WO2016112913A1

WO2016112913A1 - Underwater barrier

Info

Publication number: WO2016112913A1
Application number: PCT/DK2016/000002
Authority: WO
Inventors: Ole Fjord Larsen
Original assignee: Ole Fjord Larsen
Priority date: 2015-01-15
Filing date: 2016-01-13
Publication date: 2016-07-21

Abstract

Submarine barrier of trapezoidal shape for deposition of sediment, the barrier including a hose of watertight or water- permeable material which is adapted upon pumping up, to form longitudinal channels and cross-channels connecting a top side and a bottom side of the barrier.

Description

UNDERWATER BARRIER

DESCRIPTION

The invention relates to an underwater barrier construction for deposition of the migrant sediment to protect coasts and other water construction purposes.

So far, the alternatives have been either local traditional structures such as groynes or breakwaters, causing erosion of the downstream stretch of coastline, or costly continuous artificial beach nourishment by pumping sand from the seabed to the eroded beach.

This increases the steepness of the coastal profile, so the waves break ever closer to the beach and every year increases erosion here.

The present construction advances and transforms the coast, so the sediment remains on the coast.

It is underwater and therefore does not mar and is also a so cheap one-time measure that it can be laid and protect the entire coast in one go, so the problem of the lee-erosion is avoided.

The construction's deposition techniques include a. reduction of wave-energy

b. a minimum of turbulence formation

c. converting part of the energy to downward

stabilizing force on the sediment inside and outside the barrier.

None of the already patented similar constructions fulfill all these conditions and is therefore

vulnerable to undermining due to waves and currents.

US 3696623 A (Heine, 0 et al), 10.10.1972,

GB 1355979 A (E Nielsen et al) 06.12.1974 and

US 2011/044759 Al (Lancaster, et al) 02.24.2011 protects existing bottom and do not build up deposition for changing the coastal profile.

US 2013/125825 Al (Kania, B G et al) 201,305.23 simulates coral structure using different porous plastic materials that do not meet the conditions b. and c.

FR 2393111 Al (Soc Des Textiles Industriels de la Cite STIC) 12/29/1978 is an underwater barrier which, because of its steep sides and structure does not meet the conditions b. and c.

US 3830066 A (Larsen, 0) 08/20/1974

are elements to deposit the migrating sediment and are formed so that they on the downstream side form a negative pressure resulting in local deposition.

As the pressure and consequently the deposition is not distributed to the whole structure, the elements are unstable during storm conditions.

NZ 197 388 A (Larsen, 0, F) 06.11.1966

In contrast to US 3830066 A, the construction here is massive and placed directly on the bottom.

But since the condition c. is not met, the structure is subjected to erosion, and its discontinuous bottom fabric makes it prone to slipping and collapse.

The description of the invention will take place in connection with the accompanying drawings of a preferred embodiment in which

Fg. 1 is a cross-sectional view of the construction taken along the line I-I in Fig. 2

Fig. 2 is plan view of the construction

Fig. 3 is a cross-section through a ring which locks the two layers of fabric of the construction together and forms a vertical flow opening

Fig. 4 is a side view in two different scales of arrangement for the joining of the two halves of the ring of Fig. 3

The middle section of the figure is detailed in greater scale than the sections above and below the fracture lines.

Fig. 5 is a cross-section II-II in Fig. 6 through two corresponding halves of a ring of alternative

embodiment in the interlocked position

Fig. 6 is a plan view of the halves of the ring of Fig. 5 during the interlocking process

Fig. 7 is a cross-section of the two halves of a ring of alternative embodiment

Fig. 8 is a cross-section through the two halves of the ring of Fig. 7 during the interlocking process corresponding to section II-II of Fig. 6

Fig. 9 is plan view of an amphibious vehicle for laying of the barrier.

The invention's three characteristics is obtained as follows: ad a.

The wave energy is reduced by the barrier (1) which artificially decreases the depth of water and thereby expands the range of wave heights breaking here.

The wave energy in the lee of the barrier is thereby reduced greatly, so that deposition of sediment takes place here.

At the ends of a non-continuous barrier, wave

diffraction and -refraktion further contribute to the deposition of sediment in the lee of the barrier. ad. b.

The sides of the barrier, Fig. 1, have very flat slope gradients which give it a streamlined cross-section.

If a barrier is placed parallel to shore on a

horizontal seabed, the slope of the sea side might be of the order of 1:5, and on the land side of the order of 1:2.

For instance on the inclining sea side of a natural sandbar the slopes might have to be adjusted

correspondingly.

The top of the barrier may suitably be substantially horizontal and make room for the channels (4) with upward flow. ad c.

The negative pressure which the upwardly directed flow leaves at the top causes an upward flow (9) that is distributed through the channels (4) and the base material to the entire construction, so that part of the erosive wave energy is transformed to a downward stabilizing current (10) and pressure on the resulting sedimentation (7) inside and outside of the barrier.

Along with the natural kelp forests that inevitably arises at this fixed point on the seabed, the

stabilisation of the sediment (7) will cause total sediment coverage of the barrier.

The hose (1) constituting the barrier may be produced as segments joined together or as a whole, the production methods may be extrusion, 3-D printing or other methods used by the plastic industry.

In the preferred method described here the hose (1) is made up of two ready-made layers of sheet (11) and (12) that are joined together along the edges and pointwisely here between in points spaced varyingly from maximum along the middle section to minimum along the edges. Upon filling up of the space between the two layers (11) and (12), the relative distances between the joinings determine the cross-section of the barrier.

The fabrics (11) and (12) can be reinforced or unreinforced waterproof plastic or woven or non-woven fibrous water-permeable fabric, for example,

geotextile.

Clear plastic permits visual inspection of the interior of the barrier during and after the filling process. A combination, for example of hard-wearing material on the upper surface and permeable fabric on the underside of the barrier, may be appropriate.

The joining of the layers (11) and (12) can be made by welding, stitching and or by means of the conventional curtain-call principle with a mandrel of the bending rings that cut through and locks the two layers together.

In all cases, the edges of the layers may be folded over so that the assembly is enhanced to the maximum.

A preferred bonding is achieved by means of rings, each made up of two halves, for example, (13) and (14), Fig. 3, preferably of plastics, which either may be prefabricated with ovality in directions perpendicular to each other or temporary compression and deformation locks together around each other and the two layers (11) and (12).

The ring diameters appropriately vary from a maximum at the center line to a minimum at the edges of the barrier.

Within each ring the cloth material may be removed to form through-flow apertures (4) between the lower and upper side of the barrier.

The installation of the rings can be made in a continuous process such as shown in Fig. 4, wherein the two layers (11) and (12) of the roller (15) via the guide roller (20) is pulled in parallel off the respective horizontal roller (16) and (17) via guide rollers (18) and (19).

Next to each longitudinal row of joinings by means of rings (2), (3), etc., the addition of the profiles (13) and (14) from opposite sides of the layers (11), (12), the profiles can be packaged with spacers (21) in the tubular containers (22), respectively (23) and with a suitable pressure from each side are pushed toward each other through the layers (11) and (12).

In that the bottom of the containers (22) and (23) stops a profile width from (11), respectively (12), gravity makes the nearest profiles (24) respectively (25) to fall down on the supports (26), respectively, (27), and the next profile in each side (28)

respectively (29) is pressed forward to support on the profiles (24) respectively (25).

In synchronism with the velocity (30) of the layers (11) and (12), the arms (31) and (32) with the rollers (33) and (34) respectively pressure, with the desired spacing, the lower edges of the two profiles (24) and (25) into engagement with each other and with the layers (11) and (12) locked in between.

Said roll (15) continuously draws (11) and (12) and thus the profiles (24) and (25) downwards, the rollers (33) and (34) thus force the rest of the circumferences of profiles (24) and (25) into engagement with each other around the the layers (11) and (12).

The arms (31) and (32) are activated, for example by eccentricities on rotating shafts, where the diameters correspond to the desired distance between the rings (2), (3), and so on.

If the entire barrier is not made of permeable fabric, allowing for passage of water but not of erosion material, the required through-flow openings or perforations within the rings (2), (3), and so on, can be cut at the conveying speed (30) by means of rotating blades or punches (35) and (36) mounted on the arms (37) and (38).

In this case, it may be necessary to cover some of the rings 's openings, particularly at the top of the barrier, with filter fabric to retain erosion material. It may suitably be mounted in the same process as removal of the sheet within the rings.

Optionally, the direction of flow through the

individual ring (2), (3), etc., is automatically aligned by rectifying means of valve action, so that through some channels only upward flow can take place, through other channels only downward flow.

The valve effect can be achieved in several ways, for example, by asymmetric design of the two sides of the two layers (11) and (12).

In a tablecloth (11), (12) of thick fabric perforation can occur one-sided by means of rotating awls, either (35) or (36). With a sufficient wall thickness of the fabric, the conical perforations only allow flow from the the rotating awls' side of the cloth and the water pressure are pressed together and close the flow in the opposite direction.

One-sided perforation through both layers 11 and 12 will only allow flow through precise stretching of (11) and (12) that existed in perforation moment.

By displacement of the layers with respect to one another, the perforated holes in the two layers do not any more be next to each other, then flow prevented.

By cutting up to a perforation (11) and (12) of narrow strips as artificial seaweed, the *seaweed* in one flow direction will lie down and prevent flow and in the other direction be brought out from (11) and (12) and allow flow.

Alternative configurations of the rings (13), (14) may be rings with with circular cross-section or shaped as concentric conical section (39) and (40), Fig. 5 and 6. The ring (40) to be pushed through the ring (39) can be of softer material than (39) such that the rollers (33) and (34) can deform (40) and thereby enable compression of the two with each other easily in the beginning split rings, as shown in Fig. 6.

The compression can also be made possible by one or both ring halves of the same hardness formed slightly oval in directions perpendicular to each other, Fig. 6. The compression begins with the rollers (33) and (34) pushing the two rings that are vertically sligtly staggered together in their lower ends so that the upper edge (41) of (40) come in level with the upper edge (43) of (39). During the further compression can edge (41) of (40) pass the lower edge (44) of (39) due to the oval planar form of at least one of the two rings. Then the lower edge (44) press the upper edge (41) upwards the direction of movement, so (41) is pressed up above (44) so that the cross-section shown in Fig. 5 at the end is obtained when the upper ends of the rings have passed through the rollers (33) and (34).

Ovality can be either pre-fabricated or obtained temporarily during the process by means of a cord (45) that draws opposing edges of example (40) together and automatically cut by a knife on one of the rollers (33) or (34).

As an alternative to the cord (45) ovality can be obtained temporarily by out-folding of the center line of the ring (48) of the the alternative form of the rings (47) and (48), Fig. 7 and 8.

During the process, the center line of the planar ring (48) is pressed out from its original plan by the balls (50) while the edges are held back by the rollers (49) so that the planar ring becomes oval during the process.

At the same time as, or following deployment of the hose on the seabed, water is pumped in from one end of the hose, which thereby is formed into a barrier with horizontal channels (6) whose diameters depend on the various distances between the rings (2), (3), etc.

With the shown distances gradually decreasing from maximum along the center section to minimum at the edges, the height of the barrier increases uniformly from the two edges toward the center section.

According to circumstances, the barrier section may be symmetric as shown, or steeper on one side than on the other.

Each end of the barrier may be provided with a valve that may be disposed in two parallel cross rails which clamp together the two barrier layers (11) and (12). Open or closed valve in the last aid-out end of the barrier may depend on whether the barrier consists of waterproof og permeable material.

The internal pressure of the barrier during the filling may be controlled by a pressure gauge which

automatically regulates the pumping velocity.

The barrier suitably being placed on the sea side of and along the top af a natural offshore sandbar, filling of the barrier with sediment appropriately may take place from the first laid corner of the upper edge of the barrier.

For stabilization of the barrier during the filling process, the pumped water may contain a certain percent sediment (5) deposited in the channels (6).

Alternatively, sediment may be pumped out over the barrier.

When the wave (8) passes over the barrier, a maximum negative pressure and upward flow (9) through the openings (4) is created at the top, and consequently a downward percolation (10) that stabilizes and

deposits erosion material (7) below and above the rest of the barrier.

Depending on the barrier dimensions, model experiments should optimize which rings (2), (3), etc., should be open, closed or equipped with sediment filter.

In order to avoid the heavy handling of the finished roll (15), the machinery of Fig. 3-4 may be placed on a vessel, for example consisting of two flat-bottomed pontoons connected by a lattice structure which simultaneously supports the machinery.

Optionally, also the preparation of the layers (11) and (12) take place on the spot, so that manufacturing, joining, laying and filling of the barrier may take place in one process.

Alternatively, the deployment of the barrier (11), (12) may take place from an amphibious vehicle, Fig. 9, consisting of a cylinder (51) that at each end is provided with a paddle wheel (53) so that the vehicle can either run on the beach or the sea bed or sail on the water surface.

In order to regulate the buoyancy, the cylinder (51) may consist of perforated material and the buoyancy be determined by the water content of the ballast tanks (52).

The vehicle includes a roller, for example in the form of a sphere (57), connected to the vehicle's axle (54) through optionally telescopic arms (55) and (56).

The sphere (57) can be filled more or less with water, accordingly as the sphere shall roll on the beach, on the seabed, float on the surface, or be attached to a surface vessel to maneuver the amphibious vehicle. The vehicle for instance may be driven by a hydraulic motor at aither end of the cylinder (51).

By pumping more or less air into the barrier (1), buoyancy may be exploited to gradually raise it, as the deposition of sediments takes place.

Similarly, the inflated barrier may be moved along with or perpendicular to the coast to new positions for economical optimization of the sedimentation,

for example in case of long seasonal change of the wind direction.

The barrier may for example be used to create a new stable advanced equilibrium coast, if straight or curved barriers are laid in front of the entire eroded stretch of coast as appropriately spaced coastal parallel underwater breakwaters or as an advanced continuous garland-shaped advanced equilibrium alignment in accordance with the local wave climate, cf. DK patent 137903 and US patent US3830066 A.

The coastal protection may be combined with extraction of wave energy by placing the wave power machines in front of the tips of the planned garland-shaped coast, where they will contribute to the attenuation of the waves.

Claims

1. Submarine barrier for deposition of sediment,

c h a r a c t e r i z e d in that the barrier includes a hose

(1) of waterproof or water-permeable material, which is adapted upon pumping up to form longitudinal channels (6) that fill the cross-section of the barrier and cross-channels (4) connecting the top and bottom sides of the barrier CI .

2. Submarine barrier for deposition of sediment according to claim 1,

c h a r a c t e r i z e d in that the profile of the barrier is trapezoidal and constituted by a substantially horizontal center section and on each side from here a slightly

downwardly inclined side surface.

3. Submarine barrier for deposition of sediment according to claim 1,

c h a r a c t e r i z e d in that the barrier consists of two layers of waterproof or water-permeable flexible fabric (11) and (12) which are joined together along the edges and here between pointwisely in points with spacing gradually

decreasing from the mid-section out towards the edges of the elongated barrier and adopted for pumping of air and or water and or sediment in between the two layers of fabric (11) and (12) resulting in the formation of longitudinal channels (6) more or less filled with sediment.

4. Submarine barrier for deposition of sediment according to claim 3,

c h a r a c t e r i z e d in that each of the pointwise joinings of the two layers consists of two halves of rings

(2) , (3), etc, with mutually interlocking cross-sections which, after compression from either side of the layers and the corresponding deformation will interlock together and thus the two layers.

5. Submarine barrier for deposition of sediment according to claim 4,

c h a r a c t e r i z e d in that each of the individual rings (2), (3), etc, as the case may be closed or open for through- flow and/or provided with a filter fabric which permits water but not sediment over a certain grain size to pass through.

6. Continuous process for the production of subsea barrier according to claim 3,

c h a r a c t e r i z e d in that the rings are mounted in a process in which the parallel two layers of fabric (11) and (12) are continuously fed through the the narrow gaps between each set of the halves (13) and (14) of the rings, and wherein the ring halves (24) and (25) of each desired position of the pointwise joints are pressed together for mutual interlocking of the layers, and wherein the perforation or cut-away of the layers within each ring is made in the continuous process by means of rotating knives or awls (35) and (36).

7. Continuous process for the production of subsea barrier according to claim 6,

c h a r a c t e r i z e d in that the interlocking process for each circular ring is facilitated by making both halves (39, 40 or 47, 48) or one half permanently or temporary oval in two mutually perpendicular directions in the plane of the ring, for example by means of different relative softness of the two halves, contraction by means of a string (45) or out-folding by means of balls (50) and rollers (49).

8. Amphibious Vehicle for laying underwater barrier according to claim 1,

c h a r a c t e r i z e d in that it includes

- A cylinder (51), in each end provided with a paddle wheel (53), so that by adjusting its water ballast compartments (52) it can run either on the beach or on the bottom or sailing on the water surface

- One or more motors that drive the axle (54) of the vehicle in relation to

- A roller (57) which via two arms (55, 56) are connected with the opposite ends of the axle (54), and which by vater balancing either can roll on the ground or sea bottom, floating on the water surface, or be attached to a surface vessel to maneuver the amphibious vehicle.

9. Protection of a stretch of coast by means of an underwater barrier according to claim 1, c h a r a c t e r i z e d in that the barrier (1) in the form of coast-parallel underwater breakwaters are placed on the seaside of and along the top of a natural sandbar as tips in the advanced garland-shaped equilibrium coast with an alignment determined by the local wave climate.

10. Protection of a stretch of coast by means of an underwater barrier according to claim 1, c h a r a c t e r i z e d in that the underwater barrier (1) is inflated completely or partially with air for utilizing buoyancy for moving the barrier in vertical or horizontal direction.