Behavior of Sands under Surface Loads

Comparisons are made herein of the instrumentation, sand types and techniques used by various workers to examine how these factors influence their results. These results are analyzed to reveal any general patterns, or lack of patterns, in the behavior of uniform sand masses subject to surface loads, and to evaluate the usefulness of a simple elastic theory in predicting this behavior. The main findings were that vertical direct stresses and radial-vertical shear stresses are reasonably well predicted by theory, while the radial and tangential direct stresses as measured show considerable differences from the theory and between the various sets of results. The measured maximum surface displacements, expressed as ratios of the product of the respective loading pressure and radius, showed extremely large differences. These reflect the influence of relative density, compaction method, and preloading.