摘要：

REPEATED LOAD TESTS HAVE RECENTLY BEEN USED TO EVALUATE THE PROPERTIES OF MATERIALS WHICH ARE OF INTEREST IN PAVEMENT DESIGN. THIS PAPER DESCRIBES SOME TESTS CARRIED OUT ON 4 IN. DIAMETER TRIAXIAL SAMPLES OF TWO DIFFERENT SANDS AT CONSTANT CONFINING PRESSURE. MEASUREMENTS OF THE RECOVERABLE COMPONENTS OF AXIAL AND RADIAL DEFLECTIONS WERE USED TO CALCULATE 'RESILIENT CONSTANTS', ANALOGOUS TO YOUNG'S MODULUS AND POISSON'S RATIO OF AN ELASTIC SOLID.THESE VALUES ARE OF USE IN THE CALCULATION OF ELASTIC STRESS DISTRIBUTIONS. THE PERMANENT OR NON-RECOVERABLE COMPONENT OF AXIAL DEFLECTION WAS FOUND TO REACH A CONSTANT RATE OF INCREASE AFTER A SUFFICIENT NUMBER OF LOADING CYCLES HAD BEEN APPLIED. THIS RATE WAS GENERALLY SO SMALL THAT FOR PRACTICAL PURPOSES A 'SHAKEDOWN' CONDITION WAS ACHIEVED. THE MAIN VARIABLES INVESTIGATED INCLUDE MAGNITUDE OF CONFINING PRESSURE, DEVIATOR STRESS LEVEL AND DEGREE OF SATURATION. THE EFFECTS OF PROOF LOADING WERE ALSO STUDIED. THE POSSIBILITIES OF APPLYING THE RESULTS TO THE USE OF GRANULAR MATERIALS IN ROAD PAVEMENTS ARE CONSIDERED, AND IT IS SUGGESTED THAT CORRELATION OF FIELD AND LABORATORY STUDIES WILL PROVIDE THE FULL ANSWER./RRL/(A)

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