This disclosure relates to load transfer or connection devices for expanded cellular confinement structures for the confinement of infill material. In particular, this disclosure relates to devices used to transfer load exerted by expanded and filled cellular confinement structures to tendons which in turn are anchored by stakes or other methods. This disclosure relates to methods used for fastening the device to the cellular confinement structures, and for fastening the device to the supporting tendon and for connecting at least two expanded sections.
A cellular confinement structure serves to increase the load bearing capacity, stability, and erosion resistance of infill materials which are placed within the cells of the system and can serve to protect underlying soils or as a protective layer over pond liners or other protective membranes. A commercially available system is Geoweb® plastic web confinement structure sold by Reynolds Presto Products Inc., Appleton, Wis. Geoweb® cells are made from high density polyethylene strips that are joined by welds on their faces in a side-by-side relationship at alternating spaces so that when the strips are stretched out in a direction perpendicular to the faces of the strips, the resulting section is honeycomb-like in appearance, with sinusoidal or undulated-shaped cells. Geoweb® sections are lightweight and are shipped in their collapsed form for ease in handling and installation. Geoweb® systems have been described in U.S. Pat. Nos. 8,092,122; 6,395,372; 5,927,906; 5,449,543; 4,778,309; and 4,965,097, each of these patents being incorporated by reference herein.
A challenge for channels and slopes includes the limitations of length of cellular confinement sections used upon slopes due to the cumulative forces of the weight of the infill contained by the cellular confinement section upon the welds that define the shape of expanded cell. Either stakes, or tendons, or both needs to be used to transfer the forces from the filled cell to the ground, and this transfer of force needs to occur in sufficient locations to allow for the forces never to exceed the capacity of the welds. Another challenge associated with the use of cellular confinement systems is that the fill material and the cellular confinement sections may be displaced during installation and long-term operation. Erosion below the cellular confinement section may cause infill to drop out of the cells. Applied forces such as hydraulic uplift or ice action may lift the cellular confinement section or lift the fill material out of the cells. Translational movement of the cellular confinement section may also occur in channel lining applications, or when installing on steep slopes.
In one improvement, a load transfer device was developed and sold by Reynolds Presto Products under the tradename Atra® Clip. This load transfer device is described in U.S. Pat. No. 5,927,906, incorporated herein by reference, and depicted in
A device for use with at least one expanded cellular confinement structure is provided. In general, the device includes an insertion member having first and second opposite insertion ends. An integral shank extends from the insertion member and is spaced from each of the first and second insertion ends. An integral body extends from the shank at an end of the shank remote from the insertion member and includes a face opposing the insertion member; a post with a tendon-receiving holding surface; and a through-hole sized to receive a tendon.
In another aspect, a cellular confinement system is provided. The cellular confinement system includes at least a first unitary section of cells made from elongated plastic strips bonded together in spaced apart areas. The strips form walls of the cells and at least some of the cells define open slots. At least one device is oriented in a first one of the slots. The device can be the type as characterized above. When used, the insertion member is located on the first side of the cell wall within a first one of slots. The body is located on a second side of the cell wall. At least one flexible tendon extends through the first one of the slots, and through the through-hole in the body, and is wrapped around the post of the body.
In another aspect, a method of transferring load from an expanded cellular confinement structure for retaining material to a flexible tendon is provided. The method includes providing an expanded cellular confinement structure having a plurality of cells formed by cell walls, the cell walls having first and second opposite sides and at least one open slot. The method includes inserting an insertion member of a device from the second side of the cell wall through the open slot to provide the insertion member on the first side of the cell wall; a body of the device on the second side of the cell wall; and a shank between the insertion member and the body extending through the slot. The method further includes inserting a tendon through a through-hole in the body and wrapping the tendon around a post of the body.
In another aspect, a kit is provided. The kit includes at least one device, at least one unitary section of cells, and at least one tendon. The device includes an insertion member having first and second opposite insertion ends. An integral shank extends from the insertion member and is spaced from each of the first and second insertion ends. An integral body extends from the shank at an end of the shank remote from the insertion member and includes a face opposing the insertion member; a post with a tendon-receiving holding surface; and a through-hole sized to receive the tendon.
In
Each of the expanded cellular confinement structures 18 has a plurality of strips of plastic 26 that are bonded together, one strip to the next at alternating and equally spaced bonding areas 28 to form cell walls 30 of individual cells 32. When the plurality of strips 26 are stretched in a direction perpendicular to the face of the strips, the strips 26 bend in a curved pattern, such as a sinusoidal manner, and form sections 18 of cells 32 in a repeating cell pattern. Each cell 32 has a cell wall 30 that is made up from one strip 26 and a cell wall 30 made from a different strip 26.
In this embodiment, the strips 26 define slots 36. The slots 36 can be used to accommodate the tendons 78 to reinforce the sections 18 and improve the stability of the installation of the cellular confinement section 18 by acting as continuous, integral anchoring members to prevent unwanted displacement of the sections 18. The slots 36 can also be used to help secure the device 24 to the section 18, thereby permitting the device 24 to transfer load from the section 18 to the tendons 78. The device 24 can be seen in
The strips 26 can also define apertures 34. The apertures 34 may help to allow for aggregate interlock and for improved drainage while maintaining sufficient wall stiffness for construction site infilling. Advantageous aperture sizes and patterns are described in U.S. Pat. No. 6,395,372, incorporated by reference herein.
In the embodiment of
Still in reference to
Attention is directed to
In one embodiment, the first insertion member end 46 has a generally tapered shape 50. This shape 50 provides a convenient and expedited use of the device 24 allowing for maximum width of the insertion member. In this embodiment, the second insertion end 47 is depicted as having a tapered shaped 52. This shape can help provide a fast and convenient use of the device 24 when connecting together and first and second sections 20, 22.
Still in reference to
The shank 64 has a length that is defined as being between the insertion member 44 and a body 70, described below. The length of the shank 64 is less than the length of the insertion member 44, in one example.
In the embodiment shown, the device 24 includes body 70. Preferably, the body 70 is integral with the shank 64. The body 70 extends from the shank 64 at an end 72 of the shank 64 remote from the insertion member 44.
In this embodiment, the body 70 includes a face 74 (
In use, the bearing surface 76 can be helpful in holding the load transfer device 24 in place while threading a tendon 78 (
In
In reference again to
In one embodiment, the post 82 has two opposite sides 86, 88. In the embodiment shown, the sides 86, 88 are angled inwardly as they extend in a direction from an end surface 90 in a direction toward the remaining part of the body 70. That is, the sides 86, 88 angle inwardly in a direction toward each other as they extend toward a through-hole 92 in the body 70.
A variety of angles can be used. In the embodiment shown, the two opposite sides 86, 88 of the post 82 are angled at angles 91, 93 respectively (
The body 70 includes an open slot 94. In the embodiment shown, the slot 94 is between the post 82 and the face 74. Specifically, in the illustrated embodiment, the slot 94 is between the side 88 of the post 82 and a portion 96 (
As mentioned above, the body 70 includes the through-hole 92. The through-hole 92 is sized to receive the tendon 78, and it is especially useful to receive plural parts of the tendon 78.
The inside radial surface 98 of the through-hole 92 can be roughened to form a roughened surface 99 (
In the embodiment shown, the through-hole 92 is circular. Of course, in other embodiments, the shape of the through-hole 92 can vary, and it need not necessarily be circular. In this embodiment, the circular through hole has a diameter that is about 50-80% of the length of the insertion member 44. The diameter of the through-hole 92 is about 110-150% of the length across a narrowest length 100 (the waist 100) (
As can be seen in
The body 70 has a shape that is advantageous in using it with tendon 78. In the example shown, the perimeter shape includes a first section 102 that is radiused, and in some embodiments, semi-circular. Adjacent to the first section 102 is second section 104, which has a radius opposite of the radius of the first section 102. Second section 104 also corresponds to waist 100, which is the narrowest section across the length of the post 82. Extending from the second section 104 is the first side 86 of the post 82. A third radiused section 106 is between the side 86 and end surface 90. A fourth radiused surface 108 is between the end surface 90 and the side 88. A fifth radiused section 110 extends from the side 88 to a side 112. The side 112 forms one side 112 of the slot 94. That is, the slot 94 is defined by side 88, section 110, and side 112. Sixth section 114 is between the side 112 and face 74. A radiused portion 115 can be between the side 112 and sixth section 114. Extending from the face 74 is seventh section 117. Seventh section 117 is generally straight and extending from the face 74 to the first section 102. Between the seventh section 117 and the face 74, can be a radiused portion 118.
The body 70 is spaced from the insertion member 44 a distance about 5-30% of the length of the insertion member 44. This provides room for manipulating the device 24 relative to the slots 36 in the section 18.
The device 24 can be made from a variety of materials including a molded plastic of resin based material, or a metal.
In reference again to
One example method includes securing the load transfer device 24 to the cell wall 18 and transferring the load to tendons 78. As shown in
In
In use, a method of transferring load from the expanded cellular confinement structure 18 to flexible tendon 78 can be implemented. The method includes providing the expanded cellular confinement structure 18 having plurality of cells 32 formed by cell walls 30, the cell walls 30 having first 55 and second 56 opposite sides and at least one open slot 36. The method includes inserting insertion member 44 of the device 24 from the second side 56 of the cell wall 30 through the open slot 36 to provide the insertion member 44 on the first side 55 of the cell wall 30; the body 70 of the device 24 on the second side 56 of the cell wall 30; and the shank 64 between the insertion member 44 and the body 70 extending through the slot 36. The method further includes inserting tendon 78 through the through-hole 92 in the body 70 and wrapping the tendon 78 around the post 82 of the body 70.
In use, the device 24 can be utilized to connect or fasten two expanded cell confinement structures 18 together. The method includes aligning two expanded cell confinement structures 18 so that at least one open slot 36 defined by the first web 20 is aligned with at least one slot 36 defined by the second web 22 to form the overlap region 38. The device 24 is used by inserting the insertion member 44 from the second side 42 (
The method may also include rotating the body 70 to turn or rotate the connector device 24 within the overlap region 38. This helps to lock the device 24 within the slots 36.
In some implementations, the method can further include a step of using tendon 78 to help further secure the load transfer device 24 to the self-confinement structure 18. In
The device 24 has advantages over prior art connectors. The structure of the device allows it to install quickly and be simple to use. The insertion member 44 is helpful in holding the device 24 in position, to allow for the user to use both hands to thread the tendon 78 onto the device 24, making this a faster tie than prior art devices. Once the device 24 is placed through the slots 36 of the adjoining sections 20, 22, the tendon 78 is pulled through the slots 36 and then pulled through the through-hole 92 and wrapped over the post 82, which completes the connection. The user then moves on to the next connection with the tendon 78. The wide face 74 provides bearing surface 76 for exerting a force against the section 18, and this bearing surface 76, in combination with the insertion member 44, helps to hold the device 24 in place so that two hands can be used for the tendon tie.
The parts of this system 14 can be placed together for use in a kit. The kit can include at least first unitary webs of cells 20, as characterized above. The kit can include at least one, and typically a plurality of devices 24 for transferring load from the section 20 to the tendon 78. Each device 24 will include an insertion member 44 having insertion member extension 48, integral shank 64 extending from the insertion member 44, and the integral body 70 extending from the shank 64 at end 72 of the shank 64 remote from the insertion member 44. The body 70 will include post 82 having tendon-receiving holding surface 84 and through-hole 92 sized to receive tendon 78. In preferred implementations, the kit will also include at least one, and preferably, a plurality of tendons 78. The tendon 78 secures the device 24 and the first and second section of cells 20, 22 by looping through the through-hole 92 in the body 70 and wrapping around the post 82.
Strength Testing
A test was done on a NIST calibrated tensile testing machine comparing the device 24 to the prior art device 150 (
The tensile test equipment used was a Curtis Sure Grip Inc. 10,000 Lb Capacity “Geo Grip,” Serial Number G-181 & G-182 and related hydraulic cylinder, air over hydraulic power supply, load cell and digital readout.
A single strip of a perforated cellular confinement section of cells, sold by the assignee under the tradename GEOWEB 20V8, was clamped into the tensile tester jaws with the device 24 engaged through the slot 36 with the tendon 78 secured to the device 24, and with the free end of the tendon 78 clamped into the opposite jaw of the tensile tester. The rate of loading used was 12 inches per minute. There were 4 techniques used to fasten the device 24 to the cellular confinement section, as follows:
The results were as follows:
An additional test was run using a single strip of a non-perforated cellular confinement section of cells and having slots 36. Again, the strip was clamped into the tensile tester jaws with the device 24 engaged through the slot 36 with the tendon 78 secured to the device 24, and with the free end of the tendon 78 clamped into the opposite jaw of the tensile tester. The rate of loading used was 12 inches per minute. The result was as follows:
To test the prior art device 150 of U.S. Pat. No. 5,927,906, currently sold by the assignee under the tradename Atra® Clip, a single strip of a perforated cellular confinement section of cells, sold by the assignee under the tradename GEOWEB 20V8, was clamped into the tensile tester jaws with the Atra® Clip device 150 secured with the tendon 78 by use of a “Moore hitch.” Specifically, and in reference to
The device 24 of the present disclosure, made from the nylon 6 with glass reinforcement, resulted in pull through loadings (tensile strength) of more than 80%, indeed at least 100% greater than that of the device of U.S. Pat. No. 5,927,906, in most instances.
The above provides a complete description. Many embodiments can be made.
Number | Name | Date | Kind |
---|---|---|---|
1455636 | McConnal | May 1923 | A |
4778309 | Bach et al. | Oct 1988 | A |
4965097 | Bach | Oct 1990 | A |
5449543 | Bach et al. | Sep 1995 | A |
5758987 | Frame et al. | Jun 1998 | A |
5927906 | Bach et al. | Jul 1999 | A |
6395372 | Bach | May 2002 | B1 |
6484473 | Hall | Nov 2002 | B1 |
7544010 | Restrepo et al. | Jun 2009 | B2 |
8092122 | Senf et al. | Jan 2012 | B2 |
8459903 | Senf et al. | Jun 2013 | B2 |
20080213521 | Halahmi et al. | Sep 2008 | A1 |
20110217117 | Halahmi et al. | Sep 2011 | A1 |
Entry |
---|
US 5,336,544, 08/1994, Bach et al. (withdrawn) |
Number | Date | Country | |
---|---|---|---|
20140205790 A1 | Jul 2014 | US |