Means and apparatus for controlling fluid currents and selectively preserving and modifying topography subjected thereto
United States Patent 3913333
Modular units are provided for utilizing the kinetic energy in waves, tides and winds to effect deposits of fluid entrained alluvium. The modules have front and rear surfaces so structured that arrays of the modules can effect shaped alluvial deposits or selective entrainment of alluvium to maintain or modify the topography at the situs of the arrays.
US Patent References:
/1175962.html
Latham - March 1916 - 1175962
Method of and apparatus for protecting water channels
Hornsby - May 1937 - 2080045
Apparatus for beach building
Martin - November 1965 - 3214916
System for reclamation of land
Hornbostel, Jr. - March 1968 - 3373568
ATTENUATION OF WATER WAVES AND CONTROL AND UTILIZATION OF WAVE-INDUCED WATER MOVEMENTS
Hammond - January 1974 - 3785159
/1175962.html
Latham - March 1916 - 1175962
Method of and apparatus for protecting water channels
Hornsby - May 1937 - 2080045
Apparatus for beach building
Martin - November 1965 - 3214916
System for reclamation of land
Hornbostel, Jr. - March 1968 - 3373568
ATTENUATION OF WATER WAVES AND CONTROL AND UTILIZATION OF WAVE-INDUCED WATER MOVEMENTS
Hammond - January 1974 - 3785159
Application Number:
05/398305
Publication Date:
10/21/1975
Filing Date:
09/18/1973
View Patent Images:
Export Citation:
Primary Class:
International Classes:
E02B3/04; E02B3/06; E02B3/06
Field of Search:
61/2,3,4,5,1,37
Primary Examiner:
Kannan, Philip C.
Attorney, Agent or Firm:
Birch, And Birch
Claims:
What is claimed is
1. Reaction means for fluid currents to selectively modify the action of such currents on the topography of a given situs and accrete alluvium entrained therein comprising:
2. A protection array for preserving navigational channels and the like against the alluvial action of incoming and outgoing tidal currents, said channel having first and second lateral boundaries extending from a backwater to a main body of water, comprising:
3. The invention defined in claim 2, wherein said modules at the extreme ends of each said row adjacent said main body of water have said reaction surfaces facing outboard of said channel.
4. The invention defined in claim 2 wherein said modules at the extreme ends of each said row adjacent said backwater have said reaction surfaces facing inboard of said channel.
5. The invention defined in claim 2, wherein said modules at the extreme ends of each said row adjacent said main body of water have said reaction surfaces facing outboard of said channel; and
1. Reaction means for fluid currents to selectively modify the action of such currents on the topography of a given situs and accrete alluvium entrained therein comprising:
2. A protection array for preserving navigational channels and the like against the alluvial action of incoming and outgoing tidal currents, said channel having first and second lateral boundaries extending from a backwater to a main body of water, comprising:
3. The invention defined in claim 2, wherein said modules at the extreme ends of each said row adjacent said main body of water have said reaction surfaces facing outboard of said channel.
4. The invention defined in claim 2 wherein said modules at the extreme ends of each said row adjacent said backwater have said reaction surfaces facing inboard of said channel.
5. The invention defined in claim 2, wherein said modules at the extreme ends of each said row adjacent said main body of water have said reaction surfaces facing outboard of said channel; and
Description:
This invention relates to means and apparatus for modifying the effect of fluid currents such as winds, tides and the like to selectively enhance, modify or reverse the natural erosion processes effected by such currents.
BACKGROUND OF THE INVENTION
The effects of winds, tides and other fluid currents on beaches, shorelines, channels and the like is a long standing and serious problem.
The erosion of beaches, silting of navigation channels, destruction of natural barriers such as sand dunes and other deleterious effects causing untold financial losses, destruction of natural environs and continuing large expenditures of funds for corrective action has been and still is a dilemma that is only solvable on a temporary and frequently recurring basis. A substantially permanent solution to such problems or even a relatively long term solution has not yet been devised.
The prior art is replete with groins, jitties, weirs, breakwaters and the like which serve only specific functions against prevailing conditions and which, unfortunately, have not been satisfactory for preserving shorelines, dunes and/or navigational channels under either prevailing or variable ambient conditions.
Furthermore, no prior art devices are know which can serve all of these functions and in addition actually increase the size of shorelines, dunes and channels or selectively create same in a predetermined configuration and location.
Because of the tremendous energies involved in preventing damage by winds, tides and currents, the prior art approach to erosion control has necessitated unwieldly, large and aesthetically displeasing structures in order to provide sufficient strength and sustainability to such structures.
Furthermore, such structures have been for the most part merely passive devices which are directed to impeding the action of fluid currents, disrupting wave action and/or creating eddy current action.
Accordingly, means and apparatus which can convert such tremendous available energy to corrective and beneficial use are sorely needed.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide a new and novel means for utilizing the energy and/or wave action in fluid currents to selectively modify or preserve the topography of the situs of that means.
Another object of the present invention is to provide a new and novel module for systems having selective interaction and control of fluid currents and/or wave motions for preserving or modifying the topography of the situs of a given one of said systems.
Another object of the present invention is to provide new and novel beach erosion control devices which are aesthetically acceptable and which are capable of complimentary uses and functions.
Still another object of the present invention is to provide new and novel systems and components for same for selectively building land from alluvial material transported by fluid currents reacting with such systems and components.
Still another object of the present invention is to provide new and novel systems and components for same for preserving and/or creating navigational channels.
Yet another object of the present invention is to provide new and novel fluid current modifying and control systems and components for same which are selectively adjustable in situs to compensate for variation in otherwise prevalent ambient conditions of fluid currents and/or wave action.
These and other objects of the present invention will become more fully apparent with reference to the following specification and drawings, which relate to several preferred embodiments of the invention.
SUMMARY OF THE INVENTION
The basic modular components of the present invention are basically elongated shells having a flat base; a convexly curved outer face coterminate with the base at one edge thereof; a complimentary concave inner surface opposite and coeterminate with the convex face; a pair of flat end walls supporting the curved faces and forming therewith an integral structure with the base and partially enclosing said inner face; and one or more internal planor ribs substantially parallel to the said end walls and having, preferably, a relieved leading edge outboard of said inner face and having a generally complimentary radius of curvature, in the plane of said rib, to the said concave inner face of the module.
In erosion control situations for enhancing the deposition of alluvial material entrained in fluid currents and/or waves on shorelines, dunes and the like, the module is oriented such that incoming force of the current is directed into the open side (against the concave inner surface) of the module with the base preferably set laterally of the incoming flow direction and the said end walls and internal ribs substantially parallel to said flow direction. In this configuration, for example, the base of an incoming wave is turned against the crest and at least components of the crest against the base, nullifying or severely attenuating the wave energy in certain strata and causing entrained alluvial material to be deposited in front of the module. This creates a buildup of this material which increases or at least preserves the level of the bottom or shoreline on which the module is situated.
Reverse (outgoing) wave action coming from the rear of the module is forced up and over the convex outer face causing further energy reduction and resulting in additional deposition of alluvial material on the back side of the module. The front and back sides are defined in relation to the incoming wave action in the foregoing description.
Predetermined arrays of these modules can be utilized to maintain navigational channels by selective angular placement of both the outer and inner surfaces of various modules to localize tides into rips in the channel and create bottom holding tide attenuating affects adjacent the existing channels.
Other arrays of the present invention can build up or create shoreline areas using wind, wave, tide and/or current actions. Conversely, other arrays can remove or alter shorelines and cut or form channels and the like by control of these natural forces.
Representative preferred embodiments of arrays for performing these functions will be discussed in more detail hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a control module of the present invention;
FIG. 2 is a top plan view of FIG. 1;
FIG. 3 is an end view of the module of FIGS. 1 and 2;
FIG. 4 is a cross-section taken along line 4--4 of FIG. 1;
FIG. 5 is a perspective of the module of FIG. 1 and includes integral mounting means;
FIG. 5A is a perspective of another embodiment of the control module of the present invention;
FIG. 6 is a perspective of a separable mounting means for the module of FIG. 1;
FIG. 7 is a diagrammatic representation of an multi-directional mounting means for the control module of the present invention;
FIG. 8 is a functional diagram of a control module of the present invention in a beach mounted erosion control mode wherein the module can extend above the water surface;
FIG. 9 is a functional diagram of a control module of the present invention in a subsurface or reef building erosion control mode;
FIG. 10 is a functional diagram of a control module of the present invention reacting with winds or air currents in a dune erosion control mode;
FIG. 11 is a functional diagram of a beach erosion control array of control modules of the present invention;
FIG. 12 is a functional diagram of a shoreline modifying array of control modules of the present invention; and
FIG. 13 is a functional diagram of a navigational channel modifying, creating or preserving array of control modules of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring in detail to the drawings and with particular reference to FIGS. 1, 2, 3, 4, and 5, the flow control module 10 of the present invention is shown as comprising an elongated molded solid having one of its longitudinal faces open to expose an interior concave wall or surface 12.
In the embodiment as shown for the control module 10, the concave inner face 12 is selectively partitioned along its length by a plurality of substantially equally spaced internal ribs 14, located between first and second end walls 16 which close the extreme ends of the module 10. Also, as shown in FIG. 1, the end wall 16 may be disposed slightly inboard of the extremities of the closed longitudinal top and rear surface 18 of the module 10 which is a convex surface extending from the top front of the module 10 all the way down to the rear of a flat base portion 20 of the said module. The said surface 18 is substantially conformally shaped with the concave inner surface 12.
Thus, in the embodiment as shown in FIG. 1, the convex rear surface 18 of the module 10 can be said to have a slight outboard lateral extension 18A overhanging the end walls 16 of the module as well as an overhanging front lip portion 18B at the upper edge of the open side of the module 10.
FIGS. 3 and 5 represent another embodiment of the module 10 of the present invention in that the lateral overhang 18A are not included and the end walls 16 of the module 10 thereby form the terminal ends thereof.
The inner face 12 of the module 10 can best be described with reference to FIG. 4 in which the module 10 is shown in cross section as disposed about a horizontal (x) and vertical (y) coordinate axis, with the x axis passing a substantially centrally through the cross sectional plane of the module 10 and the y axis being positioned more towards the open edge thereof.
The leading edge 20B of the base 20 of the module 10 extends inwardly over a rising surface 20A into a tangential transition with the lowermost portion 12A of the inner surface 12. This portion 12A of the inner surface 12 is defined by a first radius of curvature R1 over approximately 90° arc which extends from the said tangential transition with the surface 20A to the intercept of the x-axis and the inner surface 12.
The radius R1 commences from an x-axis index point I1 in-board of the x-y intercept I2. The said surface portion 12B extends from the intercept of the x-axis and surface 12 to the underside of the front lip 18B of the convex outer surface 18 at which point it makes a smooth transition outward and upward to the outermost edge of the said lip 18B.
One preferred embodiment of the inner ribs 14 of the module 10 is also shown in FIG. 4, wherein the concave contour of the leading edge of the said ribs 14 is shown as including a lower curve 14A with a radius of curvature R3B greater than the lower radius R3A. The lower radius R3A extends from a first index point 13A on the x-axis outboard of the x-y intercept I2 to the front edge 20B of the base 20, and then defines the lower curve 14A from that point up to the x-axis.
From the x-axis up to a smooth transition into the outer lip 18B of the convex surface 18, the radius R3B defines the upper curve 14B of the inner ribs 14. The upper radius R3B extends from an index 13B on the x-axis outboard of the index 13A.
This compound curvature to produce a concave leading edge on the ribs 14 of a compatible configuration with the inner surface 12 can also be imparted to the leading edges of the end walls 16 as shown in perspective in FIG. 5A which illustrates another preferred embodiment of the module 10.
At this point it should be understood that the compound curvatures described above are examples of preferred embodiments of the invention and are not intended to limit the scope thereof.
In short, the modules 10 resemble elongated scoops of crescent shaped cross-section with an open front F and a smooth closed back or rear surface 18.
For impeding fluid flow, the open front F of the module 10 is basically facing the flow of fluid current or incoming wave motion.
For channeling or directing fluid flow the smooth rear surface 18 of these modules 10 is disposed at various angles to the direction of flow or wave action to modify the behavior and direction of such natural forces.
Thus, the mounting of the module 10 at its operating situs is preferably multidirectional if variable affects are desired or if ambient conditions are subject to substantial variation.
Examples of installations for a fixed direction of the modules is shown in FIGS. 8-10 and 6;
In FIGS. 8-10, the module 10 is cast or formed with two or three integral piles 22 (shown in dotted lines) depending beneath the base thereof. When the piles 22 are driven into place beneath the soil, either above or below water as the case may be, the module 10 is thus mounted in a fixed directional orientation.
Referring to FIGS. 1, 2 and 4, the modules 10 are shown as including three triangularly arranged hold-down sockets 24 in which anchor pins 26 or the like are placed.
One of the sockets 24 comprises a master socket 24A for the purpose of multidirectional orientation of the module 10 as will be hereinafter more fully described with reference to FIG. 7.
In FIG. 6 is shown a mounting platform or bed 28 which includes land anchors or piles 30 therebeneath to provide a fixed platform for removably mounting the module 10 thereon. Mounting parts 26A are provided in the platform 28 to receive the anchor pins 26 described in connection with FIG. 1.
For multidirectional mounting of a module 10, reference is now made to FIG. 7 wherein there is shown a mounting platform 32 provided either with suitable dependent land anchors or with sufficent weight in and of itself to stay in place.
The platform 32 is substantially symmetrically formed, such as in a square or octagonal top planal configuration.
A central socket 24B is provided in the platform 32 which is adapted to be in registry with the master socket 24A.
A plurality of mounting ports 24C are also provided in the platform 32 in a symmetrical peripheral array which are selectively aligned in pairs with the remaining mounting ports 24 in the module 10 to cause the open front F and rear surface 18 of the module 10 to face in various desired directions. The central mounting port 24C and the master port 24B are adapted to mutually receive an anchor pin (such as the anchor pins 26 of FIG. 1) and thereby provide a central pivot in the mounting platform 32 about which the module 10 can be rotated to place its mounting ports 24 into registry with any desired pair of mounting ports 24C on the platform 32.
Alternatively the mounting ports 24B and 24C can be located each on one land anchor or pile of an array equivalent to the platform 32. Thus, a preset array of piles or a mounting platform 32 can be provided at each modular situs in a given array of modules to permit all of the modules in that array to be selectively oriented to effect desired constraints on ambient currents and/or wave motions.
OPERATION OF INDIVIDUAL MODULES TO HARNESS WAVE AND/OR WIND ACTION FOR TOPOGRAPHICAL RETENTION AND/OR ACCRETION
For the protection, retention and accretion of beaches, by controlling wave action the operation of a typical module 10 will now be described with reference to FIG. 8.
A module 10 is shown anchored to the shoreline by land anchors or pilings 22 at or immediately adjacent to the mean average water line or breaking surf line WL characteristic of the situs.
In the configuration shown in FIG. 8 it will be assumed that an incoming wave W from the ocean will have its crest portion WC and its foot portion WF breaking into the open front face F. of the module 10 against the concave inner surface 12.
The breaking crest WC of the wave W, as it enters the open front F of the module 10 beneath the lip 18B reacts with the concave inner surface 12 between adjacent ribs 14 or a rib 14 and an end wall 16 to create a counter-clockwise circulation as shown.
While this action is occurring, the energy in the rising foot WF of the breaking wave W is reacting with the inner bottom surface 20A and concave inner surface 12 of the module 10 such that a clockwise circulation is created.
Accordingly, approximately in a plane defined by the broken line N, the energies of the crest WC and the foot WF are in opposition, thereby causing a great dissipation or mutual suppression of the energy of both components of the wave W and causing entrained alluvium AL therein to sink or fall to the shoreline or ocean bottom immediately in front of the module 10 where it tends to form a mound ALM of such material.
During sufficiently high water conditions, the rear surface 18 of the module also reduces the energy of backwash from the beach and causes further deposition of alluvium at the rear of module as illustrated by the mound ALM 2.
In a subsurface mode of operation, the module 10 performs a similar function to build up alluvium on the underwater apron of the beach as will now be described with reference to FIG. 9.
A standing wave pattern W1 is shown approaching the module 10 and immediately adjacent the open front F thereof, said wave pattern W1 including a crest portion WC1 and a foot portion WF1 which by the nature of such standing wave patterns leads the crest WC1 into the module 10.
Thus, the energy of the foot WF1 reacts with the concave inner surface 12 to create a clockwise circulation which opposes the energy in the remainder of the foot portion WC1 substantially, the position of a plane defined by the broken line N1 immediately in front of the module 10.
As a result, with the kinetic energy of the foot portion WF1 turned on itself and the kinetic energy of the crest WC1 dissipated, the amplitude of the standing wave W1 is materially reduced from an above-surface amplitude V1 adjacent the open front F of the module 10 to a reduced abovesurface amplitude V2 adjacent the rear surface 18 of the module 10 as shown by the wave W2 and crest WC2.
The convex rear surface 18 materially contributes to this reduction in kinetic energy and attendance reduction in amplitude crest WC2 and instead directing it downward against the top of the foot portion WF2 of the reduced amplitude wave W2.
Because of the backwash or outflowing current OF from a shoreline located to the rear of the module 10, there is a stratification of the outflowing current OF and the incoming wave W2 at the rear of the module which creates a turbulent strata or barrier layer TS therebetween, the latter having a substantial entrained alluvium content.
As shown by suitable flow arrows adjacent the convex rear surface 18 of the module 10, the downwardly directed energy of the modified crest WC2 and the energy of the outflowing current OF are opposed at and below the turbulent layer TS, causing a marked reduction in kinetic energy at that point and a release of the entrained alluvium AL2 in the turbulent layer TS, causing it to be deposited at the base of the rear surface 18 to form a mound ALM2 of alluvium.
The deposition of alluvium AL1 in front of the module 10 to form another mound ALM1 of alluvium adjacent the front edge 20B of the base 10 of the module 10. This mount ALM1 is created by the reduction in kinetic energy in the wave foot WF1 in the vicinity of the plane N1 which causes entrained alluvium to be released from the wave W1.
The severe loss in kinetic energies from the wave W1 (WC1, WF1) to the modified or attenuated wave W2 (WC2, WF2) results in a corresponding reduction in forward velocity of the wave W1 such that the wave W2 approaches the beach at a markedly reduced velocity.
Air entrained alluvium and reduction of wind energies can also be effected by the module 10 as will now be described with reference to FIG. 10.
Assuming, for example, a module 10 located on a sand dune or the like between a beach and a vegetated and/or structurally developed area VA, with the open face F of the module 10 facing the prevailing wind direction coming off the ocean, then surface turbulence ST will cause asportation and entrainment of alluvium from the surface of the beach or the like into the wind currents.
As the airborne alluvium gaians altitude its velocity increases which would normally carry it far inland and cause wind erosion of the dunes and beach and unwanted deposition of the alluvium over inland areas.
As the wind currents enter the front F of the module 10, however, the various currents over the altitude between the forward edge 20B of the base 20 and the overhanging lip 18B of the convex rear surface 18 counter-react with the concave inner surface 12 to oppose one another within the module 10, thereby substantially reducing the kinetic energy of the said wind currents. This causes the entrained alluvium AL3 therein to form a mound ALM3 of such material in and to the front of the module 10.
The airfoil action of the rear surface 18 of the module 10 acts to constrain the force of some of the wind currents downwardly therealong and into an area between the said rear surface 18 and the protected area VA.
This redirection of the wind forces air entrained alluvium down toward the ground surface causing a mound ALM4 of alluvium to build up immediately behind the module 10.
Also, in the embodiment shown, because of the lack of backwash in the wind current mode of operation, the rear surface 18 can continue its curvature as at 18C so as to provide an undercut behind the base 20 of the module 10.
Thus, the curvature 18c and the resulting undercut assist in trapping alluvium at the rear of the module 10 and the dune on which the said module is situated is both preserved and caused to build up under the prevailing wind conditions shown.
Also, the protective function of the dune to the area VA is materially enhanced by the attenuation affects of the module 10 on these wind currents.
Further, in the event of severe storms, waves cresting over the dune will be substantially attenuated by the module 10 and the resulting action of the module to accrete fluid entrained alluvium will continue to preserve the dune regardless of the fluid medium to which the dune is subjected.
SHORELINE EROSION CONTROL
The operation of the individual control modules 10 of the present invention having been described under various ambient conditions, several systems of such modules will now be described to illustrate the versatility and adaptability of these modules in predetermined combinations, to effect specific control functions.
A system of the modules 10 providing a beach and shoreline erosion control function is shown in FIG. 11.
Assuming fixed conditions for the sake of example in which the wave motion from the ocean is substantially normal to the beach and shoreline, a plurality of control modules 10A, 10B, 10C and 10D, the former pair (10A, 10B) comprising a first row of spaced modules parallel to the beach and the latter pair (10C, 10D) comprising a second row of spaced modules parallel to the beach with the modules in one row respectively staggered between the modules of the other laterally along the said beach.
The open fronts FA - FD, respectively, of the modules 10A - 10D face the ocean and the back surfaces A18 - D18 thereof face the beach.
In this configuration, the modules 10A - 10D selectively impede the incoming wave action and no given row in the array is exposed to the full force of the incoming waves. Also, while only four modules are shown, it is to be clearly understood that both rows of modules can include as many modules as desired to protect any given extent of beach and shoreline. Also, additional rows of the modules 10 can be added so long as a staggered configuration and spacing is maintained.
The operation of each of the individual modules 10A - 10D in the protective array of FIG. 11 is as described in either of FIGS. 8 and 9 depending upon the depth of the water in which they are placed.
Assuming that the modules 10A and 10B (and others in the row defined thereby) are beneath the surface (as in FIG. 9 and that the modules 10C and 10D are at the mean average water line or breaking surf line (as in FIG. 8) the action of the row 10A-10B is to attenuate an incoming wave W4 to create a modified wavefront W5 which is attenuated by the second row of modules 10C - 10D.
The direct action of the incoming wave W4 is indicated by the flow paths E1 in FIG. 11; secondary diverting affects of the modules 10 are indicated by the flow paths E2; and the reverse reaction affects of each of the modules 10A - 10D on a given portion of the waves W4, W5 are shown by the flow paths E3.
Thus, it can be seen that certain portions of the wavefront W4 impinge directly on the modules 10A-10B in flow paths E1, are diverted between the said modules 10A-10B in the first row to the modules 10C-10D in the paths E2 and counter-react to attenuate energy from the wave W4 and cause accretion of alluvium via the paths E3.
Certain direct components E1 of the wave W4 passing between the modules 10A-10B in the first row impinge directly on the modules 10C-10D in the second row resulting in the attenuation and accretion flow paths E3 at the latter modules.
The secondary flow paths E2 are caused to criss-cross and interfer with normal wave motion by both rows of the modules 10A - 10B, 10C - 10D to further break up the wavefronts W4 and W5 and preclude the establishment of normal flow and rhythm of the waves impinging on the beach.
Backflow from the beach is handled by the modules 10A - 10D in a similar manner and causes accretion of alluvium as previously described with reference to FIGS. 8 and 9.
It is also contemplated that an additional row of modules 10 can be placed on the beach itself to compensate for both wind and high water conditions if desired.
All of the foregoing actions of wave energy attenuation, alluvium accretion (and hence, retention of alluvium to preserve the beach) and the creation of attenuating crosscurrents to disrupt the normal flow and rhythm of incoming waves are accomplished without subjecting any given module 10A - 10D or row of modules to the full force and effect of an incoming wave W4. The staggered arrangement of the modules 10A - 10D in their respective rows effectively accretes alluvium from the incoming wave W4 (and its backwash from the beach) in increments of a size determined by the size of the said modules and the spacing therebetween.
If conditions warrant, there can be additional rows of modules 10 places in the configuration of FIG. 9 to provide additional attenuation to incoming waves W4 in the manner of a protective reef.
CREATION OF SHORELINE, IN PREDETERMINED TOPOGRAPHICAL CONFIGURATIONS
The modules 10 of the present invention can also be arranged in arrays which tend to accumulate alluvium to modify existing shorelines by the creation of sandbars, shoals or peninsula type extensions of the said shorelines in topographical configurations determined by the configuration of a given array of the modules 10.
Such a system or array of the modules 10 is shown in FIG. 12 in which the topographical shape to be created is an accumulation or accretion of alluvium in the form of a peninsula or spit extending from an existing shoreline out into the ocean.
Referring now to FIG. 12, an existing shoreline is shown by a solid line and a building shoreline shape is shown by a broken line in the general configuration of a peninsula or spit P extending out into the ocean from the shoreline.
The array of modules 10 comprises a major array PA, and either or both of two minor arrays PB and PC symmetrically disposed with respect to the major array PA as follows:
The major array PA is in a Christmas tree shape and includes an outmost point module 10A1 outboard of the gap between first row of modules 10A2 and 10A3; a further inboard module 10A4 parallel to and in registry with the point module 10A1 on the shoreline side of the first row; a second row of modules 10A5 and 10A6 spaced shoreward from the module 10A4 on either side thereof; and a third row of modules 10A7, 10A8 and 10A9 spaced shoreward of the second row and staggered in position with respect to the modules 10A5 and 10A6 with the central module 10A8 in registry with the point module 10A1 and inboard module 10A4.
This staggering of modules 10A1 - 10A9 and additional rows thereof extending to the shoreline can be continued over the entire area P if desired.
The minor arrays PB and PC are shown arranged on the left and right flanks of the major array PA.
At this point is should be understood that the open front F of each module in the major array faces the ocean and the closed rear face 18 thereof faces the beach.
The minor array PB comprises a first pair of modules 10B1 and 10B2 spaced apart to form a row and arranged substantially tangentially of the desired building line outboard thereof. In other words, the length of the closed rear forces 18 of the modules 10B1 and 10B2 are disposed outboard of the building line parallel to a tangent thereto.
The minor array PB is completed by a module 10B3 disposed in the gap between the modules 10B1 and 10B2 as well as across the gap between the first and second rows 10A2 - A3 and 10A5 - A6 of the major array PA, substantially parallel to the row 10B1 - B2.
An alternative minor array PC is shown as comprising first and second modules 10C1 and 10C2 arranged outboard of the desired building line, with the rear surfaces 18 substantially tangential thereto and disposed, respectively across the gap between the first and second rows 10A2 - A3, 10A5 - A6 and the gap between the second and third rows 10A5 - A6, 10A7 - A8 - A9 in the major array PA. The open fronts F of the modules 10C1 and 10C2 are disposed toward the ocean side of the desired building line.
Thus, the array PA can be combined with a plurality of the minor arrays PB or a plurality of the minor array PC disposed substantially symmetrically on its flanks.
The minor arrays serve to both divert incoming currents and waves tangentially of the desired boundary or building line of the area P and also preclude side currents and varying wind and wave directions from direct access to the flanks of the major array PA.
By closely spacing and staggering the modules 10A1 - A9, 10B1 - B3 and/or 10C1 - C2, the rapid accretion of alluvium is accomplished to raise the level of the ocean floor in the desired shape of the area P.
The staggered arrangement of the said modules 10 and the flanking disposition of the minor arrays PB and PC provides a like reaction to both backwash and incoming currents and waves in shaping the area P.
NAVIGATIONAL CHANNEL ENHANCEMENT
Another erosion problem of great concern is that of preventing the closure of navigational channels such as those between bays, harbors or backwaters and the ocean.
These channesl fill with silt and require periodic and expensive dredging operations to maintain them in a navigable condition.
An array or system of the modules of the present invention for maintaining such channels free of silting will now be described with reference to FIG. 13.
In FIG. 13, a channel CH is shown between two shoals or banks S1, S2 and extends from the ocean to a bay or harbor as shown. Thus, the tidal action of the ocean flows in and out of the bay or harbor through the channel CH and over the banks or shoals S1, S2. This tidal flow in the channel CH is indicated by half-arrows T1 and T2, designating, respectively, incoming and outgoing tidal flow.
For the sake of example, FIG. 13 is drawn to show array of modules 10D1 - 10 D4 on the shoal S1 acting on and modifying the incoming tidal currents T1 and a like array of modules 10D5 - 10D8 on the shoal S2 acting on and modifying the outgoing tidal currents T2. These arrays are mirror images of each other and in actual practice, both arrays act on and modify both the incoming and outgoing tidal currents T1 and T2 as will be more fully described hereinafter.
Without the presence of the modules 10D1 - D8, the tidal action on the shoals S1, S2 entrains alluvium therefrom and erodes the channel adjacent edges of the shoals, depositing the resulting alluvium in the channel CH and thus filling the said channel until it tends to become unnavigable.
The modules 10D1 - D4 are all set on the channel adjacent edge of the shoal S1 at like angles to the center of the channel CH with the channel adjacent ends thereof pointed towards the ocean.
Likewise, the modules 10D5 - D8 are all set on the channel adjacent edge of the shoal S2 at respectively reflected angles to the modules 10D1 - D4, resulting in the channel adjacent ends of the former also pointing towards the ocean.
The two outermost pair of modules D1 and D5 have their open faces F on the ocean side and their convex rear faces 18 facing inward of the channel to form a first opposed pair of modules. A second apposed pair of modules 10D2, 10D6 are reversed from the first, the rear faces 18 facing outboard of the channel CH towards the ocean and the open faces F thereof facing inboard of the channel CH away from the ocean.
A third opposed pair of modules 10D3, 10D7 is oriented like the first pair of modules 10D1, 10D5 and a fourth (adjacent) opposed pair of modules 10D4, 10D8 is oriented like the second pair 10D2, 10D6.
Accordingly, the preferred array of modules for channel erosion control comprises opposed pairs of modules anchored along the sides of the channel CH with adjacent pairs being in mutually reversed orientation, i.e., the open front faces F are in opposition and the convex rear faces 18 are in opposition alternately down the entire line thereof on each of the shoals S1, S2 and this alternation is also a mirror image in the array on opposite sides of the channel CH.
In operation, the shoal S1 and the array 10D1 - D4 is diagramed to show the action of the array to incoming tidal currents T1.
The first module 10D1 receives the current T1 on its front face F and through the action described in FIG. 9 and the additional attenuation or current impeding affects of the internal ribs 14 and end walls 16 to current components flowing laterally of the concave inner surface 12, (see FIGS. 5 and 5A, depending upon the embodiment used for the system of FIG. 13) the energy of the incoming tide T1 and its wave action is turned back upon itself and alluvium is accreted, the shoal S1 preserved and the current T1 diverted outboard of the channel CH at the first module 10D1.
Between the first and second modules 10D1 and 10D2, the smooth convex rear faces of the modules form an unimpeded passageway for the current T1 constraining an outboard flow of the current T1 from the channel CH over the shoal S1. This tends to carry entrained alluvium onto the shoal S1 rather than into the channel CH and the harbor bay.
The third module 10D3 has its open face F reacting against the incoming tide T1 and its rear surface 18 coacting with that of the fourth module 10D4. This accretes alluvium on the shoal S1 at the front face F of the third module 10D3 and diverts incoming current T1 outboard of the channel CH between the said third and fourth modules 10D3 and 10D4.
The net result of the array 10D1 - D4 and its mirror image array 10D5 - D8 on the shoal S2 is to attenuate the incoming current T1, entrain alluvium at the edges of the channel CH and divert much of the incoming tidal current T1 onto the shoals S1, S2 and away from the channel CH.
This precludes silting of the channel CH and the bay or harbor by the incoming tide T1 and tends to preserve the boundaries of the channel CH.
The affect of the array 10D1 - D8 on the outgoing tidal current T2 (or a predominantly one way outflow such as in a river) is illustrated in connection with the array 10D5 - D8 on the second shoal S2.
Instead of diverting the outflowing current T2 from the channel CH, the action of the modules 10D5 - D8 is to concentrate the outgoing tidal flow T2 into a tide rip in the channel CH by the angular placement of the modules 10D1-D8 as shown by the flow arrows in the modules 10D5 - D8 on the second shoal S2.
The inboard end of the channel CH is preserved by the accreting and attenuating action of the eight module 10D8 (and its mirror image 10D4) in reaction to the outflow T2. Accretion of alluvium is also effected by the sixth module 10D6 (and its mirror image 10D2) in reaction to the outflow T2.
Entrained alluvium in the outflow T2 is accelerated by the convergent action of the array 10D1 - D8 such that the channel CH is purged of silt in the direction of outflow T2, thereby maintaining the channel CH navigable and carrying entrained alluvium (silt,etc.) out into the ocean.
Thus, certain modules (10D1, 10D5, 10D3, 10D7) attenuate incoming tidal action T1 and accrete alluvium therefrom while all the modules 10D1 - D8 cause divergence and attenuation of the incoming tide rip T1 in the channel CH.
On outflowing currents T2, the other modules (10D2, 10D6, 10D4 and 10D8) attenuate the outgoing tidal action and accrete alluvium therefrom while the net effect of the modules 10D1 - D8 is to augment the outgoing tide rip T2 in the channel CH and scavenge same to maintain it in a navigable condition.
The alternate accretion effects of the various modules 10D1 - D8 serve to preserve the boundaries of the channel CH by preserving the channel adjacent edges of the shoals S1 and S2.
Where substantial tidal currents exist and if the shoals S1 and S2 of FIG. 13 were continuous, a channel CH could be carved out of the said shoals by the action of the array 10D1-10D8.
The foregoing specification and drawings illustrate the ability of the present invention to harness the tremendous energies present in the tides and control the effects thereof to desired useful results in the preservation, creation and maintenance of shorelines, navigational channels and the like.
Therefore, the present invention solves long standing problems in the art and satisfies the attendant long felt need for straightforward relatively economical solutions to the problems of shoreline and navigational channel erosion and maintenance.
The present invention may be modified as would occur to one of ordinary skill in the art without departing from the spirit and scope of the present invention.
BACKGROUND OF THE INVENTION
The effects of winds, tides and other fluid currents on beaches, shorelines, channels and the like is a long standing and serious problem.
The erosion of beaches, silting of navigation channels, destruction of natural barriers such as sand dunes and other deleterious effects causing untold financial losses, destruction of natural environs and continuing large expenditures of funds for corrective action has been and still is a dilemma that is only solvable on a temporary and frequently recurring basis. A substantially permanent solution to such problems or even a relatively long term solution has not yet been devised.
The prior art is replete with groins, jitties, weirs, breakwaters and the like which serve only specific functions against prevailing conditions and which, unfortunately, have not been satisfactory for preserving shorelines, dunes and/or navigational channels under either prevailing or variable ambient conditions.
Furthermore, no prior art devices are know which can serve all of these functions and in addition actually increase the size of shorelines, dunes and channels or selectively create same in a predetermined configuration and location.
Because of the tremendous energies involved in preventing damage by winds, tides and currents, the prior art approach to erosion control has necessitated unwieldly, large and aesthetically displeasing structures in order to provide sufficient strength and sustainability to such structures.
Furthermore, such structures have been for the most part merely passive devices which are directed to impeding the action of fluid currents, disrupting wave action and/or creating eddy current action.
Accordingly, means and apparatus which can convert such tremendous available energy to corrective and beneficial use are sorely needed.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide a new and novel means for utilizing the energy and/or wave action in fluid currents to selectively modify or preserve the topography of the situs of that means.
Another object of the present invention is to provide a new and novel module for systems having selective interaction and control of fluid currents and/or wave motions for preserving or modifying the topography of the situs of a given one of said systems.
Another object of the present invention is to provide new and novel beach erosion control devices which are aesthetically acceptable and which are capable of complimentary uses and functions.
Still another object of the present invention is to provide new and novel systems and components for same for selectively building land from alluvial material transported by fluid currents reacting with such systems and components.
Still another object of the present invention is to provide new and novel systems and components for same for preserving and/or creating navigational channels.
Yet another object of the present invention is to provide new and novel fluid current modifying and control systems and components for same which are selectively adjustable in situs to compensate for variation in otherwise prevalent ambient conditions of fluid currents and/or wave action.
These and other objects of the present invention will become more fully apparent with reference to the following specification and drawings, which relate to several preferred embodiments of the invention.
SUMMARY OF THE INVENTION
The basic modular components of the present invention are basically elongated shells having a flat base; a convexly curved outer face coterminate with the base at one edge thereof; a complimentary concave inner surface opposite and coeterminate with the convex face; a pair of flat end walls supporting the curved faces and forming therewith an integral structure with the base and partially enclosing said inner face; and one or more internal planor ribs substantially parallel to the said end walls and having, preferably, a relieved leading edge outboard of said inner face and having a generally complimentary radius of curvature, in the plane of said rib, to the said concave inner face of the module.
In erosion control situations for enhancing the deposition of alluvial material entrained in fluid currents and/or waves on shorelines, dunes and the like, the module is oriented such that incoming force of the current is directed into the open side (against the concave inner surface) of the module with the base preferably set laterally of the incoming flow direction and the said end walls and internal ribs substantially parallel to said flow direction. In this configuration, for example, the base of an incoming wave is turned against the crest and at least components of the crest against the base, nullifying or severely attenuating the wave energy in certain strata and causing entrained alluvial material to be deposited in front of the module. This creates a buildup of this material which increases or at least preserves the level of the bottom or shoreline on which the module is situated.
Reverse (outgoing) wave action coming from the rear of the module is forced up and over the convex outer face causing further energy reduction and resulting in additional deposition of alluvial material on the back side of the module. The front and back sides are defined in relation to the incoming wave action in the foregoing description.
Predetermined arrays of these modules can be utilized to maintain navigational channels by selective angular placement of both the outer and inner surfaces of various modules to localize tides into rips in the channel and create bottom holding tide attenuating affects adjacent the existing channels.
Other arrays of the present invention can build up or create shoreline areas using wind, wave, tide and/or current actions. Conversely, other arrays can remove or alter shorelines and cut or form channels and the like by control of these natural forces.
Representative preferred embodiments of arrays for performing these functions will be discussed in more detail hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a control module of the present invention;
FIG. 2 is a top plan view of FIG. 1;
FIG. 3 is an end view of the module of FIGS. 1 and 2;
FIG. 4 is a cross-section taken along line 4--4 of FIG. 1;
FIG. 5 is a perspective of the module of FIG. 1 and includes integral mounting means;
FIG. 5A is a perspective of another embodiment of the control module of the present invention;
FIG. 6 is a perspective of a separable mounting means for the module of FIG. 1;
FIG. 7 is a diagrammatic representation of an multi-directional mounting means for the control module of the present invention;
FIG. 8 is a functional diagram of a control module of the present invention in a beach mounted erosion control mode wherein the module can extend above the water surface;
FIG. 9 is a functional diagram of a control module of the present invention in a subsurface or reef building erosion control mode;
FIG. 10 is a functional diagram of a control module of the present invention reacting with winds or air currents in a dune erosion control mode;
FIG. 11 is a functional diagram of a beach erosion control array of control modules of the present invention;
FIG. 12 is a functional diagram of a shoreline modifying array of control modules of the present invention; and
FIG. 13 is a functional diagram of a navigational channel modifying, creating or preserving array of control modules of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring in detail to the drawings and with particular reference to FIGS. 1, 2, 3, 4, and 5, the flow control module 10 of the present invention is shown as comprising an elongated molded solid having one of its longitudinal faces open to expose an interior concave wall or surface 12.
In the embodiment as shown for the control module 10, the concave inner face 12 is selectively partitioned along its length by a plurality of substantially equally spaced internal ribs 14, located between first and second end walls 16 which close the extreme ends of the module 10. Also, as shown in FIG. 1, the end wall 16 may be disposed slightly inboard of the extremities of the closed longitudinal top and rear surface 18 of the module 10 which is a convex surface extending from the top front of the module 10 all the way down to the rear of a flat base portion 20 of the said module. The said surface 18 is substantially conformally shaped with the concave inner surface 12.
Thus, in the embodiment as shown in FIG. 1, the convex rear surface 18 of the module 10 can be said to have a slight outboard lateral extension 18A overhanging the end walls 16 of the module as well as an overhanging front lip portion 18B at the upper edge of the open side of the module 10.
FIGS. 3 and 5 represent another embodiment of the module 10 of the present invention in that the lateral overhang 18A are not included and the end walls 16 of the module 10 thereby form the terminal ends thereof.
The inner face 12 of the module 10 can best be described with reference to FIG. 4 in which the module 10 is shown in cross section as disposed about a horizontal (x) and vertical (y) coordinate axis, with the x axis passing a substantially centrally through the cross sectional plane of the module 10 and the y axis being positioned more towards the open edge thereof.
The leading edge 20B of the base 20 of the module 10 extends inwardly over a rising surface 20A into a tangential transition with the lowermost portion 12A of the inner surface 12. This portion 12A of the inner surface 12 is defined by a first radius of curvature R1 over approximately 90° arc which extends from the said tangential transition with the surface 20A to the intercept of the x-axis and the inner surface 12.
The radius R1 commences from an x-axis index point I1 in-board of the x-y intercept I2. The said surface portion 12B extends from the intercept of the x-axis and surface 12 to the underside of the front lip 18B of the convex outer surface 18 at which point it makes a smooth transition outward and upward to the outermost edge of the said lip 18B.
One preferred embodiment of the inner ribs 14 of the module 10 is also shown in FIG. 4, wherein the concave contour of the leading edge of the said ribs 14 is shown as including a lower curve 14A with a radius of curvature R3B greater than the lower radius R3A. The lower radius R3A extends from a first index point 13A on the x-axis outboard of the x-y intercept I2 to the front edge 20B of the base 20, and then defines the lower curve 14A from that point up to the x-axis.
From the x-axis up to a smooth transition into the outer lip 18B of the convex surface 18, the radius R3B defines the upper curve 14B of the inner ribs 14. The upper radius R3B extends from an index 13B on the x-axis outboard of the index 13A.
This compound curvature to produce a concave leading edge on the ribs 14 of a compatible configuration with the inner surface 12 can also be imparted to the leading edges of the end walls 16 as shown in perspective in FIG. 5A which illustrates another preferred embodiment of the module 10.
At this point it should be understood that the compound curvatures described above are examples of preferred embodiments of the invention and are not intended to limit the scope thereof.
In short, the modules 10 resemble elongated scoops of crescent shaped cross-section with an open front F and a smooth closed back or rear surface 18.
For impeding fluid flow, the open front F of the module 10 is basically facing the flow of fluid current or incoming wave motion.
For channeling or directing fluid flow the smooth rear surface 18 of these modules 10 is disposed at various angles to the direction of flow or wave action to modify the behavior and direction of such natural forces.
Thus, the mounting of the module 10 at its operating situs is preferably multidirectional if variable affects are desired or if ambient conditions are subject to substantial variation.
Examples of installations for a fixed direction of the modules is shown in FIGS. 8-10 and 6;
In FIGS. 8-10, the module 10 is cast or formed with two or three integral piles 22 (shown in dotted lines) depending beneath the base thereof. When the piles 22 are driven into place beneath the soil, either above or below water as the case may be, the module 10 is thus mounted in a fixed directional orientation.
Referring to FIGS. 1, 2 and 4, the modules 10 are shown as including three triangularly arranged hold-down sockets 24 in which anchor pins 26 or the like are placed.
One of the sockets 24 comprises a master socket 24A for the purpose of multidirectional orientation of the module 10 as will be hereinafter more fully described with reference to FIG. 7.
In FIG. 6 is shown a mounting platform or bed 28 which includes land anchors or piles 30 therebeneath to provide a fixed platform for removably mounting the module 10 thereon. Mounting parts 26A are provided in the platform 28 to receive the anchor pins 26 described in connection with FIG. 1.
For multidirectional mounting of a module 10, reference is now made to FIG. 7 wherein there is shown a mounting platform 32 provided either with suitable dependent land anchors or with sufficent weight in and of itself to stay in place.
The platform 32 is substantially symmetrically formed, such as in a square or octagonal top planal configuration.
A central socket 24B is provided in the platform 32 which is adapted to be in registry with the master socket 24A.
A plurality of mounting ports 24C are also provided in the platform 32 in a symmetrical peripheral array which are selectively aligned in pairs with the remaining mounting ports 24 in the module 10 to cause the open front F and rear surface 18 of the module 10 to face in various desired directions. The central mounting port 24C and the master port 24B are adapted to mutually receive an anchor pin (such as the anchor pins 26 of FIG. 1) and thereby provide a central pivot in the mounting platform 32 about which the module 10 can be rotated to place its mounting ports 24 into registry with any desired pair of mounting ports 24C on the platform 32.
Alternatively the mounting ports 24B and 24C can be located each on one land anchor or pile of an array equivalent to the platform 32. Thus, a preset array of piles or a mounting platform 32 can be provided at each modular situs in a given array of modules to permit all of the modules in that array to be selectively oriented to effect desired constraints on ambient currents and/or wave motions.
OPERATION OF INDIVIDUAL MODULES TO HARNESS WAVE AND/OR WIND ACTION FOR TOPOGRAPHICAL RETENTION AND/OR ACCRETION
For the protection, retention and accretion of beaches, by controlling wave action the operation of a typical module 10 will now be described with reference to FIG. 8.
A module 10 is shown anchored to the shoreline by land anchors or pilings 22 at or immediately adjacent to the mean average water line or breaking surf line WL characteristic of the situs.
In the configuration shown in FIG. 8 it will be assumed that an incoming wave W from the ocean will have its crest portion WC and its foot portion WF breaking into the open front face F. of the module 10 against the concave inner surface 12.
The breaking crest WC of the wave W, as it enters the open front F of the module 10 beneath the lip 18B reacts with the concave inner surface 12 between adjacent ribs 14 or a rib 14 and an end wall 16 to create a counter-clockwise circulation as shown.
While this action is occurring, the energy in the rising foot WF of the breaking wave W is reacting with the inner bottom surface 20A and concave inner surface 12 of the module 10 such that a clockwise circulation is created.
Accordingly, approximately in a plane defined by the broken line N, the energies of the crest WC and the foot WF are in opposition, thereby causing a great dissipation or mutual suppression of the energy of both components of the wave W and causing entrained alluvium AL therein to sink or fall to the shoreline or ocean bottom immediately in front of the module 10 where it tends to form a mound ALM of such material.
During sufficiently high water conditions, the rear surface 18 of the module also reduces the energy of backwash from the beach and causes further deposition of alluvium at the rear of module as illustrated by the mound ALM 2.
In a subsurface mode of operation, the module 10 performs a similar function to build up alluvium on the underwater apron of the beach as will now be described with reference to FIG. 9.
A standing wave pattern W1 is shown approaching the module 10 and immediately adjacent the open front F thereof, said wave pattern W1 including a crest portion WC1 and a foot portion WF1 which by the nature of such standing wave patterns leads the crest WC1 into the module 10.
Thus, the energy of the foot WF1 reacts with the concave inner surface 12 to create a clockwise circulation which opposes the energy in the remainder of the foot portion WC1 substantially, the position of a plane defined by the broken line N1 immediately in front of the module 10.
As a result, with the kinetic energy of the foot portion WF1 turned on itself and the kinetic energy of the crest WC1 dissipated, the amplitude of the standing wave W1 is materially reduced from an above-surface amplitude V1 adjacent the open front F of the module 10 to a reduced abovesurface amplitude V2 adjacent the rear surface 18 of the module 10 as shown by the wave W2 and crest WC2.
The convex rear surface 18 materially contributes to this reduction in kinetic energy and attendance reduction in amplitude crest WC2 and instead directing it downward against the top of the foot portion WF2 of the reduced amplitude wave W2.
Because of the backwash or outflowing current OF from a shoreline located to the rear of the module 10, there is a stratification of the outflowing current OF and the incoming wave W2 at the rear of the module which creates a turbulent strata or barrier layer TS therebetween, the latter having a substantial entrained alluvium content.
As shown by suitable flow arrows adjacent the convex rear surface 18 of the module 10, the downwardly directed energy of the modified crest WC2 and the energy of the outflowing current OF are opposed at and below the turbulent layer TS, causing a marked reduction in kinetic energy at that point and a release of the entrained alluvium AL2 in the turbulent layer TS, causing it to be deposited at the base of the rear surface 18 to form a mound ALM2 of alluvium.
The deposition of alluvium AL1 in front of the module 10 to form another mound ALM1 of alluvium adjacent the front edge 20B of the base 10 of the module 10. This mount ALM1 is created by the reduction in kinetic energy in the wave foot WF1 in the vicinity of the plane N1 which causes entrained alluvium to be released from the wave W1.
The severe loss in kinetic energies from the wave W1 (WC1, WF1) to the modified or attenuated wave W2 (WC2, WF2) results in a corresponding reduction in forward velocity of the wave W1 such that the wave W2 approaches the beach at a markedly reduced velocity.
Air entrained alluvium and reduction of wind energies can also be effected by the module 10 as will now be described with reference to FIG. 10.
Assuming, for example, a module 10 located on a sand dune or the like between a beach and a vegetated and/or structurally developed area VA, with the open face F of the module 10 facing the prevailing wind direction coming off the ocean, then surface turbulence ST will cause asportation and entrainment of alluvium from the surface of the beach or the like into the wind currents.
As the airborne alluvium gaians altitude its velocity increases which would normally carry it far inland and cause wind erosion of the dunes and beach and unwanted deposition of the alluvium over inland areas.
As the wind currents enter the front F of the module 10, however, the various currents over the altitude between the forward edge 20B of the base 20 and the overhanging lip 18B of the convex rear surface 18 counter-react with the concave inner surface 12 to oppose one another within the module 10, thereby substantially reducing the kinetic energy of the said wind currents. This causes the entrained alluvium AL3 therein to form a mound ALM3 of such material in and to the front of the module 10.
The airfoil action of the rear surface 18 of the module 10 acts to constrain the force of some of the wind currents downwardly therealong and into an area between the said rear surface 18 and the protected area VA.
This redirection of the wind forces air entrained alluvium down toward the ground surface causing a mound ALM4 of alluvium to build up immediately behind the module 10.
Also, in the embodiment shown, because of the lack of backwash in the wind current mode of operation, the rear surface 18 can continue its curvature as at 18C so as to provide an undercut behind the base 20 of the module 10.
Thus, the curvature 18c and the resulting undercut assist in trapping alluvium at the rear of the module 10 and the dune on which the said module is situated is both preserved and caused to build up under the prevailing wind conditions shown.
Also, the protective function of the dune to the area VA is materially enhanced by the attenuation affects of the module 10 on these wind currents.
Further, in the event of severe storms, waves cresting over the dune will be substantially attenuated by the module 10 and the resulting action of the module to accrete fluid entrained alluvium will continue to preserve the dune regardless of the fluid medium to which the dune is subjected.
SHORELINE EROSION CONTROL
The operation of the individual control modules 10 of the present invention having been described under various ambient conditions, several systems of such modules will now be described to illustrate the versatility and adaptability of these modules in predetermined combinations, to effect specific control functions.
A system of the modules 10 providing a beach and shoreline erosion control function is shown in FIG. 11.
Assuming fixed conditions for the sake of example in which the wave motion from the ocean is substantially normal to the beach and shoreline, a plurality of control modules 10A, 10B, 10C and 10D, the former pair (10A, 10B) comprising a first row of spaced modules parallel to the beach and the latter pair (10C, 10D) comprising a second row of spaced modules parallel to the beach with the modules in one row respectively staggered between the modules of the other laterally along the said beach.
The open fronts FA - FD, respectively, of the modules 10A - 10D face the ocean and the back surfaces A18 - D18 thereof face the beach.
In this configuration, the modules 10A - 10D selectively impede the incoming wave action and no given row in the array is exposed to the full force of the incoming waves. Also, while only four modules are shown, it is to be clearly understood that both rows of modules can include as many modules as desired to protect any given extent of beach and shoreline. Also, additional rows of the modules 10 can be added so long as a staggered configuration and spacing is maintained.
The operation of each of the individual modules 10A - 10D in the protective array of FIG. 11 is as described in either of FIGS. 8 and 9 depending upon the depth of the water in which they are placed.
Assuming that the modules 10A and 10B (and others in the row defined thereby) are beneath the surface (as in FIG. 9 and that the modules 10C and 10D are at the mean average water line or breaking surf line (as in FIG. 8) the action of the row 10A-10B is to attenuate an incoming wave W4 to create a modified wavefront W5 which is attenuated by the second row of modules 10C - 10D.
The direct action of the incoming wave W4 is indicated by the flow paths E1 in FIG. 11; secondary diverting affects of the modules 10 are indicated by the flow paths E2; and the reverse reaction affects of each of the modules 10A - 10D on a given portion of the waves W4, W5 are shown by the flow paths E3.
Thus, it can be seen that certain portions of the wavefront W4 impinge directly on the modules 10A-10B in flow paths E1, are diverted between the said modules 10A-10B in the first row to the modules 10C-10D in the paths E2 and counter-react to attenuate energy from the wave W4 and cause accretion of alluvium via the paths E3.
Certain direct components E1 of the wave W4 passing between the modules 10A-10B in the first row impinge directly on the modules 10C-10D in the second row resulting in the attenuation and accretion flow paths E3 at the latter modules.
The secondary flow paths E2 are caused to criss-cross and interfer with normal wave motion by both rows of the modules 10A - 10B, 10C - 10D to further break up the wavefronts W4 and W5 and preclude the establishment of normal flow and rhythm of the waves impinging on the beach.
Backflow from the beach is handled by the modules 10A - 10D in a similar manner and causes accretion of alluvium as previously described with reference to FIGS. 8 and 9.
It is also contemplated that an additional row of modules 10 can be placed on the beach itself to compensate for both wind and high water conditions if desired.
All of the foregoing actions of wave energy attenuation, alluvium accretion (and hence, retention of alluvium to preserve the beach) and the creation of attenuating crosscurrents to disrupt the normal flow and rhythm of incoming waves are accomplished without subjecting any given module 10A - 10D or row of modules to the full force and effect of an incoming wave W4. The staggered arrangement of the modules 10A - 10D in their respective rows effectively accretes alluvium from the incoming wave W4 (and its backwash from the beach) in increments of a size determined by the size of the said modules and the spacing therebetween.
If conditions warrant, there can be additional rows of modules 10 places in the configuration of FIG. 9 to provide additional attenuation to incoming waves W4 in the manner of a protective reef.
CREATION OF SHORELINE, IN PREDETERMINED TOPOGRAPHICAL CONFIGURATIONS
The modules 10 of the present invention can also be arranged in arrays which tend to accumulate alluvium to modify existing shorelines by the creation of sandbars, shoals or peninsula type extensions of the said shorelines in topographical configurations determined by the configuration of a given array of the modules 10.
Such a system or array of the modules 10 is shown in FIG. 12 in which the topographical shape to be created is an accumulation or accretion of alluvium in the form of a peninsula or spit extending from an existing shoreline out into the ocean.
Referring now to FIG. 12, an existing shoreline is shown by a solid line and a building shoreline shape is shown by a broken line in the general configuration of a peninsula or spit P extending out into the ocean from the shoreline.
The array of modules 10 comprises a major array PA, and either or both of two minor arrays PB and PC symmetrically disposed with respect to the major array PA as follows:
The major array PA is in a Christmas tree shape and includes an outmost point module 10A1 outboard of the gap between first row of modules 10A2 and 10A3; a further inboard module 10A4 parallel to and in registry with the point module 10A1 on the shoreline side of the first row; a second row of modules 10A5 and 10A6 spaced shoreward from the module 10A4 on either side thereof; and a third row of modules 10A7, 10A8 and 10A9 spaced shoreward of the second row and staggered in position with respect to the modules 10A5 and 10A6 with the central module 10A8 in registry with the point module 10A1 and inboard module 10A4.
This staggering of modules 10A1 - 10A9 and additional rows thereof extending to the shoreline can be continued over the entire area P if desired.
The minor arrays PB and PC are shown arranged on the left and right flanks of the major array PA.
At this point is should be understood that the open front F of each module in the major array faces the ocean and the closed rear face 18 thereof faces the beach.
The minor array PB comprises a first pair of modules 10B1 and 10B2 spaced apart to form a row and arranged substantially tangentially of the desired building line outboard thereof. In other words, the length of the closed rear forces 18 of the modules 10B1 and 10B2 are disposed outboard of the building line parallel to a tangent thereto.
The minor array PB is completed by a module 10B3 disposed in the gap between the modules 10B1 and 10B2 as well as across the gap between the first and second rows 10A2 - A3 and 10A5 - A6 of the major array PA, substantially parallel to the row 10B1 - B2.
An alternative minor array PC is shown as comprising first and second modules 10C1 and 10C2 arranged outboard of the desired building line, with the rear surfaces 18 substantially tangential thereto and disposed, respectively across the gap between the first and second rows 10A2 - A3, 10A5 - A6 and the gap between the second and third rows 10A5 - A6, 10A7 - A8 - A9 in the major array PA. The open fronts F of the modules 10C1 and 10C2 are disposed toward the ocean side of the desired building line.
Thus, the array PA can be combined with a plurality of the minor arrays PB or a plurality of the minor array PC disposed substantially symmetrically on its flanks.
The minor arrays serve to both divert incoming currents and waves tangentially of the desired boundary or building line of the area P and also preclude side currents and varying wind and wave directions from direct access to the flanks of the major array PA.
By closely spacing and staggering the modules 10A1 - A9, 10B1 - B3 and/or 10C1 - C2, the rapid accretion of alluvium is accomplished to raise the level of the ocean floor in the desired shape of the area P.
The staggered arrangement of the said modules 10 and the flanking disposition of the minor arrays PB and PC provides a like reaction to both backwash and incoming currents and waves in shaping the area P.
NAVIGATIONAL CHANNEL ENHANCEMENT
Another erosion problem of great concern is that of preventing the closure of navigational channels such as those between bays, harbors or backwaters and the ocean.
These channesl fill with silt and require periodic and expensive dredging operations to maintain them in a navigable condition.
An array or system of the modules of the present invention for maintaining such channels free of silting will now be described with reference to FIG. 13.
In FIG. 13, a channel CH is shown between two shoals or banks S1, S2 and extends from the ocean to a bay or harbor as shown. Thus, the tidal action of the ocean flows in and out of the bay or harbor through the channel CH and over the banks or shoals S1, S2. This tidal flow in the channel CH is indicated by half-arrows T1 and T2, designating, respectively, incoming and outgoing tidal flow.
For the sake of example, FIG. 13 is drawn to show array of modules 10D1 - 10 D4 on the shoal S1 acting on and modifying the incoming tidal currents T1 and a like array of modules 10D5 - 10D8 on the shoal S2 acting on and modifying the outgoing tidal currents T2. These arrays are mirror images of each other and in actual practice, both arrays act on and modify both the incoming and outgoing tidal currents T1 and T2 as will be more fully described hereinafter.
Without the presence of the modules 10D1 - D8, the tidal action on the shoals S1, S2 entrains alluvium therefrom and erodes the channel adjacent edges of the shoals, depositing the resulting alluvium in the channel CH and thus filling the said channel until it tends to become unnavigable.
The modules 10D1 - D4 are all set on the channel adjacent edge of the shoal S1 at like angles to the center of the channel CH with the channel adjacent ends thereof pointed towards the ocean.
Likewise, the modules 10D5 - D8 are all set on the channel adjacent edge of the shoal S2 at respectively reflected angles to the modules 10D1 - D4, resulting in the channel adjacent ends of the former also pointing towards the ocean.
The two outermost pair of modules D1 and D5 have their open faces F on the ocean side and their convex rear faces 18 facing inward of the channel to form a first opposed pair of modules. A second apposed pair of modules 10D2, 10D6 are reversed from the first, the rear faces 18 facing outboard of the channel CH towards the ocean and the open faces F thereof facing inboard of the channel CH away from the ocean.
A third opposed pair of modules 10D3, 10D7 is oriented like the first pair of modules 10D1, 10D5 and a fourth (adjacent) opposed pair of modules 10D4, 10D8 is oriented like the second pair 10D2, 10D6.
Accordingly, the preferred array of modules for channel erosion control comprises opposed pairs of modules anchored along the sides of the channel CH with adjacent pairs being in mutually reversed orientation, i.e., the open front faces F are in opposition and the convex rear faces 18 are in opposition alternately down the entire line thereof on each of the shoals S1, S2 and this alternation is also a mirror image in the array on opposite sides of the channel CH.
In operation, the shoal S1 and the array 10D1 - D4 is diagramed to show the action of the array to incoming tidal currents T1.
The first module 10D1 receives the current T1 on its front face F and through the action described in FIG. 9 and the additional attenuation or current impeding affects of the internal ribs 14 and end walls 16 to current components flowing laterally of the concave inner surface 12, (see FIGS. 5 and 5A, depending upon the embodiment used for the system of FIG. 13) the energy of the incoming tide T1 and its wave action is turned back upon itself and alluvium is accreted, the shoal S1 preserved and the current T1 diverted outboard of the channel CH at the first module 10D1.
Between the first and second modules 10D1 and 10D2, the smooth convex rear faces of the modules form an unimpeded passageway for the current T1 constraining an outboard flow of the current T1 from the channel CH over the shoal S1. This tends to carry entrained alluvium onto the shoal S1 rather than into the channel CH and the harbor bay.
The third module 10D3 has its open face F reacting against the incoming tide T1 and its rear surface 18 coacting with that of the fourth module 10D4. This accretes alluvium on the shoal S1 at the front face F of the third module 10D3 and diverts incoming current T1 outboard of the channel CH between the said third and fourth modules 10D3 and 10D4.
The net result of the array 10D1 - D4 and its mirror image array 10D5 - D8 on the shoal S2 is to attenuate the incoming current T1, entrain alluvium at the edges of the channel CH and divert much of the incoming tidal current T1 onto the shoals S1, S2 and away from the channel CH.
This precludes silting of the channel CH and the bay or harbor by the incoming tide T1 and tends to preserve the boundaries of the channel CH.
The affect of the array 10D1 - D8 on the outgoing tidal current T2 (or a predominantly one way outflow such as in a river) is illustrated in connection with the array 10D5 - D8 on the second shoal S2.
Instead of diverting the outflowing current T2 from the channel CH, the action of the modules 10D5 - D8 is to concentrate the outgoing tidal flow T2 into a tide rip in the channel CH by the angular placement of the modules 10D1-D8 as shown by the flow arrows in the modules 10D5 - D8 on the second shoal S2.
The inboard end of the channel CH is preserved by the accreting and attenuating action of the eight module 10D8 (and its mirror image 10D4) in reaction to the outflow T2. Accretion of alluvium is also effected by the sixth module 10D6 (and its mirror image 10D2) in reaction to the outflow T2.
Entrained alluvium in the outflow T2 is accelerated by the convergent action of the array 10D1 - D8 such that the channel CH is purged of silt in the direction of outflow T2, thereby maintaining the channel CH navigable and carrying entrained alluvium (silt,etc.) out into the ocean.
Thus, certain modules (10D1, 10D5, 10D3, 10D7) attenuate incoming tidal action T1 and accrete alluvium therefrom while all the modules 10D1 - D8 cause divergence and attenuation of the incoming tide rip T1 in the channel CH.
On outflowing currents T2, the other modules (10D2, 10D6, 10D4 and 10D8) attenuate the outgoing tidal action and accrete alluvium therefrom while the net effect of the modules 10D1 - D8 is to augment the outgoing tide rip T2 in the channel CH and scavenge same to maintain it in a navigable condition.
The alternate accretion effects of the various modules 10D1 - D8 serve to preserve the boundaries of the channel CH by preserving the channel adjacent edges of the shoals S1 and S2.
Where substantial tidal currents exist and if the shoals S1 and S2 of FIG. 13 were continuous, a channel CH could be carved out of the said shoals by the action of the array 10D1-10D8.
The foregoing specification and drawings illustrate the ability of the present invention to harness the tremendous energies present in the tides and control the effects thereof to desired useful results in the preservation, creation and maintenance of shorelines, navigational channels and the like.
Therefore, the present invention solves long standing problems in the art and satisfies the attendant long felt need for straightforward relatively economical solutions to the problems of shoreline and navigational channel erosion and maintenance.
The present invention may be modified as would occur to one of ordinary skill in the art without departing from the spirit and scope of the present invention.