VOID RATIO OF NONCOHESIVE SOILS AND SIMILAR MATERIALS

A new approach to the topic of numerical description of void characteristics of noncohesive soils and similar granular materials is presented. Based upon a simple stochastic model of the void structure and void sizes, theoretical equations are derived by means of which the void ratio of a soil can be calculated from its grain-size distribution, The calculations also give information about type of grain structure, and the grain size that separates fixed grains and possible loose grains is determined. The equations also consider grain shape, degree of densification, and size of compaction container. Results of numerous laboratory compaction tests on uniform to broadly graded sand, gravel, and crushed-rock materials confirm the general forms of the derived equations and are the basis for evaluation of certain parameters. In a companion paper, the theory is extended to hydraulic conductivity (and, in a forthcoming paper, to filter performances).