NZ548573A - Erosion protection device with recess and protrusions at ends for interengagement with similar elements - Google Patents

Abstract

A construction element has two or more longitudinally extending surfaces, one of which defines a base. First and second ends have a respective recess and protrusion so as to allow for engagement to similar elements to form an erosion protection barrier. A cavity extends longitudinally through the element so as an aperture is formed at each end of the element.

Description

NEW ZEALAND PATENTS ACT, 1953 No: 548573/549150 Date: 17 July 2006/11 August 2006 # % -; DEC an COMPLETE SPECIFICATION A CONSTRUCTION ELEMENT SUITED FOR EROSION PROTECTION AND OTHER APPLICATIONS I, NORMA DORIS MCCULLOCH, a New Zealand citizen of 9 Tait Street, Ruby Bay, Nelson, New Zealand, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: -1 The present invention relates to an improved construction element suited for erosion protection and other applications. More particularly, although not solely, the present invention relates to an erosion protection barrier. Even more particularly, although not solely, the present invention relates to a modular erosion protection barrier construction element for assembly with other like construction elements for the purposes of restricting coastal and/or seabed erosion.

Structures for preventing erosion of shorelines, sandy beaches and river banks are known in the art. Such devices operate by facilitating the dissipation of energy by processes of refraction and reflection to at least slow any water passing over the structures.

The movement of sand residing on the shoreline has been found to vary significandy depending upon water way movements and the geographical contouring of the localised sea/river bed. In calm situations, and similar environmental climates, movement of sand seabed material may be minimal. Gradual movement of seabed material may be experienced during moderate weather conditions. A greater change of seabed conditions can be expected during heavy weather conditions such as storms where wave and tidal movements can cause significant disruption to the underlying seabed terrain.

Break water structures attempt to cause some of the most transient sand to be deposited near the shore line. This allows the gradual and routine build up of sand during moderate conditions over an extended period of time. During rougher conditions, larger sand quantities may be removed from shore lines. As moderate conditions prevail over greater periods of time, small gains in sand deposits over time generally yield reasonable deposits. As such the effect of erosion protection structures serve to preserve and eventually enlarge the area of the beaches, coastlines and riverway shorelines.

Some of the processes above occur in rivers and water ways where water currents can, steadily over time, erode river banks and the like. This erosion can be enhanced in the event the water levels fluctuate regularly. Water levels decrease and rise over time.

This effect coupled with currents and resulting various localised eddy currents, can contribute a significant amount to erosion over an extended period of time causing significant property loss. Implementation of erosion protection structures in such environments can assist greatly in preventing further erosion as well as restoring land portions that have been altered or are at risk.

Breakwater structures have been the focus of patents in recent times.

Publications US 5123780, US 5259695 and US 5509755 are indicative of erosion protection structures used for erosion protection. Many structures of this nature are constructed from concrete and/or steel materials and designed in a permeable fashion allowing sand and seabed matter to flow and settle within the structure itself. Such structures can be difficult to implement in water ways due to the structures being of heavy and large unitary nature. Furthermore, using prior art erosion protection structures provide to create large erosion barrier systems contoured to the seabed terrain can be difficult. Such structures may also not lend themselves to use for other applications. They hence lack versatility.

Accordingly, it is an object of the present invention to provide a construction element suited for erosion protection and other applications that addresses the above desiderata and or at least provides the public with a useful choice.

Accordingly, in a first aspect the present invention consists in a construction element comprising an elongate and unitary body including: (i) at least two longitudinally extending surfaces wherein one of said at least two longitudinally extending surfaces defines a base, (ii) a first end having a portion thereof being an inward recess, (iii) a second end having a portion thereof being a protrusion, (iv) an internal cavity extending longitudinally and terminating at both said first and said second ends, wherein an aperture is provided at each end to said cavity, wherein said recess is of a complimentary shape to said protrusion, to allow engagement of a said protrusion of an adjacent and like said construction element to form an erosion protection barrier.

Preferably said inward recess is defined at the perimeter of said unitary body.

Preferably said inward recess is a step defines in the longitudinally distal most end of said first end.

Preferably said unitary body is of a constant cross section elongate shape, save for at said distal ends, wherein said unitary body defines a continuously closed cross sectional perimeter.

Preferably said cavity is of a constant cross sectional perimeter shape of said unitary body.

Preferably said unitary body is of a perimeter defined by a substantially constant thickness perimeter wall.

Preferably said protrusion is defined by a lip extending at said second distal end of said unitary body.

Preferably said unitary body is of a cross section having a triangular outer perimeter Preferably said cross section of said cavity is triangular.

Preferably said recess is wider than said protrusion allowing for a lose engagement so as to allow for a longitudinal misalignment when placed longitudinally adjacent another like construction element to allow curved longitudinal placement of a plurality of said construction elements.

Preferably said longitudinally extending surface includes at least one protrusion of a complementary shape to allow the interlocking engagement thereof with an adjacent of said construction elements in a lateral to the longitudinal direction.

Preferably said body includes at least one protruding member extending outwards from said base.

Preferably said protruding member extends outwards perpendicular to said base.

Preferably said protruding member extends along the length of said body.

Preferably said protruding member is at or towards one side of said base.

Preferably said construction element includes two protruding members, located at opposite sides of said base.

In a further aspect the present invention consists in an interlocking erosion protection device comprising a construction element of a kind as hereinbefore described.

In a further aspect the present invention consists in a plurality of interlocking erosion protection devices as described with reference to Figure 9.

In a further aspect the present invention consists in a plurality of construction elements as hereinbefore described, wherein the construction elements are stacked vertically to form an erosion protection structure.

This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

Figure 1 shows a unitary, permeable concrete erosion protection structure indicative of the prior art, Figure 2 shows a perspective view of a structure of the present invention for use as a single erosion protection barrier in accordance with the present invention showing the general cross sectional shape and hollow internal cavity, Figure 3 shows an end view of a portion of an erosion protection structure of the present invention as shown in Figure 2, Figure 4 shows a side elevation of the portion showTn in Figures 2 and 3, Figure 5 shows a front elevation view of two portions of the erosion protection barrier structure in accordance with the present invention whereby the two portions are engaged, Figure 6 shows a cross section view, as indicated in Figure 7, of the engaging portions of the erosion protection barrier structure of the present invention, Figure 7 shows section view A-A(as indicated in Figure 6), of a front elevation view of the two engaging portions of the erosion protection barrier units of the present invention, Figure 8 is a further perspective view of the erosion protection barrier unit in accordance with the present invention showing the opposite side to that indicated in Figure 2.

Figure 9 is a plan view of an erosion protection barrier made from a plurality of interconnecting units of the present invention, Figure 10 shows an end section view of the erosion protection device of the present invention in use, Figure 11 shows an end section view of the erosion protection device of the present invention in use, Figure 12 shows a stack of erosion protection devices of the present invention, Figure 13 shows a stack of a plurality of erosion protection devices of the present invention when stacked to connect laterally to form a protection barrier when in use, Figure 14 shows a stack of a plurality of erosion protection devices of the present invention when stacked to connect laterally to form a protection barrier when in use, Figure 15 shows an end view of an erosion protection device of the present invention having of the present invention having a leading edge sheltered by a rock riprap, Figure 16 shows an end view of an erosion protection device of the present invention having an apron hinged to an exposed face, Figure 17 shows a cross sectional view device of the prevent invention with a protrusion from the base, Figure 18 shows a cross sectional view of the erosion protection device of the present invention having two protrusions from the base, Figure 19 shows a cross sectional view of the erosion protection device of the present invention in the form of an isosceles triangle, Figure 20 shows a cross sectional view of the erosion protection device of the present invention featuring a side contoured for a sea wall, Figure 21 shows a cross sectional view of an erosion protection device having a protrusion extending from each side, Figure 22 shows a cross sectional view of an erosion protection device having two protrusions extending from each side, Figure 23 is a perspective view showing a series of erosion protecting devices located adjacent to a road, Figure 24 is a perspective view showing triangular structures acting as structural supports for a bridge, Figure 25 is a perspective view showing a series of triangular arranged to form a tunnel under a road, Figure 26 is a perspective view showing a triangular structure being used as housing for animals.

The most preferred embodiment of the present invention will be now discussed with reference to the drawings following the specification.

The erosion protection devices of the current invention may be used in any location (including inland waterways such as riverbeds and the like) where any form of erosion is occurring; this includes areas affected by erosion due to wind and other natural forces. The structures comprise of a solid yet permeable shape and construction.

The unitary form of the construction element 21 of the present invention is shown in Figure 2. The modular erosion protection construction element of the present invention preferably incorporates a substantially closed perimeter in cross section. The perspective view shown in Figure 2 shows the most simplest embodiment being of triangular form where a fjrst slanting surface 1, a second slanting surface 5 (as shown in Figure 3) are able to be presented to oncoming water and tidal motion. A third surface 28 is lowermost facing, forming the base of the erosion protection construction element can remain substantially horizontal when located in position. The most preferred embodiment adopts a substantially triangular cross sectional shape for the erosion protection construction element of the current invention, however, it may be appreciated that any shape with a predominantly flat base may be used effectively with the present invention. The two upper facing surfaces 1 and 5 may be replaced by a single surface being of a curve, elliptical or other continuous arc to still effectively perform the advantageous characteristics inherent within the present invention. The erosion protection construction element of the present invention is preferably made from pre-cast concrete type construction so that manufacturing and deployment is relatively easy. It may be appreciated that other high density substrates may be used to construct the construction element. It may further be realised that the erosion protection construction element of the present invention may be moulded from plastic or similar material and fabricated as a tank or vessel to be filled with a fluid or solid or similar upon installation on site. Such embodiment would allow easy transport and implementation / installation.

Figure 3 presents an end view of the erosion protection construction element as shown in Figure 2, where the substantially triangular cross sectional form is clearly presented. Shown are the slanting faces 1 and 5 forming an upward apex 6 thus forming an upper longitudinal edge 7 (as shown in Figure 2). Similarly, the base 4 is shown forming apexes 8 and 10 with slanting surfaces 1 and 5 respectively. As such, apexes 8 and 10 extend longitudinally to form edges 9 and 11 respectively as shown in Figure 2. It may be appreciated that the edge may not necessarily be acute in nature but could also be rounded with soft or hard radii or edge chamfers if required. The use of such edge geometries may depend upon how many outward facing surfaces are used.

The unitary erosion protection construction element in accordance with the present invention incorporates a means to securably engage other like erosion protection construction elements of the same form and construction. Figure 2 shows a substantially triangular protrusion 2 emanating from a transverse face of a proximal end 12. The protrusion 2 preferably extends longitudinally a distance X allowing reliable and robust engagement with a complimentary recess of another like erosion protection construction element 21'.

In the most preferred embodiment of the present invention, each erosion protection construction element incorporates a hollow cavity portion 3 of a similar cross section to that of the transverse perimeter. The cavity 3 extends in a direction substantially aligned with the longitudinal length of the erosion protection construction element of the present invention. It may be appreciated that the hollow cavity 3 may be a cross section of any shape and may differ to the cross sectional shape of the transverse perimeter of the erosion protection construction element. Similarly, the protrusion 2, can be of any cross sectional geometrical shape and independent of the cross sectional shape of the hollow cavity 3 and/or the external cross sectional shape of the transverse perimeter of the erosion protection construction element. The most preferred embodiment of the present invention involves a triangular cross sectional form used to define the cross sectional shape of the protrusion and the cavity 3. Preferably its an equilateral triangular form.

The protrusion 2 is preferably of a dimension Z that also allows the protrusion 2 sufficient structural integrity to engage the complimentary recess of a like erosion protection construction element to form a robust barrier, collectively capable of withstanding the movement of large volumes of water and land and conforming to the geographical seabed terrain where required.

A distal end 13 incorporates a complimentary recess to receive the protrusion 2 of an adjacent and like unitary erosion protection construction element so that adjacent construction elements may be secured effectively forming a chain or extended barrier. It may be appreciated that the cross sectional shape and length of the recess will be of a complimentary nature to accommodate the insertion and/or engagement of the protrusion 2. It may also be appreciated that other forms of securing adjacent like erosion protection barrier portions or construction elements may be incorporated into the present invention.

Figure 4 shows a front elevation of an erosion protection construction element of the present invention. Figure 5 further shows a front elevation of two adjacent construction elements engaged to form an appropriate sea wall barrier. The internal engagement between construction elements 21 and 21' may be shown in Figure 7 where a longitudinal sectional view A-A (as identified in Figure 6) is shown along the length of the erosion protection barrier. Figure 7 shows sectional detail of the recess region 25 establishing a loose fit between two adjacent erosion protection barrier construction elements 21 and 21'. The cross sectional view of section B-B (indicated in Figure 7) is shown in Figure 6. It may be seen from both Figure 6 and Figure 7 how a plurality of like adjacent construction elements may provide an extended sea or river, wall or barrier of substantial length. It may also be appreciated that further clearance can be achieved between the interconnection of protrusion 2 and the complimentary recess 20 to allow like construction elements to be engaged to allow for a small degree of misalignment in allowing a plurality of like construction elements to establish a curved contour line m accordance with the geographical nature of the localised bed terrain. It would be appreciated that the degree of clearance between the protrusion 2 and complimentary recess 20 can be altered by enlarging the dimension(s) of the recess region 20 to more than accommodate the protrusion 2. In this instance, due to the excess freedom, adjacent and interconnecting construction elements can be positioned in an off-axis alignment so as to approximate the curve of a sea bed or river bed contour. Further, Figure 9 shows a plan view a plurality of interconnecting construction elements 21 aligned in such a way as to adhere and approximate the contours of the sea bed terrain at a distance from the shoreline 40.

Installation of the construction elements can be much easier than the construction elements of the prior art as shown in Figure 1. The small modular nature of the construction elements allow for simple and easy manipulation to desired positions for installation. The hollow enclosed nature of each construction element of the present invention considerably reduces the weight of the construction element and allows for sand or other on site material i.e. clay, stones and gravel 39 to be packed in to the internal cavity 3 as shown in Figures 10 and 11. This can be achieved by packing the material from the apertures at either ends 13 or 11 during installation or from the top edge 7 of the construction elements where upward facing apertures regions 30 provide a fluid link to the internal cavity 3. The upward facing apertures regions 30 can be of any shape or form provided sufficient space is allowed for material to be inserted into the internal cavity 3. The aperture regions 30 can be conveniently spaced along the edge 7 to allow easy manual manipulation of the construction elements for installation. The insertion of the on site material into the cavity provides for the structure to resist movement from tidal flows. Over time, and with many cycles of tidal flow, sand and various sea bed debris is deposited forming a built up area of deposited material 38.

A further benefit derived from the erosion protection construction elements of the present invention is that the geometrical form of the structures allows for easy storage prior to installation as is shown in Figure 12, the structures may be stacked in a safe and secure position prior to use.

Similarly, such stacking of the erosion protection barrier construction elements of the present invention may be achieved when in an in use condition. Figure 13 shows that larger erosion protection structures can be constructed by stacking the break water construction elements 21 vertically (some being inverted) to achieve a larger desired erosion protection barrier. As with the single construction elements, sea bed debris 39 can also be packed in each erosion protection barrier construction element as the structure is stacked and built up. It may be appreciated that many different sizes of erosion protection barriers may be achieved by stacking construction elements in this way.

As with the inherent characteristic of a single longitudinally aligned erosion protection barrier, the loose engaging fit achieved by the generous recess portion 20 of adjacent construction element allows the stack configuration to also be aligned in such a way as to adhere to an approximate a geographical contour of the sea or river bed. The erosion protection barrier construction elements 21 may also provide for a lateral connection between adjacent construction elements 21 when in a vertically stacked orientation as shown in Figures 12-14. As previously discussed the construction elements provide at each end a protrusion and complimentary recess respectively to allow for a loose engagement between like construction elements. Similarly, the lower and upper surfaces of each erosion protection barrier construction elements can exhibit a protrusion and complimentary recess (or vice versa) respectively to allow the erosion protection barrier modules of the present invention to be stacked and thus secured in position appropriately. It may be appreciated that such interlocking features for vertical and lateral stacking may incorporate a number of similar means and simple mechanisms for achieving a safe and secure position.

Preferably prior to installation of the modular construction elements, a trench is created in which the modular construction elements are placed. The onsite material removed to create the trench will be preferable to be placed or to be packed into the hollow cavity. When the modules are packed and interconnected the total structure will remain strong providing a smooth flexible length of protection forming a desired contour responding to the geographical nature of the sea or rivet bed terrain.

Figure 15 illustrates a rock riprap 60 that surrounds the leading edge 61 of the erosion protection construction element of the present invention. The rock riprap 60 resists water currents from penetrating beneath the erosion protection construction element. Water currents that enter beneath the construction element base partially result in the fluidisation of ground material. Fluidised ground material may lead to instability of the erosion protection construction elements.

Figure 16 illustrates the erosion protection construction elements of the present invention where an apron 62 is attached to the seaward facing side 63 of the construction elements, just above the leading edge 61. The apron is connected to the side of the construction element by a hinge 64. The hinge allows the apron a degree of movement in an arc centred about the hinge.

The apron settles upon the sea or river bed and directs water or tidal flow over its top surface. In this way, the apron prevents water or tidal currents from penetrating beneath the ground material beneath the construction elements.

Figure 17 illustrates the erosion protection device of the present invention incorporating a protrusion 50 from the base of the construction elements. The protrusion extends downward from the base just behind the leading edge 61, and along the length of the construction element to penetrate the ground beneath the construction element. The protrusion is square or rectangular in cross section and cast as part of the existing construction element. The protrusion is cast adjacent the leading edge 61 of the base.

The protrusion may extend perpendicular to the plane of the base, or it may extend outward at an angle.

The construction element may also include a second protrusion 51 extending from an opposite side of the base as is illustrated in Figure 18. Alternatively the construction element may include a number of protrusions extending from each side of the construction element. The protrusion arrangements shown in Figures 21 and 22 illustrate protrusions extending outwardly from each side of a construction element. Protrusions from each side of the construction element are beneficial when the construction element is to be dropped without control of its orientation. For example, if the construction elements are used as part of a breakwater structure.

Each protrusion provides stability7 to the erosion protection construction element of the present invention by anchoring the construction element from shear forces that may act on the sides of the construction element.

The protrusions also allow for greater degree of ground fluidity beneath the device before any instability occurs.

A hollow may be dug beneath the construction element to accommodate each protrusion. However if the ground material is soft enough then the protrusions will penetrate the ground material under the weight of the construction element.

Figure 19 illustrates the erosion protection construction element of the present invention that has a rear wall 52 perpendicular to the horizontal base of the construction element, thus forming an isosceles triangle with the front wall 53 in cross section. The vertical rear surface may be a preferable design where soil pressure on the rear face is detrimental. The face 53 is angled rearward when the construction element is positioned in use.

An incoming wave striking the angled face 53 of the construction element in a tidal environment will have its kinetic energy slowly dissipated as it travels upwards and along the face of the construction elements.

Figure 20 illustrates the erosion protection construction element of the present invention that features a contoured seaward facing side 55 (concave in the preferred embodiment) and a land facing side 56 substantially vertical and perpendicular to the plane of the base. The sides 55, 56 and the base form a 3-sided sectional in cross-section. The seaward facing side of the construction element has a chamfered leading edge 54. The chamfered leading edge provides minimal initial impact resistance to an approaching wave. The contoured seaward facing side 55 is a concave arc that connects the chamfered leading edge to the top most edge of the device 57. The top most edge of the device features an over hanging lip. The overhanging lip guides the flow of water approaching the device away from the land facing side 56. In this way, approaching water flow is directed away from the shore line thus minimising erosion.

With reference to Figure 23 there is shown multiple construction elements 21 in an interlocking relationship. The construction elements 21 may be positioned adjacent to a road 70 for the purpose of protecting the road from falling debris. In Figure 23 there is shown a hillside 71 which may be prone to slips. By positioning a line of interlocking construction elements 21 between the road 70 and the hillside 71 the construction elements 21 may act as a barrier to prevent debris 72 (such as rocks, dirt, boulders or any other material) from slipping onto the road 70.

The empty construction elements 21 may also act as storm water drains for the side of the road 70. As the construction elements are preferably orientated as shown in Figure 23, any debris 72 is caught behind the construction elements preventing any drain blockages from occurring.

Figure 24 shows a bridge 80 which may be used for vehicles 81, or as a pedestrian bridge. The bridge 80 may employ multiple construction elements 21 as structural members. The construction elements 21 may provide adequate structural support for a bridge and may provide a passageway for water to flow through should the construction elements 21 be located in or on a river bed. The construction elements 21 may be positioned side by side in an interlocking relationship as shown in figure 24. Alternatively they may be positioned in any way to provide suitable structural support for the bridge 80.

As an alternative, the construction elements 21 may be suitable as a temporary structural support for a bridge, should the primary supports have been damaged in any way.

Figure 25 shows a tunnel 85 located under a road 86. The tunnel 85 may be formed from multiple construction elements 21 arranged in a interlocking relationship. The tunnel 85 may serve as a passageway for humans or animals to get from one side of the road to the other. The tunnel 85 may be particularly useful in the instance in which it is difficult to cross the road because of busy traffic.

Alternatively the tunnel 85 may be used as an access for a stream or for storm water to flow under the road.

With reference to Figure 26 there is shown a shelter 91 consisting of at least one construction element 21. The shelter 91 may be suitable for one or more animals 90. The shelter 91 may provide a place for animals to sleep or seek refuge from bad weather.

Alternatively, the shelter 91 may be used to house humans. In such an instance, the shelter, comprising of one or more construction elements 21 would be a low-cost, low maintenance structure for housing humans.

The shelter 91 may be modified or adapted in any way to provide a suitable environment for humans to live in, and may be of any size as required.

Claims (19)

CLAIMS:

1. A construction element comprising an elongate and unitary body including: (i) at least two longitudinally extending surfaces wherein one of said at least two longitudinally extending surfaces defines a base, (ii) a first end having a portion thereof being an inward recess, (iii) a second end having a portion thereof being a protrusion, (iv) an internal cavity extending longitudinally and terminating at both said first and said second ends, wherein an aperture is provided at each end to said cavity, wherein said recess is of a complimentary shape to said protrusion, to allow engagement of a said protrusion of an adjacent and like said construction element to form an erosion protection barrier.

2. A construction element as claimed in claim 1 wherein said inward recess is defined at the perimeter of said unitary body.

3. A construction element as claimed in claim 1 or 2 wherein said inward recess is a step defines in the longitudinally distal most end of said first end.

4. A construction element as claimed in any one of claims 1 to 3 wherein said unitary body is of a constant cross section elongate shape, save for at said distal ends, wherein said unitary body defines a continuously closed cross sectional perimeter.

5. A construction element as claimed in any one of claims 1 to 4 wherein said cavity is of a constant cross sectional perimeter shape of said unitary body.

6. A construction element as claimed in any one of claims 1 to 5 wherein said unitary body is of a perimeter defined by a substantially constant thickness perimeter wall.

7. A construction element as claimed in any one of claims 1 to 6 wherein said protrusion is defined by a lip extending at said second distal end of said unitary body.

8. A construction element as claimed in any one of claims 1 to 7 wherein said unitary body is of a cross section having a triangular outer perimeter

9. A construction element as claimed in anv one of claims 1 to 8 wherein said cross j section of said cavity is triangular.

10. A construction element as claimed in any one of claims 1 to 9 wherein said recess is wider than said protrusion allowing for a lose engagement so as to allow for a - 16- longitudinal misalignment when placed longitudinally adjacent another like construction element to allow curved longitudinal placement of a plurality of said construction elements.

11. A construction element as claimed in any one of claims 1 to 10 wherein said longitudinally extending surface includes at least one protrusion of a complementary shape to allow the interlocking engagement thereof with an adjacent of said construction elements in a lateral to the longitudinal direction.

12. A construction element as claimed in any one of claims 1 to 11 wherein said body includes at least one protruding member extending outwards from said base.

13. A construction element as claimed in claim 12 wherein said protruding member extends outwards perpendicular to said base.

14. A construction element as claimed in claims 12 or 13 wherein said protruding member extends along the length of said body.

15. A construction element as claimed in any one of claims 12 to 14 wherein said protruding member is at or towards one side of said base.

16. A construction element as claimed in any one of claims 12 to 15 wherein said construction element includes two protruding members, located at opposite sides of said base.

17. An interlocking erosion protection device comprising a construction element of a kind as claimed in any one of claims 1 to 16.

18. A plurality of interlocking erosion protection devices as described with reference to Figure 9.

19. A plurality of construction elements as claimed in any one of claims 1 to 16, wherein the construction elements are stacked vertically to form an erosion protection structure dated THIS 2 PAY OP t>PC£MB<E& 3-00& A] PARK ..^r PER M3 C'*-0 P*" agents for the applicant