Abstract:
A fiber block segment suitable for controlling erosion and stabilizing soil is described that comprises an elongated fiber block formed of a densely packed elongated thick fibrous material. The fiber block is wrapped with a fabric around three sides so that the fabric defines a top anchor portion and a bottom anchor portions extending from the block. The fiber block is securely attached to the wrapped fabric by another fabric or twine spanning the fourth side of the block. Additionally, the fabric is wrapped only up to the edges defining one end (a male end) and beyond the edges defining the opposite end (the female end) to define a pouch-like structure at the female end. The fiber block is made of coconut fibers (coir). The fabric is woven from coir twine, and coir twine secures the fabric to the fiber block.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application claims priority to U.S. Provisional patent application Ser. No. 60/354,072 entitled “Self-anchoring fiber block system for shoreline and waterway bank restoration” filed Jan. 30, 2002. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    The invention relates to a self-anchoring fiber block system for lining lake or ocean shorelines or the banks of streams or rivers to control erosion of the soil near the water&#39;s edge and to promote growth of environmentally friendly vegetation near the waterline. Urban development has led to construction of more and more impervious solid surfaces such as parking lots and paved roads among other man-made structures that impede the natural watershed&#39;s ability to absorb and filter rainwater carrying silt from soil erosion and other pollutants before it runs off into streams and other waterways. This unfiltered runoff harms the environment by increasing pollution levels in the waterways within the watershed. The increased runoff also increases the danger of flash flooding and flows through the watershed at increased velocities. The faster the runoff flows through existing waterways and the higher the volume of the runoff, the more the runoff erodes the banks of the waterways and the more the runoff harms the ecosystem of the watershed. Additionally, severe washouts along the banks of the eroded waterway may damage property located near the banks.  
           [0003]    Various structures and methods exist for stabilizing waterway banks and shorelines. One current method for stabilizing the banks of a waterway is to line the banks of a waterway or shoreline with concrete. However, this method completely destroys the localized ecosystem along the bank because it requires completely removing the vegetation growing along the bank. This method also eliminates or reduces the size of much needed green spaces in urban areas.  
           [0004]    Another method of stabilizing the banks of a waterway is to stack rocks or boulders along the banks or shorelines to create riprap. Along with the disadvantages inherent in concrete lining, the use of riprap alongside waterways can block water flow during severe flow conditions if pieces of the riprap move from their intended locations. Additionally, both concrete and riprap are expensive to install on waterway banks and shorelines.  
           [0005]    U.S. Pat. Nos. 5,338,131; 5,425,597; 5,641,244; and 5,678,954 to Bestmann describe prior methods of preventing waterway banks and shoreline erosion by placing various objects along a waterway to promote vegetation growth, initially on the objects themselves and later on the banks and shorelines. Although various methods described in Bestmann&#39;s patents involve the growth of vegetation as a mechanism for slowing or eliminating erosion on waterway banks and shorelines, they all have a common problem in installation of the objects. Bestmann extensively uses anchors to install his erosion control objects in waterway banks and shorelines including wooden stakes, steel cables, and anchor plates, each of which suffer from various deficiencies. Because Bestmann&#39;s wooden stakes are submerged under water but not buried in the soil, their buoyancy causes them to loosen and eventually work free from their anchoring position, which can cause the erosion control system to fail. Bestmann&#39;s wooden stakes can also rot and lose their structural integrity within short period of time when compared to the coir material used in much of the remaining structure in Bestmann&#39;s erosion control systems. Bestmann&#39;s wooden stakes also require extensive labor, which increases the costs associated with using Bestmann&#39;s erosion control systems. Bestmann&#39;s steel anchoring structures do not float or rot quickly, but they also require extensive labor. These steel anchoring structures may also be prohibited in many environmentally sensitive areas. Therefore, there is a need for waterway bank and shoreline protection and restoration system, which is capable of protecting waterway bank and shoreline over an extended time and with an environmentally friendly and stable anchoring structure and method. Furthermore, the system should promote growth of vegetation on it and protected waterway bank and shoreline.  
           [0006]    Bestmann&#39;s erosion control systems also suffer the disadvantage of having structurally weak connections between the erosion control objects when the objects are installed over an extended length to cover long sections of a shoreline or bank. When the objects described by Bestmann are placed end-to-end along the length of the protected area shoreline or bank they tend to shift from their alignment with each other over time. The shift in alignment exposes the soil between the objects to water and thus erosion.  
           [0007]    U.S. Pat. No. 6,234,721 to Cronkhite et al. describes an erosion prevention block of a hollow and L-shaped plastic block. Use of these blocks in waterway banks and shorelines to stop erosion is not an environmental friendly approach. When installed, these block systems behave similar to a concrete wall in that they remain virtually indefinitely and they inhibit growth of vegetation on the protected surface. Moreover, these blocks are complicated to handle during installation. Because these blocks are permanent structures, they must be removed if the waterway on which they are installed is expanded. Once removed, these plastic blocks are very difficult to dispose of properly because they are not biodegradable. Moreover, environmental regulations make using these plastic blocks in environmentally sensitive wetland and wildlife habitat difficult if not impossible.  
           [0008]    U.S. Pat. No. 5,951,202 to Brown describes a shoreline erosion control system for installation on a shoreline or waterway bank. Brown&#39;s system is anchored to the shoreline or bank using cables, steel anchor piles, and metal staples (see FIGS.  2 - 4 ). These anchors are expensive and their installation is labor intensive. Brown also describes the use of metallic mesh, a synthetic erosion mat, and wire mesh, none of which is biodegradable. Moreover, synthetic nets of the type described by Brown can entrap and kill reptiles, birds, and fish leading to trap them and eventually kill them. Therefore, it is difficult, if not impossible to use these materials in environmentally sensitive wetland and wildlife habitat promoting areas.  
           [0009]    U.S. Pat. No. 6,267,533 to Bourg describes a shoreline erosion control system comprising interlocking and layered elements made of concrete. Once installed, this system behaves like a paved concrete surface. Because Bourg&#39;s erosion control system suffers all the problems inherent with the concrete lining method described earlier, it is inappropriate to use them along environmentally sensitive watershed and wildlife habitat areas.  
           [0010]    U.S. Pat. No. 6,168,349 to Perslow, et al. describes a system for lining a bank of a waterway. The system comprises two parallel linings of soil cement along the waterway bank. Placing soil cement process includes removal of soil along the bank, mixing them with cement and water, placing them back and compacting. If the soil in the bank is not suitable for soil cement process, suitable soil has to be imported from another site. Therefore, placing soil cement on a waterway bank is expensive and time consuming. Moreover, Perslow, et al&#39;s soil cement waterway bank lining system is not friendly to ecosystem along the waterway bank. Soil cement does not promote growth of vegetation and it does function as a natural wildlife habitat.  
         SUMMARY OF THE INVENTION  
         [0011]    The invention is a self-anchoring fiber block system that can be positioned along a shoreline or waterway bank to stabilize the shoreline or waterway bank by preventing soil erosion, supporting the soil behind the system (i.e., the soil on the other side of the system from the water) and promoting growth of vegetation. The structure is easy to install, made of natural materials, friendly to wildlife habitat, protects the shoreline or waterway bank against erosion from its installation onward, promotes growth of vegetation along the shoreline or waterway bank, and can be anchored in place with few, if any, separate anchoring structures. Because the fiber block system is made of natural materials and controls erosion so effectively, it may be installed closer to the water to protect as much of the shoreline or waterway bank from erosion as is desired. The natural materials of which the fiber block system is made can also support vegetation growth in the fiber block system itself. Thus, vegetation can be implanted in the fiber block system itself in a manner that protects the vegetation from forces of erosion and accelerates its growth along the shoreline or waterway. The fiber block system can be made of interlocking fiber block segments that connect easily and without the need for specialized tools or connecting hardware. The fiber block system also protects the bare soil behind (in relation to the water) the structure from erosion because, among other reasons, it is thick enough to function as a barrier between the soil and the water. Thus, the fiber block system promotes growth of vegetation in the soil behind the structure also. Because the fiber block segments can be stacked atop each other, the installer can construct an artificial bank of a chosen elevation to further control the path of water flowing in a waterway or shape the shoreline. The embodiment of the fiber block system with a fiber block segment having a rectangular cross section has an improved ability to retain soil behind it because of the increased contact area between the bottom of the rectangular fiber block segment when compared to a fiber block system using a fiber block segment having a circular cross section. Nonetheless, a fiber block system using fiber block segments with a circular cross section can also be used if desired. These and other advantages of the invention will become apparent to a skilled artisan based on his or her review of the following description and the accompanying illustrations.  
           [0012]    Therefore, in one preferred embodiment, an erosion control device of a fiber block segment is provided, comprising an elongated fiber block formed of a densely packed elongated thick fibrous material. The fiber block has a fabric wrapped around three sides of the block, wherein the wrapped fabric extends from the block to define a top anchor portion and a bottom anchor portion. The fiber block is securely attached to the wrapped fabric by another fabric or twine spanning the fourth side of the block. Additionally, the fabric is wrapped only up to the edges defining one end (a male end) and beyond the edges defining the opposite end (the female end) to define a pouch-like structure at the female end. In this preferred embodiment, the fiber block is made of coconut fibers (coir), the fabric wrapped around the fiber block is woven from coir twine, and the twine used in securing the wrapped fabric to the fiber block is coir twine.  
           [0013]    In accordance with this invention, erosion of a shoreline or waterway bank can be accomplished by installing fiber block segments adjacent the shoreline or waterway bank with the anchor portions extending away from the water. The bottom anchor portions are covered with soil, the soil is compacted, and the top fabric portions are either laid on top of the compacted soil or covered with additional soil. Live plant cuttings and live plants such as willows are planted in the soil underlying or covering the top anchor portions.  
           [0014]    The fiber blocks defining the water side faces of fiber block segments enable construction of an erosion control system of a substantially constant height. In general, the slope angle of the bank can be varied by moving the layers of the fiber block segments relative to each other. The fiber block segments are installed over an extended length along the shoreline or waterway bank by connecting fiber block segments end-to-end and mating the male end of one fiber block segment to the female end of an adjacent fiber block segment to create a continuous erosion control system along the shoreline or waterway bank. The pouch at the female end of the fiber block segment securely holds an inserted male end of the adjacent fiber block segment and maintains the continuity and the structural integrity of the system. The weight of soil on top of the anchor portions also keeps the fiber block segments in place. Other arrangements of the fiber block system are described below.  
           [0015]    The foregoing general description and the following detailed description are exemplary and explanatory only and do not restrict the claims directed to the invention. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one embodiment of the invention and together with the description, serve to explain the principles of the invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    [0016]FIG. 1 is a perspective view from the soil side of an embodiment of the fiber block according to the invention.  
         [0017]    [0017]FIG. 2 is a perspective view from the water side of the embodiment of the fiber block system of FIG. 1.  
         [0018]    [0018]FIG. 3 is a side view of the embodiment of the fiber block system illustrated in FIG. 1.  
         [0019]    [0019]FIG. 4 is a cross sectional view of the fiber block system illustrated in FIG. 1 taken alone line  4 - 4  of FIG. 3.  
         [0020]    [0020]FIG. 5 is a cross sectional side view of the fiber block system illustrated in FIG. 1 as it can be installed in a waterway bank.  
         [0021]    [0021]FIG. 6 is a cross sectional side view of the fiber block system illustrated in FIG. 1 as it alternatively can be installed in a waterway bank.  
         [0022]    [0022]FIG. 7 is a perspective view showing how the two fiber blocks as shown in FIGS. 1 and 2 can be arranged to be mated end-to-end.  
         [0023]    [0023]FIG. 8 is a perspective view illustrating the two fiber block systems of FIG. 7 in a mated condition to make a continuous fiber block system.  
         [0024]    [0024]FIG. 9 is a cross sectional side view of the installation of the fiber block system illustrated FIG. 5 several years after it was installed in a waterway bank.  
         [0025]    [0025]FIG. 10A is a perspective view from the soil side of a first alternative embodiment of the fiber block system of the invention.  
         [0026]    [0026]FIG. 10B is a perspective view from the soil side of second alternative embodiment of the fiber block system of the invention.  
         [0027]    [0027]FIG. 10C is a perspective view from the soil side of a third alternative embodiment of the fiber block system of the invention.  
         [0028]    [0028]FIG. 11A is a perspective view from the soil side of a fourth alternative embodiment of the fiber block system of the invention.  
         [0029]    [0029]FIG. 11B is a cross sectional side view of the fiber block system illustrated in FIG. 11A as it can be installed in a waterway bank.  
         [0030]    [0030]FIG. 11C is a perspective view showing how the two fiber block systems, shown in the FIG. 11A, are arranged to make a continuous fiber block system.  
         [0031]    [0031]FIG. 12A is a perspective view from the soil side of a fifth alternative embodiment of the fiber block system of the invention.  
         [0032]    [0032]FIG. 12B is a cross sectional side view of the fiber block system illustrated in FIG. 12A as it can be installed in a waterway bank.  
         [0033]    [0033]FIG. 13A is a side view of a sixth alternative embodiment of the fiber block system of the invention.  
         [0034]    [0034]FIG. 13B is a cross sectional view taken alone line  13 B- 13 B of FIG. 13A.  
         [0035]    [0035]FIG. 13C is a side view of a seventh alternative embodiment of the fiber block system of the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0036]    This application refers in detail below to the exemplary embodiments of a self-anchoring fiber block segment  10  according to the invention, which are illustrated in the accompanying drawings. The fiber block segment  10  can be used as a component of a fiber block system  40  to stabilize a shoreline or waterway bank by providing support for and preventing erosion of the soil behind the fiber block system  40  (on the other side of the fiber block system  40  from the side exposed to water). Wherever possible, the application uses the same reference numbers throughout the drawings to refer to the same or similar items.  
         [0037]    FIGS.  1 - 11  illustrate a first embodiment of a fiber block segment  10  of the self-anchoring fiber block system of the invention. As shown in FIGS. 1 and 2, fiber block segment  10  includes a compressed coir fiber block  12  and a high strength coir fabric  14  wrapped around three sides of the compressed coir fiber block  12 . The coir fiber block  12  may also be wrapped with coir twine (not illustrated) to ensure that coir fiber block  12  maintains its shape. When the fiber block  12  is wrapped with twine, the fabric  14  need not surround the fiber block  12 , but may be connected to one edge of the fiber block  12  so that it extends from the fiber block to define an anchor portion between the fiber block and the fabric end  22 . Additionally, the twine used to weave fabric  14  may be made of coir fibers, other biodegradable fibers, or synthetic fibers, or the twine may be made with biodegradable fibers wrapped around a synthetic core. High strength coir fabric  14  wrapped on compressed coir fiber block  12  includes bottom fabric end  22  and top fabric end  24  (FIGS.  1 - 3 ) that extend freely from the back face  34  (facing the soil when installed) of the fiber block segment  10  (FIGS. 1 and 3). FIG. 4 is a cross sectional view of the fiber block illustrated in FIG. 1 taken alone line  4 - 4  of FIG. 3. Compressed coir fiber block  12  is secured to the high strength coir fabric  14 , for example by tying fabric  14  to coir fiber block  12  with coir twine  16  running up and down on the back face  34  of the fiber block segment  10  (FIGS. 1 and 3). High strength coir fabric  14  in fiber block segment  10  is preferably also woven out of coir twine  16 . At the male end  18  of the fiber block segment  10 , high strength coir fabric  14  is preferably wrapped only up to the end of the compressed coir fiber block  12  (FIGS. 1, 2 and  4 ). At the female end  20  of the fiber block segment  10 , high strength coir fabric  14  is preferably wrapped beyond the end of the compressed coir fiber block  12  creating a pouch like formation (FIGS. 1, 2 and  4 ).  
         [0038]    FIGS.  5 - 9  illustrate the use of the fiber block segments  10  to restore an eroded shoreline or waterway bank or protect a shoreline or waterway bank from erosion. A fiber block segment is placed on the shoreline or waterway bank with front face  32  of fiber block segment  10  facing water side  36  and back face  34  of fiber block segment  10  facing the bank side  38  (FIGS. 5 and 6). The bottom fabric end  22  extends away from water side  36  and wooden wedges  30  are driven through fabric  14  to keep fabric end  22  in place. Fabric  14  from coir fiber block  12  to fabric end  22  is covered with soil up to about the height of fiber block segment  10  and the soil is compacted. Fabric end  24  is extended away from water side  36  such that fabric  14  covers the compacted soil. Wooden wedges  30  can be driven through fabric  14  atop the compacted soil to secure top fabric end  24  in place. Because none of wooden wedges is exposed to or submerged under water, the buoyancy of wooden wedges  30  will not tend to work wooden wedges loose from their securing position.  
         [0039]    [0039]FIG. 5 illustrates a fiber block system constructed in three vertical layers of stacked fiber block segments  10  which results in a shoreline or waterway bank of a desired height. In this installation, multiple layers of fiber block segments  10  filled with soil are arranged to reconstruct the waterway bank. As shown in FIG. 5, a preferred slope angle of the bank is achieved by moving back each subsequent upper layer toward bank side  38 . Additionally, coir fiber blocks  12  can be stacked atop each other at a steeper angle than raw soil. Live plant cuttings  26  are planted on soil between layers of fiber block segments  10  and on the top layer of soil through the fabric  14  extending from the top fiber block segment  10  toward the fabric end  24  of this top fiber block segment  10 . FIG. 5 and FIG. 6 show use of wooden wedges  30  to maintain connections between fiber block segments  10  or between existing soil and fiber block segment  10 . Without wooden wedges  30 , fiber block segments  10  may tend to move away from their positions during soil filling. Once filling and compacting of soil is done on bottom fabric end  22 , cover it with top fabric end  24  the anchoring of the fiber block segment  10  is come from the weight of soil filled on its bottom fabric end  22 . This self-anchoring feature of installed fiber block segment  10  guarantees its stability and eliminates the extensive use of external anchors.  
         [0040]    [0040]FIG. 6 illustrates a fiber block system that includes one vertical layer of fiber block segments  10  to construct a shoreline or waterway bank of a shorter desired height. In this installation, live plant cuttings  26  and live plants  28  are inserted on the soil through the top fabric end  24  to help stabilize the soil on the bank above fiber block segment  10 . The use of fabric  14  on top of the soil also permits coir blocks  12  to be stacked atop each other at a steeper angle than for coir fiber blocks without fabric  14  connected to the top of coir fiber block  12 .  
         [0041]    [0041]FIGS. 7 and 8 illustrate how two fiber block segments  10   a  and  10   b  can be connected at the joint  42  to form a fiber block system  40  that can extend indefinitely and continuously along a shoreline or waterway bank. When connecting two fiber block segments  10   a  and  10   b  in the field, the male end  18  of fiber block segment  10   b  is mated with female end  20  of fiber block segment  10   a . For example, fiber block segment  10   b  can be moved in direction M to form a joint  42  with fiber block segment  10   a  in which fabric  14  of the fiber block segment  10   a  overlaps the coir block  12  and fabric  14  of fiber block segment  10   b . The fabric  14  from the face  34  to the bottom fabric end  22  of each fiber block segment  10   a  and  10   b  is covered with soil as described above. The pouch like formation in the female end  20  supports and holds inserted male end  18  in place and maintains the continuity of front face  32  and back face  34  of fiber block segment  10  without any separate connecting hardware. By repeating this procedure and adding inserting the male end  18  of a fiber block segment  10  into the exposed female end  20  of another fiber block segment  10 , a series of fiber block segments  10  can be installed easily along the entire desired length of the shoreline or waterway bank.  
         [0042]    [0042]FIG. 9 is a cross sectional side view of the installation of the fiber block system illustrated FIG. 5 several years after it was installed in a waterway bank. In time, grown plants  44  cover the bank and roots  46  of the grown plants  44  grow into the waterway bank or shoreline behind the coir fiber blocks  12 . These roots  46  may extend through the fiber block  12  and fabric  14  to hold the fiber block segments  10  in place and effectively contain and restrain the soil in the bank behind the fiber block segments  10 . By doing this, roots  46  hold fiber block segments  10  and so that the fiber block segments  10  protect the bank until they degrade (typically 5-10 years). By the time the biodegradable fiber block segments  10  have completely decayed, the mature grown plants  44  and roots  46  in the soil mass behind the fiber block segments  10  easily and naturally resist the erosive forces created by water flowing in a waterway or by wave action along a shoreline.  
         [0043]    [0043]FIGS. 10A, 10B and  10 C are perspective views of first, second, and third alternative embodiments respectively of the fiber block segment  10  according to the invention. As shown in these figures, compressed coir fiber block  12  is secured to the high strength coir fabric  14  by coir twine  16  extending across back face  34  and optionally extending across the male end  18  and/or the female end  20  of the fiber block segment  10 . These figures primarily illustrate differing weaving patterns for twine  16  that is used to tie fabric  14  to coir block  12 .  
         [0044]    [0044]FIG. 11A is a perspective view from the soil side of a fourth alternative embodiment of a fiber block segment  10  according to the invention. In this embodiment, top fabric end  24  extends only to back face  34  of the fiber block segment  10 . FIG. 11B is a cross sectional side view of application of fiber block segment  10  shown in FIG. 11A in a waterway bank. In this installation, fabric  14  from face  34  to bottom fabric end  22  is covered with soil to anchor the fabric  14  and thus fiber block segment  10  to the soil. Because top fabric end  24  does not extend past the edge of coir fiber block  12 , soil cannot be used to anchor the top edge of fiber block segment  10  shown in FIG. 11A. Wooden stakes  52  are driven into the soil adjacent front face  32  to support coir block  12  (with its relatively unrestrained top fabric end  24 ) from toppling toward the surface  52  of the water in stream bed  56 . However, wooden stakes  52  do not effectively anchor fiber block segments  10  to the soil. FIG. 11C illustrates how fiber block segment  10   a  can be connected to fiber block segment  10   b  to form a fiber block system  40 . The male end  18  of fiber block segment  10   b  is inserted to the female end  20  of fiber block segment  10   a  to form joint  42 . There is a slit left to permit the bottom portion of fabric  14  to pass through fabric  14  surrounding female end  20 . This arrangement of female end  20  enables fiber block segment  10   a  to mate with fiber block segment  10   b  without any twine tying the two segments to each other.  
         [0045]    [0045]FIG. 12A is a perspective view from the soil side of a fifth alternative embodiment of a fiber block segment  10  according to the invention. In this embodiment, fabric  14  is connected to the edge of coir block  12  defined by the top of coir block  12  and front face  32  (rather than the edge defined by the top of coir block  12  and back face  34 ). Thus, fabric  14  covering the top of coir block  12  is free to move away from the top of coir block  12 . This feature is achieved by tying fiber block  12  to the high strength coir fabric  14  at top of front face  32  and bottom of back face  34  using coir twine  16 . This embodiment is particularly suited for installation in which the soil on the bank above the topmost layer of fiber block segments  10  is angled (see, e.g., FIG. 12B illustrating a such an installation with a single layer of fiber block segments  10 ).  
         [0046]    [0046]FIG. 13A is a side view of a sixth alternative embodiment of a fiber block segment  10  according to the invention. In this embodiment, coir block  12  has an approximately circular cross section. FIG. 13B is a cross sectional view of FIG. 13A along the line of  13 B- 13 B of FIG. 13A. FIG. 13C is a side view of a seventh alternative embodiment of the fiber block segment  10  according to the invention. In this embodiment, shape of cross section in the fiber block  12  is circular and top fabric end  24  ends at the topmost point of the circular cross section of coir block  12 .  
         [0047]    Rectangular coir fiber block  12  of the fiber block segment  10  can be made, for example, in dimensions of 10 feet in length, 16 inches in height and 9 inches in thickness. It is also easily possible to vary these dimensions and change the size of the fiber block segment  10 . Each size could have its advantages according to application in the field. As described earlier, it is also possible to use circular block in different diameters in place of rectangular fiber block  12  to create the fiber block segment  10  explained in FIG. 13A, FIG. 13B and FIG. 13C.  
         [0048]    Other embodiments of the invention will be apparent to those skilled in the art from their consideration of the specification and practice of the invention disclosed in this document. The applicant intends that the specification and examples be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.