INFLUENCE OF RELATIVE DENSITY ON THE STRENGTH AND STRESS-STRAIN CHARACTERISTICS OF SAND

PLANE STRAIN AND TRIAXIAL COMPRESSION TESTS WERE CONDUCTED ON SATURATED CHATTAHOOCHEE RIVER SAND TO DEMONSTRATE THE EFFECT OF RELATIVE DENSITY AND STRAIN CONDITIONS ON THE STRENGTH AND STRESS-STRAIN CHARACTERISTICS OF SAND. SPECIMENS WERE PREPARED AT RELATIVE DENSITIES RANGING FROM 30 TO 100 PERCENT AND CONSOLIDATED ISOTROPICALLY TO AN EFFECTIVE CONFINING PRESSURE OF 70 PSI BEFORE SHEAR. ON THE BASIS OF EXPERIMENTAL DATA PRESENTED IN THIS STUDY, IT APPEARS THAT THE INCREASE IN RELATIVE DENSITY OF THE SAND TESTED DECREASES ITS COMPRESSIBILITY DURING CONSOLIDATION AND INCREASES THE INITIAL SLOPE OF THE STRESS-STRAIN CURVE, THE TENDENCY FOR VOLUMETRIC EXPANSION IN DRAINED SHEAR, AND THE TENDENCY FOR NEGATIVE PORE PRESSURE IN UNDRAINED SHEAR FOR BOTH PLANE STRAIN AND TRIAXIAL COMPRESSION TESTS. THE DATA ALSO INDICATED THAT THE ANGLE OF INTERNAL FRICTION FOR THE TESTED SAND WAS HIGHER,THE VOLUMETRIC STRAIN DURING SHEAR WAS MORE COMPRESSIONAL,AND THE AXIAL STRAIN AT FAILURE WAS LOWER IN PLANE STRAIN TESTS THAN IN TRIAXIAL COMPRESSION TESTS OF SAND WITH NEARLY THE SAME RELATIVE DENSITY. /AUTHOR/