Abstract:
A soil stabilization system comprised of recent courses of soil bags woven and/or intertwined with geogrid and soil stabilization bodies pierce the soil stabilization bodies and protrusions on sides which protrude into the soil bags of the adjacent courses. Protrusions on the soil stabilization bodies shall protrude through holes in the geogrid to help anchor the soil bags relative to each other.

Description:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0001]    Not applicable. 
       FIELD OF THE INVENTION 
       [0002]    The present invention pertains to woven soil stabilization systems and methods of constructing soil stabilization systems. In particular, it pertains to soil stabilization systems comprised of soil bags interfaced with geogrid materials. 
       BACKGROUND OF THE INVENTION 
       [0003]    It is known to build retaining walls, containment systems, levies and/or other similar structures using soil bags. Often, soil bags in retaining walls are not affixed to each other. Rather, gravity and friction are often relied upon to help hold soil bags in place. It is also known to use an impervious plate having a plurality of spikes protruding therefrom to hold soil bags in place, and to anchor sheets of geogrid material extending from between courses of soil bags into the fill retained by the soil bag wall. Such plate is positioned on top of a first layer of soil bags, and then a second layer of soil bags is placed thereupon. Accordingly, the spikes, which generally extend from the top and the bottom of the plate, puncture the vertically and horizontally adjacent soil bags in contact with those spikes to help hold the soil bags in place. Such plates may also have projections to protrude through holes in the geogrid sheet to anchor the soil bag wall to the reinforced soil structure. 
         [0004]    While gravity, friction and the known plates may initially hold soil bags in place, the soil bags may shift and move over time. In particular, impervious plates serve as a barrier to water and plant growth that might otherwise drain and grow through the soil bags. For example, such plates prevent plant growth from penetrating the soil bags to help lock them into place. As such, a retaining wall structure incorporating the known plates may be prone to deteriorate more quickly. Further, such plates are not recommended for use with soil bags comprised of material that may degrade or decompose over time as the material comprising the soil bags is needed to help retain particles in the soil bags and otherwise stabilize the structure incorporating the soil bags. 
         [0005]    Thus, there is a long felt need for an improved system that may be used to help hold soil bags in place and otherwise strengthen a retaining wall, containment system, levy and/or other similar structure. In addition, there is a need for a system with components that may be easily penetrated by roots and water to support plant growth between soil bags. 
       SUMMARY 
       [0006]    The present invention provides an improved system and method for stabilizing and securing a retaining wall or similar structure, comprising an interwoven system of soil bags and geogrid weaver strips. 
         [0007]    The present invention overcomes the aforementioned drawbacks by providing an improved system for stabilizing a retaining wall comprising soil bags. 
         [0008]    It is one aspect of the present invention to provide an apparatus and system having a plurality of passages therethrough to facilitate the draining of water and growth of plants through and between soil bags to improve the overall strength of a retaining wall or similar structure. 
         [0009]    It is yet another aspect of the present invention to provide a system that may be successfully used with soil bags comprising a degradable or decomposable material. 
         [0010]    In accordance with one aspect of the invention, a system is disclosed that comprises at least one geogrid weaver strip that may be woven or twined between a plurality of soil bags to bind the soil bags together as a unit. 
         [0011]    This Summary is neither intended nor should it be construed as being representative of the full extent and scope of the present invention. The present invention is set forth in various levels of detail in the Summary as well as in the attached drawings and the detailed description of the exemplary embodiments, and no limitation as to the scope of the present invention is intended by either the inclusion or non-inclusion of the elements, components, etc., in this Summary. Additional aspects, features and advantages of the present invention will become more readily apparent from the Detailed Description of Embodiments, particularly when taken together with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0012]    The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the general description of the invention given above and the detailed description of the drawings given below, serve to explain the principles of these inventions. 
           [0013]      FIG. 1  is a perspective view of an exemplary embodiment of a soil stabilization system. 
           [0014]      FIG. 2  is a perspective view of an exemplary embodiment of a soil stabilization system. 
           [0015]      FIG. 3  is a is a plan view of an exemplary embodiment of a geogrid strip. 
           [0016]      FIG. 4  is a perspective view of an exemplary embodiment of a soil stabilization body. 
           [0017]      FIG. 5  is a side view of an exemplary embodiment of a soil stabilization body. 
           [0018]      FIGS. 6(   a )- 6 ( p ) illustrate various exemplary methods for constructing exemplary embodiments of a soil stabilization system. 
       
    
    
       [0019]    It should be understood that the drawings are not necessarily to scale. In certain instances, details which are not necessary for understanding the invention and/or which render other details difficult to perceive may have been omitted. In some drawings, soil bags which are normally positioned closely adjacent to each other are shown in spaced relation to facilitate a description and understanding of the weaving method employed. It should be understood, of course, the invention is not necessarily limited to the particular embodiments illustrated herein. 
       DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0020]    Referring to  FIGS. 1-2 , in one embodiment the soil stabilization system  100  comprises a plurality of generally horizontally-laid courses of soil bags  120  which form a soil retainer wall, each course being arranged substantially vertically relative to the others. As shown in  FIG. 1 , the soil stabilization system  100  may also be substantially sloped if desired. In one exemplary embodiment, the soil stabilization system  100  may be stepped back at a 2 to 1 slope, wherein each succeeding course of bags is set back from the front of the underlying course of bags a horizontal distance of approximately one half the vertical thickness of the filled soil bags. 
         [0021]    In the specification, “soil bag”  120  means a cover filled with any suitable fill material, including sand, soil, and mixtures thereof, and may also include fill mixed with seeds for grass or other plants. It is contemplated that the covers of the soil bags  120  may be formed from a variety of materials or combinations of such materials. In accordance with one embodiment, the covers of the soil bags  120  are comprised of needle-punch non-woven fabric such that, as will be described, plants may grow through the soil bags  120  and/or holes formed in at least the covers of the soil bags  120 . For example, the covers of the soil bags  120  may be a polypropylene, staple fiber, needle-punched, or non-woven geotextile. In one embodiment, the covers of the soil bags  120  may be comprised of woven fabric that allows plant growth to grow through the soil bags  120  and/or holes formed in the covers of the soil bags  120 , and may also ultimately decompose over time. The covers of the soil bags  120  may also comprise any other materials or combination of materials that will decompose or otherwise degrade over time. 
         [0022]    The soil bags  120  and/or the fill material may include seeds that, after formation of the soil stabilization system  100  will produce plant growth  160 . In the specification, “plant growth” means any portion of any type of plant or plants, including portions such as roots and crowns of a plant or plants. A wide variety of seeds may be used to create various plant growth  160  from any number of types of plants including wild flowers, legumes, grasses, sedges and woody plants with extensive root structures. In one exemplary embodiment, indigenous plants and plant growth may be used. In one embodiment, as the plant growth matures, the plant growth extends through the soil bags  120 , and even into the ground or other surface below the soil stabilization system  100 , to reinforce the soil. 
         [0023]    The soil stabilization system  100  further comprises at least one geogrid weaving strip  130  and/or geogrid twining strip  140 . In one embodiment, at least one geogrid weaving strip  130  is woven longitudinally between courses of soil bags of the soil stabilization system  100 . In one embodiment, at least one geogrid twining strip  140  is twined between courses of soil bags  120  in at least one of a substantially vertical and a substantially lateral direction relative to the soil stabilization system  100 . As will be shown below, the soil stabilization may advantageously comprise various combinations of soil bags and geogrid weaving and twining strips to hold the bags in a desired way. Because the soil stabilization system  100  utilizes plant growth and/or at least one geogrid strip  130 / 140 , one or more of the soil bags  120  used in forming the soil stabilization system  100  may comprise biodegradable, photo degradable, or otherwise decomposable material without substantially compromising the durability of the soil stabilization system  100 . As will be discussed in greater detail below, the soil stabilization system  100  may also comprise soil stabilizer bodies (not shown in  FIGS. 1-2 ) to help hold the soil bags  120  and/or and geogrid strips  130 / 140  in a desired position. 
         [0024]    Geogrid material is known and commercially available as plastic mesh sheet products commonly used for soil reinforcement. Conventional geogrid material is typically sold in roll of material having a sheet width of 12 to 14 feet, and such sheets are cut to desired lengths from a roll and embedded in soil and various applications to reinforce the soil and resist erosion thereof.  FIG. 3  shows a modified geogrid material according to the present invention, wherein strips of material are specially fabricated in their desired widths for the purpose of weaving the strips around and between soil bags to anchor and retain the soil bags in position within a retaining wall or other soil retaining structure constructed of soil bags. While the overall length and width of each geogrid strip of the present invention may vary for various soil bag stabilization systems according to the present invention, the geogrid strips  130 / 140  are generally narrow in width to allow the strips to be wrapped under, over, around and between individual soil bags in a wall or other structure to lock or anchor the soil bags in position within an integrated wall structure wherein the individual soil bags and geogrid strips woven there through are held together by the combined action of the soil bags and woven geogrid material. Typically, the width of the weaving strips will be less than the width of the soil bags with which the strips will be used. In one embodiment, each geogrid strip  130 / 140  is between 2 inches and 6 inches in width and between 50 feet and 250 feet in length. In one embodiment, each geogrid strip  130 / 140  is approximately 4 inches in width and 100 feet in length. The only limits on the desired length of the strips are the size of the rolls produced, and the ease and economy of working with several rolls on a job to facilitate use by several workers on the same job. 
         [0025]    Referring to  FIGS. 4-5 , a perspective view and a side view of an exemplary embodiment of a soil stabilizer body  150  of the present invention are shown. As shown in  FIG. 4 , in one exemplary embodiment, the soil stabilizer body  150  includes a circular-shaped outer frame  160 ; however, it is contemplated that the outer frame  160  may be formed in any of a variety of geometric shapes, including, without limitation, a trapezoid, rectangle, polygon, circle and/or oval. 
         [0026]    In one embodiment, a plurality of truss members  170  extend within the margin of the outer frame  160  to provide additional structural support to the soil stabilizer body  150 . In one embodiment, a plurality of truss members  170  extend from the margin of the outer frame  160  to form a transverse web. 
         [0027]    In one embodiment, the soil stabilization body  150  comprises at least one inner frame  190  interconnected to the truss members  170 . Each truss member  170  and the inner frame  190  and outer frame  160  define, at least in part, a plurality of passages within the margins of the outer frame  160 . While the truss members  170 , inner frame  190  and outer frame  160  are shown in  FIG. 4  as having a rectangular cross section, the truss members may be tubular, rectangular, or take other cross-sectional forms. 
         [0028]    As shown in  FIG. 4 , in one embodiment, the collective passages are relatively large with respect to the overall structure of the soil stabilizer body  150 . For example, in various embodiments, it is contemplated that the collective passages may cover or otherwise comprise from 30% of the soil stabilizer body  150  up to and including 80% or more of the soil stabilizer body  150 . Thus, the frame and truss members of the body  150  are adapted to bear against the outer surface of a soil bag, while permitting moisture and the roots of vegetation to freely pass through the body members and into the soil bags. 
         [0029]    In one embodiment, the soil stabilization body  150  includes a protruding member  180  extending from each side of the body. Each protruding member  180  may be of any shape or rigidity suitable for protruding spike-like into a soil bag. At least one of the distal ends of at least one protruding member  180  is generally tapered. In one embodiment, at least one of the distal ends of at least one protruding member  180  is substantially pointed, such as a spike or cleat. In the embodiment shown in  FIGS. 4 and 5  the protruding members each comprise a plurality of radiating longitudinal ribs which resist twisting of the soil stabilization body  150  when the protruding members  180  are embedded in a soil bag. 
         [0030]    It is contemplated that the soil stabilizer body  150  may be formed from a variety of materials or combinations of materials. For example, a soil stabilizer body  150  may be formed from plastic material. Additionally, the soil stabilizer body  150  may be formed from a biodegradable and/or photo-degradable material. For example, the soil stabilizer body  150  may be formed from a “green plastic,” such as corn starch polymer, wheat germ polymer, or other similar materials that eventually decompose to an organic material. 
         [0031]      FIGS. 6(   a )- 6 ( p ) illustrate steps in an exemplary method for constructing a soil stabilization system  100  according to the present invention. In one embodiment, ground  300  or other surface is suitably prepared as needed or desired for construction of a soil stabilization system  100 . For example, the ground  300  may be suitably prepared with a leveling pad or a concrete footing in order to support the retaining wall. Such ground  300  and/or surface preparation is conventional in the building of retaining walls. 
         [0032]    Referring to  FIG. 6(   a ), in one embodiment, at least one geogrid weaving strip  130  is placed on the ground  300  or other surface along the length of the soil stabilization system  100 . In one exemplary embodiment, soil bags  120  are placed substantially above the geogrid weaving strip  130  at a first end of the soil stabilization system  100 , and at a second end of the soil stabilization system  100 , leaving a strip weaving end  210  at the first end of the soil stabilization system  100  and a strip remainder  220  at the second end of the soil stabilization system  100 . Referring to  FIG. 6(   b ), in one embodiment, a first plurality of soil bags  120  are then placed adjacent to each other on the geogrid weaving strip  130  between the soil bags  120  placed at the first and second ends of the soil stabilization system  100  to form a first course  230  of soil bags  120 . While the individual bags appear to be slightly separated in  FIGS. 6(   a )- 6 ( p ), for ease of illustration and understanding, it should be understood that the bags in the soil stabilization system of the present invention will normally be in tight abutment with each other and tamped in a known manner to provide a substantially continuous barrier wall to contain and stabilize soil fill  400  or other structure existing or to be placed behind the wall. Each soil bag  120  may have a seam running the length of one side of the soil bag  120 . In one or more exemplary embodiments, one or more soil bags  120  will be oriented in the soil stabilization system  100  seam side out to facilitate location of seeds for promoting plant growth, which seeds may be placed by hydroseeding of the finished wall. In one embodiment, the remainder  220  is wrapped around at least a portion of the soil bag  120  placed at the second end and over a portion of the first course  230  of soil bags  120  as shown in  FIGS. 6(   b )- 6 ( d ). In  FIGS. 6(   c )- 6 ( d ), the weaving end  210  is wrapped at least partially around the soil bag  120  placed at the first end of the soil stabilization system  100  and over at least a portion of the first course  230 . It should be noted that the weaving end  210  may be wrapped at least partially around at least one soil bag  120  located between the first and second ends, if so desired. 
         [0033]    Referring to  FIGS. 6(   e )- 6 ( f ), in one embodiment, at least one geogrid twining strip  140  will be placed substantially cross-wise to the weaving strip  130  and under at least one of the plurality of soil bags  120  forming the first course  230 . The geogrid twining strips  140  may be oriented generally perpendicular to at least one of the longitudinal axes of the soil stabilization system  100  and the longitudinal axis of an overlying soil bag  120 . The geogrid twining strips  140  may be positioned such that there is at least one twining end  250  left uncovered by the overlying soil bag  120 . A twining remainder  260  may also remain uncovered by the soil bag, and may extend under the back fill (not shown) to be brought in and retained behind the soil bag wall being formed, or may be used for vertical double twining of the upwardly placed bags in the wall as shown in  FIG. 6(   o ). 
         [0034]    In one embodiment, the twining end  250  is wrapped around a side of a soil bag  120  and over the top of the soil bag  120 . In one embodiment, the twining end  250  will be wrapped directly over a soil bag  120  and under a geogrid weaving strip  130 . In one embodiment, the twining end  250  is wrapped around and over the soil bag  120  and the geogrid weaving strip  130  atop that soil bag. 
         [0035]    While gaps are shown between soil bags  120  in  FIGS. 6(   a )- 6 ( p ), the gaps are shown for ease of illustration. In various embodiments, the soil bags  120  will commonly be placed together tightly. Further, the geogrid weaving strips  230  and geogrid twining strips  240  should be woven and twined, respectively, quite tightly to the soil bags  120  and/or soil stabilization system  100 . 
         [0036]    For example, as shown in  FIGS. 6(   c ),  6 ( h ),  6 ( k ),  6 ( l ) and  6 ( n ), as various courses are added, at least one soil bag  120  in each course may be pulled out from underneath the geogrid weaving strip  130  and re-placed in substantially the same location above the geogrid weaving strip  130  to help cinch and tighten the geogrid weaving strip  130  within and over that course and otherwise anchor it within the soil stabilization system  100 . Depending upon the length of each course of bags and the number of bags in each course, every third or fourth bag  120  in a course may be pulled from beneath the weaving strip  130  and replaced over the weaving strip back between the adjacent bags in its original position. 
         [0037]    Referring to  FIGS. 6(   g )- 6 ( h ), in one embodiment, a second plurality of soil bags  120  are placed substantially above the first course  230  and at least one of the geogrid weaving strip  130  and geogrid twining strip  140  to form a second course  240  having a first end and a second end. In one embodiment, the weaving end  210  is wrapped around and over the soil bag  120  placed substantially at the second end of the second course  240  of the soil stabilization system  100  and over at least a portion of the second course  240 .  FIGS. 6(   g )- 6 ( a ) also show that it is advantageous to employ soil bags tied at the one-half full level at one end of a course of bags so that as the wall goes up, the bags will be staggered in brick-like fashion so that the full bags of each course rest upon each of two bags of the previous course. Alternatively, a full bag can be turned 90° at the end of a course to simulate a half full bag and maintain the overlapping positioning of the full bags. 
         [0038]    As shown in  FIG. 6(   i ), in one embodiment, the twining end  250  of at least one geogrid twining strip  140  is wrapped at least partially around and over a soil bag  120 . In one embodiment, the twining end  250  may be wrapped directly over a soil bag  120  and under the geogrid weaving strip  130  substantially atop the second course of soil bags  120 . In one embodiment, the twining end  250  is wrapped around and over the soil bag  120  and the geogrid weaving strip  130  above that soil bag  120 . As further shown in  FIGS. 6(   i ),  6 ( j ),  6 ( m ) and  6 ( p ), the twining strip  140  may alternately pass around a single bag, then the end portion of the two bags lying on the single bag, and then a single bag lying on the two bags, and so on to bind the courses of bags together as a single unit. The twining strip  140  may be located at any point or points along the soil bag wall and bind any portions of the bags lying in a vertical path upwardly from such point in a single twined or double twined manner. 
         [0039]    In an exemplary embodiment, the soil bags  120  of the second course  240  should be positioned such that each soil bag  120  comprising the second course  240  of soil bags  120  is placed on top of two soil bags  120  in the first course  230  in any staggered manner. In such an embodiment, completion of the second course  240  may require utilization of a less than a full soil bag  120  or lateral orientation of at least one soil bag  120 . 
         [0040]    As shown in  FIG. 6(   i ), in one embodiment, one or more soil stabilizer bodies  150  may also be used in connection with the soil stabilization system  100 . In one exemplary embodiment, a plurality of soil stabilizer bodies  150  are placed over the geogrid strips  130 / 140  positioned above the soil bags  120  with the protrusions protruding down through holes in the geogrid strips  130 / 140  into the soil bags  120 . In one embodiment, the soil stabilizer bodies  150  may also be placed directly on top of soil bags  120  and the geogrid strips  130 / 140  may then be placed on top of the soil stabilizer bodies  150  and soil bags  120  so that the protruding member of the soil stabilizer body  150  protrudes through holes in the geogrid strips  130 / 140 . In one embodiment, when a second course  240  of soil bags  120  is put atop a first course of soil bags  120 , protruding members of the soil stabilizer body  150  will extend both into the underside of the second course  240  and through the geogrid strips  130 / 140  and into the top of the soil bags  120  in that first course  230 . The soil stabilizer bodies  150  may advantageously be placed, two on a bag, so that the bags of the next course, placed across the abutting ends of two bags in overlapping position, will each be engaged by two stabilizer bodies  150 , one projecting upward from each underlying overlapped bag. 
         [0041]    Throughout the construction of the soil stabilization system  100 , one or more soil bags  120  may advantageously be tamped down in a conventional manner to help compact the soil bags  120  and/or help one or more soil stabilizer bodies  150  in contact with the soil bags  120  to be pierced by a protruding member of the soil stabilizer body  150 . 
         [0042]    As shown in  FIGS. 6(   k )- 6 ( p ), construction of the wall may be continued in the same or similar manner until a soil stabilization system  100  of the required dimensions is completed. For example, additional courses may be added. During the construction of the soil stabilization system  100 , it may be necessary or desirable to utilize multiple geogrid weaving strips  130  and/or geogrid twining strips  140  during construction of the soil stabilization system  100 . Geogrid strips  130 / 140  may be tied together to lengthen the strips to allow completion of the soil stabilization system  100 . In another embodiment, the ends of the geogrid strips  130 / 140  may be wrapped around one or more soil bags  120  to help lock the geogrid strips  130 / 140  into place. In one embodiment, soil stabilization bodies  150  may be used to help anchor one or more geogrid strips  130 / 140  to the soil stabilization system  100  and to each other as desired. 
         [0043]    In one embodiment, as discussed above, the soil bags  120  may contain a variety of seeds for vegetating at least a portion of the soil stabilization system  100 . To expedite the vegetation process, more mature vegetation  160  may be planted in the soil bags comprising the soil stabilization system  100 . Any combination of native plants, plugs, sod and seed may be so implanted. To implant the plants, plugs, sod and/or seed, one or more of the soil bags comprising the soil stabilization system  100  should be hydrated. In one exemplary embodiment, each soil bag is thoroughly soaked with water. By hydrating soil bags of the soil stabilization system  100 , the material comprising the soil bags may be punctured with minimal loss of soil and other soil bag content. 
         [0044]    In one embodiment, any number of soil bags may be punctured where native plugs are to be inserted. One or more plugs may be inserted into each soil bag. In one exemplary embodiment, three native plugs are inserted into the top front face of a plurality of soil bags. The plugs may be pushed deeply into the soil bag until the soil bag fabric closes over the top of the soil core of the plug, leaving only the crown of the plug exposed. In one embodiment, the soil bag is tamped closely around the throat of the plug after insertion of the plug into the soil bag. 
         [0045]    Plants, sod and/or seed may also be inserted between soil bags. In one exemplary embodiment, plants, sod and/or seed may be planted substantially where three soil bags meet and more specifically where two soil bags meet atop a soil bag of an underlying course. Flats made of sod may also be graded into the soil stabilization system  100 . In one embodiment, sod may be cut into strips and added between the soil bags and the outside of the soil bags as desired. 
         [0046]    Vegetation of the soil stabilization system may be continued in the same manner, as desired. After the soil stabilization system is vegetated, the soil stabilization system may be watered immediately to help insure that vegetation  160  is hydrated. 
         [0047]    The soil stabilization system  100  of the invention, consisting in combination of soil bags  120 , interwoven geogrid weaving and twining strips  130 / 140 , soil stabilizer bodies  150  and fibrous vegetation  160 , or selected ones thereof, effectively provides a uniform wall or other soil stabilization structure which will stabilize soil or fill material  400  retained behind the structure to minimize soil erosion in a substantially permanent manner, with the capability of becoming stronger and more securely bound together as the fibrous vegetation grows and matures. 
         [0048]    While various embodiments of the present invention have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications within the scope and spirit of the present invention, as set forth in the following claims.