Abstract:
An erosion control barrier including a boom having a tube, formed of geotextile, that is filled with an absorbent batting. An aboveground wing, formed of geotextile, is affixed to the tube and extends along the length of the tube. The top of the aboveground wing projects above the top of the boom and is provided with a pocket. A ground-penetrating post is positioned adjacent the boom. The top of the post is inserted into the pocket for supporting the top of the aboveground wing.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to hydraulic and earth engineering and, more particularly, to apparatus for bank, shore, or bed protection purposes. 
       BACKGROUND OF THE INVENTION 
       [0002]    Soil erosion has occurred since landmasses formed upon the earth. Prior to the industrial revolution, forests and grasses covered most of the land and protected the soil under layers of leaf litter. Erosion proceeded at a relatively slow rate and was hardly noticed by man. 
         [0003]    Accompanying widespread settlement over the last few centuries came a need to dwell upon, and derive other benefits from, large swaths of land. People purposefully removed trees, shrubs, and grasses from selected areas first to establish farms and villages and, then, to construct cities, factories, roadways, utility right-of-ways, mines, and residential subdivisions. This removal of vegetation has permitted storm runoff to erode soil more quickly and noticeably. 
         [0004]    The erosion of soil scars the landscape. Topsoil lost from an area may have taken centuries to develop and can be exceedingly costly to replace. Eroded soil loses its ability to retain precipitation, resulting in faster runoff and flooding. Roadways, bridges and other structures can wash out due to flooding and undercutting. Vegetation also withers and dies. 
         [0005]    Eroded sediment can be damaging too. It clogs storm water drainage systems. Also, it pollutes rivers and streams, choking aquatic life and increasing water purification costs. Finally, it can diminish the aesthetic quality of the environment. 
         [0006]    Around construction sites and new developments, temporary barriers are often employed to control erosion and contain sediment. A silt fence is one such barrier that is installed below a small disturbed area, or at the toe of a slope, to catch sediment. A silt fence is normally used where: 1) there are no water channels draining toward the fence, 2) erosion will occur with runoff moving as a sheet over the soil, 3) protection of a property line or other boundary is required, and 4) the length of the slope above the fence is less than 100 feet and the grade is less than 25 percent. 
         [0007]    A typical silt fence includes a sheet of cloth stapled to a series of fence posts driven into the ground. The cloth is a sheet of geotextile woven from filaments or yarns of polypropylene, polyethylene, polyester, polyamide or polyvinylidene-chloride—materials resistant to rot, mildew, insects and rodents. The fence posts, however, are wooden strips that are normally 48 inches long and have a nominal diameter of two inches. 
         [0008]    Constructing a silt fence is straightforward. First, fence posts are driven 24 inches into the soil, no more than  6  feet apart, along a line where the fence is to be established. Then, a trench about 18 inches deep is excavated immediately upslope of the posts along the line of the fence. Next, the fence cloth is stapled to the posts allowing for a downward extension to the bottom of the trench and an upward extension to a point proximate the tops of the posts. Finally, the trench is backfilled with soil and the backfill is compacted to secure the bottom of the cloth within the trench. 
         [0009]    Properly constructed silt fences are known to fail at a high rate and require close inspection after every rain event. A “blowout” occurs when high runoff volumes topple a fence post, and the fence cloth attached to it, so that runoff can move over the fence cloth and downslope in an uncontrolled, erosive fashion. More common, however, is a “washout” caused by the poor compaction of backfill within a trench that permits runoff to pass beneath the fence cloth that, itself, is pushed from the trench. With either mode of failure, costly replacement of the entire fence may be the only way to prevent unchecked runoff flows. 
       SUMMARY OF THE INVENTION 
       [0010]    In light of the problems associated with conventional silt fences, it is a principal object of the invention to provide an erosion control barrier that minimizes the possibility of blowouts and washouts and the resulting, uncontrolled flow of sediment downslope from an excavated area. 
         [0011]    It is another object of the invention to provide an erosion control barrier of the type described that filters particulates from runoff passing through the barrier. 
         [0012]    It is a further object of the invention to provide an erosion control barrier of the type described that can be easily set up and taken down in the field. The work can be performed by individuals with minimal training and a few basic tools. 
         [0013]    It is an object of the invention to provide improved features and arrangements thereof in an erosion control barrier for the purposes described that is relatively lightweight in construction, inexpensive to manufacture, and dependable in use. 
         [0014]    Briefly, the erosion control barrier in accordance with this invention achieves the intended objects by featuring a boom having a tube, formed of geotextile, that is filled with an absorbent batting. An aboveground wing, formed of geotextile, is affixed to the tube and extends along the length of the tube. The top of the aboveground wing projects above the top of the boom and is provided with a pocket. An underground wing, formed of geotextile, is affixed to the tube and extends along the length of the tube. The bottom of the underground wing projects below the bottom of the boom. A ground-penetrating post is positioned adjacent the boom. The top of the post is inserted into the pocket for supporting the top of the aboveground wing. 
         [0015]    The foregoing and other objects, features, and advantages of the present invention will become readily apparent upon further review of the following detailed description of the preferred embodiments as illustrated in the accompanying drawings. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    The present invention can be more readily described with reference to the accompanying drawings, in which: 
           [0017]      FIG. 1  is an isometric view of an erosion control barrier in accordance with the present invention with portions broken away to reveal details thereof. 
           [0018]      FIG. 2  is an isometric view of an alternative erosion control barrier in accordance with the present invention with portions broken away to reveal details thereof. 
       
    
    
       [0019]    Similar reference characters denote corresponding features consistently throughout the accompanying drawings. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0020]    Referring now to  FIG. 1 , an erosion control barrier in accordance with the present invention is shown at  10 . Barrier  10  includes an elongated boom  12  anchored by posts as at  14  driven into the ground  16 . Extending upwardly from boom  12  is an aboveground wing  18  that traps runoff that may spill over boom  12 . Extending downwardly from boom  12 , however, is an underground wing  20  that prevents runoff from passing beneath boom  12 . 
         [0021]    The principal features of barrier  10  are made by folding and stitching a rectangular sheet of cloth  22 . As shown, the top of cloth sheet  22  is folded upon itself and stitched along the length of the overlapping parts by a plurality of laterally spaced seams  24  so as to produce a hem  26  whose interior is accessed through pockets or openings  28  provided by gaps between seams  24 . Sheet  22  is also folded a second time and stitched to produce a tube  30  spaced from, and parallel to, hem  26  and a pair of wings  18  and  20  extending outwardly from tube  30 . Tube  30  has a circumference approximately equal to one-half of the width of sheet  22 . Each of wings  18  and  20  has a width of about one-fourth that of the width of sheet  22 . 
         [0022]    Cloth sheet  22  is a woven geotextile, permeable to air and water, that measures about 20 feet by 5 feet. After folding and stitching, hem  26  has a width of 3 to 5 inches. Pockets  28 , providing access into hem  26 , are spaced about 5 feet apart and are about 3 inches across. Tube  30  has a diameter of 10 inches, but flattens somewhat when positioned on the ground  16 , whereas wings  18  and  20  measure of about 12 inches and 10 inches in width, respectively. Of course, the dimensions of all features of barrier  10  are a matter of design choice and are subject to be changed by manufacture to the conditions presented by a particular working environment. 
         [0023]    Tube  30  is filled with an absorbent batting  32 . Preferably, batting  32  comprises a shredded hardwood mulch of the sort that can be found in garden centers. Nonetheless, batting  32  could comprise, by way of example only, materials like: straw, pine needles, pine bark, dried leaves, nut hulls, and natural or synthetic sponges. After filling, the open ends of tube  30  are stitched closed by seams  34  to prevent the loss of batting  32  thereby completing boom  12 . For convenience sake, one of seams  34  can be sewn in a factory by a manufacturer leaving the other to be sewn in the field so that a user can fill tube  30  with batting  32  at the point of use. 
         [0024]    The use of barrier  10  is different from that of a conventional silt fence. First, a 1-foot deep trench  36  is dug in the ground  16  along a line where barrier  10  is to be installed. Then, sheet  22  is unfolded or unrolled at a location where barrier  10  is to be used, i.e., the toe of a hill where erosion is likely to occur. Next, tube  30  is manually filled with batting  32  and any open ends of tube  30  are stitched closed by applying seam(s)  34  with a needle and suitable cording completing boom  12 . If desired, the open end(s) of tube  30  can be closed by other means such as: staples, hook and loop material, snap fasteners, and buckles. 
         [0025]    Boom  12  is placed on the ground  16  on the downslope side of trench  36  and wing  20  is draped into trench  36 . Then, trench  36  is backfilled and the backfill is thoroughly tamped and compressed to anchor wing  20  within the ground  16 . Boom  12  is now rolled atop backfilled trench  36 . With batting  32  being normally loose, boom  12  is permitted to flatten, conform to contours of the ground  16 , and establish a large area of contact with the ground  16 . 
         [0026]    By using the positions of pockets  28  in aboveground wing  18  as a guide, posts  14  are driven, at spaced intervals, vertically into the ground  16  adjacent trench  36  so that the tops of posts  14  extend aboveground. Now, wing  18  is hung upon posts  14  by inserting the tops of posts  14  into pockets  28 . Finally, staples  38  are driven through wing  18  to affix such to each of posts  14 . Barrier  10  is now ready to trap sediment washed downslope during the next rain event. 
         [0027]    Should light precipitation happen to fall on the ground  16 , barrier  10  is ready. Minor amounts of sheet wash that make their way to barrier  10  permeate through the woven mesh of geotextile cloth sheet  22  forming tube  30  and are absorbed by batting  32 . Subsequent evaporation releases the moisture absorbed by batting  32  into the atmosphere, precluding the possibility of erosion and sediment transport immediately downslope of barrier  10 . 
         [0028]    Significant runoff volumes are handled well by barrier  10 . During occurrences of high runoff, moisture is initially absorbed by batting  32  that swells, becomes heavier, and more firmly seats boom  12  upon the ground  16 . As more runoff makes its way to barrier  10  and batting  32  becomes saturated, runoff will filter through boom  12  and wings  18  and  20 . The filtrate drains from barrier  10  on its downslope side leaving behind substantially more sediment than could be trapped by a conventional silt fence. Of course, the actual amount of material filtered from runoff by boom  12  will depend upon the characteristics of both sheet  22  and batting  32  as well as the sediment-laden runoff; so, generalizations regarding filtration rates are difficult to make. 
         [0029]    Should runoff volumes become so great that boom  12  is overflowed, aboveground wing  18  impounds the overflow and diverts such back into boom  12 . Some runoff will pass through aboveground wing  18 , but much of the sediment carried thereby, particularly the larger particulates, will be trapped against the upslope side of wing  18 . Because of the firm connection between the top of wing  18  and posts  14  afforded by pockets  28 , wing  18  is unlikely to sag appreciably under the heaviest of loads thereby minimizing the likelihood of blowouts. 
         [0030]    The significant weight of boom  12  when batting  32  is saturated firmly anchors boom  12  to the ground  16  and reduces the likelihood of washouts wherein runoff channels beneath boom  12 . Underground wing  20  further ensures against washouts by preventing the significant flow beneath boom  12  altogether. Thus, with barrier  10  in place, the control of erosion from a disturbed area is maximized. The amount of time and effort that would otherwise be used to inspect, repair, or replace a silt fence replaced by barrier  10  is minimized. 
         [0031]    While barrier  10  has been described with a high degree of particularity, it will be appreciated by those skilled in the art that modifications can be made to it. For example, as illustrated in  FIG. 2 , a barrier  110  can be constructed that is similar to barrier  10  except that it lacks a belowground wing  20 . Thus, barrier  110  is made by folding and stitching a cloth sheet  122  to form an aboveground wing  118  having a hem  126  with pockets  128  at the top thereof and a tube  130  at the bottom thereof. Tube  130  is filled with an absorbent batting  132  to form a boom  112 . The opposite ends of tube  130  are stitched closed to prevent the loss of batting  132 . Posts  114  driven into the ground  116  hold boom  112  in place. Staples  138  fasten wing to posts  114 . No trenching is required to set up and use barrier  110  that lends itself to use in drier environments where washouts beneath boom  112  are unlikely. Thus, the use of barrier  110  can provide cost savings in some settings. Therefore, it is to be understood that the present invention is not limited to the pair of embodiments described above, but encompasses any and all embodiments within the scope of the following claims.