Abstract: The loading inclination and mooring point position of a suction anchor are crucial design elements that can alter the failure posture of anchor body, thereby influencing the ultimate bearing capacity. In a centrifugal model test of tensioned suction anchor under displacement control in saturated soft clay foundation, different loading inclinations and mooring point positions were selected. The influence of these factors on the failure posture and ultimate bearing capacity was quantitatively analyzed using a six-degree-of-freedom magnetometer device. It was observed that when the mooring point position was at about 2/3 height of the anchor body, the suction anchor experienced translational failure. However, when the loading inclination angle changed from 35° to 20° at the same mooring point position, the suction anchor exhibited backward tilting failure and the normalized ultimate bearing capacity increased slightly. Even after reaching the ultimate bearing capacity, it still maintained a certain amount of load-bearing capacity margins. On the other hand, when the mooring point position was above 2/3 height of the anchor body, the suction anchor experienced forward tilting failure, leading to a decrease of about 25% in the normalized ultimate bearing capacity, and a significant reduction in the load capacity margin after failure. Regardless of the failure posture, no significant separation of the soil plug from the anchor was observed within the anchor.

Key words: centrifugal model test, suction anchor, loading inclination, mooring point position, failure posture, ultimate bearing capacity