Model test study on the response of coral sand foundation reinforced by vibroflotation

• Published in: Acta geotechnica Vol. 18; no. 11; pp. 6201 - 6212
• Main Authors: Zhao, Jinqiao, Ou, Qiang, Ding, Xuanming, Chen, Zhixiong
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.11.2023; Springer Nature B.V
• Subjects: Civil engineering; Complex Fluids and Microfluidics; Corals; Densification; Density; Distance; Dredging; Earth; Earth pressure; Engineering; Foundations; Geoengineering; Geotechnical Engineering & Applied Earth Sciences; Grain size; Hydraulics; Investigations; Liquefaction; Model testing; Pore pressure; Pressure; Research Paper; Sand; Soft and Granular Matter; Soil Science & Conservation; Solid Mechanics; Technology; Variables; Vibration; Vibrators; Coral sand; Vibroflotation; Excess pore pressure; Horizontal earth pressure; Vibro-compaction method
• ISSN: 1861-1125; 1861-1133
• DOI: 10.1007/s11440-023-01986-2

Vibroflotation without backfill is an effective foundation treatment method for the hydraulic dredged coral sand foundation. In this study, a series of model tests were conducted to compare four construction variables of vibroflotation. The dynamic responses of excess pore pressure and horizontal earth pressure are recorded and analyzed. The results show that the shallow layer is more likely to be liquefied at the first penetration when the double-point vibroflotation technology works on, while the single-point vibroflotation technology makes homogeneous distribution of excess pore pressure ratios. Furthermore, the first vibration duration shows a large effect on rising the anti-resistance of liquefaction and more than three times of vibration process is redundant for densification. In addition, the reinforcement effect at the shallow layer can be better with suitably larger vibration frequency of the vibrators and less distance between two vibrators. In terms of horizontal earth pressure, the maximum horizontal earth pressure appears at the middle of the movement stage rather than at the end. The peak values attenuate with increasing distance from vibrators during the penetration. Furthermore, the horizontal earth pressure caused by single-point vibro-compaction is distinctly larger than the other cases at the middle of two vibrators. Larger vibration frequency and vibration distance come significantly less peak horizontal earth pressure near the vibro-point.