This task was conducted at Project Shoal to observe the response of simulated Dribble area building founda tions to ground motions induced by a nuclear detonation. The following conclusions pertinent to the Dribble residence bracing problem have been drawn. Peak particle velocities of from 15 to 20 cm. sec. 6 to 8 inches per second and peak accelerations of up to 1.3 g did not cause lateral collapse of the unbraced pier foundations observed in this project. Such motions did crack the more heavily loaded interior pier blocks. Timber bracing cribs, such as those prescribed in the Holmes and Narver, Inc. Preshot Damage Report for Dribble, were effective in reducing pier damage. Damage was not, however, completely prevented by the cribs. No damage to unbraced buildings resulted from peak particle velocities of 9.6 cm. sec. 3.8 inches per second and peak accelerations of 0.75 g. Peak motions of this magnitude will probably occur as far as 1.6 miles from the Dribble Salmon Surface zero, and possibly as far as 2.4 miles from Surface Zero.
Rept. on Vela Uniform Proj. Shoal, Fallon, Nev., 26 Oct 1963. Sponsored also by the Atomic Energy Commission, Washington, D. C. Legibility of this document is in part unsatisfactory. Reproduction has been made from best available copy. DOI: 10.21236/AD0607922