Abstract:
A sand and soil internal reinforcement system including a plurality of individual modules removably connectable together act to reinforce sand and/or soil against shifting caused by erosive forces such as water and wind in high energy environments such as coastal beaches and watershed areas which produce large volumes of runoff or in hill sides subject to sliding due to ground water hydrostatic pressure. The modules include a cell having a front panel, rearward extending side walls which are held together by an open soil ballast and anchor membrane, and a refractor panel. Fill placed on top of the ballast and anchor membrane provides structural stability for each individual module independent of other adjoining modules of the reinforcement system. The interface established between adjacent modules requires no supplemental coupling devices, such as shear and alignment pins, to removably secure them together.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims the priority benefit of U.S. provisional patent application Ser. No. 61/008,597, filed Dec. 20, 2007, entitled “SAND/SOIL CELL MODULE SYSTEM” of the same named inventor. The entire contents of that prior application are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of Invention 
         [0003]    The present invention relates to systems designed to reinforce the inherent structural characteristics of a body of sand or soil to assist in the resistance against erosive action. More particularly, the present invention relates to modular structures that may be selectable configured to conform with the geography, geology and contour of the location where the sand or soil to be reinforced exists. The present invention may be arranged as a plurality of modules establishing a multi-tiered system that when buried or otherwise integrated with the sand/soil, increases the tensile strength of the sand/soil strata, which would otherwise be weakened by super saturation, hydrostatic pressure, movement, shaking and/or shifting/sloughing by the dynamic forces of water, wind and/or earth tremors. 
         [0004]    2. Description of the Prior Art 
         [0005]    Problems associated with sand and/or soil due to erosive wave attack or scouring by rapidly moving water in the coastal and inland environment are described in U.S. Pat. No. 5,499,891 (&#39;891 patent) issued Mar. 19, 1996, by the inventor of the present invention. The entire content of the &#39;891 patent is incorporated herein by reference. 
         [0006]    The &#39;891 patent describes an earth retaining system forming what is generally perceived as a wall constructed of a plurality of pre-cast concrete blocks with fill spaces. The wall requires assembly in place, with individually blocks joined and secured with shear and alignment pins, which shear and alignment pins may be coated with a protective non-metallic material, such as neoprene. The system of the &#39;891 patent required off-site manufacturing of the wall components and then shipment of the components to the site of interest for placement, thereby requiring heavy construction machinery. The wall is intended to be arranged to create a terrace-type infrastructure, which is buried or can remain uncovered. 
         [0007]    The structural stability of the &#39;891 patented system is derived primarily by the mass of concrete of each block consisting of a front panel and side panels. It has been determined that there are limitations of design associated with the use of heavy concrete blocks fabricated and arranged in the manner described in the &#39;891 patent. The individual blocks of the prior system, when aligned side by side, are limited in the formation of a curve such that gaps between individual blocks cannot be avoided while also establishing the required curvature. These gaps, created between the vertical side panels of adjacent blocks, result in the washout of sand or soil as water or wind forces pass over and, eventually, through the prior retaining system. 
         [0008]    In addition to the existence of interblock gaps, the prior system has solid rearward extending side panels, which in conjunction with dead-man anchors provide stability, depending primarily on weight of the block. That arrangement is intended to maintain the system in place under the loading conditions anticipated, but make the system difficult to maneuver in place without substantial moving equipment, which may be difficult to bring to the location requiring the erosion stabilization. The prior system also requires the use of steel rods to anchor the blocks in place to prevent sliding. Sufficient anchoring may not be available, dependent upon the stability and retaining capability of the underlying substrate. Alternatively, it may be necessary to supplement standard anchoring rods with extensions, supplemental footings or the like to reach suitable substrate support, such as underlying bedrock well below the surface where the erosion occurs. 
         [0009]    A further limitation of the prior retaining system described in the &#39;891 patent is the existence of governmental restrictions on the introduction of concrete structures on public land, particularly in coastal locations. Prior alternatives to address the desire to eliminate concrete structures from public lands has led to the option of using less dense materials to form the modules, such as plastics, for example. However, prior plastic-fabricated retaining structures had to be assembled on site and then filled with sand/soil to establish the necessary load integrity. It is not particularly desirable to undertake assembly activity on site, particularly when that site is a public setting, such as a coastal beachfront. Moreover, the process of assembly can be costly in itself. 
         [0010]    When concrete structures are permitted, if the placement site is difficult to access, it may be necessary to pour the structure on site. That then requires a time delay as the concrete sets up. In that situation, the process is slow and the curing concrete may be exposed to the damaging environmental conditions it is intended to blunt. A better system would involve the use of preassembled components easily installed at the location of need and ready for use once installed. 
         [0011]    These and other features of the prior retaining systems limit their capability to provide an effective, cost efficient and marketable device suitable and competitive in the art of mitigating and preventing beach erosion and the failure of soil in embankments or bluffs. What is needed is a sand and soil internal reinforcement system configured to resolve these limitations. 
       SUMMARY OF THE INVENTION 
       [0012]    It is an object of the present invention to provide a sand and soil internal reinforcement system that may be easily installed at any location of interest. Further, it is an object of the present invention to provide such a system that does not require the use of heavy machinery for either assembly or installation. Yet further, it is an object of the present invention to provide a sand and soil reinforcement system that allows for customized configuration formation without compromising its functionality including, for example, allowing for curved arrangements without modular gaps sufficient to compromise the integrity of the system. 
         [0013]    These and other objects are achieved with the present invention, which is a sand and soil internal reinforcement system including a plurality of individual modules that when releasably coupled together in varied combinations through the linking of adjoining flexible slip joints form a multi-tiered, step-up, set-back, staggered and interlocked internal method to reinforce sand/soil against shifting, sloughing and other erosive action caused by water and wind in high energy environments such as coastal beaches and watershed areas which produce large volumes of runoff or in hill sides subject to sliding due to ground water hydrostatic pressure. In effect) the system of the present invention functions somewhat like a root system that one might expect from the existence of a trees and/or vegetation, which acts to reinforce the sand or soil associated therewith. 
         [0014]    The modules of the system of the present invention are in a selectable geometric form, such as an open rectangular shape, for example, when viewed from above. The module includes a cell body and a refractor panel. The cell body includes a front panel, rearward extending side walls, and a ballast and anchor membrane, slightly raised above the bottom of the vertical components of the cell. The cell body is open on the top so that fill may be placed on top of the ballast and anchor membrane to provide structural stability for each individual cell module independent of other adjoining cell modules. The refractor panel may be removably or permanently affixed to the front panel of the cell body. 
         [0015]    The side walls of each cell are configured to establish interface joints between adjacent cells. The interface joints established eliminate the need to use shear and alignment pins to secure adjacent cells together. Cells may be easily joined and separated due to the interface joints of the present invention. In an embodiment of the invention to be described herein, one of the two side walls of the cell body include a slip-type joint component and a protruding extension with a flat bottom and tapered surface. The opposing side wall includes an opening generally corresponding in configuration to the configuration of the protruding extension such that adjacent cell modules will fit together. One side wall acting as a male component and the adjacent side wall of the adjacent cell module acting as the female component when the two adjacent cell modules are positioned together. Each cell of the module is loaded with sand/soil fill placed on top of the ballast and anchor membrane and is anchored against sliding by, in addition the interface between adjacent cells, the ballast fill passing through an opening in the center of the ballast membrane to form a solid vertical column of sand/soil. 
         [0016]    The modules may be combined in a multi-row setback, staggered stacked formation through interlocking placement at a bottom center point of the front panel of each upper cell into top alignment notches of the side panels of two adjoining lower cells. The stress of weight of the upper cell is distributed over the top of the underlying cells by both the interlocking portion of the front panel and also the underside of the soil ballast membrane. 
         [0017]    The reinforcement system of the present invention comprising a plurality of the modules is set in place by burying it inside the toe of a coastal bank, dune, cliff or bluff. Its primary function is to provide a second line of defense during severe coastal storms or intense precipitation generating large amounts of runoff. Unlike any other system used to address erosion problems, the present invention, after it becomes partially or filly exposed during a severe wave attack, has the ability to dissipate the wave energy and decelerate the velocity of the moving mass of water. Specifically, one or more setback rows of a plurality of modules shear the volume of water pushed by an incoming wave into one or more horizontal layers depending on the height of the wave. 
         [0018]    The dynamic energy of the moving mass of water is divided as it reaches the refractor panels of each module of a multi-tiered, step-up, set-back and interlocked system of the present invention, with the dividing events separated by microseconds. During that event delay measured in microseconds when the incoming wave is sheared into horizontal layers to create shear planes within the body of water, the shear planes themselves dissipate energy due to the friction generated. The volume of water between the shear planes after making contact with the refractor panels of the modules of the lowest row of the reinforcement system is lifted upward by the configuration of the refractor panel, which in an embodiment is backward inclined and recessed. The underside of the wave shear bar, located at the top of the refractor panel, reverses the flow of the water, pushing it into the underside of the upper flowing mass of water between the shear planes, effectively dissipating the dynamic energy by decelerating the wave velocity. The remaining scouring forces are directed upward and sideways away from the dune or upland, which are protected by the system. The turbulence created by the sudden stoppage of the moving mass of water occurs in mid air, effectively dissipating the scouring forces, minimizing the wave return velocity and preventing bottom scour. 
         [0019]    These and other advantages of the present invention can be seen in the following detailed description, the accompanying drawings and the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is a front view of a module of the reinforcement system of the present invention. 
           [0021]      FIG. 2  is a plan view of the module of  FIG. 1 . 
           [0022]      FIG. 3  is a first side view of the module of  FIG. 1 . 
           [0023]      FIG. 4  is a second side view of the module of  FIG. 1 . 
           [0024]      FIG. 5  is a cross sectional front view of the module of  FIG. 1 . 
           [0025]      FIG. 6  is a cross sectional side view of the module of  FIG. 1 . 
           [0026]      FIG. 7  is a cross sectional partial front view of an intermodular interface of the reinforcement system of the present invention. 
           [0027]      FIG. 8  is a plan view of a combination of interlocked modules of the reinforcement system of the present invention. 
           [0028]      FIG. 9  is a perspective view of a first embodiment of the reinforcement system of the present invention. 
           [0029]      FIG. 10  is a front view of the reinforcement system of  FIG. 9 . 
           [0030]      FIG. 11  is a side view of a second embodiment of the reinforcement system of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0031]    The present invention is a sand and/or soil internal reinforcement system as illustrated in the accompanying drawings. The reinforcement system is a combination of individual modules that may be combined to form an interlocked and terraced arrangement of selectable configuration to internally reinforce sand and soils in coastal banks, dunes, beach berms, cliffs, bluffs, dikes, levees, and to effectively mitigate erosion caused by wave action, wind forces, hydrostatic pressure, super saturation and liquefaction. An important aspect of the invention is the configuration of a module  10  shown in  FIGS. 1-6 . 
         [0032]    The module  10  includes a cell body with a front panel  12 , a first side panel  14 , a second side panel  16  and a bottom ballast and anchor membrane  18 . The first side panel  14  and the second side panel  16  extend rearward from the front panel  12  and may be formed integrally with the front panel  12  or by separate components removably or permanently affixed to the front panel  12 . Further, the first side panel  14  and the second side panel  16  each include a top and a bottom areas of both the first side panel  14  and the second side panel  16  are joined together by the ballast and anchor membrane  18 . They may be removably or permanently joined to the membrane  18 . One or more of the front panel  12 , the first side panel  14 , the second side panel  16  and the membrane  18  may be formed as a unitary structure or as individual structures joined together. 
         [0033]    The module  10  further includes a refractor panel  12   a  that is permanently or removably joined to the front panel  12  of the module  10 . The refractor panel  12   a  may extend above and cover a top portion of the front panel  12 . As shown in the figures, an upper region of the refractor panel  12   a  is a flange that is positioned on an upper forward surface of the front panel  12 . The upper flange of the refractor panel  12   a  may extend rearwardly along the upper forward surface of the front panel  12   a  selectable distance. The refractor panel  12   a  may be added to or removed from the cell of the module  10  as desired prior to module fill. The refractor panel  12   a  may be a separate structure to the cell body or it may be fabricated integrally therewith. 
         [0034]    The refractor panel  12   a  includes one or more angled recesses  13 . The recesses  13  are preferably angled rearwardly from a perimeter frame of the refractor panel  12   a,  with the recess deeper at the upper portion of the refractor panel  12   a  than at the lower portion of the refractor panel  12   a.  This arrangement enhances wave shearing action upon first contact of a wave or other erosive actor so as to dissipate the energy of that action upon initial contact with the module  10 . The refractor panel  12   a  may further include an anti-scouring lip  15  at a lower portion thereof. The anti-scouring lip reduces the scouring effect of particulates that may be entrained in the fluid impacting the cell module  10 . The refractor panel  12   a  further includes beveled edges to redirect scouring forces in an upward and sideway direction. The refractor panel  12   a  may optionally be coated with a friction-reducing coating selected to resist scouring forces and atmospheric corrosive elements. 
         [0035]    The cell and the refractor panel  12   a  of the module  10  may be fabricated of the same non-metallic material, such as a polymeric material. The refractor panel  12   a  may be coated to reduce the roughness coefficient of its surface so that scouring of that surface may be minimized. The cell may be an uncoated structure having a roughness coefficient approximating that of sand but not restricted thereto. With the refractor panel  12   a  substantially covering the portion of the cell most likely to come in direct contact with the most erosive action. This arrangement of the refractor panel  12   a  with respect to the front panel  12  and the remainder of the cell embeds the entire cell in the sand/soil and also covers interlocking notches of adjoining modules as shown in  FIGS. 9 and 10 . It is also to be noted that the refractor panel  12   a  acts to minimize the strongest form of erosive forces on the cell of the module  10 . It is to be noted that with the two-piece arrangement of the module  10 , any damage is likely to occur at the refractor panel  12   a,  which may be replaced without the need to replace the entire module  10 . this arrangement, embeds the entire Cell Body in Sand and also covers the interlocking notches below the wave refractor panel. 
         [0036]    Each of the first side panel  14  and the second side panel  16  includes a notch  20  at the top areas thereof and footings  21  at the bottom areas thereof. The notches  20  are adapted to accept in an interlocking manner bottom flange  22  of the front panel  12  substantially centered thereat. In this way, one cell module may be removably positioned on top of a pair of other cell modules by inserting the bottom flange  22  into adjacent notches  20 . The location of the notches  20  front to back on top of the side panels  14 / 16  is determined by the characteristics of the substrate to be retained and stabilized by the module  10 . Those characteristics include, but are not limited to, the shear stress of the substrate pressing against internal surface  24  of the front panel  12  when in position, and also the existing slope gradient of the coastal bank, dune or cliff at the stabilization location of interest. In particular, the angle of repose of a particular set of modules  10  is defined by differing locations of the notches  20 . That angle of repose is preferably selected to parallel the angle of repose of the particular soil type to be reinforced. In effect, the selected angle of repose is chosen to negate loading forces directed against the internal surface  24  of the front panel  12 . 
         [0037]    The first side panel  14  includes a receiving port  26  that may be configured as a half-round tapered opening with a flat bottom. The second side panel  16  includes an interface protrusion  28  that is configured to correspond in design to the receiving port  26  of the first side panel  14  such that it fits within the receiving port  26  but with a loose fit between the two to allow for movement of one module in relation to an adjacent module without the interface protrusion  28  and the receiving port  26  completely separating from one another. For example, the dimensions of the receiving port  26  may be greater than the dimensions of the protrusion  28 . In the configuration of the module  10  shown in  FIGS. 3-5 , the interface protrusion  28  is a half-round tapered extension with a flat bottom. 
         [0038]    As shown in  FIG. 7 , when two adjacent ones of the module  10  are to be removably interlocked together, the protrusion  28  of one module is inserted into the receiving port  26  of the other. Those two components of the module  10  are fabricated with sufficient difference in the respective dimensions of the protrusion  28  and the receiving port  26  that one module  10  may be angled with respect to the other without the protrusion  28  of that module being completely spaced away from the receiving port  26  of the other module. The flexible joint established in this manner secures adjacent modules together without the need for any additional coupling devices including, for example, the shear and alignment pins of the prior system described herein. The flexible joint established by the interface of the receiving port  26  of one module  10  with the protrusion  28  of an adjacent module  10  accounts not only for horizontal deflections of a system of modules, but also for vertical deflections, such as uplifts, as well. Further, and more specifically, the flat bottoms of the receiving ports  26  and the protrusions  28  establish both vertical and horizontal alignment of adjoining modules. 
         [0039]    One or more of the side panels  14 / 16 , front panel  12 , and membrane  18  include reinforcement ribs and/or supporting cleats to equalize the dead weight of the fill and prevent side panels  14 / 16  from deforming. The reinforcement ribs associated with the side panels  14 / 16  also minimize or eliminate splaying of those panels during the fill operation, and further function as anchor elements to prevent forward and/or backward sliding of the cell body after embedment in sand or soil. Examples are shown in  FIGS. 2 and 7  of a reinforcement rib  31  and a support cleat  33  for the side panels  14 / 16 . An example of a front panel reinforcement rib  35  is shown in  FIG. 6 . 
         [0040]    The thickness of the protrusion  28  and the depth of the receiving port  26  must be sufficient to allow the two to remain interfaced when one is moved with respect to the other. For example,  FIG. 8  illustrates a row of three modules adjacent to one another. Center module  40  has a first alignment, second module  42  has a second alignment, and third module  44  has a third alignment, wherein each alignment is distinct from the others. The second module  42  is angled slightly forward with respect to the center module  40  and the third module  44  is angled in a more pronounced manner but in a rearward direction from the center module  40 . In this arrangement, first module interface  46  established by the joining of the protrusion  28  of the center module  40  and the port  26  of the second module  42  exists, but the protrusion  28  of the center module  40  extends at an angle slightly outwardly from the port  26  of the second module  42  at the rear thereof. A gap thus exists between the center module  40  and the second module  42 , but at the rear of the row of modules. In addition, second module interface  48  established by the joining of the protrusion  28  of the third module  44  and the port  26  of the center module  40  exists, but the protrusion  28  of the third module  44  extends at an angle slightly outwardly from the port  26  of the center module  40  at the front thereof A gap thus exists between the center module  40  and the third module  44 , but at the front of the row of modules. Maintenance of module interfaces while allowing for gaps between adjacent modules permits the user to customize the shape of the reinforcement system of the present invention by selective positioning of individual modules with respect to one another while keeping adjacent ones interlocked. 
         [0041]    The bottom ballast membrane  18  illustrated in  FIGS. 2 and 8  includes a cutaway section  19  and fill opening  30 . The cutaway section  19  and the fill opening  30  allow for fill to pass around and under the module  10  so as to enhance anchorage of the module  10  in the location of interest. The membrane  18  may be fabricated of any material considered to be suitable for the intended purpose including, but not limited to, a non-metallic material. The membrane  18  itself may be solid or porous but should be of sufficient strength to maintain the spacing between the first side panel  14  and the second side panel  16 . The inner space of the cell module  10  defined by the arrangement of the front panel  12 , the first side panel  14 , the second side panel  16  and the membrane  18  may be partially or completely filled with sand/soil to provide enough ballast to the cell module  10  so that it becomes substantially immovable once positioned where desired. 
         [0042]    The loaded membrane  18  together with the bottom flange  22  of the front panel  12  and the footings  21  of the first side panel  14  and the second side panel  16 , once the cell module  10  is filled, establish a solid footing for each module independent of the condition of any adjoining modules. Further, the cell module  10  is configured so that any portion of the fill within the open space of the cell module  10 , when exposed to attack by plunging type waves, will cause saturation of the fill strata directly behind the front panel  12 . The top of the ballast membrane  18  and the volume of any dry fill within the cell module  10  will hold the saturated fill in place, allowing excess content of water to be absorbed into the mass of dry fill without being blown out and causing a void in the embedment fill. 
         [0043]    The cell module  10  may be fabricated of high strength geo-synthetic polymer or similar non-metallic material, provided it is sufficiently resistive to atmospheric corrosive elements. The use of a non-metallic material provides sufficient strength of the structure while maintaining relatively lightweight. The cell module  10  derives its stability mainly from the fill placed on the ballast membrane  18  rather than from the structure itself which was a limitation of the prior stabilization devices. When a plurality of cell modules  10  are positioned adjacent to and on top of one another, a terraced-type soil and sand internal reinforcement system is established, such as system  200  shown in  FIGS. 9 and 10  in a two-tier arrangement, and as system  300  in  FIG. 11  in a four-tier arrangement. In the four-tier arrangement, an anchor tier  100  is first positioned below existing grade  110  and each cell module thereof filled. A second tier  120  is then positioned set back on the anchor tier  100 , with the bottom flanges  22  of the front panels  12  inserted into the notches  20  of the side panels  14 / 16  of the cell modules of the anchor tier  100 . The cell modules of the second tier  120  are filled and a third tier  130  is then positioned set back on the second tier  120 , with the bottom flanges  22  of the front panels  12  inserted into the notches  20  of the side panels  14 / 16  of the cell modules of the second tier  120 . The cell modules of the third tier  130  are filled and a fourth tier  140  is then positioned set back on the third tier  130 , with the bottom flanges  22  of the front panels  12  inserted into the notches  20  of the side panels  14 / 16  of the third tier  130 . Finally, the cell modules of the fourth tier  140  are filled and the surrounding sand/soil graded as desired. 
         [0044]    The tiered arrangement of cell modules of the present invention, of which  FIGS. 9-11  represent examples, create a sand and/or soil internal reinforcement system that increases the effective tensile strength of the sand/soil and that can be formed without the need for heavy moving equipment. The system has the capacity to be penetrable by sand/soil and water and enables the release of hydrostatic pressure. The cell modules may be configured and arranged such that at no point within the vertical rise of the multi-tiered reinforcement system does the hydrostatic pressure exceed one pound per square inch, regardless of the number of tiers. The horizontal tiers may be extended selectively to widen the overall footprint of the system so that the energy of plunging-type waves is uniformly absorbed by the mass of sand/soil where the system is located. 
         [0045]    It is to be noted that the reinforcement system also forms horizontal terraces, which after exposure by wave or wind action, may remain uncovered and is thereby suitable to establish separate planter boxes for native coastal vegetation. Further, the arrangement of the multi-tiered reinforcement system, upon exposure after aggressive wave action, can be traversed by pedestrians without difficulty. More generally and as earlier noted, the present invention is advantageous in that the modules may be arranged at angles with respect to one another such that curved and other complex shapes of the reinforcement system may be created, particularly to conform with the condition of the environment where the internal reinforcement is required. The modules are lightweight and can therefore be manually transported and set in place. They do not require additional coupling components to establish a multi-tiered reinforcement system such as, but not limited to, coated shear pins for alignment. 
         [0046]    One or more example embodiments to help illustrate the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the claims appended hereto.