US20070183852A1

US20070183852A1 - High-friction geo-textiles for increasing the stability of landfill drainage layers and other high-friction angle installations, and related methods

Info

Publication number: US20070183852A1
Application number: US11/167,561
Authority: US
Inventors: Cesare Beretta
Original assignee: TENAX INTERNATIONAL BV
Current assignee: TENAX INTERNATIONAL BV
Priority date: 2005-06-28
Filing date: 2005-06-28
Publication date: 2007-08-09

Abstract

The present invention relates generally to geo-textiles having an increased resistance to the negative effects of shear forces in installations or layered structures which can be adapted and arranged to utilize geo-textiles. Geo-textiles of the invention comprise at least one high-friction compound, such as one or more high-friction polymers, and methods for making and utilizing them. The high-friction characteristics of components of the invention provide increased resistance to the negative effects of shear forces in layered installations which employ them. Geo-textiles of the invention may have one or more high-friction compounds provided on either or both surfaces. Geo-textiles according to the invention are particularly useful in sloped installations where at least a portion of the layered structure is at a slope angle of greater than 4 degrees, and can be interposed between one or more of geo-membranes, geo-grids, geo-cells, geocomposite laminates and conventional geo-textiles.

Description

FIELD OF THE INVENTION

The present invention relates generally to woven and non-woven geo-textiles which comprise high-friction components, such as polymers, on one or both of their surfaces, and methods for making and utilizing such high-friction geo-textiles. Geo-textiles of the invention provide increased resistance to the negative effects of shear forces in layered installations which employ them, such as those comprising geo-membranes, geo-nets, void-maintaining geo-composite core elements and other layered geo-composite structures. Moreover, the present invention provides means and methods for decreasing the destructive effects of shear forces on layered temporary covers used in landfills and the like.
The high-friction characteristics of the many embodiments of the invention provide engineers and designers with the ability to design, plan and build installations having sloping portions of steeper angles than those achievable without the present invention. Thus, the geo-textiles and methods of the present invention enable a significant increase in the effective volume of installations such as landfills and artificial basins to collect drainage fluids and other effluent. Advantageously, this increases the efficiency of land usage, and the available storage capacity of landfills, storage basins and similar structures.

BACKGROUND OF THE INVENTION

Water is the principal cause of distress in many types of structures. For this reason among others, geotechnical engineers and others skilled in the field of designing drainage systems for large structures often specify sand, stone, piping manifolds, clay and gravel as a means of providing drainage layers and structures, such as collection pipe fields and sumps, to convey effluent away from the structure. More recently, layered structures of polymer or other synthetic materials have been used to provide drainage capacity for large structures such as landfills, highways, parking lots and runways. Such polymer materials, typically geo-membranes, geo-nets and geo-composites, are currently used to complement or replace natural earthen materials such as stone, gravel and clay. In another common function, geo-membranes and geo-textiles are employed as permanent or temporary (“day”) covers for covering landfills.
In some applications, layered combinations of geo-membranes, geo-textiles, geo-nets and other synthetic planar or sheet-like structures are provided in order to achieve desired drainage capacities. Typically, these layered structures are intended to retain the drainage or void spaces that exist in the geo-net core element, in part, by retaining the relative positions of the layers with respect to one another over time. By retaining the relative positions of the layers, the overall integrity of the layered installation is preserved, and the drainage capacity is kept within desired specifications.
A typical problem with conventional geo-textiles, geo-composites, geo-nets, geo-grids and methods for their use are numerous. For example, in many applications, such as in landfills, the various layers are subject to mechanical stresses such as horizontal shear forces. Typically, these shear forces occur approximately parallel to the plane of the layers in the installation, for example, between a geo-membrane which lines the sloping sides of a landfill and the adjacent geo-grid, geo-composite or geo-textile layer. Such shear forces tend to disrupt the relative positions of the various layers thus causing a partial or complete failure of the drainage system because, for example, intrusion of the outer layers into the void spaces.
Such horizontal forces are increased in installations of significant slope, such as those sloping more than 3 degrees. There is thus a need in the field for geo-composites that are resistant to shear forces and particularly for use in those installations having a slope of more than 3 degrees. There is a similar need for means and methods which exhibit superior resistance to the shear forces typically present in layered drainage installations.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide woven and non-woven geo-textiles comprising high-friction compounds on one or both surfaces which provide an increased resistance to shear forces between the geo-textiles and one or more adjacent surfaces, such as one or more of geo-membranes, geo-nets and geo-grid.
It is another object of the invention to provide high-friction geo-textiles which are useful in layered structures and have superior characteristics with respect to functional longevity, performance and inter-layer resistance to shear forces.
It is a similar object of the invention to provide methods for manufacturing such high-friction geo-textiles, and methods for using them in landfills and similar large structures.
In accordance with these and other objects, a geo-textile having a first surface and a second surface is provided, wherein the geo-textile further comprises at least one high-friction compound on at least a portion of the first surface, such that the geo-textile possesses an increased resistance to shear forces when the geo-textile is in adjacent contact with the surface of another layer, for example, in a landfill or other high slope angle installations. In accordance with the specifications and context of use of a particular high-friction geo-textile of the invention, one or more high-friction compounds are provided on at least part of the surface area of the first side of the geo-textile, that is, on a first area portion of the first side of the geo-textile.
Preferably, the one or more high-friction compounds are provided on a first area portion of the first surface, and the first portion comprises a percentage of the surface area of the first surface, for example, on at least 20% of the surface area of the first surface, or on at least 45% of the surface area of the first surface, depending on the particular high-friction angle, the type or types of high-friction compounds, the type and nature of the adjacent layers, and the pressures and other conditions to which the geo-textile and adjacent layers will be subjected. In other embodiments, the one or more high-friction compounds are provided on at least 70% of the surface area of the first surface, or at least 95% of the surface area of the first surface. In accordance with other advantages of the invention, the first side of the geo-textile can be completely covered by one or more high-friction compounds, that is, the first area portion covered by the high-friction compound or compounds can be 100% of the surface area of the first surface of the geo-textile. In a like manner, the same compound or compounds may be applied also to the second surface of the geo-textile.
In accordance with other significant aspects of the invention, the one or more high-friction compounds can be any that satisfy the requirements of a particular installation, such as, the degree of effectiveness of the frictional characteristics of the compound, the particular high-friction angle, the type or types of adjacent layers, the resistance to chemical degradation, and the pressures and other conditions which the geo-textile will experience. Particular compounds which are especially useful as high-friction compounds of the invention include silicone-based compounds, ethylene vinyl acetates (“EVA's”), styrene butadiene rubbers, polyesters, ABS, polybutylenes, recycled latexes, recycled tire compounds, polyethylenes, polyvinyl acetates (“PVA's”), rubberized polyethylenes, ethylene propylene diene monomers, ethylene vinyl alcohol copolymers, polypropylenes, rubberized polypropylenes, polybutadienes, plasticized polyvinyl chlorides, thermoplastic olefms, silicone compounds, and compounds derived from recycled tires. Such compounds may similarly be used on the second surface of the geo-textile, or may be interwoven or interposed among fibers of the geo-textile during manufacture.
Geo-textiles of the invention can be any of natural or synthetic fibers as long as they are adaptable to bond with the high-friction compound or compounds of the invention, for example, woven or non-woven geo-textiles, and needle-punched or non-needle-punched geo-textiles and geo-mats. The geo-textile and high-friction compounds of the invention can be bonded or adhered to one another by any means or methods which result in application of the high-friction compound to the geo-textile such that the desired engineering parameters are achieved. For example, the high-friction compound or compounds can be adhered to the at least one of the surfaces of the geo-textile by one or more of thermal bonding, by one or more adhesives, by laser welding, by hot-melt bonding, by ultrasound, and by the adhesive properties of the high-friction compound itself. Thus, the selection of the one or more high-friction compounds to be used on one or both surfaces of the geo-textile may be made with respect to the aspect of the adhesive properties of the selected one or more high-friction compounds themselves.
Thermal bonding of the high-friction compound to the geo-textile can be accomplished by any means or methods which result in a sufficient bond between the compound and the geo-textile. For example, thermal bonding can be accomplished by effecting deposition of one or more of the high-friction compounds upon the first surface of the geo-textile, and then supplying sufficient heat to one or more of the high-friction compound and the geo-textile such that the bonding is accomplished. Thermal bonding can be accomplished regardless of the form of the one or more high-friction compounds to be bonded to the geo-textile. For example, the one or more high-friction compounds can be deposited in the form of one or more of strands, fibers, beads, globules, flakes, powders, pellets, gels, liquids, crystals, films, matrices and sheets, and then sufficient heat may be added to bond the high-friction compound to the geo-textile.
As an additional advantage, the high-friction compound can be applied to the geo-textile in one or more patterns, for example, straight rows, curved rows, straight stripes, curved stripes, intermittent squares, intermittent circles, intermittent eccentric shapes, regular polygons, irregular polygons, checkerboards, lattices, wave patterns and repeating free-form or miscellaneous designs. The high-friction compound can also be applied randomly as may be desired or advantageous. In another significant aspect, geo-textiles of the invention may have one or more high-friction compounds on all or portions of both surfaces, thereby adding to the diverse circumstances in which geo-textiles of the invention may be used.
Thus, a geo-textile of the invention may further comprise a high-friction compound provided on a second area portion of the second surface, wherein the second portion comprises a percentage of the surface area of the second surface, for example, on at least 20% of the surface area of the second surface, or on at least 45% of the surface area of the second surface, depending on the particular high-friction angle, the type or types of high-friction compounds, the type and nature of the adjacent layers, and the pressures and other conditions to which the geo-textile and adjacent layers will be subjected. In other embodiments, the one or more high-friction compounds are provided on at least 70% of the surface area of the second surface, or at least 95% of the surface area of the second surface. In accordance with other advantages of the invention, the second side of the geo-textile can be completely covered by one or more high-friction compounds, that is, the second area portion covered by the high-friction compound or compounds can be 100% of the surface area of the second surface.
As yet an additional advantage, the one or more high-friction compounds may be interwoven among the fibers of the geo-textile during manufacture of the geo-textile such that the high-friction compound is disposed on at least a portion of the first surface or on at least a portion of both first and second surfaces. The one or more high-friction compounds may be provided in the form of fibers, strands or pellets which are interposed or interwoven among the fibers of the geo-textile during manufacture of the geo-textile such that the high-friction compound is disposed on at least portions of one or both of the first and the second surfaces.
Geo-textiles of the invention are suitable for a myriad of uses, and especially those uses wherein the adjacent surface of another layer is one or more surfaces or layers from the group comprising geo-membranes, geo-grids, geo-textiles, paved surfaces, earthen surfaces, earth-aggregate surfaces, geo-nets, geo-mats and geo-cells.
As yet another advantage, the one or more high-friction compounds may have inherently adhesive properties, or those properties that can be activated by one or more of the processes suitable for forming or manufacturing geo-textiles of the invention. Thus, the one or more high-friction compounds may be selected for their adhesive properties and thus be suitable for adhering the geo-textile to another surface, for example, to one or more surfaces of a geo-net, a geo-membrane, a geo-cell, a void-maintaining core structure, and a second geo-textile.
Geo-textiles of the invention may be adapted and arranged such that the high-friction compound extends above the first or second surfaces of the geo-textile to which it is bonded. Thus the high-friction compound may have a thickness above the surface of the geo-textile to which it applied the thickness being measured perpendicularly from the average mean surface of the geo-textile. Because the one or more high-friction compounds extend above the surface of the geo-textile, it provides additional gripping ability, for example, when the geo-textile is adjacent another layer, such as a geo-net or geo-grid, which also possesses dimensional features which can interact with the raised thickness of the high-friction compound. In some preferred embodiments, the thickness of the one or more high-friction compounds on the first surface of the geo-textile is preferably 0.1 millimeter, or at least 0.1 millimeter. In other preferred embodiments the first thickness is at least 1.0 millimeters, or at least 2.0 millimeters, or least 3.0 milli-meters. In embodiments of the invention where geo-textiles have one or more high-friction compounds on both surfaces, the compound on the second surface has a second thickness, and the second thickness can be of similar dimensions as those of the first surface, or can be of different dimensions. Moreover, the high-friction compound provided on each of the two surfaces may be provided in different, or varying, thick-nesses, and in different patterns or dispositions.
In accordance with additional advantages of the invention, methods for forming geo-textiles having an increased resistance to horizontal shear forces with respect to one or more adjacent surfaces are provided. In one preferred embodiment, a method of the invention comprises the steps of A, providing a geo-textile, the geo-textile having a geo-textile first surface and a geo-textile second surface, and then B, effecting application of at least one high-friction compound to the geo-textile first surface. The at least one high-friction compound can be applied to, or bonded to, the geo-textile in any way or by any means appropriate to joining the compound to the geo-textile sufficiently so that the desired degree of functionality is achieved.
For example, application of the high-friction compound to the geo-textile first surface may effected by first i) providing the high-friction compound onto the first surface as the geo-textile is being formed, and then ii) applying sufficient heat to one or more of the high-friction compound and the geo-textile such that the high-friction compound and the geo-textile are bonded to one another. In another preferred embodiment of methods of the invention, the application of the high-friction compound to the geo-textile first surface is effected by providing the high-friction compound onto the first surface after the geo-textile is formed, and then applying sufficient heat to one or more of the high-friction compound and the geo-textile such that the high-friction compound and the geo-textile are bonded to one another.
Heat sufficient to bond the high-friction compound to the geo-textile may be provided by any combination of means and methods which result in a sufficiently bonded product. As examples, the heat may be provided by one or more of flames, heated air, steam, infrared radiation, heated rollers, heated platens between which the geo-textile and high-friction compound are passed, microwaves, ultra-sound, the melt heat of the high-friction compound itself, the heat of formation of the geo-textile and the residual heat from the processing of either or both of the high-friction compound and of the geo-textile.
Application of the high-friction compound to the geo-textile first surface may be effected by any means or methods desired, for example, by one or more of spraying, random spattering, ultrasound, extrusion of the high-friction compound onto the first surface as the geo-textile is being formed, extrusion of the high-friction compound onto the first surface after the geo-textile is formed, laser melting of the high-friction compound onto the first surface, and hot-melting of the high-friction compound onto the first surface.
The at least one high-friction compound may be provided in any form appropriate to achieving the desired parameters of the final product, such as the proportion of surface area to be covered, the final thickness, the final pattern and relative bond strength. Examples of appropriate include, but are not limited to one or more of strands, fibers, beads, globules, flakes, powders, pellets, gels, liquids, films, matrices and sheets. High-friction compounds appropriate for the methods of the invention are any that achieve the desired characteristics in bonding to the geo-textile and performance parameters, and include those listed above with respect to the high-friction geo-textile products.
In accordance with other aspects of the methods of the invention, the high-friction compound may be provided on at least a first area portion of the first surface, wherein the first area portion comprises a percentage of the surface area of the first surface. Preferably, the one or more high-friction compounds are provided on the first area portion of the first surface, for example, on at least 20% of the surface area of the first surface, or on at least 45% of the surface area of the first surface, depending on the particular high-friction angle, the type or types of high-friction compounds, the type and nature of the adjacent layers, and the pressures and other conditions to which the geo-textile and adjacent layers will be subjected.
In other preferred embodiments, the one or more high-friction compounds can be provided on at least 70% of the surface area of the first surface, or on at least 95% of the surface area of the first surface. In accordance with still other advantages of the invention, the first side of the geo-textile can be completely covered by one or more high-friction compounds, that is, the first area portion covered by the high-friction compound or compounds can be 100% of the surface area of the first surface of the geo-textile. In a like manner, the same or similar compound or compounds may be applied also to the second surface of the geo-textile.
Methods of the invention also offer the advantage of producing high-friction geo-textiles wherein the high-friction compound applied to either or both surfaces may be provided in one or more desired thicknesses, for example, the high-friction compound applied to the first surface may have at least one first thickness, the thickness being measured perpendicularly from the average mean surface of the geo-textile, wherein the first thickness is at least 0.1 millimeters. In some preferred embodiments of methods according to the invention, the thickness on the first surface of the geo-textile, that is, the first thickness of the high-friction compound, is preferably 0.1 millimeter, or at least 0.1 millimeter. In other preferred embodiments the first thickness is at least 1.0 millimeters, or at least 2.0 millimeters, or least 3.0 millimeters. In embodiments of the invention where geo-textiles have high-friction compound on both surfaces, the compound on the second surface has a second thickness, and the second thickness can be of similar, or different, dimensions as those of the high-friction compound on the first surface.
High-friction geo-textiles of the invention can be used in numerous ways. They are particularly suitable for increasing the stability of landfills and in other high-friction angle installations. Thus, in accordance with other advantageous aspects of the invention, methods for increasing resistance to the undesirable effects of horizontal shear forces between one or more layers of geo-membranes, geo-textiles, geo-composites, geo-nets, geo-cells and void-maintaining layers in a landfill installation, are provided.
In one preferred embodiment, the method comprises the step of providing a sheet-like high-friction geo-textile, the geo-textile having a first surface and a second surface,wherein the geo-textile comprises means disposed on at least the first surface of the geo-textile for increasing the coefficient of friction between the geo-textile and an adjacent layer, and then the step of placing, or effecting the disposition of the high-friction geo-textile, adjacent to one or more of the geo-membranes, the geo-textiles, the geo-nets, the geo-cells, and the void-maintaining layers.
Thus, a high-friction geo-textile of the invention may be utilized by placing it, for example, between a geo-membrane and a geo-grid, between two geo-membranes, between a geo-membrane and a second geo-textile, between a geo-membrane and a void-maintaining layer, between a geo-membrane and a geo-net, between two geo-textiles or between two geo-nets. Geo-textiles of the invention can also be used to increase the frictional forces, that is, the resistance to shear forces, between the earthen, stone or aggregate surfaces of a landfill or similar structure, and an adjacent layer such as one or more of a geo-membrane, a geo-grid, a geo-cel, a geo-net, a second geo-textile, and a void-maintaining layer. In a like manner, the geo-textiles of the invention may be used as part of, or among the layers of the one or more covers, for example, for landfill installations or for covering other large structures where the cover is at least partially on a slope. Thus, the disposition of a high-friction geo-textile of the invention may be on top of at least a portion of the landfill and underneath at least one of the geo-membranes, the geo-textiles, the geo-nets and the void-maintaining layers.
Methods of the invention include use of any high-friction textile or textiles, such as those described herein. High-friction textiles for use with the present methods include those wherein the means for increasing the coefficient of friction between the geo-textile and an adjacent layer comprises at least one high-friction compound selected from those described elsewhere herein, and bonded to the geo-textile. The present methods include also the use of geo-textiles comprising means on both the first and the second surfaces of the geo-textile for increasing the coefficient of friction between the geo-textile and the adjacent layers. The first and second surfaces of the geo-textiles may have some or all of their respective surfaces areas covered by the one or more high-friction compounds as is described herein with respect to the disclosed high-friction geo-textiles. Moreover, the present methods include wherein the high-friction compound on the subject geo-textiles has one or more thicknesses as described elsewhere herein. In embodiments where the high-friction compound projects above the surface of the geo-textile, the mechanical engagement of the compound with the adjacent layer increases the resistance to shear forces even further.

DETAILED DESCRIPTION OF THE INVENTION

Geo-textiles of the invention may comprise any substance having a coefficient of friction sufficiently high enough, so that when it is incorporated into one of the present geo-textiles, and placed in an installation having a desired slope, the desired performance characteristics, longevity, and resistance to slope failure are achieved. The one or more high-friction compounds can be thus any that satisfy the requirements of a particular installation, such as, the degree of effectiveness of the frictional characteristics of the compound, the particular high-friction angle, the type or types of adjacent layers, the resistance to chemical degradation, and the pressures and other conditions which the geo-textile will experience.
Particular compounds which are especially useful as high-friction compounds of the invention include silicone-based compounds, ethylene vinyl acetates (“EVA's”), styrene butadiene rubbers, polyesters, ABS, polybutylenes, recycled latexes, recycled tire compounds, polyethylenes, polyvinyl acetates (“PVA's”), rubberized polyethylenes, ethylene propylene diene monomers, ethylene vinyl alcohol copolymers, polypropylenes, rubberized polypropylenes, polybutadienes, plasticized polyvinyl chlorides, thermoplastic olefins, silicone compounds, and compounds derived from recycled tires. Such compounds may similarly be used on the second surface of the geo-textile, or may be interwoven or interposed among fibers of the geo-textile during manufacture.
The adhesion or bonding of the geo-textile to the high-friction compound can be effected by any means or methods that result in sufficient resistance to movement under shear forces, including one or more of thermal bonding, such as flame welding, the simultaneous or serial application of one or more adhesives or solvents, laser welding and ultrasound. As one of skill in the art will appreciate, such additional bonding means increases further the degree of adhesion between the geo-textile and the high-friction compound. As one of skill in the polymer arts will also comprehend, in addition to the high-friction compounds iterated herein, there are numerous other polymers that have, or that can be treated or processed to have, high-friction characteristics that are suitable for use as high-friction compounds of the present geo-textiles.
In numerous permutations and embodiments, the high-friction geo-textiles and methods of the invention are particularly useful in situations where all or at least a portion of the layered installation is on a slope, for example, a slope away from a large structure or one or more slopes leading to the lower levels of a waste landfill. Numerous variations and permutation of methods and woven and non-woven geo-textiles of the invention are particularly suitable for slopes in the range of from 1 degree to 25 degrees, preferably from 4 degrees to 20 degrees, more preferably from 4 degrees to 15 degrees and most preferably from 4 degrees to 10 degrees.
The present invention utilizes one or more high-friction compounds to provide numerous embodiments and combinations of high-friction geo-textiles, which yield the advantageous characteristics of high resistance to horizontal shear forces. The present invention relates generally to means and methods for making and utilizing them but also pertains to numerous specific combinations of high-friction compounds and woven or non-woven geo-textiles. The high-friction characteristics of components of the invention also provide increased resistance to the negative effects of shear forces in laminates which employ them. Geo-textiles of the present invention exhibit superior strength with respect to resisting the destructive effects of shear forces on the void-maintaining capacities of adjacent geo-nets or other void-maintaining layers, particularly in sloped installations. Because of this, geo-textiles of the present invention can be used, for example, to more effectively permit the design and formation of landfills having steeper than conventional and in similar sloped geotechnical applications.
By providing a synthetic drainage system or impermeable barrier that includes the heretofore unknown high-friction geo-textile components, the present geo-textile invention overcomes the disadvantages of layered geo-composite failure caused by displacement of the layers with respect to one another by the stresses caused by horizontal shear forces. The geo-textiles and geo-fabrics used in the present invention are preferably manufactured with specified or defined permeability and perrnittivity properties in order to adapt or integrate them into drainage systems that have effective useful lives. A high-permittivity core element, such as the geo-net shown in U.S. Pat. No. 5,891,549 to Beretta et al., is exemplary of geo-nets suitable for use adjacent to the high-friction geo-textiles of the present invention. Numerous other geo-nets, geo-membranes, geo-cells, geo-grids, and void-maintaining layers are also suitable for use in the invention.
Tire rubber compounds useful for practicing the present invention are those that are known in the art of tire manufacturing and tire recycling. Thus, a geo-textile of the invention may comprise one or more high-friction compounds derived from recycled tire rubber. Used tires that have been processed into usable elastomers, for example, by the methods disclosed in U.S. Pat. Nos. 5,114,648; 6,129,877 and 5,494,510, all to Kuc, Sr., are adaptable for use in the present invention. The Kuc, Sr. patents are hereby incorporated by reference.
High-friction compounds produced in whole or in part from the polymers and rubber used to make tires have high-friction characteristics adaptable for use with the present geo-textiles. Pelletized tire chips marketed under the trademark Duroplas® are one source of re-formulated tire rubber and tire polymer compounds suitable for application to woven or non-woven geo-textiles along with other polymers according to the present invention. Other sources of such re-formulated tire materials are also suitable for practicing the invention.
The present invention provides high-friction geo-textile elements that can be combined with one another or with one or more conventional geo-structures such as geo-nets, geo-membranes and geo-textiles, or combinations of these, such as are typically found in geo-laminates, or in similar layered drainage structures. Such high-friction elements increase the layer-to-layer adhesion and resistance to horizontal shear between adjacent layers in a layered structure. Because of this, geo-structures incorporating the present invention, such as void-maintaining drainage layered structures, can be installed and used at greater slope angles while increasing the resistance to failure caused by shear forces thereby decreasing slope failure and the need for anchors in sloped installations.
The effectiveness of the present invention is demonstrated by its superiority of performance when compared with a conventional geo-textile, and particularly with respect to the performance of conventional geo-textiles adjacent a smooth geo-membrane. In most uses, smooth geo-membranes are preferable to textured geo-membranes because they are less expensive and have superior mechanical properties.
The interface shear strength between a geo-textile of the present invention and a smooth HDPE geo-membrane is greatly enhanced. A test embodiment of the present invention utilizing EVA as the high-friction compound on one of its two surfaces was evaluated. The test embodiment, having one high-friction surface, was tested in accordance with ASTM D5321. ASTM D5321 is the standard direct shear test (2002) for determining the coefficient of friction between soil and an adjacent geo-synthetic product, or between two adjacent geo-synthetic products.
The test embodiment, having a thickness of 2.0-3.0 mm, was tested in according with ASTM D5321 and under normal compressive loading typical of a landfill capping system, that is, at pressures of 1, 2, and 4 lb/in2. The test embodiment achieved a peak friction angle of 26.7 degrees. This is in stark contrast with the typical 11.0 degree peak friction angle of a conventional non-woven geo-textile when placed adjacent a smooth HDPE geo-membrane. With non-woven needle punctured geo-textiles of various weights, based on a database of 149 large scale direct shear tests, with the square of the correlation coefficient being at 0.93. In other words, the present invention increases the peak friction angle of the test embodiment by 142%, an enormous increase.
Moreover, the large displacement, sometimes called the residual friction angle, yields a value of 19.8 degrees for the test embodiment. This is in sharp contrast to the typical 9.0 degrees of a conventional non-woven geo-textile when tested adjacent a smooth HDPE geo-membrane, and with non-woven needle punctured geo-textiles of various weights, based on a database of 82 large scale direct shear tests, with the square of the correlation coefficient being 0.96, thus yielding an increase of 120% over conventional geo-textiles.
Furthermore, the shear strength of the test embodiment equals or exceeds typical behavior of a conventional non-woven geo-textile when tested adjacent a non-smooth, or “textured” geo-membrane. Typical peak and large displacement friction angles between a conventional non-woven geo-textile and a textured HDPE geo-membrane are 25.0 degrees. These results are based upon non-woven needle punctured geo-textiles of various weights, and on a database of 254 large scale direct shear tests, with the square of the correlation coefficient being 0.96 and 17.0 degrees, and on non-woven needle punctured geo-textiles of various weights, based on a database of 217 large scale direct shear tests, with the square of the correlation coefficient being 0.95, respectively.”
Although the present invention has been described in connection with specific forms and permutations, those skilled in the art will appreciate that various modifications and other than those discussed herein are within the scope and spirit of the invention. For example, equivalent elements may be substituted for those specified herein, certain features may be used independently of other features, and process steps may be modified, reversed or interposed, all without departing from the invention as recited herein and in the following claims.

Claims

1. A geo-textile having a first surface and a second surface,

wherein said geo-textile further comprises a high-friction compound on at least a portion of said first surface, such that said geo-textile possesses an increased resistance to shear forces when said geo-textile is in adjacent contact with the surface of another layer.

2. The geo-textile of claim 1, wherein said high-friction compound is provided on a first area portion of said first surface, and said first portion comprises a percentage of the surface area of said first surface.

3. The geo-textile of claim 1, wherein said first area portion is at least 20% of said surface area of said first surface.

4. The geo-textile of claim 1, wherein said wherein said first area portion is at least 45% of said surface area of said first surface.

5. The geo-textile of claim 1, wherein said wherein said first area portion is at least 70% of said surface area of said first surface.

6. The geo-textile of claim 1, wherein said wherein said first area portion is at least 95% of said surface area of said first surface.

7. The geo-textile of claim 1, wherein said wherein said first area portion is 100% of said surface area of said first surface

8. The geo-textile of claim 1, wherein said high-friction compound comprises one or more from the group comprising silicone-based compounds, ethylene vinyl acetates (“EVA's”), styrene butadiene rubbers, polyesters, ABS, polybutylenes, recycled latexes, recycled tire compounds, polyethylenes, polyvinyl acetates (“PVA's”), rubberized polyethylenes, ethylene propylene diene monomers, ethylene vinyl alcohol copolymers, polypropylenes, rubberized polypropylenes, polybutadienes, plasticized polyvinyl chlorides, thermoplastic olefins, silicone compounds, and compounds derived from recycled tires.

9. The geo-textile of claim 1, wherein said geo-textile is one or more of woven, non-woven, needle-punched, and non-needle-punched.

10. The geo-textile of claim 1, wherein said high-friction compound is adhered to said at last one of said surfaces by one or more of thermal bonding, one or more adhesives, laser welding, hot-melt bonding, ultrasound, and the adhesive properties of said high-friction compound itself.

11. The geo-textile of claim 10, wherein said thermal bonding of said high-friction compound to said geo-textile is accomplished by

A. effecting deposition of one or more of said high-friction compounds upon said first surface of said geo-textile, wherein said high-friction compound is deposited in the form of one or more of strands, fibers, beads, globules, flakes, powders, pellets, gels, liquids, crystals, films, matrices and sheets, and then

B. supplying sufficient heat to one or more of said high-friction compound and said geo-textile such that said bonding is accomplished.

12. The geo-textile of claim 1, wherein said high-friction compound is applied in one or more patterns.

13. The geo-textile of claim 1, wherein said high-friction compound applied to said first surface has a first thickness, said thickness being measured perpendicularly from the average mean surface of said geo-textile, wherein said first thickness is at least 0.1 millimeters.

14. The geo-textile of claim 13, wherein said first thickness is at least 1.0 millimeters.

15. The geo-textile of claim 13, wherein said first thickness is at least 2.0 millimeters.

16. The geo-textile of claim 13, wherein said first thickness is at least 3.0 millimeters.

17. The geo-textile of claim 12, wherein said one or more patterns are selected from the group comprising, straight rows, curved rows, straight stripes, curved stripes, intermittent squares, intermittent circles, intermittent eccentric shapes, regular polygons, irregular polygons, checkerboards, lattices, wave patterns and repeating free-form or miscellaneous designs.

18. The geo-textile of claim 1, wherein said high-friction compound is applied randomly.

19. The geo-textile of claim 1, further comprising a high-friction compound provided on a second area portion of said second surface, wherein said second portion comprises a percentage of the surface area of said second surface.

20. The geo-textile of claim 19, wherein said first area portion is at least 20% of said surface area of said second surface.

21. The geo-textile of claim 19, wherein said wherein said first area portion is at least 45% of said surface area of said second surface.

22. The geo-textile of claim 19, wherein said wherein said first area portion is at least 75% of said surface area of said first surface.

23. The geo-textile of claim 19, wherein said wherein said first area portion is at least 95% of said surface area of said second surface.

24. The geo-textile of claim 19, wherein said wherein said first area portion is 100% of said surface area of said second surface.

25. The geo-textile of claim 19, wherein said high-friction compound comprises one or more from the group comprising silicone-based compounds, ethylene vinyl acetates (“EVA's”), styrene butadiene rubbers, polyesters, ABS, polybutylenes, recycled latexes, recycled tire compounds, polyethylenes, polyvinyl acetates (“PVA's”), rubberized polyethylenes, ethylene propylene diene monomers, ethylene vinyl alcohol copolymers, polypropylenes, rubberized polypropylenes, polybutadienes, plasticized polyvinyl chlorides, thermoplastic olefins, silicone compounds, and compounds derived from recycled tires.

26. The geo-textile of claim 1, wherein said high-friction compound is interwoven among the fibers of said geo-textile during manufacture of said geo-textile such that said high-friction compound is disposed on at least a portion of said first surface.

27. The geo-textile of claim 1, wherein said high-friction compound is provided in the form of fibers, beads, globules, flakes, powders, pellets, gels, liquids, crystals, films, matrices and strands, which are interwoven among the fibers of said geo-textile during manufacture of said geo-textile such that said high-friction compound is disposed on at least portions of both said first and said second surfaces.

28. The geo-textile of claim 1, wherein said adjacent surface of another layer is one or more from the group comprising geo-membranes, geo-grids, geo-textiles, paved surfaces, earthen surfaces, earth-aggregate surfaces, geo-nets, geo-mats and geo-cells.

29. The geo-textile of claim 1, wherein said high-friction compound comprises adhesive properties.

30. The geo-textile of claim 29, wherein said high-friction compound is suitable for adhering said geo-textile to one or more of a geo-net, a geo-membrane, a geo-cell, a void-maintaining core structure, and a second geo-textile.

31. The geo-textile of claim 1, wherein said geo-textile is adapted and arranged to comprise at least part of a removable or permanent cover for a landfill, artificial basin or other large structure.

32. A method for forming a geo-textile, said geo-textile having an increased resistance to horizontal shear forces with respect to one or more adjacent surfaces, comprising the steps of

A. providing a geo-textile, said geo-textile having a geo-textile first surface and a geo-textile second surface,

B. effecting application of at least one high-friction compound to said geo-textile first surface.

33. The method of claim 32, wherein said application of said high-friction compound to said geo-textile first surface is effected by

i) providing said high-friction compound onto said first surface as said geo-textile is being formed, and then

ii) applying sufficient heat to one or more of said high-friction compound and said geo-textile such that said high-friction compound and said geo-textile are bonded to one another.

34. The method of claim 32, wherein said application of said high-friction compound to said geo-textile first surface is effected by

providing said high-friction compound onto said first surface after said geo-textile is formed, and then

applying sufficient heat to one or more of said high-friction compound and said geo-textile such that said high-friction compound and said geo-textile are bonded to one another.

35. The method of claim 32, wherein said sufficient heat is provided by one or more of flames, heated air, steam, infrared radiation, heated rollers, heated platens, microwaves, ultra-sound, the melt heat of said high-friction compound, and the heat of formation of said geo-textile.

36. The method of claim 32, wherein said application of said high-friction compound to said geo-textile first surface is effected by one or more of spraying, random spattering, ultrasound, extrusion of said high-friction compound onto said first surface as said geo-textile is being formed, extrusion of said high-friction compound onto said first surface after said geo-textile is formed, laser melting of said high-friction compound onto said first surface, and hot-melting of said high-friction compound onto said first surface.

37. The method of claim 32, wherein said at least one high-friction compound is provided in the form of one or more of strands, fibers, beads, globules, flakes, powders, pellets, gels, liquids, crystals, films, matrices and sheets.

38. The method of claim 32, wherein said high-friction compound comprises one or more from the group comprising silicone-based compounds, ethylene vinyl acetates (“EVA's”), styrene butadiene rubbers, polyesters, ABS, polybutylenes, recycled latexes, recycled tire compounds, polyethylenes, polyvinyl acetates (“PVA's”), rubberized polyethylenes, ethylene propylene diene monomers, ethylene vinyl alcohol copolymers, polypropylenes, rubberized polypropylenes, polybutadienes, plasticized polyvinyl chlorides, thermoplastic olefins, silicone compounds, and compounds derived from recycled tires.

39. The method of claim 32, wherein said high-friction compound is provided on at least a first area portion of said first surface, and said first portion comprises a percentage of the surface area of said first surface.

40. The method of claim 32, wherein, after application and heating of said high-friction compound, said compound covers at least 20% of the surface area of said first surface of said geo-textile.

41. The method of claim 32, wherein, after application and heating of said high-friction compound, said compound covers at least 45% of the surface area of said first surface of said geo-textile.

42. The method of claim 32, wherein, after application and heating of said high-friction compound, said compound covers at least 70% of the surface area of said first surface of said geo-textile.

43. The method of claim 32, wherein, after application and heating of said high-friction compound, said compound covers at least 95% of the surface area of said first surface of said geo-textile.

44. The method of claim 32, wherein, after application and heating of said high-friction compound, said compound covers 100% of the surface area of said first surface of said geo-textile.

45. The method of claim 32, further comprising the step of

C. effecting application of said high-friction compound to said geo-textile second surface.

46. The method of claim 45, wherein said high-friction compound is provided on at least a second area portion of said second surface, and said second portion comprises a percentage of the surface area of said second surface.

47. The method of claim 45, wherein, after application and heating of said high-friction compound, said compound covers at least 20% of the surface area of said second surface of said geo-textile.

48. The method of claim 45, wherein, after application and heating of said high-friction compound, said compound covers at least 45% of the surface area of said second surface of said geo-textile.

49. The method of claim 45, wherein, after application and heating of said high-friction compound, said compound covers at least 70% of the surface area of said second surface of said geo-textile.

50. The method of claim 45, wherein, after application and heating of said high-friction compound, said compound covers at least 95% of the surface area of said second surface of said geo-textile.

51. The method of claim 45, wherein, after application and heating of said high-friction compound, said compound covers 100% of the surface area of said second surface of said geo-textile.

52. The geo-textile of claim 32, wherein said high-friction compound applied to said first surface has a first thickness, said thickness being measured perpendicularly from the average mean surface of said geo-textile, wherein said first thickness is at least 0.5 millimeters.

53. The geo-textile of claim 32, wherein said first thickness is at least 1.0 millimeters.

54. The geo-textile of claim 32, wherein said first thickness is at least 2.0 millimeters.

55. The geo-textile of claim 32 wherein said first thickness is at least 3.0 millimeters.

56. A method for increasing resistance to the undesirable effects of horizontal shear forces between one or more geo-membranes, geo-textiles, geo-composites, geo-nets, geo-cells and void-maintaining layers in a landfill installation, comprising the steps of

A. providing a sheet-like high-friction geo-textile, said geo-textile having a first surface and a second surface,

wherein said geo-textile comprises means disposed on at least said first surface of said geo-textile for increasing the coefficient of friction between said geo-textile and an adjacent layer, and

B. effecting disposition of said high-friction geo-textile adjacent to one or more of said geo-membranes, said geo-textiles, said geo-nets and said void-maintaining layers.

57. The method of claim 56, wherein said disposition of said high-friction geo-textile is between a geo-membrane and a geo-grid.

58. The method of claim 56, wherein said disposition of said high-friction geo-textile is between two geo-membranes.

59. The method of claim 56, wherein said disposition of said high-friction geo-textile is between a geo-membrane and a second geo-textile.

60. The method of claim 56, wherein said disposition of said high-friction geo-textile is between a geo-membrane and a void-maintaining layer.

61. The method of claim 56, wherein said disposition of said high-friction geo-textile is on top of at least a portion of said landfill and underneath at least one of said geo-membranes, said geo-textiles, said geo-nets and said void-maintaining layers.

62. The method of claim 56, wherein said means for increasing the coefficient of friction between said geo-textile and an adjacent layer comprises at least one high-friction compound selected from the group comprising silicone-based compounds, ethylene vinyl acetates (“EVA's”), styrene butadiene rubbers, polyesters, ABS, polybutylenes, recycled latexes, recycled tire compounds, polyethylenes, polyvinyl acetates (“PVA's”), rubberized polyethylenes, ethylene propylene diene monomers, ethylene vinyl alcohol copolymers, polypropylenes, rubberized polypropylenes, polybutadienes, plasticized polyvinyl chlorides, thermoplastic olefins, silicone compounds, and compounds derived from recycled tires.

63. The method of claim 56, wherein said high-friction geo-textile comprises means on both said first and said second surfaces of said geo-textile for increasing the coefficient of friction between said geo-textile and said adjacent layers.

64. The method of claim 56, wherein said high-friction compound is provided on at least a first area portion of said first surface, and said first portion comprises a percentage of the surface area of said first surface.

65. The method of claim 56, wherein said first portion of said high-friction compound covers at least 20% of the surface area of said first surface.

66. The method of claim 56, wherein said first portion of said high-friction compound covers at least 60% of the surface area of said first surface.

67. The method of claim 56, wherein said first portion of said high-friction compound covers at least 95% of the surface area of said first surface.

68. The method of claim 56, wherein said first portion of said high-friction compound covers 100% of the surface area of said first surface.

69. The method of claim 56, wherein said high-friction compound applied to said first surface has a first thickness, said thickness being measured perpendicularly from the average mean surface of said geo-textile, and wherein said first thickness is at least 0.5 millimeters.

70. The method of claim 56, wherein said first thickness is at least 1.0 millimeters.

71. The method of claim 56, wherein said first thickness is at least 2.0 millimeters.

72. The method of claim 56, wherein said first thickness is at least 3.0 millimeters.

73. The method of claim 62, wherein said upper surface is disposed for contacting one or more adjacent surfaces, and

wherein said high-friction compound is provided on at least a first area portion of said upper surface, and said first portion comprises a percentage of the surface area of said upper surface.

74. The method of claim 63, wherein said first area portion of said high-friction compound covers at least 20% of said upper surface area of said upper surface.

75. The method of claim 63, wherein said first area portion of said high-friction compound covers at least 60% of said upper surface area of said upper surface.

76. The method of claim 63, wherein said first area portion of said high-friction compound covers at least 95% of said upper surface area of said upper surface.

77. The method of claim 63, wherein said first area portion of said high-friction compound covers 100% of said upper surface area of said upper surface.