To increase the bearing behavior of conventional suction foundation,a modified type of the suction caisson,named as skirted suction caisson,was studied by using both the numerical method and model tests.Vertical loading-settlement curves and deformation of surrounding soil were obtained.It was shown that the skirted suction caisson can enhance the vertical bearing capacity due to adding the skirted structure.It was also found that the lid,inner and outer walls of the main bucket may provide 90% of the vertical loading,and the tip parts and inside and outside walls of the skirt account for 10%.Frictional resistance along the outer and inner walls of the main bucket increases with the increase of the ration of height to diameter.However,the resistance of tips and the outer and inner walls of the skirt accounts for less than 10% of the total resistance.Soil heave decreases with the increase of the skirt height,but increases with the increase of the e skirt width on the contrary.Contribution of skirt width to vertical bearing capacity is much greater than skirt height,but the skirt height reduces soil heave effectively.
