Dynamic Behavior of Strip and Spread Footings Buried in Sand

摘要

This report describes the response of 1-, 2-, 4-, and 6-inch-square footings and of 6 x 72-inch and 12 x 72-inch strip footings loaded dynamically in dry sand. The load applied to the experimental footing by the NCEL atomic blast simulator through the loading beam-load cell apparatus simulated the load applied by a buried structure to its footings as the result of a nuclear-blast-induced air overpressure acting on the surface of the soil in which the structure was buried. For some of the tests there was no overburden. For others, a static load simulating 20 feet of overburden was applied at one side of the footing. This report also outlines the adaptation of conventional static bearing capacity formulas to explain the dynamic behavior of deeply buried footings in sand. The results are applied in an iterative procedure for calculating the loading and motion of a buried, footing-supported structure, taking into account the effects of soil arching. (Author)