Applications of the oedometer, triaxial and resonant column tests to the study of micaceous sands

Abstract

Intergranular void ratio, e s, can be used as an alternative indicator to assess the mechanical and dynamic properties of composite matrix of coarse and fine grains. In this paper, an intensive laboratory study of saturated coarse rotund sand (i.e., Leighton Buzzard Sand) and fine (i.e., mica) mixtures with various mix ratios is performed by a series of oedometer, triaxial and resonant column tests. Oedometer tests performed on coarse rotund sand–fine mixtures show that initial conditions, fines percentages, and stress conditions affect the compression behaviours. Tests indicated that, up to a fraction of mica, which is named as transition fines content (FC t), compression behaviour of the mixture is mainly governed by the sand grains. As the percentage of mica exceeds FC t, mica governs the compression. In the triaxial tests, deviatoric stress ( q), pore pressure ( u), and undrained Young's modulus (Eu) have been obtained in a triaxial testing apparatus. Results revealed that there is a close relationship between the FC t and q, u, and Eu values. In the resonant column tests, a study of dynamic properties of saturated mixtures was investigated by measuring its shear modulus ( G) and damping ratio ( D), which is harmonic with the oedometer test results.