EARTH PRESSURE AT REST RELATED TO STRESS HISTORY

VARIATIONS OF THE COEFFICIENT OF EARTH PRESSURE AT REST ARE STUDIED. DIFFICULTIES ENCOUNTERED IN EXPERIMENTAL DETERMINATION ARE DESCRIBED. FOR EXAMPLE, VERTICAL AND RADIAL STRESSES AND STRAINS IN THE CONFINING RING USED MUST BE TAKEN INTO ACCOUNT. REFERENCES' BROOKER AND IRELAND, GEOSCIENCE ABSTRACTS, 7-2773.