Fabric evolution of granular assembly under K-0 loading/unloading

Abstract

This study attempted to investigate the fabric evolution in K-0 loading/unloading. The work made use of a field simulator to control K-0 loading/unloading in large specimens prepared by air-pluviation. In each loading stage, wave velocities along various propagation directions were measured. On the basis of the theories of micro-mechanics and wave propagation, the microscopic parameters of the granular assembly were back calculated to investigate the fabric evolution of granular soil during K-0 loading/unloading. In this study, the Geometric fabric was modelled by fabric tensors of ranks 2 and 4. The comparison of calibrated results using ranks 2 and 4 revealed the advantage of the usage of rank-4 fabric tensor in modelling fabric evolution in spite of its complexity. By comparing relative magnitudes of vertical and horizontal components of geometric fabric, it was demonstrated that relative constraint in lateral directions increased during K-0-unloading in order to maintain a K-0 condition. It revealed that fabric evolution was responsible for a higher K-0 in unloading than K-0 in loading. Copyright (C) 2003 John Wiley Sons, Ltd.