Bearing capacity of gravity caisson on cohesive foundation during earthquakes

A series of dynamic centrifuge tests was carried out, in order to study the seismic bearing capacity of gravity caissons. In the tests, bearing capacity factor of safety in a static condition, load eccentricity, and earthquake intensity were varied. Static bearing capacity tests were also performed. Complete failure or Limited settlement were observed in the shaking tests for the cases with relatively small bearing safety factor at rest and excited by large amplitude of shaking. The results were compared with a conventional Limit equilibrium theory in which the earthquake effect is represented with the pseudo-static seismic force applied to the caisson. It was found that the conventional method is conservative.