On the influence of stress path upon the mechanical properties of granular material: 44. A. Drescher and W. BojanowskiArch. Inzynierii Ladowej14, 3, 351–365 (1968)

Abstract

RESULTS FROM CONSTANT STRAIN RATE TRIAXIAL TEST ON DRY COARSE SAND IN A DENSE STATE ARE PRESENTED. THE END FRICTION WAS REDUCED BY POLISHED GREASED PLATES, AND THE VOLUME CHANGE OF THE SAMPLE WAS MEASURED WITH A SPECIAL DEVICE PERMITTING ENTERING OR LEAVING AIR VOLUME TO BE MEASURED. IT WAS FOUND THAT AN INITIAL STRESS PATH NOT EXCEEDING MAXIMUM STRESS INTENSITY ACCORDING TO SIMPLE TRIAXIAL TESTS DOES NOT AFFECT FURTHER BEHAVIOR. HOWEVER, LOADING UP TO MAXIMUM STRESS INTENSITY AND UNLOADING AFFECTS FURTHER BEHAVIOR BY RELOADING ALONG A DIFFERENT STRESS PATH. CERTAIN STRESS PATHS AFFECT THE MOHR-COULOMB YIELD CONDITION CORRESPONDING TO MAXIMUM STRESS INTENSITY, AND THE ANGLE OF INTERNAL FRICTION IS THEREFORE NOT CONSTANT. THE AUTHORS ARE PLANNING FURTHER THEORETICAL ANALYSIS OF THE EXPERIMENTAL DATA. FURTHER EXPERIMENTS ARE ALSO NEEDED-INCLUDING EXTENSION TESTS-TO MAKE CLEAR WHETHER THE OBSERVED EFFECTS HOLD IN MORE COMPLEX STRESS STATES. /AMR/