Determining the weights of two types of artificial reefs required to resist wave action in different water depths and bottom slopes

• Published in: Ocean engineering Vol. 36; no. 12; pp. 900 - 913
• Main Authors: Duzbastilar, F, Senturk, U
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.09.2009; Elsevier
• Subjects: Applied sciences; Artificial reef; Bottom slope; Buildings. Public works; Deployment depth; Design weight; Exact sciences and technology; Hydraulic constructions; Marine; Port facilities and coastal structures. Lighthouses and beacons; Stability; Turkish Seas; Wave force; Stability; Wave force; Design weight; Turkish Seas; Deployment depth; Artificial reef; Bottom slope; Wave resistance; Wave effect; Shallow water; Weight; Depth; Coastal zone; Design; Bottom; Computing method; Quantitative analysis
• ISSN: 0029-8018; 1873-5258
• DOI: 10.1016/j.oceaneng.2009.06.008

The interaction between waves and artificial reefs (ARs; a hollow cube weighing 8.24 kN (0.84 t) and a water pipe weighing 1.27 kN (0.13 t)) in shallow waters was investigated with respect to variations in design weight, orientation (for cube; 45° and 90° angles, for pipe; 0°, 90°, and 180° angles to flow), depth (1–20 m), and bottom slope (10 −1, 30 −1, and 50 −1). Physics equations and FLUENT software were used to estimate resisting and mobilising forces, and drag coefficients. Drag coefficients for the hollow cube were 0.76 and 0.85 at 45° and 90° angles to the current, respectively, and 0.97, 0.38, and 1.42 for the water pipe at 0°, 90°, and 180° angles to the current, respectively. Deepwater offshore wave conditions at six stations were transformed into shallow nearshore waters representative of the artificial reef site. Waters deeper than 12 and 16 m are safe to deploy blocks with angles of 45° and 90°, respectively. However, water pipes constructed at angles of 90° and 180° to the current were estimated as being unstable for 365 out of 720 cases at all stations (only one station was stable for all cases). Water pipes angled at 0° were found to be stable in all 360 cases. Slope had a significant effect on weight and depth. Results from this study provide an important reference for engineers performing projects aiming to increase the performance and service life of ARs.