Accession Number : AD0640440

Title :   MOTION OF SUBSURFACE SOIL INCLUSIONS SUBJECTED TO SURFACE BLAST LOADING - RESULTS OF SERIES II TESTS.

Descriptive Note : Technical rept.,

Corporate Author : NAVAL CIVIL ENGINEERING LAB PORT HUENEME CALIF

Personal Author(s) : Heller,L. W.

Report Date : OCT 1966

Pagination or Media Count : 52

Abstract : Tests were conducted to determine how shape and mass affect the motion of buried inclusions subjected to blast loading applied to the surface of the soil. Five inclusions, representing elemental portions of a buried complex, were placed 6 inches below the surface of a dry sand material sieved into a reinforced-concrete test container. Two of the inclusions had the same shape and stiffness but differed in mass. The three other inclusions had comparable mass and stiffness but differed in shape. The displacement and acceleration of the inclusions and the displacement of the soil at two elevations were measured during a sequency of 13 blast loadings at peak overpressure levels of 5 to 25 psi. Reed gages were attached to one inclusion and cantilevered into the soil to indicate the motion of the inclusion with respect to the surrounding soil. Accurate measurement of inclusion motion was not made. However, the following results were obtained: (1) the reed gages indicated that the inclusion displaces into the soil in the direction of the propagated soil stress wave, (2) an increase in the mass of an inclusion by a factor of 13 only halved its peak acceleration, and (3) differences in shape of the inclusions tested resulted in only 10% to 15% differences in their peak accelerations. A tentative method for estimating the blast-induced differential motion between a structural inclusion and its surrounding soil field is described. (Author)

Descriptors :   (*UNDERGROUND STRUCTURES, BLAST), MOTION, SHOCK WAVES, NUCLEAR EXPLOSIONS, SIMULATION, SOIL MECHANICS, LOADS(FORCES)

Subject Categories : Structural Engineering and Building Technology

Distribution Statement : APPROVED FOR PUBLIC RELEASE