Influence of Compaction and Loading Conditions of the Dynamic Properties of a Silty Sand

Elastic properties of a compacted silty sand were measured in a precision triaxial cell at the École Centrale de Paris in the range of very small strains (between 10-6 and 10-4), using improved Hall effect-based local strain gauges and data acquisition system. The dynamic properties of the soil were also derived from resonant column tests at the IST, in Lisbon, as functions of shear strain, compaction water content and confining pressure. Elastic limits as low as 5.10-6 were found in both devices, with Poisson’s ratio from triaxial tests ranging from 0.05 at very strains (\u3c 10-4) to 0.37 at larger strains. Comparison between quasi-static and dynamic values were found to be in good agreement, with a reasonable value of Poisson’s ratio, despite the complex properties of this soil such as viscosity, ageing effects and anisotropy