Shear Strength of Clay in Centrifuge Models

Abstract

Since centrifuge time is expensive it is necessary to keep testing times to a minimum. Where clay forms an important part of the soil model, reasonable drainage periods can only be achieved by using a high permeability clay. This leads to serious problems if clay strengths and deformations, to be used in analyzing the test, are measured after the centrifuge is stopped. Any excess water available, such as drainage ducts or surcharge layers, can quickly enter the soil and cause softening. The critical state theory is used to estimate undrained shear strength and the results compared with values measured by vane in-flight. Measured shear strengths during flight and after stopping the centrifuge are compared.