Physical modelling of suction foundations of TLPs under horizontal loads

The results of centrifuge model tests on the behavior of suction bucket foundations of a TLP under static and cyclic horizontal loads were presented.The ice-sheet induced structural vibration was simulated as an equivalent cyclic lateral load by an electro-magnetic actuator.The effects of the load intensity and the geometry of the foundation were investigated.The static horizontal bearing capacity of the foundation was determined by the static tests.It was indicated by the results of dynamic centrifuge tests that the excess pore water pressure reached the highest value within a depth of 1～2 m below the mud line.The pore pressures and the induced settlement increased with the increase of the amplitudes of the cyclic loadings.Two failure modes might be involved: liquefaction in the early excitation and settlement induced problem after long term excitation.However,with the increase of stiffness of the bucket foundation,the pore pressures and the induced settlement decreased.