Shoreline and Coastal Protection and Rebuilding Apparatus and Method
Shoreline and Coastal Protection and Rebuilding Apparatus and Method having a plurality of slanted wall sections in a rising stepped formation with open areas between, arrayed on frame structures, which dissipates wave energy in a gradual and controlled way and which neutralizes the impact of a wave and its backwash, thereby protecting the shoreline, and which allows for the settling of sediment, thereby rebuilding the shoreline, while allowing tidal exchange of water and the migration of aquatic species, using modular components that can be manufactured and deployed at low cost and in a manner suited to remote shoreline deployment.
Priority is claimed from U.S. Provisional Patent Application No. 60/964,851 filed 14 Aug. 2007, and U.S. Provisional Patent Application number 61/065,354 filed 11 Feb. 2008, which are both hereby incorporated by reference.
BACKGROUNDThe shorelines of oceans, lakes, bayous, and rivers are important ecosystems which are subject to erosion by their respective bodies of water. The waves of water which cause the erosion result from natural causes and maritime activity.
A wave, such as an ocean wave or the wake of a vessel, is a mechanical wave caused by the perturbation of water. As a wave approaches shallow water, such as a shoreline, the change in water depth causes the wave to pile up on itself and rise, possibly to the point of breaking. The rising and breaking of waves at the shoreline creates turbulence and erosion. Waves create a backwash, which can carry eroded sediment farther into the water.
Simply stopping a wave by placing a wall in its path presents several problems. Such a wall must be sufficiently strong to withstand the full wave impact. The wall does not prevent the erosion of the sloping submerged land on the water side of the wall, and the backwash of a wave abruptly stopped is additionally erosive. A solid wall might also interrupt the tidal exchange of water and the migration of aquatic species that are important in shoreline ecosystems. Improperly designed gaps in such a wall might reduce the effectiveness of the wall or create channels of pronounced erosion.
Erosion is a serious problem, especially in coastal Louisiana, which is literally washing away into the Gulf of Mexico. Coastal Louisiana has seen over 900,000 acres wash away since the 1930s. Currently the loss rate is about 16,000 acres per year. It is estimated an additional 320,000-acres of Louisiana's wetlands will be lost by the year 2050 at the present rate. The economic impact of the loss of coastal wetlands is very large. Louisiana's coastal wetlands are at the end of the Central and Mississippi Flyways and provide winter refuge for nearly 70 percent of all waterfowl migrating these flyways.
Attempts to slow the rate of coastal erosion have been made throughout coastal Louisiana using various methods, including low-cost attempts such as the placement of objects such as discarded Christmas trees, automobile tires, various types of large plastic bags filled with sand, mats of materials ranging from willow tree limbs to concrete, and various types of plants. None of these methods has been shown to stop erosion, and in some cases these methods may have increased the rate of erosion. Most cannot withstand the daily wave action in the coastal environment or the force of a storm surge. Others cause water pollution and present navigational hazards. Various types of walls made from concrete, steel, or wood have been placed away from the shoreline in an attempt to stop wave action and protect the shoreline, with limited success and sometimes causing unintended environmental consequences.
Tidal exchange of water is an element of shoreline ecosystems that is disrupted by some methods of preventing erosion. The migration of aquatic species is similarly disrupted by these methods.
A high cost of deployment is characteristic of many existing erosion-prevention methods, especially given that the shoreline is a tough environment for construction or installation activities and is often very remote from roads or navigable water. In some cases, dredging of the water bottom is required in order to accommodate the work vessels necessary to install the shoreline protection, adding to the cost of deployment and further destroying the shoreline in an attempt to save it.
Other problems with present devices and methods are their inability to remain in place, either from sinking in the soft soil or being moved by winds and storm surges, their tendency to sink and damage pipelines, and the navigational hazards they present.
SUMMARY OF INVENTIONThe present invention is a Shoreline and Coastal Protection and Rebuilding Apparatus and Method having a plurality of slanted wall sections in a rising stepped formation with open areas between, arrayed on frame structures, which dissipates wave energy in a gradual and controlled way and which neutralizes the impact of a wave and its backwash, thereby protecting the shoreline, and which allows for the settling of sediment, thereby rebuilding the shoreline, while allowing tidal exchange of water and the migration of aquatic species, using modular components that can be manufactured and deployed at low cost and in a manner suited to remote shoreline deployment.
This invention reduces coastal erosion caused by wave action by transforming destructive wave energy, deflects wave energy gradually in order to dissipate its energy while reducing scour, encourages new sedimentation by allowing sediment time to settle before the discharge of water, provides a barrier to guard against the seaward migration of sediment and/or sand, is environmentally neutral by allowing tidal exchange and the migration of aquatic species, minimizes scour from wave action, protects vegetation from the effects of wave action, utilizes wake action from vessels to collect sediment caused by such wake action, accommodates the planting of new vegetation, transforms sediment into an economical retaining wall, is removable and reusable, is simple and inexpensive to manufacture and deploy, can be made buoyant to regulate sinking into soft soil, can be manufactured from a variety of materials, can be manufactured in sizes and configurations appropriate to any given conditions, and can be adjusted in elevation or slope if necessary.
This invention is an apparatus and method for shoreline and coastal protection and rebuilding. The invention protects a shoreline with a plurality of wall sections arranged on frame structures on a slant and with open spaces between, creating modular units that may be connected and deployed along a shoreline.
Referring to
Each wall section may be initially thought of as a plank or a slat, although the wall sections can be of a more complex shape and can be made of a variety of materials, as will be shown. Using the plank analogy, such a wall section plank is mounted to more than one frame structure so that the wall section's longest dimension is oriented generally parallel to the shoreline and the lower edge is in contact with the ground. The frame structure holds the wall section at an angle or slant, with the lower edge being toward the water and the higher edge being toward the land, and with the slant oriented in the same direction as the slope of the land down into the body of water, and where a wave will touch the lower edge first and then travel at an upward slant across the face of the wall section toward the higher edge.
At the higher edge of the wall section is an open space, allowing water traveling up and over the wall section to plunge back down toward ground level. A second wall section is mounted at a slant on the landward side of the first wall section, leaving the open space between, and with the lower edge of the second wall section being lower than the higher edge of the first wall section. More wall sections may be added, always leaving an open space between and always with the lower edge of a given wall section being lower than the higher edge of the preceding wall section.
Referring to
A perspective view of one unit of substantially the same embodiment is shown as
Tests on functioning models and prototypes of the invention show that the exact angle of the slant of the wall sections is not critical. Placing the wall sections in a vertical or near-vertical position would cause waves to reflect rather than be gradually dissipated and is not desirable. Placing the wall sections in a horizontal or near-horizontal orientation would reduce the effectiveness of the invention and is not desirable. Reversing the slant with a rise toward the water side intensifies the scouring action of the waves by forcing them downward and is only desirable in special situations. A slant of thirty degrees rising toward the landward has proven in tests to be an effective angle, although a wide range of slanted angles are also effective.
The overall size of various embodiments of the invention is dependent on the nature of the shoreline being protected, the tidal range, and the type of waves reaching the shore. The banks of a small river or bayou could be protected with a smaller and lighter apparatus than would be required on a seashore.
In a preferred embodiment, referring again to
The longest dimension of the wall sections, corresponding to the distance between frame structures, are dependent on the materials and construction techniques used, weight and handling considerations of transportation and deployment, and the forces to which the apparatus will be subject.
The components of the invention can be built out of a variety of materials, with cement, concrete, reinforced concrete, wood, fiberglass, vinyl, steel, and plastic being among the choices. The apparatus can be constructed in such a way as to be of a determined buoyancy in order to control sinking into soft ground or to function as a floating breakwater. Construction from buoyant materials or the inclusion of buoyant chambers are methods of causing buoyancy.
Although a flat-surfaced wall section is effective and is used in this explanation of the principles of this invention, wall sections having other profiles are also contemplated, such as curved or angled wall sections, which might, for example be stronger or more easily manufactured from a given material, and also might provide a variation of the basic operation of the apparatus appropriate for a given shoreline site, such as, for example, a site where only protection and no rebuilding by sedimentation is desired.
In operation, and with reference to
Eventually all of the water of the original wave becomes part of the new wave, but with substantially all of the force dissipated. Any water and force from the original wave that overcomes all of the wall sections and tops the apparatus drops onto the already-still water of the new wave, and is dissipated substantially radially. There is no rejoining or regeneration of the force of the original wave, since the segregated portions of the wave are used as dissipating forces.
The water of the original wave, after being stilled by the invention, can be allowed to flow back as backwash into the body of water whence it came or can be directed through channels or pipes for other purposes. The initial force of the backwash is only the force of gravity on the water, since the invention does not reflect any of the original wave's force, but deflects and dissipates such force. Water returning through the open spaces of the invention is redirected by having to pass under at least one lower edge of a wall section and then rising through an open space and over the upper edge of an adjacent wall section. Water passing through the higher open spaces will run down the face of a wall section and drop through the next lower open space and hit another portion of the backwash water, complicating and dissipating the force of the backwash. The backwash will build up or stack briefly behind the wall sections.
Because the movement of the water of the original wave and of its backwash is slowed down, sediment or sand particles in the water tend to settle beneath and around the apparatus, rebuilding the shoreline. In situations where such rebuilding is not desirable, such as a navigation channel, the apparatus can be configured to avoid slowing the water to the point of settling or to channel the water to a location where rebuilding is desired, or to give the sediment-laden water a path to stream back into the body of water. Alternatively, sediment building up where it is not desired could be regularly removed and placed elsewhere.
Because the backwash of a wave returning to the body of water is dissipated and reduced in force, the submerged ground on the water-side of the invention is subject to less scouring than would be seen in front of a reflective seawall.
The settling of sediment or sand particles is also promoted by the operation of friction and gravity on particles traveling up and over the wall sections, with the particles falling downward through the open spaces after their forward movement is arrested.
Depending upon the conditions at a given deployment location, the component wall sections and frame structures and other components may be pre-assembled into modular units to be deployed side-by-side, or the components may be assembled on-site or near the site of deployment. Conditions may also allow for fabrication of the components on-site or near the site of deployment.
Several varied embodiments of the invention are disclosed below, with such embodiments having features beneficial under varied shoreline conditions or offering economies of construction and/or deployment. Additional embodiments or variations of the principles of this invention are possible.
Referring again to
Referring to
Referring to
While this invention has been described in detail with particular reference to its preferred embodiments, the principles and modes of operation of the invention have also been described in this specification. The invention should not be construed as being limited to the particular forms disclosed, which are illustrative rather than restrictive. Modifications, variations, and changes may be made by those skilled in the art without departure from the spirit and scope of the invention as described by the following claims.
Claims
1. An apparatus for shoreline and coastal protection and rebuilding to be deployed along a shoreline, the shoreline having a landward and a waterward side and a ground level, the apparatus comprising:
- more than one frame structure, said frame structure having a cross-line dimension substantially perpendicular to said shoreline;
- more than one wall section arranged upon said frame structures, said wall section having a face, said wall section face having an in-line dimension substantially parallel to said shoreline, a cross-line dimension substantially perpendicular to said shoreline, a lower edge along the in-line dimension, and an upper edge along the in-line dimension and separated from said lower edge by said cross-line dimension; and
- open space between said wall sections arranged on said frame structures;
- wherein a first wall section is arranged upon said frame structures with said lower edge substantially in contact with the ground at the shoreline and with said upper edge higher off the ground and farther landward than said lower edge, causing said face of said wall section to slant upward and landward, the subsequent wall sections being arranged upon said frame structure farther landward and higher off the ground than an immediately preceding wall section, causing said apparatus to extend upward and landward, with said open space between said wall sections, and with said lower edge of an immediately subsequent wall section being closer to ground level than the upper edge of an immediately preceding wall section.
2. The apparatus for shoreline and coastal protection and rebuilding of claim 1, wherein the profile of said wall section face is selected from the group consisting essentially of flat, angled, curved, reverse-facing, and double-facing.
3. The apparatus for shoreline and coastal protection and rebuilding of claim 1, wherein said frame structures are securely attached to the ground by pilings.
4. The apparatus for shoreline and coastal protection and rebuilding of claim 1, wherein said frame structures are securely attached to the ground by cleats.
5. The apparatus for shoreline and coastal protection and rebuilding of claim 1, wherein said apparatus is stabilized against wave action by at least one shift plate.
6. The apparatus for shoreline and coastal protection and rebuilding of claim 1, further comprising at least one water control wall.
7. The apparatus for shoreline and coastal protection and rebuilding of claim 1, further comprising at least one seal plate.
8. The apparatus for shoreline and coastal protection and rebuilding of claim 1, wherein said slant of said wall sections is in the approximate range of twenty to sixty degrees.
9. The apparatus for shoreline and coastal protection and rebuilding of claim 1, wherein said slant of said wall sections is in the range of twenty-five to forty-five degrees.
10. The apparatus for shoreline and coastal protection and rebuilding of claim 1, wherein said slant of said wall sections is thirty degrees.
11. The apparatus for shoreline and coastal protection and rebuilding of claim 1, wherein said wall sections are arranged with said upper edge of said first wall section below the low-tide water level and the upper edge of a third said subsequent wall section below the high-tide water level.
12. The apparatus for shoreline and coastal protection and rebuilding of claim 1, wherein said apparatus is buoyant.
13. The apparatus for shoreline and coastal protection and rebuilding of claim 1, further comprising unit wall sections of said wall sections arranged together.
14. The apparatus for shoreline and coastal protection and rebuilding of claim 1, wherein said apparatus is deployed in a substantially opposite-facing orientation.
15. The apparatus for shoreline and coastal protection and rebuilding of claim 1, further comprising migration wall sections of said wall sections having openings for the migration of aquatic species.
16. The apparatus for shoreline and coastal protection and rebuilding of claim 1, further comprising a universal frame structure.
17. An apparatus for shoreline and coastal protection and rebuilding to be deployed along a shoreline, the shoreline having a landward and a waterward side and a ground level, the apparatus comprising:
- more than one frame structure means, said frame structure means having a cross-line dimension substantially perpendicular to said shoreline;
- more than one wall section means arranged upon said frame structures, said wall section means having a face, said wall section means face having an in-line dimension substantially parallel to said shoreline, a cross-line dimension substantially perpendicular to said shoreline, a lower edge along the in-line dimension, and an upper edge along the in-line dimension and separated from said lower edge by said cross-line dimension; and
- open space between said wall sections means arranged on said frame structures means;
- wherein a first wall section means is arranged upon said frame structures with said lower edge substantially in contact with the ground at the shoreline and with said upper edge higher off the ground and farther landward than said lower edge, causing said face of said wall section means to slant upward and landward, the subsequent wall sections means being arranged upon said frame structure farther landward and higher off the ground than an immediately preceding wall section means, causing said apparatus to extend upward and landward, with said open space between said wall sections means, and with said lower edge of an immediately subsequent wall section means being closer to ground level than the upper edge of an immediately preceding wall section means.
18. A method for shoreline and coastal protection and rebuilding to be deployed along a shoreline, the shoreline having a landward and a waterward side and a ground level, the method comprising:
- providing more than one frame structure, said frame structure having a cross-line dimension substantially perpendicular to said shoreline;
- providing more than one wall section arranged upon said frame structures, said wall section having a face, said wall section face having an in-line dimension substantially parallel to said shoreline, a cross-line dimension substantially perpendicular to said shoreline, a lower edge along the in-line dimension, and an upper edge along the in-line dimension and separated from said lower edge by said cross-line dimension; and
- providing open space between said wall sections arranged on said frame structures;
- wherein a first wall section is arranged upon said frame structures with said lower edge substantially in contact with the ground at the shoreline and with said upper edge higher off the ground and farther landward than said lower edge, causing said face of said wall section to slant upward and landward, the subsequent wall sections being arranged upon said frame structure farther landward and higher off the ground than an immediately preceding wall section, causing said apparatus to extend upward and landward, with said open space between said wall sections, and with said lower edge of an immediately subsequent wall section being closer to ground level than the upper edge of an immediately preceding wall section.
19. The method of claim 18, wherein said wall sections arranged on said frame structures with said open spaces dissipate the force of incoming waves by segregating portions of the wave's force and redirecting said portions of the wave's force to dissipate said wave's force.
20. The method of claim 18, wherein modular units of said wall sections arranged on said frame structures with said open spaces are made buoyant.
Type: Application
Filed: Aug 13, 2008
Publication Date: Jun 18, 2009
Inventor: Vincent Paul Liner (Chauvin, LA)
Application Number: 12/191,177