This paper discusses the failure of the soil below a footing when dynamic time-dependent nonvibratory forces act on the footing. Experimental studies have been conducted on small footings placed on dense sand. Dynamic loads were applied by means of a pneumatic-hydraulic loading apparatus which permitted varying the peak force and the time history. Both the applied force-time history and the resulting displacement-time history of the footings were measured. Static load deflection data was also obtained for footings on the soils of interest.
This paper discusses these experimental studies, with particular emphasis on the experimental approach and interpretation of results. The determination of dynamic bearing capacity and its meaning are discussed.
In addition to quantitative data from electronic instrumentation, laboratory studies have also been conducted to obtain qualitative information using a glass-sided container. It has been possible to obtain photographs and Fastax movies of the behavior of the soil under the footings. This photography has helped in understanding the measured behavior and is used here to clarify the presentation.