TECHNIQUES AND EQUIPMENT FOR DETERMINING DYNAMIC PROPERTIES OF SOILS

RESULTS ARE SUMMARIZED OF A PROGRAM UNDERTAKEN TO INCREASE THE GENERAL KNOWLEDGE OF SOIL BEHAVIOR UNDER DYNAMIC LOADING. EQUIPMENT WAS DESIGNED, DEVELOPED, AND EMPLOYED FOR TESTING GRANULAR MATERIALS. A SMALL EFFORT WAS EXPENDED TO OUTLINE A TECHNIQUE FOR CONSTRUCTING MATHEMATICAL MODELS FOUNDED ON THE DISCRETE NATURE OF SOILS. EQUIPMENT AND TECHNIQUES WERE DEVISED WITH WHICH CYLINDRICAL SAMPLES CAN BE LOADED TO PEAK STRESS LEVELS AS HIGH AS 3,000 PSI WITHIN TIMES OF ABOUT ONE MILLISECOND. IN AN ATTEMPT TO SIMULATE BOUNDARY CONDITIONS IN A SEMI-INFINITE FIELD, THE SAMPLES HAVE BEEN LOADED WHILE CONSTRAINED LATERALLY BY A RELATIVELY FRICTIONLESS AND INCOMPRESSIBLE FLUID BOUNDARY. DURING BOTH TRANSIENT AND EQUILIBRIUM LOADING PERIODS, RESPONSE IS DETERMINED FROM MEASUREMENTS OF AXIAL AND LATERAL STRESS, AXIAL DISPLACEMENT OF THE LOADING END OF THE SAMPLE, AND ORTHOGONAL LATERAL DISPLACEMENT OF A POINT ON THE LATERAL BOUNDARY. THE BULK OF THE TESTING COMPLETED WAS ON THREE DRY, GRANULAR, COHESIONLESS PARTICLE ASSEMBLAGES - MANY- FACETED BUT WELL-ROUNDED SAND GRAINS (20 - 30 OTTAWA), HIGHLY ANGULAR SAND GRAINS (20 - 30), AND HIGHLY SPHERICAL GLASS GRAINS (30 - 40 AND 80 - 100). EFFORTS TO DATE HAVE BEEN AIMED AT DETERMINING THE RELATIVE IMPROTANCE OF VARIOUS MEDIA, LOADING, AND BOUNDARY PARAMETERS OF RESPONSE. THIS REPORT IS AN ATTEMPT AT A SUMMARY STATEMENT OF THE EFFECTS OF SUCH PARAMETERS AS SAMPLE LENGTH, DENSITY, AND MOISTURE CONTENT, PARTICLE MATERIAL, SIZE, AND SHAPE, STRESS LEVEL, RATE OF STRESS RISE, OVERSTRESS, HOLD TIME, AND UNLOADING. AND BOUNDARY LATERAL RESTRAINT.

  • Supplemental Notes:
    • No S-1, Urs 155-30 (DASA 1421)
  • Corporate Authors:

    Defence Atomic Support Agency /US

    ,    
  • Authors:
    • Zaccor, J V
    • Wallace, N R
  • Publication Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 00229069
  • Record Type: Publication
  • Source Agency: Urs Technical Abstracts
  • Files: TRIS
  • Created Date: Aug 15 2004 2:11AM