Correlation of Impact and Explosively Created Ground Shock Phenomena
Abstract
A technique for prediction of ground motions in the transition and far-out regions where outrunning surface waves are transporting most of the energy is described. A statistically significant number of surface ground motion velocity measurements were produced by detonating high-explosive (HE) spheres of differing yields and depths of burst. Similar measurements were obtained from energy sources realized by impacting free-falling weights. The tests in this study were conducted on a nearly homogeneous sandstone formation in October 1973 at a site near Grand Junction, Colorado, along with Project CENSE (Coupling Efficiency of Near Surface Explosions). The CENSE series consisted of detonations of eight 1000-lb nitromethane spheres and the SHE (Small High Explosive) series consisted of 20 detonations of C-4 spheres ranging in weights from 1 to 27 lb. Fourteen SMIT (Spherical Mass Impact Technique) tests were conducted by releasing a 6800-lb demolition ball from heights ranging from 20 to 40 ft. Dimensional analysis produced a scaling method in which vertical velocity at any given range scales by charge weight to the one-sixth power. This scaling is borne out by data from large-scale HE and nuclear tests, from which independent linear regression produced essentially the same scaling. All wave forms, both explosive and impact created, exhibit the same characteristics similarities. HE prediction equations were developed from correlations between the impact and surface tangent ground motion data, using the impact results as the model and the explosive results as the prototype.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1976
- Accession Number
- ADA027059
Entities
People
- Max B. Ford