PROCEDURES FOR PREDICTION OF GROUND SHOCK PHENOMENA BASED ON ONE-DIMENSIONAL SHOCK PROPAGATION CONSIDERATIONS. REPORT 2. EXPERIMENTAL STUDY OF LOADING-UNLOADING STRESS WAVE INTERACTIONS IN A SOIL SHOCK TUBE,
Abstract
The report describes a definitive experimental study in which shock-induced square-wave pulses in soil were observed to give way to decaying pulse shapes, as in a gas shock tube, and rapid attenuation of peak stress occurred thereafter due to nonlinear propagation in the rarefaction. In the study three different duration pulses were applied to an 8-ft vertical column of granular material confined under boundary conditions leading to a stress-strain (Sigma - Epsilon) behavior described by d to the 2nd power Sigma/d Epsilon to the 2nd power > 0, i.e., a strain-hardening type of response. Applied stresses ranged from 50 to 500 psi. The report describes a simple modification to be applied to the prediction procedure described in the first report of this series in order to take into account, to a first approximation, the nonlinear propagation of unloading waves that occurs in real media because of nonlinear stress-strain behavior in the unloading branch. The procedure which predicts stress and motion histories based on the conservation laws, a measured constitutive relationship, and the applied pressure-time profile, is demonstrated by predicting the entire sequence of an experimentally observed square-wave pulse transformation into a decaying pulse. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1967
- Accession Number
- AD0663830
Entities
People
- D. F. Walter
- J. V. Zaccor
- V. W. Davis
Organizations
- URS Corporation