Sand deformation mechanisms mobilised with active retaining wall movement

A series of centrifuge tests was conducted to explore the deformation mechanisms mobilised in loose and dense sand for a complete set of active rigid retaining wall movement modes: rotation about the base and top and translation. The sand deformation was measured by particle image velocimetry and data relating to displacements and strains are reported. A simplified deformation mechanism is proposed for sand behind a rigid wall rotating about the top and this is validated with the centrifuge test results. The paper reveals that the sand deformation caused by wall translation can be well characterised by the superposition of mechanisms with equal but opposite wall rotation about the top and base. Integration of these displacement mechanisms together with a constitutive law into an equilibrium solution for wall bending would allow designers to predict deformations during construction as well as ultimate collapse.