Accession Number : AD0824347

Title :   EFFECTS OF AIRBLAST AND AIRBLAST-INDUCED GROUND SHOCK ON EARTH WALLS OF EXCAVATIONS,

Corporate Author : ARMY MOBILITY EQUIPMENT RESEARCH AND DEVELOPMENT COMMAND FORT BELVOIR VA

Personal Author(s) : Hobbs, Richard A.

Report Date : NOV 1967

Pagination or Media Count : 51

Abstract : During Project 3.3, Operation 'SNOWBALL,' four excavation types were subjected to blast effects from 500-ton TNT detonation at overpressure regions of 30, 40, and 50 psi. Excavations ranged from basic foxholes to foxholes designed to reduce or increase overpressure loadings on horizontal surfaces adjacent to vertical walls while either including or excluding ground shock. Failure of earth walls closest to ground zero was caused by blast-induced ground shock compressive wave which was reflected as a tensile wave at earth-air interface. At some distance back from earth wall, tensile resultant of compressive and tensile waves exceeded tensile strength of soil, and failures developed. Momentum imparted to material thus separated resulted in ejection of material from surface. Failure of walls away from and radial to ground zero occurred as incident wave diffracted around excavations. (Author)

Descriptors :   *WALLS), (*EXPLOSION EFFECTS, SOILS, BLAST, SHOCK WAVES, FAILURE(MECHANICS).

Subject Categories : Structural Engineering and Building Technology
      Explosions
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE