Elastic and inelastic strain relationships of granular soils subjected to repeated stressing

Abstract

The influence of highly repetitive stressing upon the magnitudes of elastic and inelastic strains, the elastic parameters-modulus of elasticity and Poisson's ratio- and resistance to degradation of particles has been explored. Compacted crushed and gravel limestone materials, partially saturated, have been considered. Methods for the evaluation of elastic constants have been developed, with numerical values determined for the materials within the bounds of the experiment. Values for Poisson's ratio were approximately 0.2 for the test conditions. Values for static modulus of elasticity varied from 10,000 to 100,000 psi, depending upon confinement pressure and stress history; values for dynamic modulus of elasticity varied from 50,000 to 150,000 psi. The intricate stress-deformation relationships, resolved into elastic and inelastic components, have been observed and analyzed. This study has culminated in proposals for rational methods of evaluating materials of design, such as for base course layers of pavements, using repetitive techniques for combined field and laboratory study. The methods examined in this research have been shown to be representative of field performance, and implemented through intensive additional research and field correlation, should bring many of the perplexing problems of highway design closer to correct solution.