupledconsolidation numerical analysis was carried out. Findings from both physical and numerical investigationsare discussed and reported.