Model tests on lateral bearing capacity and deformation of skirted suction caissons in saturated fine sand under horizontal monotonic loading

Applications of offshore wind energy are increasingly attracting world attention. Horizontal loads play a predominant role in the foundation design. The skirted suction caisson, as a novel type of foundation, is capable of providing greater lateral bearing capacity and limiting the horizontal displacement, especially suitable for foundations of offshore wind turbines. A series of model tests are conducted to investigate the behaviors of skirted suction caissons under monotonic lateral loading in saturated marine natural fine sand. The test results show that the horizontal bearing capacity of the skirted suction caisson is significantly improved compared with that of the traditional suction caisson, and its horizontal displacement is effectively controlled. The bearing capacity increases with the increasing size of the skirted structure, and decreases with the increase of the loading eccentricity. The skirted suction caisson mainly rotates with a rotation center which locates approximately at a depth of 0.45~0.7 times the main structural length. When the ultimate load is reached, toward the loading direction, the range of ground surface have is approximately 2.5 times the main structural diameter away from the edge of caissons.