TECHNICAL FIELD OF THE INVENTION
The invention pertains to the art of erosion control. In particular, it pertains to erosion-control elements and structures which include attached sandbags and are suitable for use along shorelines and on sloping ground, including underwater uses.
BACKGROUND OF THE INVENTION
Erosion-control structures are commonly constructed using poured concrete or blocks that are affixed together with concrete. For underwater erosion-control applications, permanent rock covers such as riprap and gabions are used on streambanks and other shoreline areas. All such structures are costly to construct in view of the materials and labour required.
A recent development that has been made in the art of erosion control is to provide construction elements made of sandbags connected together with cords. Such erosion-control elements can be positioned on underwater shoreline areas. WO 2007/028228 A1 (Kim) published Mar. 15, 2007, discloses such a structure, which can be used in place of riprap, gabions and similar structures.
SUMMARY OF THE INVENTION
The invention provides an erosion-control element comprising a plurality of sandbags. Each sandbag has a flexible bag wall forming a chamber containing fill material, and has a hole extending through the bag wall, the hole being unconnected to the chamber. A bag attachment member extends through the holes forming a closed loop and attaching the sandbags together.
According to another embodiment of the invention, there is provided a structure for protecting a ground area, including an underwater shoreline area, from erosion, comprising a plurality of erosion-control elements assembled together, each of the erosion-control elements comprising a plurality of attached sandbags.
According to a further embodiment of the invention, there is provided a bag for containing a fill material, the bag comprising a flexible bag wall forming a chamber for containing the fill material, a sealable opening for insertion of the fill material into the chamber, and a hole adjacent to an edge of the bag extending through the bag wall for receiving a bag attachment member, the hole being unconnected to the chamber.
These and other features of the invention will be apparent from the following description and drawings of the preferred embodiments.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of a bag according to one embodiment of the invention, adapted for use as part of an erosion-control element.
FIG. 2 is a cross-sectional view of a part of the bag showing a hole and grommet extending through the bag wall.
FIG. 3 is a perspective view of one embodiment of the erosion-control element.
FIG. 4 is a perspective view of a second embodiment of the erosion-control element.
FIG. 5 is a schematic view of an erosion-control structure made from the erosion-control elements of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Exemplary embodiments are illustrated in the referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.
In the following description and the drawings, corresponding and like parts are referred to by the same reference characters.
Referring to FIG. 1, a bag 12 has flexible walls 14 made of geotextile or other material suitable for use as sandbags. The material of the bags is not biodegradable. It may optionally include a UV-stabilizer. The bag 12 has a mouth or opening 16 at one end thereof. A line of sewing along one side edge and the bottom edge of the bag attaches two thicknesses of the bag wall together and forms a narrow edge portion 24 of the bag. The bag is thus made of a single, folded sheet of material. The interior of the bag is a chamber 18 which does not include the edge portion 24. The opening 16 is intended for permitting fill material to be put into the chamber 18 of the bag to make a sandbag. In this specification, “fill material” means any material that is suitable for use in bags in the construction of erosion-control structures, including sand, soil, gravel, dry-mix concrete and mixtures thereof, and including fill material with seeds for vegetation. The term “sandbag” as used herein means a bag containing any “fill material.” For further clarity, the term is not limited to a bag in which the fill material is sand. In use, the bag 12 is filled with fill material and the opening 16 is then closed, for example by means of a tie 17, or by stapling, sewing, etc.
The bag 12 has holes 20 in the walls 14 thereof. Each hole 20 is ringed by a grommet 28. In the illustrated embodiment of the bag, two holes 20 are provided, adjacent to an edge of the bag, one in each bottom corner. More or fewer holes 20 may be provided in the bag, and at other positions, such as at the midpoint of a side edge. Since the grommet 28 forms the walls of the hole 20, and extends through two thicknesses of the bag wall 14, i.e. the front side and the back side of the bag, the holes 20 extend through the bag walls 14 without connecting with the chamber 18, as best seen in FIG. 2. Thus, fill material in the chamber 18 cannot escape through the holes 20.
Referring next to FIG. 3, an erosion-control element 10 comprises a plurality of bags 12, three in the illustrated embodiment, filled with fill material and closed with ties 17, attached together by means of bag attachment members 22. The bag attachment members may be made of any suitable and durable material, preferably a strong synthetic non-degradable material such as plastic or metal. Plastic cable ties (zip ties) having a gear rack and rachet, are preferred. The bag attachment member 22 forms a closed loop, so bags do not become detached once connected together. The bag attachment members can be inserted through the holes 20 in the bags after the bags are filled, without contacting or being impeded by the fill material.
In the erosion-control element 10 shown in FIG. 3, one bag 12 is connected to each of the two other bags by means of two separate holes in the corners of the first bag. Other configurations of attachment are possible, for example, attachment using the same hole 20 in the first bag, or attachment of additional bags to any of the three bags, depending on what is desired for a particular application. For convenience of illustration, the erosion-control elements are shown in the drawings having three bags, but it will be understood that they may comprise any number of bags that would be suitable for a particular application, for example two bags, five bags, ten bags, etc.
FIG. 4 shows another embodiment of the erosion-control element 30 in which three sandbags are connected together by a connector ring 32. Each bag 12, filled with fill material, has a bag attachment member 22 extending through one opening 20 in each bag and forming a closed loop 22 attached to the connector 32. Additional sandbags can be attached to the loop or to any of the three sandbags, if desired. In use, the connector 32 can be anchored to the ground to retain the erosion-control element 30 in position.
FIG. 5 shows the erosion-control elements in use. A shoreline 34, which may be for example the shore of a river, lake or saltwater body, has a sloping area 36 which is partly or wholly underwater and would be subject to erosion by the action of water. The erosion-control elements 30 are placed on this area 36 and collectively form an erosion-control structure 36 which protects the underwater shoreline area from erosion. The erosion-control elements 30 may be placed in random orientations and may overlie or be intermingled or entangled with each other to function in a relatively unitary manner. Optionally, they may be secured to the underwater surface 36, for example by attaching some of the bags to the ground by means of spikes or the like. The erosion-control elements 10 of FIG. 3 may be used in the same manner to collectively form erosion-control structures 36.
Optionally, the fill material in the bags 12 include seeds, and vegetation may be grown on the sandbags prior to use, for some applications.
While exemplary embodiments have been discussed above, those of skill in the art will recognize that certain modifications thereof may be made. It is therefore intended that the following appended claims are interpreted to include all such modifications, as are within their true scope.
Patent Application
20090169301
