AIR BLAST EFFECTS ON UNDERGROUND STRUCTURES

The report describes the results of a test to determine the nature of forces transmitted through earth to buried structures from the explosion in air of an atomic bomb. The structures were primarily reinforced concrete boxes having a large number of simply supported steel beam strips forming their roofs. Three structures were included in the program, having respectively 1 ft, 4 ft, and ft of earth cover over the beam strips, and each of the structures had a number of individual beam strips, with several strips of each of three different degrees of flexibility to provide information concerning the effect of flexibility of the structure on the loading transmitted to it. All of the beam strips had the same span, namely 8 ft. The structures were tested in two shots, the first producint an overpressure level of about 15 psi, and the second about 63 psi.
Rept. on Operation Upshot-Knothole, Nevada Proving Grounds, Mar-Jun-53, Project 3.8.