ELASTIC RESPONSE OF SHOCK-ISOLATED CYLINDERS BURIED IN A DENSE, DRY SAND.

摘要

The objective of the study was to investigate the elastic response of a stiff,horizontally oriented,steel cylinder backpacked with a low-strength cellular concrete and buried in a dense,dry sand,whose surface was subjected to static and dynamic overpressures. Four series of tests were conducted on the cylinder (one static and one dynamic series without backpacking,and two dynamic series with backpacking). The cylinder had an outside diameter of 6inches, a 0.120-inch wall thickness,and a stiffness of 164psi. Static and dynamic surface overpressures ranged from 0to 250psi and from 100to 250psi,respectively. In the tests with backpacking, a layer of cellular concrete with a thickness of either 1-3/8or 2-7/8inches encompassed the cylinder. The cylinder was buried at a depth of 15inches,which was held constant for all tests. Measurements were made of the strains and accelerations experienced by the cylinder,test chamber bonnet pressure,surface overpressure,and free-field pressure and acceleration. Backpacking reduced the peak strains experienced by the cylinder,and a redistribution of the strains in the cylinder occurred. For all tests utilizing backpacking,the accelerations of the cylinder were reduced to approximately 10to 50percent of those measured in corresponding tests without backpacking. (Author)