STRESS WAVE PROPAGATION IN CONFINED SOILS

Abstract

Phenomenon involved with the propagation of air-induced stress waves in soil were investigated in experiments on Edgar Plastic Kaolin (EPK) clay and Ottawa sand. The principal soil variables were moisture content and density in the case of clay, and density in the case of sand. The soil specimens were loaded with overpressures in the range of from approximately 50 to 300 psi. Two overpressure wave shapes were used, one where peak overpressure had a dwell time of approximately 1 msec and the other having essentially a zero dwell time of peak pressure. Stress-time and strain-time relationships were measured at various points along the length of the specimens. Peak stress attenuation, strain and strain-rate relationships, propagation velocity, changes in wave shape, and stress-strain relationships are discussed in the light of the data obtained. Experimental data are compared with theoretical predictions of a linear hysteretic model in the case of Ottawa sand, and a constant tan Omega viscoelastic model, in the case of the EPK clay. It was found that in both cases the theories could be used to predict the experimental results with proper evaluation of critical attenuation parameters to be input with the theories.

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1966
Accession Number
AD0801912

Entities

People

  • Delon Hampton
  • R. A. Wetzel

Organizations

  • IIT Research Institute

Tags

Communities of Interest

  • Ground and Sea Platforms
  • Weapons Technologies

DTIC Thesaurus Topics

  • Dwell Time
  • Experimental Data
  • Load Cells
  • Measurement
  • Moisture Content
  • Piezoelectric Crystals
  • Plastic Explosives
  • Pressure Transducers
  • Square Waves
  • Strain Gages
  • Strain Rate
  • Stress Strain Relations
  • Stress Waves
  • Stresses
  • Test And Evaluation
  • Wave Propagation
  • Waveforms

Readers

  • Explosive Engineering.
  • Mechanical Engineering/Mechanics of Materials.
  • Plasma Physics / Magnetohydrodynamics