Sand characterization by combined centrifuge and laboratory tests

Abstract

The purpose of this paper is to evaluate new methods of interpretation of in situ tests in sand from correlations established from centrifuge and laboratory data. Emphasis is given to methods that are based on the combination of measurements from independent tests, such as the ratio of the elastic stiffness to ultimate strength (G0/qc) and the ratio of cone resistance and limit pressure (qc/ΨL). For that purpose, a series of centrifuge tests using a cone penetrometer and a cone pressuremeter was carried out at the Laboratoire Central des Ponts et Chaussées, France. The experimental work prompted the evaluation and development of correlations to derive relative density, friction angle, state parameter, horizontal stress and coefficient of lateral earth pressure at rest. Assessment of the strain field generated by the penetration of a cone is made by carefully monitoring the magnitude of the horizontal stress during penetration using earth pressure cells embedded into sand samples. A proper account of the increasing of horizontal stresses at the location of the borders of the strongbox ensures that usual correlations between parameters can be used in the centrifuge.