Integrating articulated concrete blocks with gabion/reno cages

Abstract

An articulated concrete block system that includes a gabion mattress drainage layer. The two major components of the system reduce the effects of erosion and increase the hydraulic stability in areas that experience high velocity water flows, hydraulic jumps, and will dissipate wave energy action for shoreline and coastal erosion. Geosynthetics are first placed on the ground surface, followed by a gabion mattress drainage layer, a smaller aggregate layer for fine grading, another optional geosynthetic layer, and then the articulated concrete blocks overlie the system.

Claims

1. A method of preventing erosion, comprising: using a wire cage having wire sides and a wire bottom, and installing said wire cage over a surface to be protected from erosion; filling the wire cage with a coarse material; using said coarse material of a size such that at least parts of said coarse material protrude through the wire bottom of said wire cage but said coarse material remains contained in said wire cage, and so that the portion of said coarse material protruding through the wire bottom engages with an underlying material on which said wire cage is installed, whereby said coarse material-filled wire cage is stabilized against lateral movement, and if the underlying material on which said wire cage is installed erodes, said wire cage remains filled with said coarse material contained therein; and installing a plurality of erosion control blocks connected together so as to form a unit of blocks overlying a top surface of the coarse material filling the wire cage.

2. The method of claim 1, further including installing using said erosion control blocks having one or more vertical holes therein.

3. The method of claim 1, further including using the erosion control blocks as a lid for said wire cage, and using no wires of said cage as a lid.

4. The method of claim 1, wherein said coarse material comprise a rock material, and further including using an aggregate covering a top surface of said rock material, where said aggregate has a size smaller than the rock material filling said wire cage, and leveling the aggregate.

5. The method of claim 4, further including placing the aggregate on top of the rock material so as to fill in spaces between the rock material.

6. The method of claim 1, wherein plural said wire cages and said erosion control blocks comprise a revetment system, and wherein said coarse material comprises a rock material, and further including forming at least a portion of a perimeter of said revetment system by excavating said portion of the perimeter so as to form a downward extending slope, extending said rock-filled wire cages on at least a portion of said slope, extending said erosion control blocks down said slope over said rock-filled wire cages and beyond said wire cages, and overfilling the sloped erosion control blocks with a filler material.

7. The method of claim 6, further including installing a geotextile material on the ground slope before said wire cages are extended thereon.

8. The method of claim 6, further including using wire cages that taper in height down said slope.

9. The method of claim 1, further including levelling a top surface of the coarse material before installing the erosion control blocks, and placing a geogrid netting material on a top surface of said leveled aggregate.

10. The method of claim 1, further including using rocks as said coarse material, and further including selecting said netting material with each said opening having a size that allows at least a portion of said individual rock to protrude therethrough but not generally pass an individual said rock therethrough.

11. The method of claim 1, further including using said coarse material which comprises an aggregate rock that has a general diameter greater than 1.5 inches.

12. The method of claim 1, further including using a wire cage having a height of about 18 inches or less, and overlying the top of said coarse material-filled wire cage with said connected erosion control blocks to provide additional weight to said wire cages having the height of about 18 inches or less, thereby increasing the stability of said coarse material-filled wire cages.

13. A product made according to the method of claim 1.

14. A product made according to the method of claim 1, further including placing a geogrid netting material on the bottoms of said wire cage.

15. A method of preventing erosion of a sloped grade, comprising: installing a geotextile material on the sloped ground surface to be protected from erosion; installing a geogrid netting material over the geotextile material; placing wire cages over said geogrid netting material so that respective bottom wire portions of said wire cages engage said geogrid netting material and said geogrid netting material prevents movement of the overlying wire cages; using said wire cages having respective sides and bottoms and interconnecting said wire cages together, and overlying said wire cages on said sloped grade to contain a rock material placed in said wire cages so that the rock material does not migrate down the sloped grade during installation of said rock material; using the rock material to substantially fill each said wire cage, whereby the rock material in a bottom portion of said wire cages engages said geogrid netting material to resist lateral movement of said rock material-filled wire cages and said wire cages are thereby prevented from moving down the sloped grade; spreading a fine aggregate over a top surface of said rock material filling said wire cages and leveling said fine aggregate to provide a level surface suitable for supporting thereon erosion control blocks; and installing a plurality of said erosion control blocks interconnected together so as to form a unit over the leveled top surface of the rock material-filled wire cages.

16. The method of claim 15, wherein respective wire tops are not used to cover said wire cages.

17. The method of claim 16, further including using the erosion control blocks as interlocking erosion control blocks having interlocking arms and sockets, and installing said interlocking erosion control blocks over the leveled top surface of said rock material and using said interlocking erosion control blocks as a lid to said wire cages.

18. The method of claim 15, wherein apparatus thereof comprises a system, and further including forming a perimeter of said system, and burying said system and at least a portion of said rock material-filled wire cages underground.

19. The method of claim 15, further including using said rock material having a diameter of greater than 1.5 inch, and using said rock material having protrusions sufficient to protrude through a bottom wire mesh of said wire cages and engage the underlying geogrid netting, thereby interlocking said rock material-filled wire cages to said underlying geogrid netting.

20. An erosion prevention product, comprising: a geotextile material on a sloped ground surface to be protected from erosion; a geogrid netting material over the geotextile material; one or more wire cages installed over said geogrid netting material so that respective bottom wire portions of said wire cages engage said geogrid netting material, and said geogrid netting material prevents movement of the overlying wire cages; a rock material substantially filling each said wire cage, whereby the rock material in a bottom portion of said wire cages engages said geogrid netting material to resist lateral movement of said rock material-filled wire cages and said rock material is contained in said wire cages and is thereby prevented from moving down the sloped grade; a fine aggregate spread and leveled over a top surface of said rock material filling said wire cages, said level surface suitable for supporting thereon erosion control blocks; a mat of interconnected said concrete erosion control blocks placed over the leveled top surface of the rock material-filled wire cages; and said one or more wire cage each having a height about 18 inches or less, and said interconnected erosion control blocks overly the top of said leveled fine aggregate to provide additional weight to said wire cages having a height of about 18 inches or less, thereby increasing the stability of said rock material-filled wire cages.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further features and advantages will become apparent from the following and more particular description of the preferred and other embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters generally refer to the same parts, functions or elements throughout the views, and in which:

(2) FIG. 1 is a cross-sectional view of the layered erosion control system according to an embodiment of the invention;

(3) FIG. 2 is an isometric view of the various layers of the erosion control system of FIG. 1;

(4) FIG. 3 is an isometric view of a gabion mattress employed according to the invention;

(5) FIG. 4 is an isometric view of a gabion mattress and associated geogrid netting; and

(6) FIG. 5 is a cross-sectional view of another embodiment of the erosion control system in which the perimeter thereof is embedded in the ground.

DETAILED DESCRIPTION OF THE INVENTION

(7) FIGS. 1 and 2 illustrate an example of the use of the system components according to an embodiment of the invention. The integrated reno/gabion mattress and articulated erosion control block system 10 is well adapted for use on slopes where it is desired to protect the ground from erosion due to heavy rains and wave action in lakes, rivers, shores, dams, berms, etc. The terms “reno” and “gabion” are used herein as interchangeable structures and terms. The system 10 illustrated is installed on a slope 11. Initially, the ground 12 is worked to remove any ridges and valleys and make the surface sufficiently smooth. This can be accomplished by workers using either hand equipment, or using motorized equipment, or both. The surface of the ground 12 can be smoothed so that the surface texture or contour deviates in height no more than about 0.5 inch. However, the necessity of smoothing the ground surface is not as critical with the revetment system of the invention, as the wire cage gabions (described below) can accommodate rougher ground surfaces, it being realized that the top aggregate fill of the wire cage gabions can be smoothed to the required surface contour. Nevertheless, the ground surface contour is specified in many job specifications, and is standard in the industry.

(8) Next, the smoothed ground 12 is covered with a conventional geotextile 14 that is either woven or non-woven to allow water to pass therethrough. In practice, a non-woven geotextile material is utilized. The geotextile layer 14 is sufficiently tough so as not to be easily punctured or torn during installation and actual use. The geotextile material 14 suitable for use with the invention can be obtained from TenCate Mirafi or Propex Global Solutions. An enlargement of the tightly-woven geotextile material 14 is illustrated in FIG. 2. The non-woven geotextile material 14 is fabricated in rolls of about twelve feet wide and three hundred feet long and trucked to the work site. The non-woven geotextile material 14 can also be obtained in rolls of fifteen foot wide by three hundred feet long. The rolls of the geotextile material 14 are unrolled to cover the smooth surface of the ground 12, either up/down the slope 11, or laterally across the slope 11. The edges of the geotextile material 14 can be staked down permanently using conventional stakes (not shown) hammered into the ground 12. Overlapping the elongate edges of the strips of geotextile material 14 is customary to assure that complete coverage of the underlying ground 12 is obtained. A single row of stakes is used to anchor the overlapped edges of the geotextile material 14 to the ground 12.

(9) A geogrid netting material 16 is installed over the geotextile material 14. The geogrid netting 16 constitutes a first netting layer, as a subsequent top geogrid netting material is optional and can also be employed. Those skilled in the art may also find that the lower geogrid netting material layer 16 is unnecessary, whereupon the gabion mattress can be laid directly on the prepared ground. The geogrid netting material 16 is a conventional synthetic mesh netting with large openings, typically openings of about 1.0 inch by 1.3 inch. The purpose of the geogrid netting material 16 is to engage with the overlying rock layer (to be described below) and prevent lateral movement or migration of the caged rock layer. The geogrid netting material 16 is constructed with strands of a synthetic plastic so that it is sturdy and tough, with openings therein sufficient such that the netting material becomes lodged with the rough surface of the rocks, and prevents lateral movement of the rocks. Typical geogrid netting material 16 suitable for use with the invention is identified as TX120 475 and can be obtained from Tensar International Corporation in rolls having a width of about 13.12 feet and 246 feet long. An enlargement of the geogrid netting material 16 is illustrated in FIG. 2. As can be appreciated, the openings in the geogrid netting material 16 are related to the size of the rock being stabilized in the gabion mattress. Like the geotextile material 14, the geogrid netting material 16 is unrolled by workmen to completely cover the geotextile material 14, or to at least cover the area that is to be overlaid with rocks. The geogrid netting material 16 may or may not be anchored at its edges with stakes or other mechanisms well known in the field. The geogrid netting material 16 can be installed or unrolled in alignment with the lengths of the strips of geotextile material 14, or perpendicular thereto.

(10) Once the geogrid netting material 16 is installed, then the wire cage gabion mattresses are installed over the synthetic geogrid netting material 16. A wire cage gabion 18 suitable for use with the invention is illustrated in FIG. 3. Other wire cages suitable for use can be utilized. The wire cage 18 is of conventional construction and constructed of a heavy gauge wire mesh 20 with horizontal and vertical wires (or diagonal wires) that are welded or twisted together to make an integral rigid box structure. An enlargement of a portion of the wire cage 18 is illustrated in FIG. 2. The wire gauge is sufficient so that the rocks placed therein, of whatever size, do not distort the box-like shape of the cage 18. Of course, with larger rocks placed in the wire cages 18, larger wire mesh holes can be used, and a larger gauge wire for the cages 18 would be employed as well. Conversely, with smaller size rocks, the construction of the wire cages 18 can be carried out using smaller wire holes and smaller gauge wire 20. Both the reno mattress cage and the gabion mattress cage 18 can be obtained from Maccaferri Inc., Phoenix, Ariz., or other suppliers of such products.

(11) As noted in FIG. 3, the wire cage 18 includes four upright sides, one identified as numeral 21, and with two end panels, all forming a rectangular box shape. Further included is a bottom wire panel 22, totaling five wire cage panels. In accordance with the invention, a top wire panel or lid (not shown) can be used, but is not necessary, as the overlying mat of concrete blocks 36 can function as a lid. As such, the top wire lid of the wire cage may or may not be used. Another important feature of the invention is that the wire cages all have a heavy duty wire bottom to maintain the rocks therein, even if the underlying material layers become distorted due to the erosion of the ground, generally if the erosion is confined to an area smaller than the footprint of the gabion. Accordingly, the gabion structure maintains its integrity and the overlying articulated concrete blocks 30 also remain in place to prevent erosion from water flowing over the blocks 30.

(12) All panels of the wire cages 18 are constructed using a sturdy wire, with openings that are smaller than the general diameter of the rocks placed therein. When employed on steep slopes, the wire cage 18 can be equipped with dividers or diaphragms 24. The dividers 24 create compartments 26, each of which can be filled with rock material. The dividers 24 prevent the rocks from rolling downhill to the lower portion of the wire cage 18, and thus allow each compartment 26 to be completely filled while yet maintaining a generally level contour as the top surface thereof that is parallel to the slope 11.

(13) As noted above, the reno/wire cage gabion 18 is fabricated in a roll and delivered to the worksite as such. At the worksite, the roll of the wire cage 18 is unrolled on the slope 11 overlying the lower or first geogrid netting material 16. Once unrolled, the four edges of the unrolled wire cage 18 are turned or bent upwards by workmen to form the sides and the ends 20, all of which are known herein as “sides”. The adjacent upright edges of the sides 20 are attached together using hog-tie rings that are inserted through both upright adjacent edges and crimped together using pliers or other similar tools. It should be noted that the rolls of the wire cage material 18 are fabricated so that when bending up the four sides, the vertical dimension of the sides 20 is whatever is desired. In other words, the height of the wire cage 18 is determined by the manufacturer and ordered for the job as such.

(14) After the sides 20 of the wire cage 18 are formed, the workmen can install the dividers 24. The number of dividers 24 can be related to the overall length of the wire cage 18. For example, reno wire cages are available in heights of about 6, 9, 12 and 18 inch. The dividers 24 are attached to the opposite sides 20 and the bottom 22 using hog-tie rings. Rather than utilizing the long rolled-type reno wire cages 18, prefabricated or preassembled reno wire cages 18 can be employed to facilitate the manual handling of the cages 18. Preassembled reno cages are available in lengths of six and twelve foot, with dividers therein. Many other dimensions of preassembled reno cages are available. The preassembled reno cages are formed in a box shape at the manufacturer, and need not be bent and formed at the worksite. The preassembled type of reno cages can be arranged together and fastened by conventional means, such as hog rings.

(15) Once the reno/gabion wire cage 18 is completed, it can be filled with a rock material 30 of the desired size. This is illustrated in FIG. 2. The size of the rocks used is described above for various applications. Tractor-type equipment with a hydraulic-operated bucket can be employed to move the rock 30 from a truck or pile to the wire cage compartments 26 until filled substantially level with the top edges of the sides 20. The large rock material 30 functions to allow the water from waves and the like to seep out of the layered structure and not be trapped. The rock-filled wire cages 18 also reduce the turbulence of the water, waves, and the like, to prevent erosion of the underlying soil.

(16) Importantly, smaller rock material 32 can be scattered over the top of the larger rock 30 to fill in the interstices of the large rock 30 in the wire cages 18 and provide a substantially level contour to the top surface. As noted above, it is desired to have a level top contoured surface that has irregularities no more than about 0.5 inches in height. This is to assure that the overlying articulated concrete blocks 36 have a substantially flat surface on which to rest so that the hydraulic forces of waves and the like do not dislodge the articulated concrete blocks 36. The smaller rock material 32 can be raked or otherwise worked so as to fill in the spaces of at least the top portion of the larger rock 30.

(17) In accordance with a feature of the invention, the rock-filled wire cages 18 facilitate the stability of such structure when installed on a slope 11. The rock-filled wire cage 18 functions effectively as one large rock, and is less likely to slide down the slope, as compared to just a layer of unconfined rock. As can be appreciated, the wire cage 18 maintains the rock therein confined within the cage 18, and the entire cage 18 has to move, not just a small portion of the rocks. This contrasts with the traditional practice of using an unconfined layer of loose rock. Moreover, the individual wire cages can be installed, filled with rock, and used as a platform for motorized equipment to fill adjacent empty wire cages with rock. The individual rock-filled cages 18 are fastened together using hog-tied rings or other suitable fasteners. Other techniques for fastening either the upright edges of the wire cage sides 20 together, or adjacent wire cages 18 together include those disclosed in U.S. Pat. No. 10,738,425, the disclosure of which is incorporated herein as if fully set forth in this document.

(18) As noted above, once a wire cage 18 is filled with the coarse rock 30 and the overlying finer rock 32, it is suitable for supporting motorized tractor-type equipment for filling adjacent empty wire cages with rock, thereby expediting the completion of the job so that workmen do not have to shovel the rock into the wire cage compartments 26. A bucket-equipped tractor with a long arm or boom can be employed to rest on a completed rock-filled wire cage 18 and repeatedly fill the bucket from an inventory of rock 30 and fill the compartments of many adjacent empty wire cages 18. Once the empty adjacent wire cages have been filled, then the tractor equipment can be moved onto another completed wire cage 18 to fill yet other wire cages 18 until the entire slope is covered with the rock-filled wire cages 18.

(19) Once the top of the rocks filling the wire cages 18 are prepared, as described above, then a second or top geogrid netting material 34 may be installed over the completed wire cages 18. With the use of the top geogrid netting material 34 and the lower geogrid netting material 16, it can be seen that the stability of the rocks 30 and 32 filling the wire cage 18 is achieved both above and below the rock-filled wire cage 18. The top geogrid netting material 34 can be of the same type as that of the lower geogrid netting material 16, or can be a different type with different size openings and/or shapes of the openings. The top geogrid netting material 34 functions to maintain the rock in the wire cage 18 during torrential water flows, and prevents the rocks from being drawn upwardly through the holes in the articulated concrete blocks 36 due to the suction of the swift water flow.

(20) The layered components covering the slope 11 to be protected from erosion is next worked to cover the same with articulated concrete blocks 36. Preferably, but not of necessity, the concrete blocks 36 can be articulated using the arm and socket type of block, and holes as described in U.S. Pat. No. 8,123,435 by Smith. Many other types of articulated erosion control blocks can be utilized with the invention. Also, blocks of a desired thickness can be utilized to address the type of water force encountered on the slope 11. For example, blocks of thicknesses of 4 to 12 inch, or more, can be employed to assure that the weight of the block 36 allows it to remain locked to the adjacent blocks and is not dislodged by the hydraulic force of turbulent waves and the like. The blocks 36 can be installed either by hand, i.e., by workers who individually install each block so that the arms and sockets interlock and the mat of blocks cannot be laterally dislodged. Alternatively, the blocks 36 and be arranged in a mat off site where the blocks are cabled together as a mat and installed using a crane or similar lifting equipment. When completed, the entire surface of the slope 11 includes a top covering of the articulated concrete blocks 36.

(21) The articulated concrete blocks 36 may be of the type that have one or more holes 38 formed therethrough. In such a case, the holes 38 can be filled with a small-size aggregate. This completes the installation of various material layers to prevent erosion of the soil on a slope.

(22) The general area to be protected from erosion is described above. The perimeter of the area can be constructed in the manner illustrated in FIG. 5. The perimeter of the erosion protected area extends downwardly into a trench or excavated area. On the left of the drawing, the articulated concrete blocks 50 extend into an unexposed downturned perimeter trench. The upper and lower geogrid netting material 34 and 16, as well as the geotextile material 14 also extend into the trench, under the articulated concrete blocks 50. The rock-filled wire cages need not extend all the way down into the trench. It is noted that the wire cages 18 that do extend down the trench at least part of the way, can be tapered in height. Rather than utilizing the rock-filled wire cage 18, the sloped area under the concrete blocks 50 can be filled with loose rock 52 that is packed. The dirt that was excavated in forming the perimeter trench is then used to backfill the area 52 above the sloped articulated concrete blocks 50. The dirt is compacted about 95% to assure that the dirt remains in place.

(23) The various layers of material can be installed one on top of the other as described above. Alternatively, various layers can be attached together. For example, hog-tie rings can be used to attach the lower geogrid netting material 16 to the underlying geotextile material 14. The wires comprising the bottom 22 of the wire cage 18 can be fastened to the underlying lower geogrid netting material 16. Similarly, the top geogrid netting material 34 can be attached to the underlying top edges of the wires 20 of the wire cages 18.

(24) As an alternative to the installation of the rolls of the lower geogrid netting material 16, such netting can be cut into sections and attached directly to the wire cage 18. This is illustrated in FIG. 4 of the drawings. Here, a respective panel 40 of the geogrid netting material can be cut so as to fit into the bottom of each compartment 26. The panel 40 of geogrid netting may or may not be fastened to the wires 20 that form the bottom 22 of the wire cage 18. As a further alternative, a larger panel 42 of the geogrid netting material can be cut to the same size as the entire bottom of the wire cage 18, and fastened to the bottom surface of the wires 20 that form the bottom 22 of the wire cage 18. While not shown, the entire surface of all of the rock-filled wire cages 18 can be covered with the geogrid netting material, or a top panel of the geogrid netting material can be cut and attached to the top of each rock-filled wire cage 18. As noted above, the erosion control blocks 36 can be laid directly on top of the rock-filled gabion cage 18 and function as a lid.

(25) As another alternative to the method of the invention, those skilled in the art may prefer to utilize gabion structures that need not be constructed of wire. Rather, gabion structures of a rigid plastic construction can be employed to provide boxes or compartments for holding the rock material 30 and 32. U.S. Pat. No. 10,781,569 by Thomas et al., illustrates the construction of such type of rigid gabion structures. The disclosure of such patent is incorporated herein as if fully set forth in this document.

(26) In this instance, the empty rigid gabion structures can be installed on top of the lower geogrid netting material 16 and then filled with the rock material. Or, the rigid gabion boxes can be filled with the rock material off site, and then trucked to the site and lifted with power equipment and lowered into place on top of the geogrid netting material 16.

(27) The wire cages described above, whether of the gabion or reno type, provide advantages over the use of perforated rigid plastic cell structures described in the prior art. The prior art plastic cellular structures do not employ top or bottom surfaces, and the sides are perforated to allow water drainage therethrough. As such, the coarse rocks do not protrude through the perforations in the rigid plastic sidewalls. With the use of wire cages, the sharp corners or protrusions can protrude through the wire openings, but still contain the coarse rocks therein. When one rock-filled cage is located adjacent to other rock-filled wire cages, the sharp corners of the rocks protruding through the wire holes engage with the sharp corners of the rocks protruding from the adjacent cages. This rough side rock profile of the cages engaging each other prevents lateral movement between the cages, even if the cages are tied together with hog-tie rings. The same is true with the rock corners protruding from the bottom wire openings, where such protrusions better engage the underlying geogrid netting to further prevent lateral movement of the rock-filled wire cages.

(28) While the preferred and other embodiments of the invention have been disclosed with reference to specific material layers to provide a reliable erosion control system, and associated methods of fabrication and installation thereof, it is to be understood that many changes in detail may be made as a matter of engineering choices without departing from the spirit and scope of the invention, as defined by the appended claims.