Effects of long-term cyclic horizontal loading on bucket foundations in saturated loose sand. (October 2019)

• Record Type: Journal Article
• Authors: Vicent, Ssenyondo; Kim, Sung-Ryul; Hung, Le Chi
• Is Part Of: Applied ocean research. Volume 91(2019)
• Publication Date: 2019-10
• Subjects: Bucket foundation -- One-way cyclic horizontal load -- Accumulated rotation -- Unloading stiffness -- Pore water pressure -- Saturated loose sand; Ocean engineering -- Periodicals; 620.416205
• DOI: 10.1016/j.apor.2019.101910
• Languages: English
• ISSNs: 0141-1187

Abstract

Highlights: 1-g experimental tests were carried out varying load magnitude. One-way cyclic horizontal loading is critical for offshore wind turbines. Accumulated rotations and unloading stiffness increase with number of load cycle. Accumulated rotations and unloading stiffness decrease with the increase in load magnitude. First load cycle causes larger suction in the foundation. Abstract: A 1- g model experimental study was conducted to investigate the accumulated rotations and unloading stiffness of bucket foundations in saturated loose sand. One-way horizontal cyclic loading was applied to model bucket foundations with embedment ratios 0.5 and 1.0. Up to 10 4 cycles of loading were applied at a frequency of 0.2 Hz varying load amplitudes. The accumulated rotation of the bucket foundations increased with the number of cycles and the load amplitudes. Empirical equations were proposed to describe the accumulated rotation of the foundations. The unloading stiffness of foundations increased with the number of cycles but decreased with an increase in load amplitude. The initial unloading stiffness of L/D = 1.0 ( L is skirt length; D is foundation diameter) was approximately twice that of L/D = 0.5. Excess pore water pressure difference of 50% was observed between L/D = 0.5 and 1.0. The suction and static capacity of the bucket increased with increase of bucket embedment ratio with a difference of 69.5% and 73.6% respectively between L/D = 0.5 and 1.0.