Jackets (breakwaters, wave dissipaters)
Jackets consist of the leg of three-dimensional truss structures made up of steel pipes and a pile driven therein, which are fixed to the ground of the seabed and combined using welding or grout. A steel pipe truss simultaneously helps to increase rigidity and rationally distribute loads to the foundation piles. Jackets can be manufactured in a plant and erected as large-size blocks through single operation, so it is possible to achieve high-quality and a reduced construction period. Jackets have been adopted for many piers and quays, and today, an increasing number of breakwaters using jackets are being applied at locations where caissons are difficult to construct, such as deep waters and soft seabed ground. In addition, if the seabed ground is strong enough, mounting type (gravity type) breakwaters of frame hybrid structure, for which piling is not required, can also be applied.
Construction examples
Name of construction work | Breakwater jacket manufacturing work in Aoura Fishery Harbor |
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Client | Nagasaki Prefecture |
Purpose/function | Breakwater |
Year of construction | 2010 |
Dimensions(m) | 24.8 (length) × 15.5 (width) × 21.5 (height) |
Quantity (/element) | Weight of steel: 196 tons |
Design overview | Installation water depth: -15.8 m |
Features | Seawater exchange type |
Name of construction work | Breakwater jacket manufacturing work in Kuzuwa Fishery Harbor |
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Client | Kagoshima Prefecture |
Purpose/function | Breakwater |
Year of construction | 2010 |
Dimensions(m) | 19.8 (length) × 26.2 (width) × 33.7 (height) |
Quantity (/element) | Weight of steel: 245 tons |
Design overview | Installation water depth: -27 m |
Name of construction work | Offshore breakwater manufacturing work on Suruga-Isshiki Beach |
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Client | Ministry of Land, Infrastructure, Transport and Tourism Chubu Regional Development Bureau |
Purpose/function | Offshore breakwater |
Year of construction | 2007 |
Dimensions(m) | 49.7 (length) × 10.4 (width) × 4.2 (height) |
Quantity (/element) | Weight of steel: 113 tons |
Design overview | Installation water depth: -7 m, design wave height (Hmax): 4.0 m |
Features | Structure intended to protect the beach from beach erosion and reduce waves |
Name of construction work | Breakwater construction work in Yokosuka Port (Kurihama Zone) |
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Client | Yokosuka City |
Purpose/function | Wave dissipater |
Year of construction | 1985 |
Dimensions(m) | 30.0 (length) × 4.0 (width) (top end width) × 8.5 (height) |
Quantity (/element) | Weight of steel: 48 tons/unit, concrete: 362 m3, asphalt mat: 135 m2 |
Design overview | Installation water depth: -5.5 m, design wave height (H1/3): 1.1 m, design coefficient kh: 0.2 |
Features | Mounting type hybrid structure |