FR2556379A1 - Method for forming an anti-swell device and device related thereto - Google Patents

Abstract

Method for constructing dykes and breakwaters intended to reduce the roughness (swell, waves) of a stretch of water (port, harbour, lake) and the consequences of this roughness on any fixed or floating body located in the zone protected by the device. It consists of posts 1, which may or may not have lateral projections 2-2 bis 3-4 arranged in such a way that the water flow between the elements of the device is turbulent and thus limits, on the one hand, the roughness of the water downstream and, on the other hand, the reflection of the swell upstream. The construction method furthermore has the advantage of significantly reducing the ground area occupied by the structure compared to conventional methods and of limiting the dangers on site during the construction period.

Description

 The invention relates to a method of building dykes intended to reduce the agitation of water and its consequences on any fixed or floating body in the area sheltered by the device. It therefore relates more particularly, but not exclusively, to the production of groynes at sea or in rivers, the protection of coasts, ports, working platforms at sea, ships at anchor against the effects of swells and waves.

 Current anti-swell devices generally consist of riprap dikes, concrete caissons, or flexible devices.

 Rockfill dams can be made of natural elements (rocks) or artificial elements (concrete blocks). They present significant construction hazards, because they can be carried away during work, and have a significant footprint.

 The concrete boxes must be seated on a very well adjusted foundation. They also present construction hazards, especially during the execution of the foundations, and also have a fairly large footprint. In addition, they reflect the entire swell, except when they are fitted with suitable devices intended to dampen this reflection.

 Finally, flexible devices, generally floating, are little used, because they are fragile, and their field of application is generally limited to low wave heights.

 The invention therefore aims to achieve a new type of anti-swell device with an extremely small floor area, for which the hazards of construction are minimized and, in any event, can not lead to the destruction of a partially completed structure, which finally limits the reflection of the swell.

 The method according to the invention is characterized in that the dyke is formed by installing piles, if necessary differentiated, in such a way that the space between the piles, if it exists, creates passages for turbulent water to limit, by pressure drop, the agitation of the water downstream of the device and the reflection of the swell upstream.

 The spacing between the piles or their lateral projections will thus be determined according to the characteristics of the swell or waves, wavelength, period, amplitude, in order to obtain the desired flow leading to sufficient pressure losses.

 In a preferred (but not exclusive) embodiment of the invention, the piles consist of beaten metal tubes and the lateral projections, if they exist, consist of metal elements, such as irons I or H, angles , elements of pal boards, etc.

 The piles, in this type of construction, have a double function: that of constituting the damping device itself, and that of ensuring its support, by being able to absorb by bending, the forces due to the swell.

 Other characteristics of the invention will be further highlighted during the description which follows with regard to the attached drawings, which description and drawings are, of course, given mainly by way of indication.

Figure 1 shows in perspective, and schematically, the essential elements of an anti-swell device established in accordance with one of the preferred embodiments and without lateral projection
Figure 2 shows, in perspective, another device consisting of piles H 1 not provided with lateral projections.

 FIG. 3 shows, also in perspective, the essential elements of the device, established in accordance with one of the preferred embodiments, with lateral projections 2 made up of flat facing half-sheet piles.

 Figure 4 is a top view of another type of projections La traux 2 and 2a.

 FIG. 5 is a top view of another type of lateral projections 3.

 FIG. 6 is a top view of another type of lateral projections 4.

 Figure 7 shows in perspective an assembly with two side projections, opposite, different.

 FIG. 8 shows a top view of an assembly consisting of cylindrical piles 1 provided with a single lateral projection 2.

 FIG. 9 is a front view of an assembly, without lateral projections, surmounted by a service gangway 6.

 Proposing, for example, to produce an anti-swell dam element requiring a minimum footprint, in accordance with a preferred embodiment of the invention, it will be made to comprise a row of tubular metal piles 1, of 1,220 mm diameter for example, beaten with diesel sheep, spaced about 10 cm apart from each other, filled with sand or concrete to ensure greater rigidity for each pile.

 The upper part of the piles 5 will be Liai rung at the head, using metal beams, in order to allow a service passage 6, to access for example a markup at the end of the dike.

 The piles can be provided with Side projections 2, Zbis, 3 and 4, flat sheet piles for example 2, on the tidal height.

 The half-sheet piles 2 are advantageously welded to the piles 1 before being driven, and the spacing between the half-piles 2 is 10 cm, which gives, for sheet piles of 40 cm in width, a spacing between the piles of 50 cm.

 This second arrangement, with lateral projections, therefore has the particularity of increasing the spacing between the piles. This can be advantageous, in particular in the case where a risk of ground jam exists when the piles are beaten too close together.

 A wide variety of arrangements can be made, depending on the shape and size of the side projections, as shown in Figures 3 to 8.

 As goes without saying, and as has already been indicated, the invention is in no way limited to those of its modes of application, no more than to those of the embodiments of its various parts, having been more special between indicated; on the contrary, it embraces all variants, in particular those where the piles consist of elements other than metal tubes, or even those where the lateral projections consist of elements other than metal sheet piles.

 The process for developing the anti-swell device, and the device relating thereto, can advantageously be used wherever breakwaters, anti-swell dykes or intended to prevent erosion are envisaged, mainly when the footprint of the device will be limited or that natural risks (floods for example) will make the construction of a traditional dyke random.

Claims (9)

 1. A dike construction method intended to reduce the agitation of water and its consequences on any fixed or floating body, characterized in that the dike is formed by installing piles 1 if necessary differentiated, in such a way that the space between the piles, creates turbulent water passages 7 making it possible to limit, by pressure drop, the agitation of the water downstream of the device and the reflection of the swell upstream.  2. Construction device, for implementing the method, Ion claim 1, characterized in that the piles 1 can be provided with one or more lateral projections 2, 2bis, 3 and 4 intended to create between two adjacent piles a pressure drop  3. Device according to claim 1, characterized in that the spacing 7 of the piles 1 not provided with lateral projections is small, less than a fifth of their width, this spacing being determined from the characteristics of the swell.  4. Device according to claims 1 and 2, characterized in that the lateral projections 2, 2bis, 3 and 4 of the piles 1 can be opposite or angularly offset, and possibly only exist on one of the two sides of the pious.  5. Device according to claims?, 2 and 4, characterized in that the spacing of the piles 1 provided with one or more lateral projections 2, 2bis, 3 and 4 is such that the spacing 7 between your lateral projections, is less than one-fifth of the width of the stake.  6. Device according to claims 1, 2, 4 and 5, characterized in that the lateral projections 2, 2bis, 3 and 4 can be essentially ment but not exclusively made up of metallic elements: elements of palpLanches 1, 2bis, irons H or I 3, angles 4.  7. Construction according to claims 1, 2, 5 and 6, characterized in that the lateral projections 2, 2bis, 3 and 4 extend over all or part of the length of the piles 1.  8. Construction according to any one of claims 1 to 7 characterized in that the piles 1 can be made of any type: metal tubes, whether or not filled with materials, sheet pile box, piles, H-irons, concrete posts, wooden posts, of various profiles, simple or composite.  9. Construction according to any one of claims 1 to 8 characterized in that the piles 1 can be linked at the head, by a device 6 such as metal beams which can also serve as an upper gangway, or as a support for example for signaling or beaconing devices.