AU646319B2

AU646319B2 - Procedure for installation of a device for protection against swell and device resulting from the implementation of this procedure

Info

Publication number: AU646319B2
Application number: AU10184/92A
Authority: AU
Inventors: Loic Marie Jacques Danguy Des Deserts; Dominique Michel
Original assignee: GOUVERNEMENT MONEGASQUE
Current assignee: GOUVERNEMENT MONEGASQUE
Priority date: 1991-01-15
Filing date: 1992-01-14
Publication date: 1994-02-17
Anticipated expiration: 2012-01-14
Also published as: JPH05132913A; BR9200066A; ITMI920051A1; MC2301A1; AU1018492A; ES2051194A2; IT1258766B; ITMI920051A0; ES2051194B1; ES2051194R; FR2671569B1; FR2671569A1

Description

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AUSTRALIA

Patents Act COPLETE SPECIFICATION

(ORIGINAL)

046319 Int. Class Class Application Number: L dged: Complete Specification Lodged: Accepted: Published: Priority *or Related Art: S0 4 S S I 0 ""Name of Applicant: oo 0 0 Doris Engineering Actual Inventor(s): Loic Marie Jacques Danguy Dominique Michel Des Deserts *.Address for Service: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: PROCEDURE FOR INSTALLATION OF A DEVICE FOR ?ROTECTION AGAINST SWELL AND DEVICE RESULTING FROM THE IMPLEMENTATION OF THIS PROCEDURE Our Ref 240994 POF Code: 1149/80072 The following statement is a full description of this invention, 4 .ncluding the best method of performing it known to applicant(s): 600- 1 6006 1A- The present invention relates to a procedure for installation of a device for protection against swell, and, more particularly, to such a procedure capable of being implemented within a fairly wide range of bottom depths, down to 100 m deep for example.

In France especially, legal constraints now oblige designers of marine works to observe a certain number of rules aimed at protecting the environment in the costal area. Thus a new work must be designed in such a manner as not to alter the local currents, in order not to give rise to changes in the profile of the coast or phenomena of erosion and/or of new deposits. The work must moreover be as inconspicuous as possible, if not completely invisible, from the surface of the water, and have little effect on the sea bed. Finally, it is often required that the procedure utilised for constructing the work entails neither dredging of nor rock damage to this bottom.

a device has to be designed for protection S° 20 of a shore, of a port or of a coastal work of any sort r I against swell reference may be given to a device of the type described in French Patent No. 1 503 543 of V 16 April 1966, relating to a work for protection against waves comprising at its upper part two vertical walls which delimit a tank in which the energy of the waves which have passed over the wall facing the open sea is dissipated. Such a tank can be supported by piles, for example, which solution has the advantage of freeing the flow of the marine currents under the tank without disturbing them, while entailing only a minimal influence of these piles on the sea bed, in conformity with the provisions of the regulations mentioned above.

The construction of such a work on a large scale, a quay or an artificial port for example, with the aid of conventional lifting device such as cranes, increases greatly the investment on the necessary equipment, these cranes being very expensive. Finally, laying one element on another with the aid of a crane car:ies risks of damage to the element by accidental impact while coming into contact. Finally, the conventional installation procedures cannot conveniently be implemented when the depth of the sea bed is no longer shallow (less than 15 m, for example).

The present invention thus has the air:. of providing a procedure for installation of a device for protection against swell.

The present invention further concerns the protection device resulting from the implementation of this procedure.

These aims of the invention are attained, as well as others which will become apparent on reading the description which will follow.

According to one aspect of this invention there is provided a method of installing a device for protection against swell and waves, the method including: a lining a plurality of elementary caissons which are at least partly submerged in water at an installation i site, wherein each caisson is capable of floating on water to facilitate it being towed to said installation site; ballasting each caisson; and fixing each caisson in a predetermined, aligned final position on the installation site above the sea bed.

stBy transporting and thus installing the caisson on site, all need of cranes or other expensive lifting equipment is avoided, and the risk of accidental damage to Sthe elements to be installed is decreased.

It is preferred that the caisson is fixed onto a pre-installed support which is itself anchored onto the sea bed. The caisson is positioned over the support and is brought to rest on the support by ballasting. Finally, a grout is injected into the means of installing of the caisson on the support to finally fix the assembly.

It is further preferred that the piles are mounted in the caisson, which are capable of sliding in sleeves provided for this purpose, the caisson is anchored on site 39 by lowering and driving these piles into the sea bed, and "VF 2 the caisson is ballasted to stablilise it by gravity on the piles.

According to another aspect of this invention there is provided a device for protection against swell and waves, including: at least one fixed support which is anchored to the sea bed at an installation site, a plurality of elementary caissons aligned end to end and mounted on said fixed support such that each caisson is at least partly submerged with respect to the surface of the water, each caisson including means for enabling it to be floated to said installation site and means for installing the caisson to effect said at least partial submerging of the caisson.

It is preferred that the means for installing comprise sleeves and docking tubes and guide pins for these tubes, these tubes and these guide pins being arranged on the caisson and the support in such a way that they fit together axially when the caisson is mounted onto the support. Means for ballasting the caisson ensure the stabilization of the caisson on the support by gravity. A grout is next placed between the sleeves, the tubes and the guide pins in order to lock the connection between the caisson and the support.

According to different variants of the device according to the invention, the support may be constituted by a structure in the form of a tubular lattice frame, a gravity base structure, or piles. The support may be fabricated onshore, then taken to sea with means provided to make it float and finally towed to the site where it 39, 39 3 -4 is to be installed. Alternatively, the support can be loaded onto a transportation barge. In both cases the caisson, as well as the support, can be fabricated entirely onshore, under the best working conditions, including when installations in deep water are concerned (down to about 100m).

Other characteristics and advantages of the procedure and of the device according to the invention j will become apparent on reading the description which follows and on examining the attached drawing in which: i- Figure 1 is a plan view of a first embodiment i of the device according to the invention, Figure 2 is a side view of the device of Figure 1, taken along the arrow F of this Figure, 15 Figures 3 and 4 are a plan view and a side view respectively of a second embodiment of the device according to the invention, Figures 5A to 5C are sketches illustrating the installation sequence of a caisson onto a support [i1 l 20 according to a first mode of implementation of the I installation procedure according to the invention, Figures 6A to 6C represent details of Figures to SC respectively, -Figure 7 is a side view of a third embodiment of the device according to the invention, Figures 8A to 8C illustrate the installation i sequence of a device according to the invention, according to a second mode of implementation of the installation procedure according to the invention, and Figures 9A to 9D are sketches illustrating the installation sequence of a variant of the device according to the invention, designed to be invisible from the surface of the water.

Reference is made to Figures 1 and 2 of the attached drawing in which is represented, by way of example, a first embodiment of the device for protection against swell, according to the invention. This device is i C~- 5 constituted essentially by one or more elementary caissons 1 which are partially submerged and resting on a support constituted, in this embodiment, by foundation piles 2 driven into the sea bed 3. A caisson 1, produced in reinforced concrete for example, comprises essentially a slab 4 from which extend two sets of vertical partitions 51, 52, 53 and 61, 62, 63, 64, oriented at right angles to each another. Four vertical sleeves are provided to receive ends of piles 2. The partitions 61 to 64 are pierced with openings 8, regularly distributed so as to establish communications between damping chambers 9 where I part of the energy of the waves which may have passed over I the partitions is absorbed. On the view of Figure 2, the ;t open sea is to the left and the protected side is to the right.

15 right A device of the required length may be constituted, for protection against swell, by installing, end to end, parallel to their length, a plurality of elementary caissons 1 mounted on piles 2.

According to a second embodiment of the invention represented in Figures 3 and 4, the piles 2 can be replaced by a metallic structure usually called "jacket" in the prior art, which takes the form of a tubular lattice frame anchored in the sea bed with piles 10. In what follows, the identical numerical references, to which a prime may have been added, concern similar or identical elements oz members.

Referring to Figures 5A to 5C and 6A to 6C of the attached drawing, the stages of a first mode of implementation of the procedure for installation of a device for protection against swell according to the invention, of the type shown in Figures 3 and 4, are now described. On Figures 5A to 5C is shown a support structure very similar to the structure 2' from which it is distinguished only by the fact that fixing piles for the structure pass into sleeves 11 which are substantially vertical and integral with this structure,

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6 while the structure 2' is fixed by piles 10 driven obliquely into the sea bed 3. The use of vertical sleeves 11 is preferred because it facilitates the driving of the piles 10'. After driving these piles, a grout can be injected into the sleeves 11 to complete the fixing of the structure to the sea bed.

According to the invention, the structure 2" is fabricated onshore and transported onto the site by towing onto a barge in a horizontal position for example.

The structure can also be transported by towing it in floating position in the water after having attached to the structure means which give the assembly sufficient buoyancy. Once it has arrived on site, the structure is brought upright by any suitable method, well known in the prior art, and placed on the sea bed before being fixed thereto by driving or boring of the piles 10' and injection of the grout into the sleeves 11, as was seen i above. The structure is then ready to receive an elementary caisson..

The caisson is also fabricated onshore accordr I ing to the conventional techniques for reinforced concrete, which may also be prestressed. The caisson is shaped so as to be capable of floating by providing chambers 9 for this purpose, the openings 8 implemented in the partitions 6, to 64 then being blocked. The caisson is set afloat and towed to the installation site above the support structure 2" (Figure 5A) previously preinstalled.

In this position, means of installing 12, 13, arranged in the caisson 1 and at the top of the structure are aligned vertically. These installing means comprise a plurality of guide pins 12 integral with the structure and docking tubes 13 capable of sliding in vertical sleeves 7 of the caisson. Alternatively, the positions of the docking tubes and the guide pins can be reversed.

Following the procedure according to the invention, in a first stage (Figure 5B) the docking tubes 13 are lowered onto the guide pins 12. In a second stage -7- (Figure 5C), the caisson is ballasted down by allowing water to enter the chambers 9. While progressively immersed the caisson is guided by the coaxial installing system of the guide pins 12 and the docking tubes 13 which then slide in the sleeves 7 in order to permit the caisson to be placed on the top of the structure 2".

Figures 6A to 6C represent in detail the phases of the coupling of the guide pins 12 and the docking tubes 13, at the stages of the procedure illustrated in Figures to 5C respectively. Once the caisson is stabilized by gravity on top of the structure the grout 20 is Y c injected in the docking tube 13 in such a manner as to lock the guide pins 12 into the tubes 13, and the tubes 13 in the sleeves 7, in order to fix the connection I I between the caisson and its support structure.

Referring now to Figure 7, a side view is shown of a third embodiment of the device for protection according to the invention. This device is distinguished from the previous devices in that the caisson 1 is 4 41 20 supported by a gravity base structure in concrete for example, constituted by a pier having a head 15 and a base 16 supported on the sea bed 3. According to the I invention, support blocks 14 made of an elastic material such as an elastomer are interposed between the head of the pile and the underside of the caisson i. By absorption of the displacements these blocks can reduce the forces applied by the swell to the caisson 1. It will be understood that supplementary means of anchoring (not represented) are provided between the caisson and the 1 30 gravity base structure in order to limit the relative movements of the caisson on its support.

In Figures 8A to 8C three stages of a procedure for installation of a device for protection, of the type of that represented in Figures 1 and 2 are illustrated, this procedure constituting an alternative of that described above in connection with Figures 5A to The procedure illustrated in Figures 8A to 8C is ad-

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8 vantageous in that it does not require a prior installation of a support for the caisson. The caisson 1' is then equipped, during its fabrication onshore, with piles 2"" which can slide in sleeves 7' and which are fixed temporarily in a raised position as represented in Figure 8A. The caisson is then put afloat and towed to the installation site, it is then fixed in position on the site by means of anchoring lines 16. Mechanical means (not represented) are then employed to make the piles 2"" slide in the sleeves in such a manner that they descend t towards the sea bed (see Figure 8B). The piles are then :driven so as to penetrate into the sea bed 3 (see Figure 8C). The caisson is next ballasted so as to slide i downwards on the piles to a predetermined height so that they partially emerge above the surface of the water. It is then fixed in this position by injections of grout 17 into the sleeves around the piles V Thus, by means of the procedure illustrated in transported and installed on the site at the same time, which considerably simplifies the installation operations, doing away with operations at open sea to position the caisson onto guide pins such as the guide pins 12 of Figures 6A to 6C.

In Figures 9A to 9D is illustrated another variant of the procedure according to the invention, which includes the installation of a device for protection against swell which is advantageously invisible above the surface of the water. It is known that such a device can be constituted by a caisson 1" or a plate entirely submerged under the surface of the water, at a certain distance from the sea bed 3, the support of the plate being such that it does not oppose the flow of marine currents under the plate. To this effect, according to the present invention, a tubular lattice structure 2" can be used of the type which has already been described in connection with Figures 5A to 5C. The caisson 1" is then ~i--I11U 9 towed above the structure (Figure 9A), then positioned (Figure 9B) and stabilized by gravity on this structure (Figure 9C) by the ballasting mechanism already described in connection with Figures 5A to 5C. However, according to one characteristic of the procedure according to the invention, the caisson is equipped, during its fabrication onshore, with removable flotation chambers 18 attached to its extremities as represented in Figures 9A to 9C. This flotation chambers 18 are required to ensure afloat condition of the caisson and to control the descent of the caisson 1" onto the top of the structure 2" by ballasting with water, as soon as the caisson is entirely Ssubmerged. Once the caisson is supported on the top of the structure (Figure 9C), the removable flotation chambers are disconnected from the caisson in order to i clear the surface of the water entirely, as represented in Figure 9D.

V It now appears that the procedure and the device according to the invention satisfy the objectives set. Thus the elements of the device can be brought to and fixed on site by safe and economical techniques of towing, assembling and ballasting, which do not call on costly lifting equipment which may cause damage by accidental impacts. Thus the erection of the elementary caissons onto supports fabricated onshore, combined with the techniques cited above, allows installation of the device even in relatively deep water (100 m of water for example), respecting the regulations relating to protection of the coastal environment, which may in particular specify free flow of the marine currents under the antiswell caissons.

Claims

2. A procedure according to claim i, wherein each caisson is fixed in said predetermined final position by being mounted on a pre-installed support which is anchored to the sea bed.
3. A procedure according to claim 2, wherein each caisson is mounted on said pre-installed support by installing means located at the interface of the caisson and the support, said installing means comprising guide pins and docking tube guides which are slid onto said guide pins.
4. A procedure according to claim 3, wherein said docking tube guides having the guide pins received therein are capable of sliding within sleeves formed in the caisson.
5. A procedure according to any one of claims 2 to 4, including permanently connecting said caisson to said support by placing a grout between the guide pins, docking tubes and sleeves.
6. A procedure according to any one of claims 2 to 5, wherein blocks made of resilient material are installed between the caisson and the support in order to reduce the forces applied by the swell.
7. A method according to claim i, including placing a support in the form of piles on each caisson prior to installation, and anchoring the caisson to the sea bed at said installation site by lowering the piles to the sea bed and driving the piles into the sea bed, and then ballasting the caisson to stabilize it by gravity on 39 the piles in said predetermined final position. 10 iIv~
8. A procedure according to any one of claims 2 to 6, including transporting each caisson to said installation site with the aid of removable flotation chambers which are disconnected from the caisson after the caisson has been mounted on the support.
9. A device for protection against swell and waves, including: at least one fixed support which is anchored to the sea bed at an installation site, a plurality of elementary caissons aligned end to end and mounted on said fixed support such that each caisson is at least partly submerged with respect to the surface of the water, each caisson including means for enabling it to be floated to said installation site and means for installing the caisson to effect said at least partial submerging of the caisson. A device according to claim 9, wherein said installing means include guide pins and docking tubes capable of sliding in sleeves formed in the caisson, said guide pins being axially received within said docking tubes when said caissons are mounted on said support.
11. A device according to claim 9 or claim wherein said caisson is permanently connected to said support, the permanent connection being effected by the I 25 injection of grout material between the guide pins, docking tubes and sleeves.
12. A device according to any one of claims 9 to 11, wherein each caisson includes damping chambers facing t outwardly towaids either the open sea or the land for 130 damping the swell, adjacent chambers being interconnected by openings which are blocked off when the caisson is towed to the installation site, thereby to provido the caisson with sufficient buoyancy. 1.3. A device according to any one of claims 9 to 12, wherein said fixed support is a tubular lattice frame, a gravity base structure, or a plurality of piles.
14. A device according to claim 13, wherein said piles are mounted to said caisson prior to said caisson 39 being floated to said installation site, each said pile VF -i being slidably received within a said sleeve. A device according to claim 14, wherein said piles are permanently rigidly connected to said caisson after said piles are driven into the sea bed and said caisson has been at least partly submerged to a predetermined depth by ballasting.
16. A device according to claim 9, wherein support blocks of resilient material are interposed between the caisson and the support.
17. A device according to, any one of claims 9 to 13, wherein each caisson is in the form of a plate arranged to be submerged when mounted on said support, removable flotation chambers being fixed to the plate to Sprovide satisfactory buoyancy during transportation to the installation site and facilitating control of the descent of the caisson onto said support by ballasting before being disconnected form the caisson.
18. A method for installation of a device substantially as herein described with reference to any one of the embodiments in the accompanying drawings.
19. A device for protection against swell substantially as herein described with respect to any one of the embodiments illustrated in the accompanying drawings. y DATED: 1 December 1993 PHILLIPS ORMONDE FITZPATRICK Attorneys for: i i 30 DORIS ENGINEERING i 39 4509b 12 -13 Procedure for installation of a device for protection against swell and device resulting from the implementa- tion of this procedure Company called: DORIS ENGINEERING Inventors: Loic, Marie, Jacques DANGUY DES DESERTS, Dominique MICHEL ABSTRACT I The device comprises at least one support (2; fixed on a predetermined sea-bed site, a S't caisson comprising means which allow it to be S floated for transporting it to the predetermined site, Sand means (12, 13; 7; for installing the caisson onto the support in such a way that the caisson is then at least partially submerged in a predetermined position with respect to the surface of the water. The caisson (1) Sis positioned on the support by docking tubes (13) interacting with guide pins (12) integral with the support. The caisson is ballasted to stabilize it by gravity on the support. Application to the protection of a coastal work or site. Figure