WO1998006570A1

WO1998006570A1 - Bonded composite engineered mesh structural textiles

Info

Publication number: WO1998006570A1
Application number: PCT/US1997/006355
Authority: WO
Inventors: Peter Edward Stevenson; Jeffrey W. Bruner
Original assignee: The Tensar Corporation
Priority date: 1996-08-14
Filing date: 1997-04-14
Publication date: 1998-02-19
Also published as: AU2672697A; ID19207A

Abstract

Bonded composite engineered mesh structural textiles are formed of woven textile (10). The textile is formed from at least two, and preferably three, components. The first component is a high tenacity, high modulus, low elongation mono- or multi-filament yarn. The second component is a polymer in yarn or other form which will encapsulate and bond adjacent yarns. The third component is an optional effect or bulking yarn. In the woven textile (10), a plurality of warp yarns (14) are woven with a plurality of weft yarns (12). At least a portion of the warp (14) and weft (12) yarns are first component load bearing yarns. The polymer component provides the bonding properties necessary for the finished product, and especially to provide improved selvages for high junction strength. The effect or bulking yarns are used as warp (14) and/or weft (12) yarns and/or leno yarns to provide the desired bulk in the textile.

Description

BONDED COMPOSITE ENGINEERED MESH STRUCTURAL TEXTILES

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to bonded composite engineered mesh structural textiles which may be a closed structure (i.e., tightly woven), or may contain as much as 10% open area in a regularly distributed pattern over the textile, or may contain certain deliberately designed apertures in a repeating pattern, and which is primarily designed for use as structural load bearing elements in earthwork construction applications such as earth retention systems (in which the load bearing element is used to internally reinforce steeply inclined earth or construction fill materials to improve their structural stability) , foundation improvement systems (in which the load bearing element is used to support and/or internally reinforce earth or foundation fill materials to improve their load bearing capacity) , pavement improvement systems (in which the load bearing element is used to internally reinforce flexible pavements or to support rigid modular paving units to improve their structural performance and extend their useful service lives) or erosion protection systems (in which the load bearing element is used to confine or internally reinforce earth or construction fill materials in structures which are subject to erosion or which prevent erosion elsewhere by dissipating wave energy in open water) . While the materials of this invention have many other diverse applications, they have been primarily designed to embody unique characteristics which are important in engineered earthwork construction and particular emphasis is placed on such uses throughout this application.

2. Description of the Prior Art Geogrids and geotextiles are polymeric materials used as load bearing, separation or filtration elements in many earthwork construction applications. Geogrids are grid-like polymeric materials typically having about 75 to 90% open area. Geotextiles are permeable textiles typically having up to about 10% open area. There are four general types of materials used in such applications: 1) integrally formed structural geogrids; 2) woven or knitted textiles; 3) open mesh woven or knitted textiles; and 4) non-woven textiles. Integrally formed structural geogrids are formed by extruding a flat sheet of polymeric material, punching apertures in the sheet in a generally square or rectangular pattern and then uniaxially or biaxially stretching the apertured sheet, or by extruding an integrally formed mesh structure which constitutes a sheet with apertures in a generally square or rectangular pattern and then uniaxially or biaxially stretching the apertured sheet. Woven or knitted textiles are formed by mechanically interweaving or interlinking polymeric fibers or fiber bundles with conventional textile weaving or knitting technologies. Open mesh woven textiles are formed in this same manner and are normally coated in a subsequent process. Non- woven textiles are produced by forming a fibrous web or batt which is subsequently bonded, often by needling, and in some processes the entangled polymeric fibers are then re-oriented in a biaxial stretching process, calendared and/or heat fused.

Integrally formed structural geogrids are well known in the market and are an accepted embodiment in many earthwork construction applications. Open mesh woven or knitted textiles, generally characterized and marketed as textile geogrids, compete directly with integrally formed structural geogrids in many applications and have also established an accepted position in earthwork construction markets. Competition between either of these "geogrid" materials and conventional woven or knitted textiles is less frequent. Woven or knitted textiles with low basis weight tend to be used in separation and filtration applications. Woven or knitted textiles with high basis weight tend to be used in load bearing applications which are tolerant to the load-elongation properties of such materials and which can beneficially use the high ultimate tensile strength of such materials. Non-woven textiles are generally subject to very high elongation under load and are not normally used in load bearing earthwork construction applications. Competition between either "geogrids" or woven or knitted textiles used in reintorcing applications and non-woven textiles is negligible.

The characteristics of integrally formed structural geogrids and woven or knitted textiles are significantly different in several respects. The integrally formed materials exhibit high structural integrity with high initial modulus, high junction strength and high flexural and torsional stiffness. Their rigid structure and substantial cross sectional profile also facilitate direct mechanical keying with construction fill materials, with contiguous sections of themselves when overlapped and embedded in construction fill materials and with rigid mechanical connectors such as bodkins, pins or hooks. These features of integrally formed structural geogrids provide excellent resistance to movement of particulate construction fill materials and the integrally formed load bearing elements relative to each other, thereby preserving the structural integrity of foundation fill materials or preventing pull out of the embedded load bearing elements in earth retention applications. Integrally formed structural geogrids interact with soil or particulate construction fill materials by the process of the soil or construction fill materials penetrating the apertures of the rigid, integrally formed geogrid. The result is that the geogrid and the soil or construction fill materials act together to form a solid, continuously reinforced matrix. Both the longitudinal load bearing members and the transverse load bearing members and the continuity of strength between the longitudinal and the transverse load bearing members of the geogrid are essential in this continuous, matrix-like interlocking and reinforcing process. If the junction between the longitudinal and the transverse load bearing members fails, the geogrid ceases to function in this manner and the confinement and reinforcement effects are greatly reduced. Their rigid structure also facilitates their use over very weak or wet subgrades where placement of such load bearing materials and subsequent placement of construction fill materials is difficult.

The woven or knitted materials exhibit higher overall elongation under load, lower initial modulus, softer hand and greater flexibility. With sufficient increase in the number- of fibers or fiber bundles comprising their structure they are capable of achieving higher ultimate tensile strength than integrally formed structural geogrids. Woven or knit geotextiles interact with soil or particulate matter by generating a high soil/textile friction angle. This bond between soil and textile reinforcement is defined by a resistance to pull out of the reinforcement and results in the transfer of the load from the soil to the textile reinforcement which is placed in axial tension by the load transfer. When joining or combining is required, individual panels of woven or knit geotextile are sewn together. Typically a geotextile seam will exhibit mechanical properties, particularly tensile, which are 50% of the unsewn textile strength. The attributes which are most pertinent to the use of polymeric materials in structural load bearing earthwork construction applications are:

(a) the load transfer mechanism by which structural forces are transferred to the load bearing element,

(b) the load capacity of the load bearing element;

(c) the structural integrity of the load bearing element when subjected to deforming forces in installation and use ; and

(d) the resistance of the load bearing element to degradation (i.e., loss of key properties) when subject to installation or long term environmental stress.

The limitations which woven or knitted textiles exhibit with respect to the first three attributes listed above primarily result from a lack of rigidity and tautness in the fibers or fiber bundles of these materials in which many separate fibers or fiber bundles are interlinked, interwoven or entangled in a manner which is characteristic of a woven or knitted structure and which does not cause the load bearing fibers or fiber bundles to be either taut or di ensionally stable relative to each other. The limitations which such materials exhibit with respect to the fourth attribute listed above primarily result from degradation of their base polymer by ultra violet or environmental attack.

Attempts have been made to dimensionally stabilize and protect the fibers or fiber bundles in the woven or knitted textiles. For instance, special weaves with flat warps and third yarn weaving systems have been produced to reduce elongation and stabilize the fiber bundles and the textile structure. This technique improves the dimensional stability of the fiber bundles to some extent. However, this technique has not delivered sufficient initial modulus to enable such materials to be functionally comparable to integrally formed structural geogrids or to be directly competitive with integrally formed structural geogrids in certain demanding earthwork construction applications which require or benefit from load transfer by direct mechanical keying or high initial modulus or high structural integrity or stiffness in the load bearing element.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a textile which has improved suitability for use as a structural load bearing element in demanding earthwork construction applications.

It is another object of the present invention to provide a textile with improvements over the prior art in one or more of the following attributes:

(a) its load transfer mechanism (specifically its high soil to textile friction angle) ;

(b) its load capacity (specifically its initial modulus, i.e., its resistance to elongation when initially subject to load) ; (c) its structural integrity (specifically its flexural and torsional stiffness) ; and

(d) its durability (specifically its resistance to degradation when subject to installation and long term environmental stress) .

These and other objects of the present invention will become apparent with reference to the following specification and claims.

Bonded composite engineered mesh structural textiles according to the present invention are woven textiles formed from at least two and preferably three independent but complementary polymeric components. The first component, the load bearing element, is a high tenacity, high initial modulus, low elongation monofilament or multifilament polymeric fiber or bundle of such fibers with each fiber being of homogenous or bicomponent structure. Where bicomponent fibers or fiber bundles are used to form such load bearing elements it is possible to achieve improved resistance to degradation (i.e., loss of key properties) when such materials are subject to installation and long term environmental stress in use (i.e. , by using a core material most suited to achievement of desired mechanical properties and a different sheath material most suited to achievement of desired durability properties in a particular field of use) . The second component, a bonding element, is an independent polymeric material in monofilament or multifilament form and of homogenous or bicomponent structure which is used to encapsulate and/or bond the load bearing fibers thereby strengthening the composite material, stiffening the composite material, increasing its resistance to elongation under load and increasing its resistance to degradation when subject to installation or long term environmental stress. The third component, when used, is an effect or bulking fiber which increases the cross section of the bonded composite structural textile thereby further increasing its stiffness and increasing its effectiveness in mechanically interlocking (keying) with particulate construction fill materials. In the bonded composite engineered mesh woven textile a plurality of warp fibers (commonly referred to as yarns) are closely interwoven with a plurality of weft yarns. The weave preferably includes a half cross or full cross leno weave. At least a portion of the warp and weft yarns are first component load bearing yarns. The second polymer component is used as required for the bonding properties necessary for the finished product. The effect or bulking yarns are used as warp and/or weft yarns and/or leno yarns. The effect or bulking yarns increase friction with adjacent yarns to provide better stability and structural integrity in the overall material. Two or more effect or bulking yarns interlacing with one another provide the greatest stability. The effect or bulking yarns also provide the desired bulk in the textile and relatively thick cross sectional profile for the finished product to improve its stability and its effectiveness in mechanically establishing a high friction angle with particulate construction fill materials.

The second component may be incorporated into the textile in several ways. The second component may be provided by a fusible bonding yarn, either monofilament or multifilament, which is preferably a bicomponent yarn having a low melting temperature sheath and a high melting temperature core. In the woven textile, the fusible bonding yarns may be used as warp and/or weft yarns and/or leno yarns to provide the improved flexural and torsional stiffness. Alternatively, the second component may be provided by a suitable polymer applied and bonded to the textile by any of a number of different processes after the textile leaves the loom. The second component also may be provided by a combination of a fusible bonding yarn and an additional polymeric material independently applied and bonded to the textile.

In accordance with one embodiment of the invention where a fusible bonding yarn is used, the woven textile is heated to melt the fusible polymer component, i.e., to melt the monofilament and/or multifilament bonding fibers or the sheath of the bicomponent bonding fibers. This causes the fusible polymer component to flow around and encapsulate the other components of the textile and protects, strengthens and stiffens the overall structure. In accordance with another embodiment-of the invention, the woven textile is impregnated with a suitable polymer which flows around and encapsulates the other components of the textile. The impregnated textile is then heated to dry and/or cure the polymer to bond the yarns which protects, strengthens and stiffens the overall structure. In accordance with yet another embodiment of the invention, a polymer sheet or web is applied to the woven textile and heated to melt the sheet or web causing the polymer to flow around and encapsulate the yarn components of the textile and protect, strengthen and stiffen the overall structure.

The materials produced according to the present invention can also be modified for various applications by selection of the type and number and location of the first component load bearing yarns and the type and number and location of the second component fusible bonding yarns and/or other independent polymeric bonding materials, and the type and location of the optional third component bulking yarns. Thus, the material can be custom tailored for particular applications. Materials produced according to the present invention can also easily be designed and manufactured to achieve specific tensile properties in the longitudinal direction or both the longitudinal and transverse directions. This flexibility enables more efficient use of the instant invention in demanding earthwork applications which often have widely varying and site specific needs. The use of fusible yarns and/or other polymeric bonding materials to increase overall material stiffness and initial modulus also permits increased flexibility in the design of civil engineering structures and commercial use of such materials. Inexpensive bulking yarns may also be used in a variety of economical ways to provide bulk and increased cross sectional profile without sacrificing strength or other desirable characteristics. For example, some or all warp or weft yarn bundles may be selected to provide a thick profile through the addition of bulking yarns or additional strength yarns. The resulting thick profile, either in all yarn bundles or in certain selected yarn bundles, for example every sixth weft yarn bundle, will provide improved resistance to pullout. The thick yarn bundle profile in the bonded composite structural textile functions in a manner to increase the soil textile friction angle. Finally, materials produced according to the present invention can be manufactured using conventional, inexpensive, widely available weaving equipment which minimizes the cost of production of such materials.

Materials produced according to the present invention have a number of advantages compared to conventional woven or knitted textiles, the collective effect of which is to render materials produced according to the present invention much more suitable for use in demanding earthwork construction applications. The primary benefits of the inventive concepts embodied in materials produced according to the present invention are described below:

Feature Benefit 1. Improved strength causes structural forces in demanding earthwork construction applications to be transferred to the load bearing elements of the instant invention by means of positive mechanical interlock with construction fill materials as well as by frictional interface with such construction fill materials

Improved cross sectional increases soil to textile profile friction angle

3. Improved initial modulus causes structural forces in demanding earthwork applications to be transferred to the load bearing elements of the instant invention at very low strain levels, thereby substantially reducing deformation in the earthwork structure and substantially increasing the efficiency of use of such load bearing elements in demanding earthwork construction applications

Improved flexural causes the matrix of stiffness transversely oriented load bearing elements in the instant invention to resist in plane deflection, thereby increasing its ease of installation, particularly over very weak or wet subgrades and increasing its capacity to suppor construction fill material initially placed on top of suc subgrades

5. Improved torsional causes the matrix o stiffness transversely oriented loa bearing elements in the instan invention to resist in plane o rotational movement o particulate construction fil materials when subject t dynamic loads such as a movin vehicle causes in an aggregat foundation for a roadwa thereby increasing the loa bearing capacity of th particulate construction fil materials and increasing th efficiency of use of such loa bearing elements in suc demanding earthwor construction applications

6. Improved resistance to causes the instant invention degradation to have improved suitability for use in earthwork construction applications which involve exposure to significant mechanical stress in installation or use and/or involve exposure to significant long term environmental (i.e., biological or chemical) stres in use 7. Improved flexibility in enables widely disparate-and product design and complementary properties to be manufacture embodied in the instant invention via the independent polymeric materials chosen for use in each of the three components of the instant invention (the load bearing element, the bonding element and the bulking element) or chosen for use in the independent polymeric materials comprising the core or sheath components of any of these three elements and also enables the type and number and location of all such components of the instant invention to be economically varied without substantial modification of manufacturing equipment

8. Improved efficiency in enables users of the instant product use invention to exploit the various product features and the flexibility in choosing and using variants of such features all as described above to achieve performance and productivity gains in a wide variety of earthwork construction applications

9. Improved suitability for causes the instant invention, use in demanding earth-work by virtue of the collective construction features and benefits described above, to have greater opportunity for use i markets involving demanding earthwork construction applications than has heretofore been enjoyed by woven or knitted textiles

BRTF.F DESCRTPTTON OF THE DRAWINGS

Figs. 1(a) through 1(e) are exploded schematic plan views of several textile weaves which may be used in the bonded composite engineered mesh structural textile according to the present invention.

Figs. 2(a) through 2(e) are exploded schematic plan views of several leno weaves which may be used in the bonded composite engineered mesh structural textile according to the present invention. Fig. 3 is an exploded schematic plan view of a portion of a textile construction for a bonded composite engineered mesh structural textile according to the present invention showing a leno weave arranged longitudinally to enhance and control the porosity/permeability of the textile. Fig. 4 is an exploded schematic plan view of a portion of a textile construction for a bonded composite engineered mesh structural textile according to the present invention showing a leno weave arranged laterally to enhance and control the porosity/permeability of the textile. Fig. 5 is an exploded schematic plan view of a portion of a textile construction for a bonded composite engineered mesh structural textile according to the present invention showing a leno weave arranged in repeating rectangular patterns to enhance and control the porosity/permeability of the textile.

Fig. 6 is a schematic sectional view of a retaining wall formed using bonded composite engineered mesh structural textiles according to the present invention.

Fig. 7 is a schematic sectional view of a reinforced embankment constructed over weak foundation soils using bonded composite engineered mesh structural textiles according to the present invention.

Fig. 8 is a schematic sectional view of reinforced steep slopes which increase the capacity of sludge containment of a sludge containment pond using bonded composite engineered mesh structural textiles according to the present invention.

Fig. 9 is a schematic sectional view of a landfill liner support provided by a bonded composite engineered mesh structural textile according to the present invention. Fig. 10 is a schematic sectional view of the stability of soil veneer on a slope liner provided by a bonded composite engineered mesh structural textile according to the present invention.

Fig. 11 is a perspective view of a sand or gravel mattress formed of a bonded composite engineered mesh structural textile according to the present invention.

Fig. 12 is a cross-sectional view taken along lines 12-12 in Fig. 11.

Fig. 13 is a schematic sectional view of a toe protection for a steep-walled caisson structure provided by the sand or gravel mattress of Fig. 11.

DETAILED DESCRIPTION OF THE DRAWINGS

The bidirectional woven textile of the present invention is formed of a plurality of weft, filling or pick yarns and a plurality of warp yarns. The weft yarns are interlaced or interwoven with the warp yarns.

Referring to Figs. 1(a) through 1(e), Fig. 1(a) illustrates a woven textile 10 in which weft yarns 12 are interlaced with warp yarns 14 in plain weave or over 1 under 1 order (1/1). Fig. 1(b) illustrates a plain weave variation, namely, a rib weave. The woven textile 20 has weft yarns 22 and warp yarns 24 in which the 1 and 1 plain interlacing has been increased to 2 and 2 (2/2) in warp and weft, respectively. Fig. 1(c) illustrates a woven textile 30 having weft yarns 32 and warp yarns 34 interlaced in a simple twill weave (2/2) . The twill effect is produced by the stepping one yarn space to the right of each successive weft yarn interlacings (warp interlacings, being equal, also move similarly). Fig. 1(d) illustrates a woven textile 40 in which weft yarns 42 are interlaced with warp yarns 44 in a basket weave (3/3). Fig. 1(e) illustrates a woven textile 50 having weft yarns 52 interwoven with warp yarns 54 in a twill weave (3/3).

Figs. 1(a) through 1(e) are merely illustrative of the types of weaves which may be employed in accordance with the present invention. In addition to the weaves illustrated, the textiles of the present invention can also be formed using other twill weaves (e.g., 1/2, 2/1, 3/1, 1/3), other basket weaves (e.g., 2x2, 3x2) and the like.

The porosity/permeability of a woven textile having a single type of weave such as illustrated in Figs. 1(a) through 1(e) can only be controlled by the selection of the yarns and weave geometry. In other words, the porosity/permeability of the textile depends on the size, thickness, and composition of the yarns in combination with the textile structure, i.e., the closeness of the yarns and frequency of interlacings, plus the effect of finishing processes.

Referring to Figs. 2(a) through 2(f), the bidirectional woven textile may include various leno weave patterns selectively placed in the textile to enhance and control the porosity/permeability of the textile. Fig. 2(a) illustrates a half cross leno 110 in which the leno ends of adjacent leno yarns 112 and 114 are twisted in one direction between adjacent weft yarns 116 to form a half twist (180°) between adjacent weft yarns 116. Fig. 2(b) illustrates an upper shed, half cross leno 120 in which the leno yarn 122 is raised to form an opening, or shed, between adjacent weft yarns 126 and through which the leno end of adjacent leno yarn 124 is inserted and twisted to form a half twist between adjacent weft yarns 126. Fig. 2(c) illustrates a one pick leno 130 with two leno ends 132 and 134, drawn into separate leno healds and one joint standard end 136, with leno ends 132 and 134 differently binding and simultaneously changing direction between adjacent weft yarns 138. Fig. 2(d) illustrates an upper shed, two pick leno 140 having leno yarns 142 and 144 and weft yarns 146. Fig. 2(e) illustrates a one pick leno changing below one pick with one leno end 162, three joint standard ends 164, 166 and 168 and weft yarns 170. Fig. 2(f) illustrates an upper and lower shed, half cross leno 170 with two leno ends 172 and 174, joint standard ends 176 and 178, and weft yarns 180. Figs. 2(a) through 2(f) are merely illustrative of the type of leno weave patterns which may be employed in accordance with the present invention. Figs. 3 and 4 show two arrangements of leno weave patterns to enhance and control the porosity/permeability of the textile in selected regions of the textile. Fig. 3 shows a woven textile 200 having relatively lower porosity regions 202 and 206 woven with the plain weave of Fig. 1(a). The textile 200 also includes a relatively higher porosity region 206 formed from the half cross leno weave of Fig. 2(a). Region 206 extends longitudinally in the warp direction as a vertical stripe. A plurality of the longitudinally extending regions or stripes 206 may be selectively arranged to enhance and control the porosity/permeability of the woven textile.

Fig. 4 shows a woven textile 210 having relatively lower porosity regions 212 and 214 woven with the twill weave of Fig. 1(c). The textile 210 also includes a relatively higher porosity region 216 formed from the one pick leno weave of Fig. 2(c). Region 216 extends laterally in the weft direction as a horizontal stripe. A plurality of the laterally extending regions or stripes 216 may be selectively arranged to enhance and control the porosity/permeability of the textile. In addition to the vertical and horizontal stripes illustrated in Figs. 3 and 4, respectively, or a combination of such vertical and horizontal stripes, leno weaves can be arranged in repeating rectangular patterns, such as schematically illustrated in Fig. 5, to enhance and control the porosity/permeability of the woven textile. As shown in Fig. 5, the woven textile 300 includes relatively lower porosity areas 302 woven with a weave such as illustrated in Figs. 1(a) through 1(f). The textile 300 also includes relatively higher porosity areas 304 which are rectangular - (square) in shape formed from a leno weave such as illustrated in Figs. 2(a) through 2(f). Areas 304 extend widthwise and lengthwise of the textile in a repeating manner to enhance and control the porosity/permeability of the woven textile. The vertical and/or horizontal stripes, or the repeating rectangular-shaped areas will typically occupy an area in the textile up to about 10% of the overall textile as woven. These relatively high porosity areas will accurately control the ability of the high strength textile to easily pass water with minimal pressure increase.

Moreover, instead of leno weaves, the woven textile may include various partial threading patterns selectively placed in the textile to enhance and control the porosity/permeability of the textile. For example, the warp yarns may be partially threaded to create laterally spaced warp yarn bundles. The weft yarns are fully threaded. As a result, the warp yarn bundles are separated by relatively open longitudinal bands containing only weft yarns. In this construction, the edge warp yarns of each warp yarn bundle may be leno yarns such as illustrated, for example, in Fig. 2(a).

The woven textile of the present invention may be formed on any conventional weaving equipment such as rigid rapier looms, flexible rapier looms, projectile looms and the like.

A majority of the weft and warp yarns are preferably the load bearing member, namely, the high tenacity, low initial modulus, low elongation mono- or multifilament yarns. Suitable mono- or multifilament yarns are formed from polyester, polyvinylalcohol , nylon, aramid, fiberglass, and polyethylene naphthalate. The yarn fibers may be of homogeneous or bicomponent structure.

The load bearing member should have a strength of at least about 5 grams per denier, and preferably at least about 9 to 10 grams per denier. The initial Young's modulus of the load bearing member should be about 100 grams/denier, preferably about 150 to 400 grams/denier. The ultimate elongation of the load bearing member should be less than about 18%, preferably less than about 10%. The load βeanng_ member will typically have a denier of about 1,000 to 2,000, preferably about 2,000 to 8,000.

The textiles can be produced with approximately equal strength and/or friction characteristics in the longitudinal or machine direction and in the lateral or cross- machine direction. Alternatively, the textiles can be produced with greater strength and/or friction characteristics in either the longitudinal direction or the lateral direction. The selection of the strength and friction characteristics of the textiles will be determined based on the requirements of the application design.

The fusible bonding yarns, if incorporated into the weave, are used as warp and/or weft yarns and/or leno yarns as required for the desired bonding properties, and especially the bonding properties needed to form the necessary strength of the textiles. When the textile is heated to melt the fusible polymer component, the fusible polymer component flows around and encapsulates other components of the textile bonding and stabilizing the textile structure and protecting the load bearing yarns from abrasion and chemical attack. The fusible yarns will lock the high permeability engineered areas into a stable structure unable to be closed by textile shifting when the hydrostatic pressure increases on the textile in use. Also, fusible yarns will further enhance and secure the stability of the weave structure by locking the yarns into a fixed position so that subsequent handling and soil dynamics under high pressure situations do not move the yarns/weave geometry in situ and substantially modify the permeability of the textiles as produced. The fusible yarn may be a monofilament or multifilament form of yarn and of homogeneous or bicomponent composition.

The preferred fusible yarn is a bicomponent yarn such as one having a low melting sheath of polyethylene, polyisophthalic acid or the like, and a high melting core of polyester, polyvinylalcohol or the like. The bicomponent yarn also may be a side-by-side yarn in which two different components (one low melting and one high melting) are fused along the axis and having an asymmetrical cross-section, or -a biconstituent yarn having one component dispersed in a matrix of the other component, the two components having different melting points. The low and high melting components also may be polyethylene and polypropylene, respectively, different melting point polyesters, or polyamide and polyester, respectively. The bicomponent yarn will typically be composed of 30 to 70% by weight of the low melting component, and 70 to 30% by weight of the high melting component. The fusible yarn also may be an extrusion coated yarn having a low melting point coating or a low melting point yarn (e.g., polyethylene) employed in the textile structure side-by-side with other yarns.

As an alternative to using fusible bonding yarns, or in addition to using fusible bonding yarns, the textile is impregnated with a suitable polymer after it leaves the loom. The textile may be passed through a polymer bath or sprayed with a polymer. The impregnating material typically comprises an aqueous dispersion of the polymer. In the impregnation process, the polymer flows around and encapsulates other components of the textile. The impregnated textile is then heated to dry and/or cure the polymer to bond the yarns.

The polymer may be a urethane, acrylic, vinyl, rubber or other suitable polymer which will form a bond with the yarns used in the textile. The urethane polymer may be, for example, an aqueous dispersible aliphatic polyurethane, such as a polycarbonate polyurethane, which may be crosslinked to optimize its film properties, such as with an aziridine crosslinker. Suitable urethane polymers and crosslinkers are available commercially from Stahl USA, Peabody, Massachusetts (e.g., UE-41-503 aqueous polyurethane and KM-10-1703 aziridine crosslinker) and Sanncore Industries, Inc. , Leominster, Massachusetts (e.g., SANCURE* 815 and 2720 polyurethane dispersions) . The acrylic polymer may be, for example, a heat reactive acrylic copolymer latex, such as a heat reactive, carboxylated acrylic copolymer latex. Suitable acrylic latexes are available from BF Goodrich, Cleveland, Ohio (e.g. , HYCAR^β 26138 latex, HYCAR*26091 latex and HYCAR^® 26171 latex-) . The vinyl polymer may be a polyvinylchloride polymer. The rubber polymer may be neoprene, butyl or styrene-butadiene polymer. As another alternative to using fusible bonding yarns, or in addition to using fusible bonding yarns, a polymer sheet or web is applied to the textile after it leaves the loom and the textile/polymer sheet or web is heated to melt the polymer sheet or web causing the polymer to flow around and encapsulate other components of the textile. The polymer sheet or web is typically in nonwoven form. The polymer sheet or web may be a polyester, polyamide, polyolefin or polyurethane sheet or web. Suitable polymer sheets are available commercially from Bemis Associates Inc. , Shirley, Massachusetts, as heat seal adhesive films. Suitable polymer webs are available commercially from Bostik Inc. , Middleton, Massachusetts (e.g., Series PE 65 web adhesive).

The bonding process results in chemical and/or mechanical bonds throughout the structure of the textile. The effect or bulking yarns are used as warp and/or weft yarns and/or leno yarns. The effect or bulking yarns increase friction with adjacent yarns to provide better stability (fiber to fiber cohesion) . Two or more effect or bulking yarns interlacing with one another provide the greatest stability and highest strength. The effect or bulking yarns also provide the desired bulk in the textile and relatively thick profile of the finished product.

The bulking yarns can be broken down into two major categories: (1) continuous multifilament textured yarns and (2) staple fiber spun yarns. Textured yarns are produced from conventional yarns by a known air texturing process. The air texturing process uses compressed air to change the texture of a yarn by disarranging and looping the filaments or fibers that make up the yarn bundle. The texturing process merely rearranges the structure of the yarn bundle with little changes in the basic properties of the individual filaments or fibers occurring. However, the higher the bulk, the higher the loss in strength and elongation. The air jet textured bulking yarns are generally made from low cost, partially oriented, polyester, polyethylene or polypropylene yarns or the like. The individual bulking yarn components will typically have a denier of about 150 to 300, preferably about 300 to about 1,000.

Other types of bulking yarns may be utilized based on staple fibers, particularly polyester staple fibers. The two major types of staple fiber yarns are conventional ring spun yarns and friction spun yarns. Friction spun yarns are produced by a new technology known as friction spinning which is more suitable for large diameter, bulky yarns. Friction spinning machines are made by Dr. Ernst Fehrer AG of Linz, Austria, and are commonly known as DREF 2- and DREF 3-type friction spinning machines. Both conventional ring and DREF friction spinning machines can produce 100% staple fiber yarns as well as core spun yarns. The core spun yarns are made by feeding a high tenacity, heavy denier multifilament yarn into the core of the yarn and spinning a staple fiber yarn (polyester, cotton, acrylic, polypropylene, etc.) around the core yarn. The staple fiber covering (exterior or sheath material) could be conventional polyester or a low melting point material (homo- or bicomponent) staple fiber to produce a multifilament, bulking and fusing composite structure all in one yarn. In addition to using individual load bearing yarns, the present invention also contemplates forming composite yarns prior to textile formation in which the load bearing yarn is combined with a fusible bonding yarn or a bulking yarn. Another composite may be formed using air jet texturing in which the load bearing yarn comprises the core and the fusible bonding yarn or bulking yarn is textured. The core is fed with minimal overfeed and with an excess quantity of fusible or bulking yarn with substantially higher overfeed. The compressed air rearranges and loops the filaments or fibers of the fusible yarn or bulking yarn to increase the bulk of the composite yarn. Composite yarns incorporating the load bearing yarn may also be made by known techniques such as twisting or cabling. The fusible yarn, especially of the monofilament type, also may be combined with the bulking yarn- prior to textile formation such as by parallel end weaving, or by twisting, cabling or covering (single or double helix cover) . Referring to Figs. 1-5 again, the fusible bonding yarn would typically be used as warp yarns, and especially at the selvage (not shown) at each side of the textile. However, the fusible yarn could be incorporated into the woven textiles illustrated in Figs. 1-5 in many other ways. Enhanced mechanical keying of the woven textile may be accomplished by the use of a number of different yarns/fibers (geometry, type, cross-section and combinations thereof) as well as textile structures. Substantial cross- sectional thicknesses can be selectively engineered into the textile structure in the machine and/or cross-machine direction, preferably in the cross-machine direction, by feeding in multiple types and sizes of yarns. For example, a relatively thin profile, compliant weft yarn can be woven in the cross-machine direction for several inches (4-6 inches) , then the weaving machine (loom) can be programmed to change to a relatively thick profile, non-compliant weft yarn such as a friction spun/core spun large diameter combination filament/staple fiber multico posite coarse yarn up to 4,000 tex (cc 0.15) which is stiff, round and non-compressible offering the textile the maximum increase in cross-sectional area. The diameter of the relatively thick profile, non- compliant yarn will typically be about 130 to 300% or more of the diameter of the relatively thin profile, compliant yarn. Correspondingly, in the machine direction, varying types and diameters of yarns can be arranged across the width of the fabric to meet the end use requirements.

The engineered placement of radically different yarn types and diameters and weave structures directly facilitates enhanced mechanical keying of the textile reinforcement into the soil by increasing the surface area from a uniform thickness to a varying thickness substrate. Horizontal, vertical, diagonal or other multilevel topographies can be engineered into the textile surface to provide varying degrees of resistance to movement of the load bearing element.

The improved cross-sectional profile can be enhanced by utilizing high twist multifilament plied yarns, high twist multifilament spun yarns, friction spun composite yarns as well as Hamel twist hollow spindle twisted and plied yarns, together with large diameter monofilament and extrusion coated yarns.

Improved initial modulus of the engineered mesh structure can be optimized by Hamel and friction spun/core spun composite yarns with and without fusible fibers in the sheath. Also, the use of hard aqueous dispersible polyurethanes, particularly polycarbonate polyurethanes, with cross-linkers will further increase the modulus. The correct selection of cross-linkers will also improve the flexural and torsional stiffness, adhesion, ultraviolet and hydrolytic stability, and cross-sectional profile of the textile.

Friction spun yarns can be engineered to provide unique combinations of fibers/properties for load bearing yarns, bulking fibers and fusible fibers, and to provide improved strength by protecting high modulus load bearing core yarns from shear forces, friction and degradation.

Air jet textured yarns are compliant and not suitable for the major profile areas, but are ideally suited for the minor profile areas within the textile. Air jet textured spun yarns could only be used for the major profile areas if plied and heavily twisted to produce round, non- compliant high profile large diameter yarns. In a twisted state, the highly looped fiber structure of the air jet textured yarn would provide fabric stability and mechanical keying with the soil environment due to the fiber loops offering increased surface contact.

Increased cross-sectional profiles can be enhanced by utilizing 3-D weaves as well as coatings, special yarns and combinations of yarns. Ribs, cords and other weaves such as waffle cloths can be engineered to maximize the textile/soil friction. The woven textile of the present invention also may include electrically conductive components as warp and/or weft yarns. The electrically conductive components may be metal yarns or strips (e.g., copper), polymeric yarns, either monofilament or multifilament, rendered electrically conductive by adding fillers (e.g., carbon black, copper, aluminum) in the polymer during extrusion, an electrically conductive filament of a multifilament yarn, or a polymeric yarn having an electrically conductive coating. The electrically conductive components permit breaks to be detected in the woven textile in a known manner. The electrically conductive components also permit failures in other components of a composite civil engineering structure to be detected. The electrically conductive components also permit the woven textile to be used in electrokinetic and related applications.

The woven textile of the present invention can be finished by applying heat energy (e.g., calendaring, radio- frequency energy, microwave energy, infra-red energy and tentering) to the textile to soften the fusible yarn (e.g., the sheath of a bicomponent yarn) , dry and/or cure the polymer impregnating the textile, or melt the polymer sheet or web to lock the yarns and textile material in place.

The results of the heating or finishing process are: (a) the textile is protected against impact and abrasion;

(b) the textile is stiffened with better resistance to elongation and with lower ultimate elongation;

(c) the textile is frozen in a fixed bulk for better soil textile interaction; and

(d) the textile is protected, strengthened and stiffened.

In accordance with the present invention, a full range of woven textiles can be engineered from approximately 50 pounds per inch to in excess of 5000 pounds per inch tensile strength. These textiles will possess high strength, low elongation and high structural stability over the full range of tensile strength performance. Fig. 6 shows a retaining wall 400 formed using bonded composite engineered mesh structural textile 402 of the present invention. Foundation or substrate 404 is graded to a desired height and slope. Retaining wall 406 is formed from a plurality of retaining wall elements 406a. A plurality of bonded composite engineered mesh structural textiles 402 are attached to the retaining wall 406 at 408. The bonded composite engineered mesh structural textiles 402 are separated by a plurality of fill layers 410. Using this construction, random fill 412 is retained and held in place.

The retaining wall 406 is illustrated generically as comprising a plurality of courses of modular wall elements 406a such as conventional cementitious modular wall blocks. It is to be understood, however, that similar wall structures can be formed using modular wall blocks formed of other materials, including plastic. Likewise, retaining walls incorporating the bonded composite engineered mesh structural textiles of this invention can be constructed with cast wall panels or other conventional facing materials. While no detail is shown for connection of the bonded composite engineered mesh structural textiles to the retaining wall elements, various techniques are conventionally used, including bodkin connections, pins, staples, hooks or the like, all of which may be readily adapted by those of ordinary skill in the art for use with the bonded composite engineered mesh structural textiles of this invention.

When embankments are constructed over weak foundation soils the pressure created by the embankment can cause the soft soil to shear and move in a lateral direction. This movement and loss of support will cause the embankment fill material to shear which results in a failure of the embankment. This type of failure can be prevented by the inclusion of bonded composite engineered mesh structural textiles 420 of the present invention in the lower portions of the embankment 422 as shown in Fig. 7. The bonded composite engineered mesh structural textiles 420 provide tensile strength that prevents the embankment from failing. Reinforced earth structures may be built to steep - slope angles which are greater than the natural angle of repose of the fill material by the inclusion of bonded composite engineered mesh structural textiles. Steep slopes can be used in many applications to decrease the amount of fill required for a given earth structure, increase the amount of usable space at the top of the slope, decrease the intrusion of the toe of the slope into wetlands, etc. In Fig. 8, a steep slope dike addition is shown. By using steep slopes 430, the amount of fill required to raise the dike elevation is reduced and the load that is placed on both the existing containment dike 432 and on the soft sludge 434 is also reduced. A dramatic increase in containment capacity is achieved through the use of steep slopes 430 reinforced with bonded composite engineered mesh structural textiles 436 of the present invention.

When embedding the bonded composite engineered mesh structural textiles of this invention in a particulate material such as soil or the like, the particles of aggregate engage the upper and lower surfaces of the textile. Thus, such textile materials are effective to provide a separating or filtering function when embedded in soil or the like.

In addition to their earth reinforcement applications, the bonded composite engineered mesh structural textiles of this invention are especially useful in landfill and industrial waste containment constructions. Regulations require that the base and side slopes of landfills be lined with an impermeable layer to prevent the leachate from seeping into natural ground water below the landfill. When landfills are located over terrain which is compressible or collapsible, as in the case of Karst terrain, the synthetic liner will deflect into the depression. This deflection results in additional strains being induced into the liner which can cause failure of the liner and seepage of the leachate into the underlying ground water thus causing contamination.

Through the use of the high tensile strength of textile 440 of the present invention as shown in Fig. 9 liner 442 support can be provided by positioning the textile 440 immediately below the liner 442. Should any depression 444 occur, the high tensile capacity of the bonded composite engineered mesh structural textile 440 provides a "bridging" affect to span the depression and to minimize the strain induced into the liner 442 thereby helping to protect the landfill system from failure.

Construction of landfills requires that the geomembrane liners be placed across the bottom of the landfill and up the side slopes of the landfill as well. In order to protect this liner, a layer of cover soil, known as a veneer, which has a dual purpose of liner protection against punctures from waste material placement and leachate collection is normally placed on top of the liner. Since the surface of the liner is smooth, the cover soil can fail by simply sliding down the slope since the friction between the soil and the liner is too small to support the weight of the soil layer. This type of failure can be prevented by the placement of a textile 450 of the present invention as shown in Fig. 10 anchored at the top and extending down to the toe of the slope 452. The textile 450 provides the tensile force required to hold this block of soil in place, thus eliminating the sliding on the liner 456.

In addition to earth reinforcement applications, and landfill and industrial waste containment applications, the textiles of this invention can be used to produce bags, mats, tubes and the like that can be used for revetment construction when filled either with sand, lean concrete, lean sand asphalt, clay granules, etc.. Bags can be placed directly on a slope in a single layer, or they can be stacked in a multiple layer running up the slope. A bag blanket revetment consists of one or two layers of bags placed directly on a slope. A stacked bag revetment consists of bags that are stacked pyramid-fashion at the base of a slope. Mattresses are designed for placing directly on a prepared slope. They are laid in place when empty, joined together and then pumped full of sand or gravel. This results in a mass of pillow-like units. Tubes are filled with sand or clay granules. The highly stabilized textiles of the present invention are ideally suited for use as such bags, mats, tubes and the like. The advantages to the present invention for these applications include lighter weight, lower cost, easier handling and superior (more consistent) hydraulic performance. Figs. 11, 12 and 13 illustrate one of the above applications in the form of a mattress. Referring to Figs. 11 and 12, the mattress 460 comprises a plurality of continuously woven parallel tubes 462 filled with sand or gravel 464. The tubes 462 are interconnected and spaced apart by selvage 466. The tubes 462 typically have a diameter of about 10 inches and a length of several feet (e.g. , 25 to 50 feet) . The selvage 466 between adjacent tubes 462 may vary from about 1/2 inch up to several feet (e.g., 10 feet). The selvage 466 at the sides of the mattress 460 may be only a few inches in length (e.g., 5 inches) . The mattress 460 is typically positioned on a filter textile 468 as illustrated in Fig. 11. As shown in Fig. 13, the mattress 460 can be used as a toe protection for a steep-walled caisson structure 470 built on a gravel berm 472 over a sea floor 474 for protection form the sea 476. Bonded composite engineered mesh structural textiles of the present invention also may be used in other applications to reinforce soil or earth structures such as base reinforcement for roadways (e.g., earth, gravel or other particulate materials, base applications, or to reinforce bituminous materials such as asphalt) and airport runways.

Additionally, these textiles may be used in the construction of geocells or retaining walls for marine use to control land erosion adjacent to waterways such as rivers, streams, lakes and oceans. As indicated, while the textile materials of this invention have particular utility in earthwork construction applications, they are also adapted for many applications where textile products have been used heretofore. For example, the novel textiles described herein have excellent strength and related characteristics for use in the formulation of gabions. Additionally, they may be readily adapted for use as industrial belting, restraint systems and the like. Having described the invention, many modifications thereto will become apparent to those skilled in the art to which it pertains without deviation from the spirit of the invention as defined by the scope of the appended claims.

Claims

WE CLAIM :

1. A bonded composite engineered mesh structural textile, comprising: a plurality of weft yarns; a plurality of warp yarns, the weft yarns and the warp yarns being interwoven into a textile having a planar, permeable structure; a portion of the warp and weft yarns comprising load bearing yarns, the load bearing yarns being high tenacity, high modulus, low elongation yarns; and at least one fusible bonding yarn which has a fusible component which will melt when heated to flow around, encapsulate and bond adjacent yarns to strengthen the textile.

2. The bonded composite engineered mesh structural textile of claim 1, wherein the textile comprises at least one leno yarn.

3. The bonded composite engineered mesh structural textile of claim 2, wherein the leno yarn forms a half-cross leno weave.

4. The bonded composite engineered mesh structural textile of claim 2, wherein the leno yarn forms a one pick leno weave.

5. The bonded composite engineered mesh structural textile of claim 2 , wherein the leno yarn forms a two pick leno weave.

6. The bonded composite engineered mesh structural textile of claim 2 , wherein the leno yarn is woven in the warp direction.

7. The bonded composite engineered mesh structural textile of claim 2, wherein the bonded composite engineered mesh structural textile is a geotextile.

8. The bonded composite engineered mesh structural textile of claim 1, wherein the fusible yarn is a bicomponent yarn having a low melting fusible component and a high melting component.

9. The bonded composite engineered mesh structural textile of claim 8, wherein the bicomponent yarn is composed of 30 to 70% by weight of the low melting sheath and 70 to 30% by weight of the high melting core.

10. The bonded composite engineered mesh structural textile of claim 1, wherein the fusible bonding yarn comprises edge warp yarns of the textile.

11. The bonded composite engineered mesh structural textile of claim 1, wherein the fusible bonding yarn comprises edge pairs of warp yarns of the textile.

12. The bonded composite engineered mesh structural textile of claim 1, wherein a portion of the warp and weft yarns comprise bulking yarns to provide a relatively thick profile for the woven textile.

13. The bonded composite engineered mesh structural textile of claim 12, wherein the bulking yarns are produced from partially oriented polyester, polyethylene or polypropylene yarns.

14. The bonded composite engineered mesh structural textile of claim 1, wherein the load bearing yarns are composite yarns in which the load bearing yarn is combined with a fusible bonding yarn or a bulking yarn.

15. The bonded composite engineered mesh structural textile of claim 14, wherein the composite yarns are formed by air jet texturing.

16. The bonded composite engineered mesh structural textile of claim 14, wherein the composite yarns are formed by twisting, cabling, covering or core spinning.

17. The bonded composite engineered mesh structural textile of claim 1, wherein the load bearing yarns have a strength of at least about 5 grams per denier, a modulus of at least about 100 grams per denier and an elongation of less than about 18%.

18. The bonded composite engineered mesh structural textile of claim 1, wherein the load bearing yarns have a strength of at least about 9 to 10 grams per denier, a modulus of at least about 100 grams per denier, and an elongation of less than about 18%.

19. The bonded composite engineered mesh structural textile of claim 1, wherein the load bearing yarns have a denier of about 1,000 to 8,000.

20. The bonded composite engineered mesh structural textile of claim 1, wherein the load bearing yarns are formed from polyester, polyvinylalcohol, nylon, aramid, fiberglass or polyethylene naphthalate.

21. The bonded composite engineered mesh structural textile of claim 1, wherein the textile contains up to about 10% open area in a regularly distributed pattern over the textile.

22. The bonded composite engineered mesh structural textile of claim 1, wherein the textile has a high initial modulus.

23. The bonded composite engineered mesh structural textile of claim 1, wherein the textile has leno weave patterns selectively placed in the textile to enhance and control the permeability of the textile.

24. The bonded composite engineered mesh structural textile of claim 23, wherein the leno weave patterns extend longitudinally in the warp direction as vertical stripes.

25. The bonded composite engineered mesh structural textile of claim 23, wherein the leno weave patterns extend laterally in the weft direction as horizontal stripes.

26. The bonded composite engineered mesh structural textile of claim 23, wherein the leno weave patterns are arranged in repeating rectangular patterns.

27. The bonded composite engineered mesh structural textile of claim 1, wherein the textile has partial threading patterns selectively placed in the textile to enhance and control the permeability of the textile.

28. The bonded composite engineered mesh structural textile of claim 27, wherein the warp yarns are partially threaded to create laterally spaced warp yarn bundles.

29. The bonded composite engineered mesh structural textile of claim 1, wherein the textile has substantial cross- sectional thicknesses selectively engineered into the textile to enhance mechanical keying.

30. The bonded composite engineered mesh structural textile of claim 29, wherein the textile includes relatively thick profile, non-compliant yarns and relatively thin profile, compliant yarns to form the substantial cross- sectional thicknesses.

31. The bonded composite engineered mesh structural textile of claim 30, wherein the diameter of the relatively thick profile, non-compliant yarns is about 130 to 300% or more of the diameter of the relatively thin profile, compliant yarns.

32. The bonded composite engineered mesh structural textile of claim 30, wherein the relatively thick profile, non-compliant yarns are core spun, friction spun, or ring spun yarns, Hamel twist covered yarns or covered yarns with a single or double helix and the relatively thin profile, compliant yarns are normal single or twisted and plied yarns.

33. A composite civil engineering structure comprising a mass of particulate material and at least one reinforcing element embedded therein, wherein said reinforcing element is a bonded composite engineered mesh structural textile according to claim 1, portions of said mass of particulate material being below said reinforcing textile, and portions of said mass of particulate material being above said reinforcing textile.

34. The composite civil engineering structure of claim 33, further including a retaining wall, portions of said reinforcing textile being secured to said retaining wall, said mass of particulate material, said reinforcing textile and said retaining wall together defining a reinforced retaining wall.

35. The composite civil engineering structure of claim 34, comprising a plurality of said reinforcing textiles in vertically spaced relationship.

36. The composite civil engineering structure of claim 33, wherein said mass of particulate material and reinforcing textile together define a stabilized embankment.

37. The composite civil engineering structure of claim 36, comprising a plurality of said reinforcing textiles in vertically spaced relationship.

38. The composite civil engineering structure of claim 33, wherein said mass of particulate material and reinforcing textile together define a steep slope.

39. The composite civil engineering structure of - claim 38, comprising a plurality of said reinforcing textiles in vertically spaced relationship.

40. The composite civil engineering structure of claim 38, wherein said steep slope is a dike addition to raise the dike elevation of a containment dike.

41. The composite civil engineering structure of claim 33, wherein said mass of particulate material and reinforcing textile together with a liner define a landfill.

42. The composite civil engineering structure of claim 41, wherein said landfill is for terrain which is compressible or collapsible and said reinforcing textile is positioned immediately below said liner.

43. The composite civil engineering structure of claim 41, wherein said landfill includes a side slope and said reinforcing textile is anchored at a top of said slope and extends down to a toe of said slope, said reinforcing textile being positioned above said liner.

44. A method of constructing a composite civil engineering structure comprising: providing a mass of particulate material, providing at least one reinforcing bonded composite engineered mesh structural textile according to claim 1, and embedding said reinforcing textile in said mass of particulate material with portions of said mass of particulate material being below said reinforcing textile, and portions of said mass of particulate material being above said reinforcing textile.

45. The method of constructing a composite civil engineering structure of claim 44, further including providing a retaining wall, securing portions of said reinforcing textile to said retaining wall, said mass of particulate material, said reinforcing textile and said retaining wall together defining a reinforced retaining wall.

46. The method of constructing a composite civil engineering structure of claim 44, comprising embedding a plurality of said reinforcing textiles in said mass of particulate material in vertically spaced relationship.

47. The method of constructing a composite civil engineering structure of claim 44 , wherein said mass of particulate material and reinforcing textile together define a stabilized embankment.

48. The method of constructing a composite civil engineering structure of claim 47, comprising embedding a plurality of said reinforcing textiles in said mass of particulate material in vertically spaced relationship.

49. The method of constructing a composite civil engineering structure of claim 44, wherein said mass of particulate material and reinforcing textile together define a steep slope.

50. The method of constructing a composite civil engineering structure of claim 49, comprising embedding a plurality of said reinforcing textiles in said mass of particulate material in vertically spaced relationship.

51. The method of constructing a composite engineering structure of claim 49, wherein said steep slope is a dike addition to raise the dike elevation of a containment dike.

52. The method of constructing a composite civil engineering structure of claim 44, wherein said mass of particulate material and reinforcing textile together with a liner define a landfill.

53. The method of constructing a composite civil - engineering structure of claim 52, wherein said landfill is for terrain which is compressible or collapsible and said reinforcing textile is embedded in said mass of particulate material immediately below said liner.

54. The method of constructing a composite civil engineering structure of claim 52 , wherein said landfill includes a side slope and said reinforcing textile is anchored at a top of said slope and extends down to a toe of said slope, said reinforcing textile being embedded in said mass of particulate material above said liner.

55. In a bonded composite engineered mesh structural textile having a planar, permeable structure, the improvement comprising: load bearing yarns defining at least a portion of the textile, the load bearing yarns being high tenacity, high modulus, low elongation yarns; and at least one fusible bonding yarn which has a fusible component which will melt when heated to flow around, encapsulate and bond adjacent yarns to strengthen the textile.

56. The bonded composite engineered mesh structural textile of claim 55, wherein the textile further comprises at least one leno yarn.

57. The bonded composite engineered mesh structural textile of claim 55, wherein the leno yarn is the fusible bonding yarn.

58. The bonded composite engineered mesh structural textile of claim 55, wherein the fusible yarn is a bicomponent yarn having a low melting fusible component and a high melting component.

59. The bonded composite engineered mesh structural textile of claim 55, wherein the load bearing yarns have a strength of at least about 5 grams per denier, a modulus of at least about 100 grams per denier and an elongation of less than about 18%.

60. The bonded composite engineered mesh structural textile of claim 55, wherein the load bearing yarns have a strength of at least about 9 to 10 grams per denier, a modulus of at least about 100 grams per denier, and an elongation of less than about 18%.

61. The bonded composite engineered mesh structural textile of claim 55, wherein the load bearing yarns have a denier of about 1,000 to 8,000.

62. The bonded composite engineered mesh structural textile of claim 55, wherein the load bearing yarns are formed from polyester, polyvinylalcohol, nylon, aramid, fiberglass or polyethylene naphthalate.

63. A bonded composite engineered mesh structural textile, comprising: a plurality of weft yarns; a plurality of warp yarns, the weft yarns and warp yarns being interwoven into a textile having a planar, permeable structure; a portion of the warp and weft yarns comprising load bearing yarns, the load bearing yarns being high tenacity, high modulus, low elongation yarns; the textile comprising at least one polymer component encapsulating and bonding yarns to strengthen the textile; and the textile further comprising at least one leno yarn and/or bulking yarn.

64. The bonded composite engineered mesh structural textile of claim 63, wherein the leno yarn forms a half-cross leno weave.

65. The bonded composite engineered mesh structura-1 textile of claim 63, wherein the leno yarn forms one or two pick leno.

66. The bonded composite engineered mesh structural textile of claim 63, wherein the polymer component is formed by a fusible polymer component of a fusible bonding yarn which melts when heated and flows around adjacent yarns.

67. The bonded composite engineered mesh structural textile of claim 66, wherein the fusible bonding yarn is a bicomponent yarn having a low melting fusible component and a high melting component.

68. The bonded composite engineered mesh structural textile of claim 67, wherein the bicomponent yarn is composed of 30 to 70% by weight of the low melting sheath and 70 to 30% by weight of the high melting core.

69. The bonded composite engineered mesh structural textile of claim 66, wherein the fusible bonding yarn comprises edge warp yarns of the textile.

70. The bonded composite engineered mesh structural textile of claim 63, wherein the polymer component is formed by a polymer coating which dries and/or cures when heated or by a polymer sheet or web which melts when heated.

71. The bonded composite engineered mesh structural textile of claim 70, wherein the polymer coating is a urethane, acrylic, vinyl or rubber coating and the polymer sheet or web is a polyester, polyamide, polyolefin or polyurethane sheet or web.

72. The bonded composite engineered mesh structural textile of claim 63 , wherein a portion of the warp and weft yarns comprise bulking yarns to provide a relatively thick profile for the textile.

73. The bonded composite engineered mesh structura-l textile of claim 72, wherein the bulking yarns are produced from partially oriented polyester, polyethylene or polypropylene yarns.

74. The bonded composite engineered mesh structural textile of claim 63 , wherein the load bearing yarns are composite yarns in which the load bearing yarn is combined with a fusible bonding yarn or a bulking yarn.

75. The bonded composite engineered mesh structural textile of claim 74 , wherein the composite yarns are formed by air jet texturing.

76. The bonded composite engineered mesh structural textile of claim 74, wherein the composite yarns are formed by twisting, cabling, covering or core spinning.

77. The bonded composite engineered mesh structural textile of claim 63, wherein the load bearing yarns have a strength of at least about 5 grams per denier, a modulus of at least about 100 grams per denier, an elongation of less than about 18% and a denier of about 1,000 to 8,000.

78. The bonded composite engineered mesh structural textile of claim 63 , wherein the load bearing yarns are formed from polyester, polyvinylalcohol, nylon, aramid, fiberglass or polyethylene naphthalate.