EP0659940B1

EP0659940B1 - Floating breakwater having improved wave impact stability

Info

Publication number: EP0659940B1
Application number: EP94120341A
Authority: EP
Inventors: Giuseppe Buongiorno
Original assignee: PATENTWERKE AG
Current assignee: PATENTWERKE AG
Priority date: 1993-12-21
Filing date: 1994-12-21
Publication date: 2000-04-19
Anticipated expiration: 2014-12-21
Also published as: EP0659940A1; IT1265316B1; ITMI932692A0; ITMI932692A1

Description

The present invention relates to a floating breakwater having improved wave impact stability.
It is known that floating breakwaters or seawalls are already available which in practice are constituted by a barrier that is submerged to a limited depth and has much longer oscillation periods than the force-applying actions, so that the kinetic energy of the waves is dissipated.
In conventional floating breakwaters it has been observed that the floating barrier can, in case of a more prolonged wave motion, tend to follow the rise of the wave, consequently being less effective in dissipating the kinetic energy of the waves.
Another drawback that can be ascribed to the solutions proposed by the prior art is also constituted by fact that conventional breakwaters have a single function and do not allow to use them as a floating wharf or as a walkway.
The aim of the invention is indeed to solve the drawbacks described above by providing a floating breakwater having improved wave impact stability that allows to reduce the rise of the breakwater in the presence of waves without however modifying its general buoyancy characteristics.
Within the scope of this aim, a particular object of the invention is to provide a breakwater that can have four functions, namely floating breakwater, walkway, sheltered landing for watercraft, and occasional unsheltered landing in case of dead calm.
Another object of the present invention is to provide a breakwater that is capable of giving the greatest assurances of reliability and safety in use by virtue of its particular constructive characteristics.
U.S. Patent 3,991,576 discloses a floating breakwater comprising floating bodies which lie longitudinally and are kept mutually spaced and joined by a framework provided with transverse elements. The floating bodies are formed by a housing containing a floating material and a weighting material.
The aims and objects of the present invention mentioned above and others which will become apparent hereinafter are achieved by a floating breakwater having improved wave impact stability comprising a first floating barrier and a second floating barrier which lie longitudinally and are kept mutually spaced and joined by a framework provided with transverse elements, said floating barriers comprising floating bodies that form an upper floating volume and a lower ballasting mass, characterized in that each floating body comprises an upper caisson and a lower caisson which are inserted into one another and respectively form said upper floating volume and the region for containing said lower ballasting mass.
Further characteristics and advantages will become apparent from the description of a preferred but not exclusive embodiment of a floating breakwater, illustrated only by way of non-limitative example in the accompanying drawings, wherein:
figure 1 is a schematic top plan view of an embodiment of the breakwater with the corresponding anchoring sinkers;
figure 2 is a view of the breakwater, taken from a side end face, illustrating the anchoring sinkers;
figure 3 is a schematic plan view of a portion of the breakwater;
figure 4 is a schematic view of the breakwater, illustrating the damping of wave motion;
figure 5 is an elevation view of a floating body;
figure 6 is a sectional view of the floating body;
figure 7 is an enlarged-scale view of a detail of the floating body, illustrating the coupling between the two components;
figure 8 is a schematic view of a floating breakwater arranged so as to protect a small harbour.
With reference to the above figures, the floating breakwater with improved wave impact stability, according to the invention, comprises a first floating barrier 1 and a second floating barrier 2 that run longitudinally and are joined by a framework, generally designated by the reference numeral 3, which is provided with transverse stiffening elements.
The overall structure is formed so as to have an appropriate transverse rigidity that allows to contrast the thrust of the waves and to dissipate their energy.
The breakwater thus formed is anchored by means of sinkers 5 which are placed on the bed and are connected to the breakwater by means of conventional chains 6.
An important particularity of the invention is constituted by the fact that the floating barriers 1 and 2 are provided by arranging floating bodies side by side; said bodies are generally designated by the reference numeral 10 and are constituted by an upper caisson 11 which forms an upper floating volume and by a lower caisson 12 that forms a lower ballasting mass.
More specifically, the upper floating volume formed by the internal surface of the upper caisson 11 is internally provided with masses 13 of single-cell foamed plastics that makes the assembly unsinkable, whereas the ballasting mass is simply provided by a mass of water 15 which can enter the region that lies between the upper caisson 11 and the lower caisson 12 by means of a hole 16 formed on the wall of the lower caisson 12.
This way of providing the ballasting mass is particularly important, since the mass of water contained in the lower caisson 12 in practice does not modify the buoyancy characteristics of the assembly in normal conditions, whereas it instead constitutes a ballast in the presence of waves, since it prevents the free rise of the wharf and accordingly creates a stronger impact with the waves, consequently dissipating the kinetic energy of the waves more effectively.
The coupling between the lower caisson and the upper caisson is provided by means of locking bolts 20 which mutually join the caissons 11 and 12 in the mutual coupling region.
At the upper edge of the caisson 11 there is also a closing profile 30 that allows to fix a walking surface 31 that makes the breakwater walkable.
It should be added to the above that it is optionally possible to provide fenders both on the sheltered side and on the unsheltered side, allowing the mooring of watercraft.
From the above description it is thus evident that the invention achieves the intended aim and objects, and in particular the fact is stressed that a floating breakwater is provided which is considerably more effective both in view of its greater overall functionality and because of the fact that at each floating body there is provided a ballasting mass that significantly increases the stability of the assembly and reduces the rise of the floating barrier when it is struck by waves, consequently achieving a better dissipation of the kinetic energy.
The floating breakwater according to the invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appending claims.
In practice, the materials employed, so long as they are compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to the requirements.
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

Floating breakwater having improved wave impact stability comprising a first floating barrier (1) and a second floating barrier (2) which lie longitudinally and are kept mutually spaced and joined by a framework (3) provided with transverse elements, said floating barriers comprising floating bodies (10) that form an upper floating volume and a lower ballasting mass, characterized in that each floating body comprises an upper caisson (11) and a lower caisson (12) which are inserted into one another and respectively form said upper floating volume and the region for containing said lower ballasting mass.
Floating breakwater according to Claim 1, further comprising masses of single-cell foamed plastics in said upper caisson (11).
Floating breakwater according to Claim 1 or 2, wherein a chamber is formed between said upper caisson (11) and said lower caisson (12), said chamber being connected to the outside by means of a hole (16) formed on the wall of said lower caisson (12), and in that the water that forms said lower ballasting mass can be introduced in said chamber.
Floating breakwater according to one or more of the preceding claims, wherein said upper caisson (11) and said lower caisson (12) are mutually joined by locking bolts (20) in the coupling region.
Floating breakwater according to one or more of the preceding claims, further comprising, at the upper edge of said upper caisson (11), profiled elements (30) for retaining a covering (31) that forms a walkable surface.
Floating breakwater according to one or more of the preceding claims, further comprising, on the sheltered side and on the unsheltered side, fenders for the mooring of watercraft.