Abstract
The shear behaviour of granular materials at moderately high pressures up to 1600 lb/sq.in. was studied in drained triaxial tests. Three angular sands were artificially prepared with the same initial grading. The materials used were aluminum oxide, quartz and limestone, in order of decreasing particle strength. Enlarged lubricated end platens were used to achieve more uniform crushing and stress-strain distribution throughout the sample. It is shown that the stress, strain, volume change behaviour are primarily governed by particle degradation. The effective angle of friction decreases with increase in confining pressure but the rate of reduction is diminished with decrease in particle strength, with the result that the φ' is actually higher for a weak-grained material than a strong-grained material. It is also important to distinguish between the two points of zero dilatancy rate for the interpretation of test results at high pressures.
