Analytical methods provide an efficient way of evaluating ground displacements caused by tunnel construction. This paper investigates the analytical estimation of greenfield soil deformation patterns above shallow tunnels in sand. Research has shown that the mechanism of tunnelling-induced ground displacements in sands is different to clay because of the contractive/dilative behaviour of the ground, yet there have been few analytical studies for tunnelling in sands. The general closed-form solution proposed by Gonzalez and Sa-gaseta (2001) is adopted in this work. This expression includes tunnel deformation parameters (ground loss, ovalization) as well as soil volumetric compressibility. Instead of attempting to accurately model the tunnel construction operations, the tunnel deformation parameters are used to reproduce their overall effects on the surrounding soil. The compressibility term is used to describe the volumetric strain contribution to the ground settlements. The results of a series of plane-strain centrifuge tests performed on tunnels in dry, dense silica sand are used to evaluate model input parameters. The effects that tunnel size, depth and volume loss have on the tunnel deformation parameter are discussed. A set of equations for the model input parameters is proposed and results compared with centrifuge test outcomes.
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