US3803852A

US3803852A - Process for building an island

Info

Publication number: US3803852A
Application number: US00349364A
Authority: US
Inventors: Luque R Fernandez; J Goppel
Original assignee: Shell Oil Co
Current assignee: Shell USA Inc
Priority date: 1972-04-11
Filing date: 1973-04-09
Publication date: 1974-04-16
Anticipated expiration: 1991-04-16
Also published as: GB1368939A; BE797728A; JPS499805A; NL7204805A; DE2317803A1

Abstract

A foundation is built up in a body of water by depositing artificial seaweed in a specified area on the bottom of the body of water then depositing sand particles in the area defined by the seaweed, and repeating the process in successively smaller areas so that a foundation such as an island is built up.

Description

United States Patent [191 Fernandez-Luque et al.

PROCESS FOR BUILDING AN ISLAND Inventors: Rafael Fernandez-Luque, Rijswijk;

Johan M. Goppel, Delft, both of Netherlands Assignee: Shell Oil Company, Houston, Tex.

Filed: Apr. 9, 1973 Appl. No.: 349,364

Foreign Application Priority Data Apr. ll, 1972 Netherlands 7204805 US. Cl. 61/46, 61/2, 61/3, 61/50, 47/1 Int. Cl. E02b 1/00, E02b 3/04, E02b 3/18 Field of Search 61/46, 52, l, 2, 3, 4, 61/37, 38; 47/1 [111 3,803,852 1 Apr. 16, 1974 V [56] References Cited UNITED STATES PATENTS 3,299,640 1/1967 Nielsen 61/3 3,323,310 6/1967 Arpin 61/3 2,939,290 6/l960 Crake 6l/46.5

Primary Examiner-Jacob Shapiro Attorney, Agent, or Firm-Tom M. Moran [57] ABSTRACT A foundation is built up in a body of water by deposit ing artificial seaweed in a specified area on the bottom of the body of water then depositing sand particles in the area defined by the seaweed, and repeating the process in successively smaller areas so that a foundation such as an island is built up.

2 Claims, 13 Drawing Figures PATENTEDAPR 16 1974 sum 1 or 3 FIG. 6

PATENTEDAPR 16 um I sum 2 of 3 PATENIEDAPR 16 m4 I 3,803Q852 sum 3 OF 3 1 PROCESS FOR BUILDING AN ISLAND Background of the Invention 1'. Field of the Invention The claimed subject matter is a process for building up a foundation in a body of water.

2. Descripton of the Prior Art Deposition of sand on an underwater base in order to raise the bottom locally in such a manner that it can serve as a foundation has been employed for a long time. However, unless special measures are taken very large quantities of sand have to be used as a result of the small tipping angle of sand deposited under water. When building an island such a special measure involves for example building an enclosing dyke in the water and depositing the sand within the dyke.

According to the present invention a simple relatively cheap method of building a sand foundation in a body of water is presented which does not require the presence of an enclosing dyke but uses instead artificial seaweed.

US. Pat. No. 3,299,640 to Nielsen, issued Jan. 24, 1967, teaches a means to influence the migration of underwater particles, i.e., artificial seaweed. US. Pat. No. 3,559,407 issued to Schuur on Feb( 2, 1971 and US. Pat. No. 3,590,585 issued to De Winter on July 6, 1971 also describe certain improved artificial seaweeds. Generally it'is taught that the artificial seaweed is used for protecting the sea-bottom or beach against erosion by water currents and waves. This seaweed consists of a plurality of oblong, flexible, buoyant strands made of syntheticmaterial, i.e., polypropylene, and secured to anchoring means for holding the strands close to the means and will be referred to hereinafter by the term' seaweed element.

SUMMARY OF THE INVENTION Generally this invention is, a process for building a foundation in a body of water which comprises:

1. depositing artificial seaweed onto the bottom of a body of water so that a particular area is defined,

2. depositing particles from the surface of said body of waterso that said particles fall within the area defined by the seaweed and so that the particles are contained within said area by the action of the seaweed to form a layer of an aggregate of said particles on the floor of said body of water,

3. depositing seaweed on top of the layer of particles so formed in step (2) and within the boundaries of said raised layer,

4. depositing particles onto the area defined by the seaweed so deposited in step (3) so that another layer of an aggregate of the particles is built up, and

5. repeating steps (1 (4) to obtain a raised foundation of particles as required for the desired purpose.

PREFERRED EMBODIMENTS The first step in the claimed process of building a foundation in a body of water is the deposition of artificial seaweed onto the bottom of the body of water so that a particular area is defined. The area may be defined by depositing the seaweed so that an enclosed area is formed, such as a rectangle or circle wherein the seaweed defines the outer portion of the rectangle or circle. The artificial seaweed may also be deposited in a pattern on the bottom of body of water so that rows of seaweed are deposited which define a specific zone, such as a rectangle, square or circle, or the seaweed may be deposited to form a criss-cross pattern.

The next step in the process of building the foundation is to deposit from the surface of the body of water particles heavier than water, such as sand, so that the particles fall within the zone or area defined by the seaweed and are confined to that area. The particles deposited from the surface are suspended in the water by currents and movement of the water and are caused to drop to the bottom of the body of water by the action of the seaweed in slowing down the water which is carrying the particles. After sufiicient amount of particles have been dropped so that an aggregate or layer is formed on the bottom of the body of water additional seaweed is deposited on the raised layer (or terrace) and within the confines of the layer so formed so that another zone is defined within the original defined area made by the first deposition of seaweed. After the second deposition of seaweed takes place, additional particles are deposited from the surface of water so that the particles again fall within the area defined by the second series of seaweed articles and so that the particle are contained within the second defined area of seaweed.

This process is carried on until a sufficient aggregate layer of particles. is built up to the requisite heightfrom the bottom of the body of water. The top of the foundation made according to the process of this invention may be either above or below the surface of the body of water depending upon the use which is desired to be made thereof. The process may be used not only to prepare an island from the bottomof the body of water but may also be used to extend a peninsula further out into the body of water than it is presently extending. By going through the same process as described above the seaweed can be deposited on the along the slope of the peninsula extending out into the body of water particles deposited within the area defined by the seaweed and additional seaweed and particles added until the peninsula is extended as required.

The claimed subject matter is further described in the Figures and the following description thereof. FIGS.

l-l0 schematically represent the successive stages of constructing an island on the sea-bottom, while FIGS. 1 [-13 schematically show the extension of a peninsula using the claimed process.

FIG. 1 shows in perspective the building of the first terrace of the island.

FIG. 2 at a different scale gives a side view of the seaweed elements in situ, looking in the direction of the arrow 3 in FIG. 1.

FIG. 3 shows (also at a different scale) a crosssection of FIG. 1 taken along the line 3-3.

FIG. 4 shows in perspective the building of the second terrace of the island.

FIG. 5 gives the cross-section of FIG. 4 along the line 5-5.

' FIGS. 6 and 7 show the building of the third terrace.

FIGS. 8 and 9 represent the pumping of sand on the part of the island lying above water level. FIG. 8 is a perspective view and FIG. 9 a view of FIG. 8 in the direction of arrow 9.

FIG. shows in perspective the building of the first terrace wherein seaweed is deposited in rows to define an approximate rectangular area.

FIGS. 11-13 depict the process of the invention wherein a peninsula is extended out into the body of water.

A zone of seaweed 22 is placed at a desired location on a sea-bottom 21 (see FIGS. 1 and 3). This zone (which is schematically shown in FIG. 1) is closed in itself and consists of a number of more or less closed rows of seaweed elements 23. A side view of some of these seaweed elements 23 is given in FIG. 2. Each element 23 consists of an anchoring means 24 and a number of weed strands 25 secured to the anchoring means. Alternatively, referring to FIG. 10, the seaweed 22 can be deposited in rows so that a particular area is defined such as the rectangle shown in FIG. 10.

In FIG. 1 sand 28 is deposited inside the zone of seaweed 22 from a vessel 26 floating on the surface of a body of water 27. Since the tipping angle of sand in flowing water is very shallow (approximately 5) the deposited sand flows towards the zone of seaweed 22. The slope of the sand at the location of the zone of seaweed is then increased by the effect of the seaweed strands (see line 29 in FIG. 3). The boundary line 30 (dotted line) gives the maximum height to which the sand can be deposited without the slope beginning to level off again. Sand deposited to this height forms the first terrace 30 (see FIG. 3).

On top of this terrace a new zone of seaweed 32 is placed lying within the vertical boundary of the zone of seaweed 22 but at a higher level. The dumping of sand is continued but this time inside the zone of seaweed 32 to build up the second terrace. This time the slope of the sand is increased at the location of the zone of seaweed 32 (see line 33 in FIG. 5) and dumping is continued until the boundary line 34 has been reached.

A third zone of weed 35 is subsequently laid on top of the second terrace 34 so formed (see FIG. 6) and by continued dumping of sand (but now inside the boundary of the weed zone 35) a'third terrace 36 laying immediately beneath the surface of the water 27 is formed. A zone of seaweed 37 is then laid on top of this terrace 36 at the edge and a-pipe 38 is led from the vessel 26 to a point 39 inside this weed zone 37. The sand which is supplied via the pipe 38 is trapped by the seaweed of the zone 37 until the deposited sand lies on a level with the surface of the sea. The build-up of the island above sea level is subsequently completed by pumping sand, this time however at increased sand/water concentrations to prevent the washing away of sand from the upper part of the island. If desired, new seaweed elements can be placed along the water line of the island during this last stage of the build-up of the island to protect this top terrace against erosion and to promote the accretion of the island by deposition of sand transported by the waves and sea currents.

During the building of the other terraces seaweed elements can also be added at those points in the seaweed zones where these zones are not performing their function to a satisfactory degree. The build-up of the terraces can be measured by means of echo-sounding or some other manner. Similarly, in FIGS. 11-13 seaweed 22 is deposited along the slope of a peninsula and sand 28 is then deposited as indicated in FIG. 11 until the first terrace is built up as in FIG. 12 then additional seaweed 22 is added on top of that terrace and the process is continued until the peninsula is extented to the desired extent.

After completion of the top terrace of the island (or peninsula extension) further steps may be taken to protect the beach formed round the island and the rest of the islands surface against erosion by waves as a result of storms. Thus as least part of the portion of the island projecting above the water may be provided with a course of rubble (or other water-permeable covering). Depending on the size and any other covering (e.g., building) of the island, this course may extend only along the beach or over the entire surface of the island. The course may also extend beyond the beach to a level beneath the zone of wave effect.

Since the tips of the seaweed elements laid on the terraces still partially project above the sand, an excellent protection against erosion is obtained at the base of the island. At those places, however, where a large degree of erosion is to be expected as a result of prevailing currents, extra seaweed elements may be added either on the seaward face of the island or on the sea-bottom around the island.

It will be clear that the zones of seaweed used should comprise a very large number of rows of seaweed elements. The elements need not be laid in rows but will produce thesame effect if they are laid criss-cross in a zone extending along the edge of each terrace. The dumping site of the sand inside the ring of seaweed may vary. More than one dumping site may also be used.

The sand may be dumped dry into the water. Since, however, sand mixed with water forms a pumpable slurry, preference is given to dumping sand together with water.

If during the method as described with reference to the drawings the dumping of sand is stopped at an earlier stage, for example after the construction of the second terrace 34, then instead of an island an artificial sandbank is obtained by simple means, which sandbank can serve as a foundation or may serve to direct water currents. Erosion of the top surface of the sandbank can be prevented by placing seaweed elements on that top surface.

It is obvious that the shape of an island or sandbank to be built by the method according to the invention is not limited to the example explained with reference to the drawings. Any other shape can be used. The seaweed zones may also run from one point on the mainland to another point on the mainland by which means a connection of land may be formed. Parallel-running zones of seaweed extending between two existing islands may be used for the construction of a connecting dam or dyke between these islands.

The seaweed zone 22 shown in FIG. 1 may also have an indentation and thus together with similarly shaped

seaweed zones

32, 35 and 37 of the other terraces form a harbour or bay.

A beach slope of l 10 can be achieved by the method according to the invention. In contrast, sand deposited without the use of artificial seaweed would have a slope of from I 50 to l 100, which makes very large quantities of sand necessary and also results in a very vulnerable beach.

The sand which is available in the vicinity of the foundation to be built may be used as the sand for building the foundation according to the invention. No special requirements are made regarding the grain size.

If desired the terrace 30 may be built up by placing seaweed elements over the entire surface where this terrace is to be raised. These elements are distributed as evenly as possible over the surface. The seaweed is subsequently left alone for some time. During this time sand is transported over the seaweed elements by the natural water currents which sand is deposited amongst the seaweed, thus building up the terrace 30. Any of the following terraces (such as 34) may also be built up by means of the sand transported by the current. The higher the terrace lies in relation to the sea-bottom, however, the more time the build-up of the terrace concerned will take. Therefore only one or more of the bottom terraces are formed in this way and the remaining terraces are built up by laying a zone of artificial seaweed along the edge of the uppermost of the terraces already formed and subsequently dumping sand onto the area bounded by the zone from a suctiondredger, hopper barge or other vessel.'The built-up of the remaining terraces is effected as hereinbefore described with reference to the drawings.

We claim as our invention:

1. The process of building a foundation in a body of water which comprises:

a. depositing artificial seaweed onto the bottom of a body of water so that a particular area is defined,

e. repeating steps (a) (d) to obtain a raised foundation of particles.

2. The process of claim 1 wherein the particles are sand and are deposited from the surface of said body of water.

Claims

1. The process of building a foundation in a body of water which comprises: a. depositing artificial seaweed onto the bottom of a body of water so that a particular area is defined, b. depositing particles within the area defined by the seaweed and so that the particles are contained within said area by the action of the seaweed to form a layer of an aggregate of said particles on the floor of said body of water, c. depositing seaweed on top of the layer of particles so formed in step (b) and within the boundaries of said raised layer, d. depositing particles onto the area defined by the seaweed so deposited in step (c) so that another layer of an aggregate of the particles is built up, and e. repeating steps (a) - (d) to obtain a raised foundation of particles.