Measurement and prediction of the initial settlement of cube-type artificial reefs caused by free-fall installation using a laboratory-scale experiment, regression analysis, and numerical collision analysis. (1st March 2021)

• Record Type: Journal Article
• Authors: Van Chau, Than; Jung, Somi; Na, Won-Bae
• Is Part Of: Ocean engineering. Volume 223(2021)
• Publication Date: 2021-03-01
• Subjects: Cube artificial reef -- Free-fall installation -- Initial settlement -- Laboratory-scale experiment -- Numerical collision analysis; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2021.108643
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: Several studies have identified stability issues related to artificial reefs (ARs) installed on the seabed. However, initial AR settlement during free-fall installation has not been well examined. We performed a laboratory-scale experiment, regression analysis, and numerical simulation to evaluate the initial settlements of two cube-type AR models during free-fall installation into soft soil. Settlement tended to increase by impact velocity and AR mass but to decrease as soil density increased. The most significant parameter controlling settlement was soil density, followed by the impact velocity and the AR mass. Of the 56 cases examined, 76.79, 71.43, and 98.21% exhibited relative differences of ±20% as revealed experimentally, and by regression analysis and simulation. Given the terminal velocities of the two AR models, the corresponding settlement ranges were 2.12–5.36 mm and 4.56–11.56 mm, respectively. Thus, the effective useable volumes of the AR models fell by approximately 4–12% (depending on clay composition) if the models attained their terminal velocities during free-fall installation. These initial settlement data indicate that free-fall installation negatively affects both AR stability and functionality. Graphical abstract: Image Highlights: Initial settlement of artificial reefs (ARs) during free fall was considered. We performed an experiment, regression analysis, and numerical simulation. Given terminal velocities of two AR models, the settlement ranges were revealed. The most significant parameter controlling settlement was soil density. Effective useable volumes of the AR models fell by approximately 4–12%.