PARTICLE PACKING IN LOESS DEPOSITS AND THE PROBLEM OF STRUCTURE COLLAPSE AND HYDROCONSOLIDATION

A major practical problem encountered in loess deposits is that of str uctural collapse when loaded and wetted, the process of hydroconsolida tion. The process is essentially a transition from an open particle pa cking to a closer particle packing. Packings are difficult to represen t and processes involving packing change are difficult to model. A sim ple transition process, using the Morrow and Graves approach, allows p acking changes to be studied. The Morrow and Graves packings can be re lated to the simple particle packings that have been used as a basis f or the study of packing structures in sediments. These regular packing models may be superseded by random systems in which the collapse of b ridging structures allows a transition from loose random packing to cl ose random packing. The Onoda and Liniger concept of loose packing and dilatancy onset is applied to the formation of a deposit and its subs equent collapse.