Drainage Effects in a Dilatant Carbonate Silty Sand

Abstract

This paper presents and discusses results from a series of cone, vane and footing tests in a carbonate silty sand, conducted in a geotechnical centrifuge, that investigate how drainage effects scale with the diameter of the device/foundation. The tests involved different penetration and rotational velocities to quantify how velocity influences the drainage response, and in turn, the magnitude of the deduced soil strength. Cone and foundation resistance, and the shear stress measured in the vane tests, were seen to increase with increasing penetration/rotational velocity, consistent with a dilatant shearing response. The collective dataset is interpreted within the ‘drainage backbone curve’ framework, with an attempt made to understand how drainage path length varies for the different devices and is affected by stress level.