Influence of model footing diameter and embedded depth on particle size effect in centrifugal bearing capacity tests

The influence of the model footing diameter and embedded depth on the bearing capacity of circular shallow footings was studied by centrifugal model testing in order to determine a model footing size and embedded depth against particle size in a model ground. In the series of 37 tests, the ground was made by river sand whose particle size was adjusted by sieving to a mean particle size of 0.6 mm. The diameter of the model footing and the embedded depth were considered as influential parameters in this study. The diameter of the model footings varied from 5 to 40 mm and the ratio of the footing diameter to the mean particle size was calculated as 8.3–66.7. The ratio of the embedded depth to the footing diameter was 0, 0.5 and 1.0. As a result, the bearing capacity in the same equivalent diameter of footing was not dependent on the diameter of model footing when the ratio of footing diameter to particle size is more than 50 with any ratio of embedded depth to footing diameter. Our results that the proposed relationship between the ratio of footing diameter to the particle size and the ratio of the embedded depth to the footing diameter can be used to choose a reasonable model footing diameter, embedded depth and the particle size of ground material for centrifugal model tests.