CYCLIC COMPACTION OF SOILS, GRAINS AND POWDERS

Experimental results obtained from the cyclic compaction tests perform ed on various particulate materials like, for example, sand, lead shot , rice, wheat, flour and bentonite are presented and discussed. Experi ments were performed in a standard Bishop-type oedometer with addition al measurement of lateral stresses. Samples of experimental material w ere subjected to repeated loading and unloading cycles for a prescribe d vertical loading history. Corresponding vertical deformation and lat eral stresses histories were recorded. An extensive discussion of expe rimental data is focused on the phenomenon of compaction and related p henomenon of compaction induced lateral stresses. It is shown that the behaviour of various particulate materials displays some common featu res which may be included into a more general theoretical framework. C onstitutive equations that describe both cyclic compaction and compact ion induced lateral stresses are proposed. The equations are based on the concept of common curves that may be recognized as an independent characteristic of the material.