Effects of the Installation Method, Loading Condition, and Failure Mechanism on the Behavior of Suction Piles under Monotonic Horizontal Loading

Juhyung Lee,Jinung Do

doi:10.3390/jmse9121333

Abstract

A suction pile is a promising option when floating offshore structures are deployed at deep and distant locations. A suction pile is typically used for the foundation system of a mooring system subjected to horizontal loading with a load inclination. In this study, the effects of installation method, loading position, and load inclination on the behavior of a suction pile under monotonic horizontal loading were evaluated via large-scale soil chamber testing. A series of horizontal load tests were performed by varying the loading position at pile embedded lengths of 1/4, 1/2, 2/3, and 3/4. A horizontal load test with a load inclination of 20° was conducted and compared with that of a load inclination of 0°. The failure mechanism of the suction piles under monotonic horizontal loading was assessed via particle image velocimetry (PIV) analysis. The movement of the suction pile during monotonic horizontal loading was elucidated in terms of the horizontal displacement, vertical displacement, and rotation angle. The results of this study show apparent differences between jacking and suction-installed piles and piles under different loading conditions. The PIV analysis shows that the rotational behavior under monotonic horizontal loading can be a critical point to affect the horizontal resistance of the suction pile.

Highlights

Among the indirect foundations for the mooring system, suction pile is an offshore foundation system that is widely used worldwide; it is known as bucket foundation, skirted foundation, suction anchor, suction caisson, etc
The different installation methods investigated involved jacking and suction pressures. These two installation methods were evaluated via horizontal load and cone penetration tests
A series of horizontal load tests were conducted at different loading positions and load inclinations

Summary

Introduction

For the zone near the shoreline (e.g., ~50 m deep), a direct foundation system, such as a gravity base, a monopile (with guy wires), a tripod, and jacket foundations, can be used for offshore structures [1]. As the distance from the shoreline and water depth increase (up to 1600 m deep), the offshore foundation system transitions to an indirect foundation with a mooring system, for example, with a dead weight, driven pile, drag anchor, suction pile, torpedo pile, vertically loaded anchor, etc. Among the indirect foundations for the mooring system, suction pile is an offshore foundation system that is widely used worldwide; it is known as bucket foundation, skirted foundation, suction anchor, suction caisson, etc. Suction piles offer many advantages compared to other types of anchors, such as easy positioning in deep water, easy removal and relocation, less dependency on

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