INTRODUCTION

Granular materials rearrange their fabric in response to deformation, giving rise to complex behaviour at a macro scale. An important component in this complexity is particle breakage. Even strong-grained geomaterials are potentially crushable, but weak-grained soils such as weathered residual soils, volcanic ash deposits, carbonate sands and some recycled materials, are crushable at low stresses and correspondingly compressible. In line with performance-based design criteria, accurate evaluation of their physical characteristics is necessary when using these materials. There have been rapid technological advances in image processing, accuracy of measuring systems and high-speed computation all of which have enhanced research in geomaterials, with a special emphasis on their particulate nature.

Re-examination of geomaterials, which consist of aggregates, from a microscopic point of view can shed light on our understanding of significant macroscopic behaviour, such as compressibility, anisotropy, yielding, creep, cyclic liquefaction and shear rupture. In this process, new methods of material characterization should emerge which may lead to greater confidence in the specification of a new generation of constitutive models with physically meaningful parameters. Invigorating this development is the new drive for sustainability leading to an increased utilization of recycled materials for geotechnical applications. Since the characteristics of recycled materials, such as compressibility and self-hardening, may differ from those of natural materials, it is believed that evaluation from a particulate perspective is indispensable.

This symposium will provide the opportunity for an international exchange of ideas, as well as serving to disseminate information regarding experiments, numerical models and practical engineering problems related to material evaluation which considers the particulate nature of geomaterials.