Erosion control barrier

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

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

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.

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.

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.

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.

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.

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.

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.

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

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.

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.

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.

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.

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.

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

The present invention can be more readily described with reference to the accompanying drawings, in which:

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.

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.

Similar reference characters denote corresponding features consistently throughout the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Claims

1. An erosion control barrier, comprising:

a boom having a tube, formed of geotextile, being filled with an absorbent batting;

an aboveground wing, formed of geotextile, being affixed to said tube and extending along the length of said tube, the top of said aboveground wing projecting above the top of said boom and being provided with a pocket; and,

a ground-penetrating post being positioned adjacent said boom, the top of said post being inserted into said pocket for supporting the top of said aboveground wing.

2. The erosion control barrier according to claim 1 further comprising an underground wing, formed of geotextile, being affixed to said tube and extending along the length of said tube, the bottom of said underground wing projecting below the bottom of said boom.

3. An erosion control barrier, comprising:

a boom having a tube, formed of geotextile, being filled with an absorbent batting;

an aboveground wing, formed of geotextile, being affixed to said tube and extending along the length of said tube, the top of said aboveground wing projecting above the top of said boom and being provided with a pocket;

an underground wing, formed of geotextile, being affixed to said tube and extending along the length of said tube, the bottom of said underground wing projecting below the bottom of said boom; and,

a ground-penetrating post being positioned adjacent said boom, the top of said post being inserted into said pocket for supporting the top of said aboveground wing.