Finite Element Analysis Of The Service Behavior Of Suction Caisson Under Vertical Load

Suction caisson is a concrete or steel pipe with an open bottom and a closed top. It penetrates into sea bed with its gravity and suction pressure produced by pumping water out of it.The use of suction caisson in marine environments has been increasing in the last two decades. However, the suction is neglected in recent researches of suction caisson. The pull-out velocity and hydraulic conductivity are also neglected.In this paper, two models of base failures are summarized: (1) failure with rapid load, (2) failure with slow load. The pullout capacity of the suction caisson is analyzed by using the finite element software ADINA. The study involves total stress analysis and effective stress analysis. The failures with pullout load and compress load is compared in different aspect ratio In total stress analysis.In effective analysis, two models of failures are stimulated by constituting two finite element models. The ratio of suction to pullout capacity, pullout capacity of transient dynamics and static analysis and the development of the porous water pressure are studied by using rapid load model. At the meantime, the load velocity and the pullout capacity are analyzed by using slow load model.It is concluded that (1) under rapid pullout loading rate the failure appears as a reversed bearing capacity mechanism. (2) the capacity under rapid load rate is larger than the one under slow load rate. (3) with the increasing of the aspect the ratio of suction press to pullout capacity decrease and the ratio of friction to pullout capacity increase.