AN EXPERIMENTAL INVESTIGATION OF THE PROJECTILE PENETRATION INTO SOFT, POROUS ROCK UNDER DRY AND LIQUID-FILLED CONDITIONS

An experimental investigation was conducted to study the response of soft, porous rock, green shale, under dry and liquid-filled conditions to normal impact of hemispherically-tipped cylindrical steel projectiles with diameter and mass of 6.35 mm and 31 g, respectively. Disk-shaped green shale specimens with nominal thickness and diameter of 32 mm and 127 mmm, respectively, were tested in the initial projectile velocity range of 18 to 42 m/s. For the liquid-filled tests, the green shale specimens were saturated with kerosene. A total of eight impact tests were conducted. Information on the extent and pattern of damage in the rock and velocity histories of the projectiles were collected. It was found that while the penetration depth was quadratically related to the initial projectile kinetic energy for the dry case, the penetration depth for the liquid-filled case was directly proportional to the initial projectile kinetic energy. The results of the impact tests under dry and liquid-filled conditions conformed well to a linearly viscous model and a Coulomb frictional model, respectively. The major deformation processes in the dry specimens were found to be compaction and equivolumnial distortion of the material. In the liquid-filled case, however, formation of cracks and equivolumnial distortion with less material compaction were observed. Furthermore, craters were formed as a result of the crack formation in the liquid-filled specimens. For the covering abstract of the symposium see TRIS 452576. (Author/TRRL)

• Supplemental Notes:
  • Proceedings of the 23rd Symposium on Rock Mechanics, Issues in Rock Mechanics, University of California, Berkeley, California, August 25-27, 1982.
• Corporate Authors:

  American Institute of Mining, Mettalurgy & Petroleum Engineers

  345 East 47th Street
  New York, NY  United States  10017
• Authors:
  • Kumano, A
  • Goldsmith, W
• Conference:
  • Proceedings of the 23rd Symposium on Rock Mechanics, Issues in Rock Mechanics, University of California, Berkeley, California, August 25-27, 1982.
• Publication Date: 1982

Media Info

• Features: Figures; Photos; References; Tables;
• Pagination: p. 488-495

Subject/Index Terms

• TRT Terms: Conferences; Cracking; Crash tests; Deformation; Depth; Dryness; Friction; Liquids; Loss and damage; Mathematical models; Pendulum tests; Porosity; Porous materials; Presplitting (Blasting); Rocks; Samples; Shale; Soft rock; Soft soils; Speed; Steel; Tests; Viscosity
• Uncontrolled Terms: Dry conditions; Projectiles
• Old TRIS Terms: Porous rock
• ITRD Terms: 5188: Blasting; 5905: Compressibility; 8525: Conference; 5211: Cracking; 1614: Damage; 5595: Deformation; 6499: Depth; 5452: Friction; 6473: Mathematical model; 6285: Penetration; 5938: Porosity; 4154: Rock; 6251: Sample (mater); 4168: Shale; 5408: Speed; 6255: Test; 5936: Viscosity
• Subject Areas: Geotechnology; Highways; Research;

Filing Info

• Accession Number: 00452593
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, TRIS
• Created Date: Jul 31 1986 12:00AM