WO2014058387A1

WO2014058387A1 - A versatile erosion control system

Info

Publication number: WO2014058387A1
Application number: PCT/SG2012/000378
Authority: WO
Inventors: Michael Lazar
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-10-09
Filing date: 2012-10-09
Publication date: 2014-04-17
Anticipated expiration: 2015-04-09
Also published as: AU2012392206A1

Description

A VERSATILE EROSION CONTROL SYSTEM

Field of the invention

[0001] The present invention relates broadly to systems, methods and means for controlling/protecting land areas from erosive water forces. More particularly, the invention relates to construction elements for use in the assembly of interfacing formations such as retaining walls, erosion control barriers or like structures.

Background of the invention

[0002] Any discussion of documents, acts, materials, devices, articles and the like in this specification is included solely for the purpose of providing a context for the present invention. It is not suggested or represented that any of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia or elsewhere before the priority date of each claim of this application.

[0003] Land areas which interface with water regions are often prone to damage from the erosive effects of high water flows and/or cyclic wave behaviour. Attempts have been made to adapt conventional erosion control systems (often comprising of a large number of unitary blocks) previously used with small scale water courses such as small rivers, canals, and'other inland waterways, for use in more extreme environments such as coastal areas. In these environs the structural integrity of such formations can be significantly

compromised should they rupture or become damaged. The risk of failure of such formations represents a significant concern for persons and/or property reliant on the protection provided by such structures.

[0004] Many conventional erosion control systems have been shown to be inefficient when adapted for use in more extreme environs as they often need to be specifically customised to the location. The need to customise and/or create specifically designed construction blocks for different sites has the tendency to unduly inflate fabrication and construction costs. Thus, although various solutions have been proposed to address these and other shortcomings, inconveniences in the provision of such structures still exist. Summary of the invention

[0005] According to one aspect of the present invention, there is provided a construction element for use in the assembly of an interfacing formation such as a retaining wall, an erosion control barrier or like structure, the construction element configured so as to be capable of interconnecting with one or more other neighbouring elements of the assembly such that relative movement is substantially restrained in a first direction but substantially unrestrained in a further direction substantially normal to the first direction.

[0006] The resulting formation may provide a semi-rigid, substantially resistant but compliant structure.

[0007] The formations of these structures may be such as to be substantially resistant to erosive activity (such as high velocity fluid flows, tidal behaviour, high velocity shock loads due to wave impact and the like) acting on the structure, yet compliant by way of the elements each having freedom of movement in a common direction. In this regard, the interconnection between neighbouring elements serves to provide, at least in part, sufficient freedom to the structure so as to be capable of self-adjusting therefore serving to, at least in part, relieve stress build-up when in use so as to reduce the risk of the structural integrity of the formation being comprised, and/or allowing the structure to adapt to movements in the foundation.

[0008] . The or each element may comprise an elongate body having an elongate axis which, when orientated normally in a seated position within a structure on a substantially horizontal surface or on substantially horizontal ground, is aligned substantially with the vertical plane. Substantially orthogonal to the elongate axis for each element is its transverse plane which, when the element is seated normally, is aligned substantially with the horizontal plane. Therefore, when in position, the transverse planes of neighbouring elements will be substantially co-planar with one another.

[0009] The interconnectivity between neighbouring elements may be such that, when interconnected, relative movement within each element's respective transverse plane is reduced while relative movement in the direction of each element's elongate axis (ie.

movement out of the transverse plane) is substantially unrestrained. When the elements are interconnected together, a structure so formed may more easily be arranged to conform to the contours of the foundation upon which the structure is erected by way of each element having the freedom to substantially comply with the natural and/or intended spatial condition of the foundation. Thus, when the elements are used for the construction of a protective barrier, their assembly and interconnection serves to improve the structural integrity of the structure while allowing the elements sufficient freedom in a direction substantially normal to their respective transverse planes to, at least in part, conform to local geography/topography, and/or assist with the relief of stress built up in the structure.

[0010] The body of the construction element may comprise a shaped member configured so as to be engageable, such as by sliding engagement, with a shaped member of a neighbouring element so that the elements may be interconnected together.

[0011] The shaped member may be configured so as to complement that of the neighbouring element.

[0012] The shaped member may be provided on at least one side or face of the body of the element. Alternatively, the shaped member may be provided on each side or face of the body and/or extend substantially the length of the body along its elongate axis.

[0013] The shaped member may comprise an open shaped recess provided in the side or face of the body, the open shaped recess having a narrowed region provided at or near a periphery of the side or face of the body.

[0014] Alternatively, the shaped member may comprise a projection arranged so as to project away from the side or face of the body, the projection having a narrowed region configured at or near a periphery of the side or face of the body.

[0015] The projection and the open shaped recess described above may substantially complement one another so that the narrowed region of the open shaped recess

substantially captures the projection when both are in engagement with one another thereby substantially restraining relative transverse movement between the elements.

[0016] The one or more neighbouring elements may comprise those elements which are immediately adjacent the construction element such that respective shaped members are able to interconnect with one another.

[0017] Embodiments of the above described construction element may comprise polygons of unitary construction. In one embodiment, the construction element is a four sided polygon of unitary construction.

[0018] According to another aspect of the present invention, there is provided a construction element for use in the assembly of an interfacing formation such as a retaining wall, an erosion control barrier or like structure, the construction element configured so as to be capable of interconnecting with one or more other neighbouring elements of the assembly such that the elements are by their interconnection constrained from moving in a first common direction but have freedom of movement in a second common direction substantially normal to the first common direction, so as to provide a substantially resistant but compliant structure.

[0019] In another aspect the present invention provides a set of construction elements for use in the assembly of an interfacing formation such as a retaining wall, an erosion control barrier or like structure, the set comprising: a first construction element arranged according to any of the above described embodiments of the construction element in which the shaped member comprises a projection; and a second construction element arranged according to any of the above described embodiments of the construction element in which the shaped member comprises an open shaped recess.

[0020] In another aspect the present invention provides an interfacing formation for use as an erosion control barrier or like structure, the interfacing formation formed from an assembly of a plurality of the above described construction elements or a plurality of the above described set of construction elements.

[0021] Neighbouring elements may be arranged in a stepped relationship relative to one another so as to provide the formation with a desired gradient, or so the formation may, at least in part, conform substantially to a pre-existing foundation

geography/topography.

[0022] The formation may be arranged as an interfacing or protective barrier for use with one of the following: an embankment associated with a seabed, a ferry landing associated with a lake, a stream associated with a dock, a canal associated with a waterway, a water craft launching ramp associated with a ferry port, a breakwater associated with a river, a retaining wall associated with a slope, a reclamation scheme, or a formation for scour protection for an underwater structure.

[0023] In another aspect, the present invention provides a method used in the production of the above described construction element, or a set of the above described construction elements.

[0024] In a further aspect, the present invention provides a method for the assembly of the above described interfacing formation. The assembly method may further comprise one or more of the following steps: forming a channel and positioning therein a plurality of first construction elements arranged in accordance with an embodiment of the first aspect of the present invention; forming a further channel, substantially adjacent the first channel, and positioning therein a plurality of further construction elements arranged in accordance with an embodiment of the first aspect of the present invention such that they interconnect with the first construction elements.

[0025] In a further aspect, the present invention provides a combination of two types of cavitied unitary construction elements having mechanical locking and/or locating means. When such construction elements are assembled or placed together in a substantially repeating or continuous arrangement, a revetment type of semi-rigid structure may be formed. The construction elements may be manufactured in varying thicknesses, weight and sizes for optimum design purposes so as to suit the desired application and/or intended location. The construction elements may be installed as appropriate so as to substantially conform to the contours of the river banks or other areas where such formations might wish to be established.

[0026] Embodiments of the present invention may serve to provide a versatile solution to erosion control so as to more capable of withstanding the erosive effects of

hydrodynamic forces without adversely affecting the natural appearance of the locale environs, associated vegetation and/or marine life.

Brief description of the drawings

[0027] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0028] Figure 1 shows a perspective view of one embodiment of a construction element arranged in accordance with the present invention;

[0029] Figure 2 shows a perspective view of another embodiment of a construction element arranged in accordance with the present invention;

[0030] Figure 3 shows a perspective exploded view showing the interconnectivity of the construction elements shown in Figures 1 and 2;

[0031 ] Figure 4 shows an elevation view of an assembly of the construction elements shown in Figures 1 and 2; and,

[0032] Figure 5 shows a perspective view of the assembly shown in Figure 4. Detailed description

[0033] Figures 1 and 2 each show respective construction elements 2, 20 configured in accordance with two embodiments of the present invention. The construction elements 2, 20 shown are intended for use in the assembly of protective interfacing formations such as those used for erosion control barriers or like structures. Construction elements 2, 20 are each configured so as to be capable of interconnecting with one or more other

neighbouring elements such that relative movement in a first direction is substantially restrained, yet substantially unrestrained in a second direction which is substantially normal to the first direction. Resulting assemblies may serve to provide a substantially resistant yet compliant barrier or like structure.

[0034] The elements 2, 20 generally comprise respective bodies 4, 22 having respective elongate axes Aj_<2 which, when the elements are each orientated normally in a seated position (the orientation of the elements shown in each of Figures 1 and 2), are aligned substantially within the vertical plane. Substantially orthogonal to the elongate axis (A]_;2) for each element is its transverse plane Ρχ which, when the element is positioned in its seated position, is aligned substantially with the horizontal plane. Therefore, when seated, the transverse planes of neighbouring construction elements will be substantially parallel with one another. Of course, variances between such planes will be largely due to the particular positioning/orientation of the individual construction.

[0035] With reference to Figure 3, the interconnectivity between neighbouring construction elements 2, 20 is such that, when interconnected, relative movement within each element's respective transverse plane is substantially reduced, while relative movement in the direction of each element's elongate axis (ie. in a direction which is out of the transverse plane) is substantially unrestrained, ie. the vertical direction. As such, when the construction elements 2, 20 are interconnected together, a structure so formed is capable of conforming to the natural (and often changing) contours of the foundation on which the structure is erected upon by way of each construction element having the freedom to accommodate spatial movement in the generally vertical plane.

[0036] Construction elements 2, 20 each comprise a four sided unitary polygon provided with respective shaped members 6, 24, each of which are arranged so as to provide a means of interconnectivity between neighbouring or adjacently disposed elements.

[0037] Construction elements 2, 20 are each preferably provided with a circular cavity 16 arranged concentric with each element's elongate axis Ai_>2. The cavity 16 may assist in the relief of hydrostatic stress and/or provide relief from ground water pressure. The cavity 16 may be a blind recess or configured so as to extend through the element. The cavity 16 may serve to reduce the weight of the element to allow for, for example, easier handling and/or cost effective manufacture so as to avoid the necessity for acquiring specialist labour resources. The weight of the elements can be increased, if required, by infilling the cavity 16 with a filler material such as for example, sand, concrete, or a readily available material (ie. on site) such as soil or sand. As such, a toe or specific anchoring means for each element (so as to secure the structure) is generally not required.

[0038] The cavity 16 may also be in-filled with a suitable material so as to encourage and promote the development of vegetation and/or marine life native to the locale of the formation. As such, use of the construction elements 2, 20 in such structures can help to provide a structure possessing aesthetics which are in keeping with the natural appearance of the locale. Furthermore, the vegetation established over time may also assist with reducing flow velocities.

[0039] With reference to Figure 1, each side of construction element 2 is provided with a respective shaping 6 which extends centrally along the full dimension (along the elongate axis Ai) of each side of the element. Each shaped member 6 comprises a channel i0 which extends along the elongate length of the element 2. Each channel 10 comprises a narrowed region defined by opposing lips 12a and 12b. As shown in Figure 1, the dimension of the narrowed region between lips 12a, 12b is smaller than the maximum internal width of the channel 10.

[0040] With reference now to Figure 2, construction element 20 is provided with a shaped member 24 which extends centrally along the full dimension (along the elongate axis A₂) of the side of the element. Shaped member 24 comprises a centrally disposed tongue 28 which projects outward from the side. Tongue 28 comprises opposing flanges 32a and 32b located either side thereof. As will be readily seen from Figure 2, the effect of opposing flanges 32a and 32b is to provide corresponding grooved regions 34a and 34b.

[0041] The interconnectivity between elements 2 and 20 is shown in Figure 3 showing an exploded view illustrating how a number of construction elements 2, 20 may

interconnect together to form an assembly. Construction elements 2, 20 are arranged so that their respective shaped members 6, 24 may interconnect with neighbouring elements having the alternative shaped member so as to allow structures of repeating interconnecting elements to be assembled. Thus, for the construction elements 2, 20 shown, each element may be connected with four neighbouring elements having complementarily configured shaped members. [0042] Assembly of construction elements 2 and 20 involves the tongue 28 of shaped member 24 of element 20 being inserted into channel 10 of construction element 2.

Construction elements 2, 20 are then moved relative one other so that the tongue 28 of element 20 is positioned within channel 10 of the element 2 as required. Once the desired relative positioning of both elements 2, 20 is achieved, the relative transverse movement between both elements is restrained due to flanges 32a, 32b of shaped member 24 of element 20 being captured within channel 10 of shaped member 6 (ie. opposing lips 12a, 12b of shaped member 6 occupying grooved regions 34a, 34b) of element 2.

[0043] It will be appreciated by the skilled reader that shaped members 6 and 24 of respective elements 2 and 20 are suitably configured so that complementary

interconnection between the two embodiments can occur. Thus, other forms of such shaped members may be realised which substantially restrain relative transverse movement but allow for relative movement normal to the transverse plane to occur when engaged such as by a relative sliding movement. Preferably, shaped members 6 and 24 are shaped so that their geometries complement one another in the transverse plane.

[0044] Using a plurality of construction elements 2, 20, structures similar to those shown in Figures 4 and 5 can be assembled. For the arrangement shown, the effective gradient of the structure can be established by off-setting neighbouring elements from one another - the relative off-set being possible due to the interconnecting means allowing for relative movement/positioning in the vertical direction when the elements are in their seated position. The structure remains, however, sturdy due primarily to each element's self weight as well as the restraint of the interconnection in the element's transverse plane.

[0045] The construction elements 2, 20 may be manufactured using any appropriate process known in the technical field. For example, the elements may be manufactured in specialist unitary block forming devices, or cast to the required dimensions (thickness, width, height, and/or weight) using normal casting processes known in the art.

[0046] The construction elements may be prefabricated on or off site so as to meet expedited installation time frames when required. The elements may be manufactured using cement and other aggregates. The specific manufacturing method used may therefore depend on its appropriateness in view of the material required. Other suitable construction materials might also include Nylon or equivalent grade fibres.

[0047] Construction elements of different dimensions and weights may be readily manufactured so that improved formation design and construction can be better realised. Specific dimensioned tolerances may be determined as appropriate. [0048] Other characteristics of the construction elements 2, 20 may include the following:

• high strength (eg. strength capacities may be in excess of around 5,000 psi - or a minimum of around 4,500 psi);

• resistance to sulphate attack.

[0049] Protective barriers or like structures constructed and arranged in accordance with the present invention may be readily deployed for use in many applications. Such applications may include an interfacing barrier for use with any of the following: an embankment associated with a seabed, a ferry landing associated with a lake, a stream associated with a dock, a canal associated with a waterway, a water craft launching ramp associated with a ferry port, a breakwater associated with a river, a retaining wall associated with a slope, a reclamation scheme or a formation for scour protection for an underwater structure. The latter is not intended to be an exhaustive list of applications but serves to illustrate different types of possible applications. It will be readily apparent to the skilled reader what other applications might benefit from the core aspects of the present invention.

[0050] Formations comprising construction elements 2, 20 may be configured so as to provide structures having a more environmentally friendly focus. For example, the cavity 16 provided within the elements 2, 20 may assist in the retention of filler material such as. soil in which native vegetation may be nurtured. The skilled reader will appreciate that retention of the filler material and vegetation in each element assists to, at least in part, stabilise the overall structure. Thus, such structures have the potential to be developed so as to provide more aesthetically pleasing structures than those typically created by conventional systems by encouraging the continued development and/or promotion of native vegetation and/or marine life.

[0051] The interconnection between neighbouring construction elements 2, 20 allows, at least in part, the structures to have a degree of compliancy. This has been found to have the effect of reducing the inherent stress on each of the structure when deployed in certain applications. Furthermore, such inherent adaptability allows the elements to conform to the existing contours of the structure's foundation - even if settlement should occur after installation. As such, due to the freedom of the element in the vertical (or sink) direction, settlement of the individual construction elements is unlikely to compromise the performance and stability of the structure.

[0052] In use, the construction elements 2, 20, may be placed on geotextiles. The permeability of such geotextiles and the configuration of the construction elements has the potential to relieve hydrostatic pressure without creating erosion channels that may erode the filler material (sand) used in the cavity 16. Drainage of ground water also has the potential to be enhanced.

[0053] Embodiments of structures incorporating the construction elements 2, 20 allows for a step like construction which can be convenient in certain situations. For instance, such construction can be advantageous for the development of structures allowing for, for example, improved access/transportation of people (eg. easier embarking and disembarking from boats or ferries) or goods.

[0054] The behaviour of flow in a channel is influenced by many physical factors and field conditions. Natural channels include watercourses that exist naturally, varying in size from creeks, through to streams, rivers and tidal estuaries.

[0055] Formations using construction elements 2, 20 may provide a retarding or dampening effect when subject to erosive water behaviour. For example, when the formation is constructed in a manner in which the construction elements are arranged in an uneven manner, the energy inherent in such erosive fluid flows may be decreased. As a result, the net energy delivered to such formations has the potential to be reduced. In addition, the design of the formation, and thus the specific arrangement of the elements, may be configured so that the fluid flows are less likely to impact directly on the structure.

[0056] Formations assembled using the herein described construction elements suggest an improved ability to withstand flows in natural channels that are almost always turbulent in nature, ie. having water particles moving flowing in irregular patterns. The weight and size of the construction elements configured for use in such structures appear to possess sufficient strength to, at least in part, absorb or deflect the energy of waves or erratic fluid flow thereby reducing the erosive capacity of fast flowing water (very high velocities in some instances) to manoeuvre the construction elements out of position. Furthermore, the construction elements may be arranged of sufficient weight and configuration so as to resist dislodgement.

[0057] Placement of the construction elements in a stepped arrangement helps decrease the velocity of the water engaging or flowing over the elements when in formation. As a result, the kinetic energy inherent in such high velocity flows can be reduced or dampened having the result of reducing the net energy ultimately delivered to the formation as a whole.

[0058] The occurrence of bottom scour caused by the rolling action of waves or high velocity fluid flows (which otherwise have the effect of water removing sediment from the base of the revetment) may be reduced. [0059] Protective formations using construction elements 2, 20 may be designed to be reinforced at the base sides and ends to prevent erosion of the sediment and allowing water to ingress behind the structure causing flank erosion.

[0060] As foreshadowed above, in the event settlement takes place due to bottom scour (or other reasons), the construction elements are capable of moving or sinking (in the out-of-plane direction) relative its neighbouring element thereby causing a reduction in relative height. In such situations, another element of the desired dimension(s) can be cast- in-situ, or placed over the sunken element, to compensate for the loss in height.

[0061] It will be readily appreciated that construction elements 2, 20 may be provided without the cavity 16 if it were desired to maintain or increase the conveyance of water, for example, in the case of narrow channels.

[0062] For the case of a river bank for example, formations incorporating the elements of the present invention may be constructed as steep as required for stability reasons. In these and similar applications the structures can be constructed so as to remain in keeping with the contours of the river. The interconnection of the construction elements 2, 20 readily allows for a step like structure to be constructed on a sloped foundation and/or at any desired angle/gradient. Such structures have the tendency to be more easily built due to improved handling by way of the reduced weight of the element due to the central cavity 16. In this regard, construction costs have the potential to be reduced as specialist labour and construction equipment can be, in many cases, avoided.

[0063] In the construction of a river bank formation, positioning of the elements may typically begin from the shoreline and move toward the embankment, then extending to the top of the shore or embankment in a step like manner.

[0064] Layers of construction elements may be positioned so as to extend above and below the shore line. For example, uppermost construction elements in the formation may be generally positioned so as to extend the formation above the anticipated high water level (such levels being based on historical measured data) so as to reduce water from going over the formation during high tides or tropical storm surges.

[0065] One implementation of a possible construction procedure is outlined as follows with regard to the assembly of a formation for use adjacent a river.

[0066] Construction of such a river bank formation typically requires a portion of the river bottom to be excavated in the form of channels or trenches below the shoreline during low tide. The trenches are excavated so as to accommodate substantially the whole construction element, and arranged so as to be substantially straight, or so as to follow the contour of the riverbed (in the flow direction). The construction elements are then positioned within the trenches as appropriate so as to form a first row of elements. Further elements, as required, are then positioned as appropriate so as to interconnect with those laid prior in the row.

[0067] A second trench is excavated beside (typically behind) the first formed trench. The second trench is excavated as appropriate so as to accommodate substantially half the element size (in the depth or vertical direction). A second row of construction elements is then positioned into the second excavated trench as appropriate so that the elements may interconnect with neighbouring elements of the first row. It will be appreciated that the depth of the second trench (and subsequent trenches) will be dependent on the desired effective gradient sought between the first and second rows of elements. Thus, a portion, as required, of the second row elements may be exposed behind the first row. The second row may be arranged so that the upper most surface of the elements remains substantially flush with that of the first row elements.

[0068] As this procedure continues, it will be appreciated that excavated material may be used to in-fill the cavity 16 of the elements, and/or used to level over one or more of the initial rows.

[0069] A third row of elements may be similarly positioned behind and interconnected with the second row of elements. The depth of the excavated trench for the third row of elements may be such that a portion of the third row elements is exposed behind the second row thereby commencing or continuing the 'step' formation.

[0070] It will be readily apparent to the skilled reader that the above procedure may be repeated as appropriate so that the intended overall gradient of the structure is established as intended. Thus, it will be appreciated that the step formations between rows may be adjusted as desired so that the structure is in keeping with the natural geography or topography of the location - if this is desired.

[0071] In some situations, in order to position the construction elements in subsequent rows, a levelled base layer (using sand or other suitable base material) built to a specific height may need to be constructed behind an earlier row. As will be appreciated by the skilled reader, such a base must be well compacted and, if required, a geotextile material placed thereover prior to positioning the elements in the row. The base material may comprise material sourced locally from the site (for the case of a river bank, sand may be sourced (and pumped) from the riverbed).

[0072] Subsequent rows in the structure may be constructed according to a similar procedure. [0073] A similar construction procedure could be applied for formations used for reclamation operations based, at least in part, on a desired gradient angle and/or height. Such formations could be constructed and the required filler material pumped to the rear of the formation so as to reclaim the land accordingly.

[0074] Filler material such as sand or other locally available material may be in-filled into the cavity 16 of the construction elements 2, 20 during the construction and/or following completion of the structure. Should cyclic fluid flows, such as for example tidal behaviour, be of sufficient concern, the formations could be reinforced or secured by inserting concrete or sheet piles through the cavity 16 at desired intervals to anchor the system firmly to the relevant foundation.

[0075] In view of the above, it will be appreciated by the skilled reader that the concept of the present invention is versatile and can be readily adapted to suit many different applications and possible locations.

[0076] Many practical and operational advantages flow from using the elements described herein for the assembly of such structures. In one respect, such formations may allow for a more simpler, safer, and cost effective form of maintenance. Furthermore, any erosion of sand from between neighbouring elements, and/or from within the cavity 16, will be clearly visible and can be readily identified by way of routine maintenance regimes - such as that required for inspection of structural deficiencies of the formation (and constituent elements) - and addressed quickly (such as by pumping material from the river bed into the relevant elements or parts of the formation). Thus, maintenance of such structures has the potential to be easier and therefore more cost effective than existing systems.

[0077] Moreover, in the event that any settlement may cause one or more elements to sink below their desired level, a new (replacement) element of elements of equivalent height may be easily inserted at the desired location as required. Alternatively, the affected elements can be elevated and adjusted by in-filling and compacting the foundation material (typically sand) under the element. Thus, the formation can be attended to such that the occurrence of settlement is less likely to compromise the integrity of the structure.

[0078] Embodiments of the above described construction elements, and assemblies thereof, may provide one or more of the following:

• the construction elements, when assembled, may serve to provide improved hydraulic efficiency and stability of the resulting formations or barrier structures; • neighbouring construction elements may engage one another so as to interconnect and/or interlock on all four sides of a given element;

• the construction elements may provide an interconnecting or interlocking resistant yet compliant unitary revetment system, capable of withstanding the erosive and/or destructive effects of high water velocities and high pressure shock loads associated with cyclic wave activity;

• sand or similar filler material may be in-filled after placement of the elements, ie. pumped into the cavity of the elements from the river bed or associated locale thereby increasing the element's weight (such increases in weight may be in the order of at least another 30%);

• the roots of native vegetation may be encouraged to penetrate the soil/geotextile substrates when employed for use so as to, at least in part, assist in anchoring the elements;

• the cavity in the elements may serve to relieve hydrostatic pressure by dissipating the pore water pressure built-up from the elements. In this regard, the cavity may assist in dissipating the pressure, while the capability of the cavity for soil retention, if used, may assist in the prevention of the leaching of filler material (for example sand/soil) throughout the structure;

• elements and associated formations thereof may offer improved stability and protection in the presence of potentially destructive water forces;

• assembled structures exhibiting an appropriate gradient may serve to deflect the energy emanating from fluid flows and cyclic wave impacts; assembled structures constructed having a vertical nature may, in some applications, serve to reduce or dampen forces impacting against the wall.

[0079] It is to be understood that, throughout the description and claims of the specification, the word "comprise" and variations of the word, such as "comprising" and "comprises", is not intended to exclude other additives, components, integers or steps.

[0080] Modifications and improvements to the invention will be readily apparent to those skilled in the art. Such modifications and improvements are intended to be within the scope of this invention.

Claims

The claims defining the invention are as follows:

1. A construction element for use in the assembly of an interfacing formation such as a retaining wall, an erosion control barrier or like structure, the construction element configured so as to be capable of interconnecting with one or more neighbouring elements of the assembly such that relative movement is substantially restrained in a first direction but substantially unrestrained in a further direction substantially normal to the first direction.

2. A construction element according to claim 1, wherein the interconnection between neighbouring elements is such that, when interconnected, relative transverse movement of the elements is reduced while relative axial movement is substantially unrestrained.

3. A construction element according to claim 1 or claim 2, wherein the element

comprises a body having a shaped member configured so as to be engageable with a shaped member of said one or more neighbouring elements so that both elements may be interconnected together.

4. A construction element according to claim 3, wherein the shaped member of the element is configured so as to complement that of the neighbouring element.

5. A construction element according to claim 3 or claim" 4, wherein the shaped

member is provided on at least one side or face of the body of the element.

6. A construction element according to claim 5, wherein the shaped member

comprises an open shaped recess provided in the side or face of the body, the open shaped recess having a narrowed region provided at or near a surface of said side or face.

7. A construction element according to claim 5, wherein the shaped member

comprises a projection arranged so as to project away from the side or face of the body, the projection having a narrowed region configured at or near a surface of the side or face.

8. A construction element according to claim 7, wherein the projection defined in claim 7 and the open shaped recess defined in claim 6 substantially complement one another so that the narrowed region of the open shaped recess substantially captures the projection when both are arranged in engagement with one another thereby substantially restraining relative in-plane movement between the elements.

9. A construction element according to any one of the preceding claims, wherein the element is a polygon of unitary construction.

10. A construction element according to any one of the preceding claims, wherein the element is provided with a cavity arranged so as to be aligned substantially parallel with an axis of the element.

11. A construction element for use in the assembly of an interfacing formation such as an erosion control barrier or like structure, the construction element configured so as to be capable of interconnecting with one or more neighbouring elements of the assembly such that the elements are by their interconnection constrained from moving in a first common direction but have freedom of movement in a second common direction substantially normal to the first common direction, so as to provide a substantially resistant but compliant structure.

12. A construction element according to claim 1 1, having the features defined by any one of claims 2 to 10.

13. A set of construction elements for use in the assembly of an interfacing formation such as an erosion control barrier or like structure, the set comprising: a first construction element arranged according to any one of claims 1 to 12 when dependent on claim 6; and, a second construction element arranged according to any one of claims 1 to 12 when dependent on claim 7.

14. An interfacing formation for use as a retaining wall, an erosion control barrier or like structure, the interfacing formation formed from an assembly of a plurality of construction elements according to any one of claims 1 to 12, or a plurality of a set of construction elements according to claim 13.

15. An interfacing formation according to claim 14, wherein neighbouring elements are arranged in a stepped relationship relative one another so as to provide the formation with a desired gradient, or so said formation conforms substantially to a pre-existing foundation.

16. An interfacing formation according to claim 14 or claim 15, wherein the formation is arranged as an interfacing barrier for use with one of an embankment associated with a seabed, a ferry landing associated with a lake, a stream associated with a dock, a canal associated with a waterway, a water craft launching ramp associated with a ferry port, a breakwater associated with a river, a retaining wall associated with a slope, a reclamation scheme, or a formation for scour protection for an underwater structure.