Abstract
A series of centrifuge model test of “Compacted Bulb Foundation Method” was carried out to investigate the effect of tamping conditions, such as ram mass, ram base area and number of blows, and foundation base area on characteristics of its bearing capacity. Main conclusions are as follows: 1) ultimate bearing capacity and coefficient of subgrade reaction of compacted bulb was hundred times or more and ten times larger than untamped ground, respectively, 2) its bearing capacity was dependent on the ram mass per unit base area, 3) compacted bulb tamped by a ram having larger base area relative to loading area had lager bearing capacity.
