WO2021110577A1

WO2021110577A1 - Sandwich geosynthetic sheet with locking needling arrangement

Info

Publication number: WO2021110577A1
Application number: PCT/EP2020/083867
Authority: WO
Inventors: Lars Vollmert; Norbert Vissing; Henning Ehrenberg; Martin Tazl
Original assignee: Naue Gmbh & Co. Kg
Priority date: 2019-12-03
Filing date: 2020-11-30
Publication date: 2021-06-10
Also published as: DE102019132849B4; DE102019132849A1

Abstract

The present invention relates to a geosynthetic sheet for stabilizing layers of soil, having a longitudinal direction and a transverse direction, which lie in a plane of the geosynthetic sheet, comprising: a first and a second layer of geosynthetic material and a first functional layer arranged in between, wherein the first layer of geosynthetic material, the functional layer and the second layer of geosynthetic material are connected to one another by a needling arrangement, which comprises a multiplicity of fibre bundles which run perpendicularly in relation to the plane of the geosynthetic sheet and in which fibres of the first geosynthetic sheet and/or fibres of the second geosynthetic sheet are drawn through the functional layer, wherein a first quantity of the fibre bundles extends between the first and the second layers of geosynthetic material and runs through the functional layer past multifilament strands of the functional layer, and a second quantity of the fibre bundles extends between the first and the second layers of geosynthetic material and runs through each multifilament strand of the first multifilament strands of the functional fibre layer.

Description

Sandwich geosynthetic sheet with interlocking needles

The invention relates to a geosynthetic sheet for stabilizing soil layers, with a longitudinal direction and a transverse direction, comprising: a first geosynthetic layer, a second geosynthetic layer, a first functional layer arranged between the first and second geosynthetic layers, which preferably consists of a plurality of parallel first multifilament strands wherein each multifilament strand consists of a first plurality of filaments.

The two geosynthetic layers or one of the two can preferably be made of nonwoven layers that enclose the functional layer, have a protective function for the functional layer and, as geosynthetic layers, take on independent functions such as reinforcing, separating, filtering, measuring, guiding, sealing or the like. Geosynthetic sheets are used for a variety of purposes. A frequent application is the reinforcement of soil layers to absorb tensile stresses, for example in the area of steep embankments, dams and dykes on soft ground, traffic areas over piles or point-shaped support members, bank reinforcements, landfills. In addition to this stabilization and reinforcement purpose, geosynthetic sheets can also be used for other functional purposes, for example for the purpose of filtering, separating or separating soil layers, for the purpose of recording and monitoring soil properties, draining the soil or supplying liquids, for example Purposes of irrigation or collection of pollutants in the soil. For example, such geosynthetic webs can be equipped with sensors or with control devices for feeding measurement samples or signals to a sensor arranged outside or on the edge of the geosynthetic web and thus serve to record physical and / or chemical measured variables from soil layers. Such geosynthetic sheets can also be used to introduce or contain liquids to control the water balance of a soil layer by adding or releasing moisture, or to divert liquid pollutants or to remove liquids that change their properties under certain environmental conditions and chemical reactions, e.g. harden, to feed. Likewise, temperatures can be recorded or changed using the appropriate equipment.

One advantage of geosynthetic sheets is that soil material located both below and above the geosynthetic sheet develops a high degree of adhesion to the geosynthetic sheet and, as a result, the stability of this soil layer on the geosynthetic sheet is higher in many applications than the stability in the soil layer itself or between two different ones Layers of soil. Geosynthetic sheets also have high strength and low elongation, which means that stabilizing forces can be transferred to the soil layers that are in contact with the geosynthetic sheet.

From DE 19 543 991 A1 a fabric for reinforcing structures made of a grid fabric is known which is connected to a fleece by needling, by gluing or under the action of heat. The mesh fabric can be connected on both sides with a fleece layer and consist of polyester or fiberglass.

DE 10 2012 111 168 A1 discloses a roof underlayment with a fleece layer and a reinforcement grid connected to it with grid bars which are formed by strips. The strips are needled with the fleece layer.

A reinforcement layer system is previously known from DE 10 2005 007 947 A1, which has a reinforcement layer with a reinforcement matrix and a barrier layer adjoining the reinforcement layer. The barrier layer can be designed as a fiber layer and in this case be glued to the reinforcement layer or connected to it by knitting, weaving, welding, needling or sewing. From DE 9 207 367 U1, a laminate made of two spunbond layers and a scrim layer made of reinforcing yarns is known, which are connected to one another ^{by needling about 20-70 stitches / cm 2.}

A three-layer sandwich composite with a cement material core layer is known from WO 2019/106559 A1, in which the three layers are needled to one another.

A geotextile grid is previously known from EP 2 880 211 B1, which comprises reinforcing fibers combined in parallel strands, which are oriented in at least two directions. The reinforcement fibers form strips that are connected to one another with high-strength threads. From US 10 488 293 B1 a conductive geotextile for use in a leak detection system is known which comprises a flexible substrate and an adjacent polymer layer which has a conductive thin film which is coextruded onto a core

A specific application of geosynthetic sheets is, for example, to stabilize the base of a dam or dike, often in connection with soils with low load-bearing capacity underneath the dam or dike. Here, a horizontal installation of geosynthetic sheets in the area of the base of the dike and a subsequent construction of the dike on the geosynthetic sheet stabilize the dyke structure in the transverse direction in relation to the dike's longitudinal axis and thereby prevent parts of the dyke structure from slipping. It is known to lay geosynthetic sheeting at the base of the dyke in the transverse direction for the purpose of this type of dike stabilization in order to bring the high strength and low elongation of the geosynthetic sheet in the longitudinal direction as stabilizing properties into the dyke base. By stringing such transversely laid geosynthetic sheets along the length of the dike, the stabilizing effect can then be achieved over the entire length of the dike.

Geosynthetic sheets can be built up in one or more layers. It is known to build geosynthetic sheets, which are supposed to fulfill several functions, also with correspondingly several layer layers, each of the individual layers having a primary functional task of the overall layer composite and being fulfilled by this alone or primarily. For example, a first, dense geosynthetic layer, which can be woven, knitted or designed as a nonwoven layer or in some other form, can be combined with a second Geosynthetic layer are combined, which consists of a grid that has mechanically strong grid threads that are connected to each other. The combination of these two geosynthetic layers can then lead to a desired separating or filtering effect through the first geosynthetic layer, paired with a mechanical stabilization or reinforcement function through the second geosynthetic layer, so that a geosynthetic sheet with these combined properties is obtained. Such a geosynthetic sheet is offered, for example, under the trade name Combigrid® by the manufacturer Naue GmbH & Co. KG. In this previously known geosynthetic sheet, a nonwoven layer is connected to a grid layer by means of welding. The grid layer for its part consists of several cross-running stable plastic strips, which are welded to one another at the intersection points on the one hand and are welded to the nonwoven layer on the other. This results in a solid and at the same time dense laminate composite that is resistant to the stresses that occur and is tear-resistant. It is fundamentally desirable to make the geosynthetic sheet resistant to damage and penetration of stones and other point loads or loads acting on a small area. Damage, in particular, for example, to the reinforcing and thus the statically relevant elements or to elements that take on a measuring function, must be avoided as far as possible. This can be done on the one hand by a stable design of the reinforcing functional layer itself, which however has the disadvantage that this layer must have an uneconomically high tensile strength with load reserves against damage, which increases the mass and thus makes laying difficult and high production costs result. In addition to these contradicting requirements of good layability, low production costs and high resistance to the ingress of small particles and other point loads, which cannot be achieved with the previous technology, it is still a desirable advantage of geosynthetics if the geosynthetic sheet allows it to be at least slightly along the laying direction to change the main direction of extension of the geosynthetic sheet. A geosynthetic sheet that is so stiff that only the axis direction perpendicular to the roll-up direction can be used as the laying direction has the practical disadvantage that if the laying direction changes in the course of the geosynthetic sheet due to terrain or contours, or such a fold can occur Wrinkles only can be avoided by accepting large overlaps in sections between two adjacent geosynthetic sheets. While the folds can weaken the filter effect, the large overlap is disadvantageous due to the associated loss of laying length. There is therefore a need for a geosynthetic sheet that can be laid sheet-by-sheet and that allows the sheet to curve to a small extent without creasing during laying and / or requires a small amount of overlap.

The invention is based on the object of providing a geosynthetic sheet which overcomes the aforementioned disadvantages and has a high resistance to point loads while at the same time being easy to lay.

This object is achieved according to the invention by a geosynthetic sheet of the type described at the outset, in which the first geosynthetic layer, the functional layer and the second geosynthetic layer are connected to one another by needling, which comprises a plurality of fiber bundles running in a thickness direction perpendicular to the longitudinal and transverse directions, in which fibers of the first geosynthetic layer and / or fibers of the second geosynthetic layer are drawn through the functional layer, a first amount of the fiber bundles extend between the first and the second geosynthetic layer and run next to the first multifilament strands through the functional layer and a second amount of the fiber bundles between the Extend the first and second geosynthetic layers and run through each multifilament strand of the first multifilament strand of the functional layer.

According to the invention, an at least three-layer structure of the geosynthetic sheet is provided. A functional layer is arranged between a first and a second geosynthetic layer. In this functional layer, several multifilament strands are arranged, which run parallel to one another and consequently provide mechanical reinforcement and reduction of the elongation in a preferred direction, namely along the course of these multifilament strands.

The three layers of the layer composite are connected to one another by means of needling. In the case of needling, the layers are connected by fiber strands running perpendicular to the layer plane, which extend through the three layers. The needling can be done in such a way that, by means of a needle that has one or more barbs, the layer composite of the three layers is perpendicular to the layer level is pierced and the needle is then pulled out of the layer composite again. During this reciprocating penetration, the needle pushes and / or pulls fibers as it moves into the composite layer or out of the composite layer during its movement, which fibers are carried along by the barbs of the needle from the first geosynthetic layer or from the second geosynthetic layer , through the entire layer composite and thereby causes a connection of the three layers by means of these entrained fibers, which are laid in a direction perpendicular to the layer plane of the three layer layers as a result of the movement path of the needle. In this embodiment, the needling takes place without additional material, such as a suture material for sewing, being supplied.

According to the invention, the needling comprises a plurality of such fiber bundles which extend between the first and the second geosynthetic layer. A first set of these fiber bundles is positioned in such a way that the fiber bundles run through the middle functional layer next to the multifilament strands. This first set of fiber bundles effectively stabilizes the multifilament strands against a displacement running transversely to their direction of extension and therefore holds the multifilament strands in place transversely to their longitudinal direction without penetrating these multifilament strands. A second set of the fiber bundles passes through the fiber bundles. This second set of fiber bundles creates an effective fixation of the multifilament strands against displacement along their longitudinal direction. Contrary to the opinion that piercing reinforcement fibers in an unfavorable way damages or weakens the reinforcement fibers, the needling of the geosynthetic sheet according to the invention is carried out in such a way that a second quantity of the fiber bundles generated with the needling runs through the multifilament strands, i.e. each individual or at least a plurality the multifilament strand passes through directly in such a way that a single multifilament strand is pierced by a corresponding fiber bundle without damaging it to a relevant extent.

This penetration of the individual multifilament strands by the fiber bundles of the needling creates an advantageous fixation of the multifilament strands even with respect to a displacement in their longitudinal direction, which is particularly advantageous in order to achieve a high resistance of the entire layer composite to shear loads acting parallel to the layer plane to reach. The shear forces introduced from the soil layers adjoining the geosynthetic sheet are passed on to the multifilament strands through the upper and / or lower geosynthetic layer, supported by the fixation given, so that the multifilament strands can take on the task of absorbing tensile force intended for them and a shifting of the three or more layers of the geosynthetic sheet against one another is reduced and or completely prevented.

In contrast, the slight weakening of the multifilament strands caused by fibers possibly also drawn through the needles in the course of the needling process is, according to the inventors' knowledge, not disadvantageous for the overall achieved advantage of local fixation of the individual multifilament strands in their longitudinal direction on the first and second geosynthetic layers mechanical composite properties of the geosynthetic sheet. According to the inventors' knowledge, this can be explained in particular by the fact that the layer composite of the geosynthetic sheet constructed according to the invention has a high local mechanical load capacity, which is more important for the overall functional properties of the geosynthetic sheet than a theoretically achievable maximum force along the longitudinal direction of the multifilament strands, which in the practical use does not represent a critical property value of the geosynthetic sheet for the use according to the invention due to the effect of the load.

It is preferably provided that in the geosynthetic sheet according to the invention, each multifilament strand is pierced along its course at least once, preferably several times, by a fiber bundle of the needling, thereby bringing about a direct mechanical connection between the fiber bundles and each multifilament strand. The ratio of the first amount of fiber bundles to the second amount of fiber bundles can be influenced by the positioning of the needles during needling and the thickness of the multifilament strands and their distance from one another. The ratio of the number of fiber bundles of the first set, which run through the functional layer in addition to the multifilament strands, and the number of fiber bundles of the second set, which run through the multifilament strands through the functional layer, can for example be a lower limit of 10: 1 and / or an upper limit of 1:50 and can basically be selected depending on the application. A particularly advantageous range for the ratio can for example have a lower limit of 5: 1 and / or an upper limit of 1:20. According to the invention, the first geosynthetic layer and / or the second geosynthetic layer can be designed as, for example, a nonwoven layer mechanically consolidated by needling. In a nonwoven layer, the fibers are disordered and intertwined and form a dense random layer. Nonwoven layers are characterized by a non-directional, homogeneous resistance Resistance to mechanical loads and, depending on the density of the intertwined fibers, can be slightly permeable and separating to highly permeable and filtering. Due to the high air pore content of e.g. mechanically strengthened nonwovens of around 90% and the irregular arrangement of the fibers, they are particularly suitable for compensating for locally occurring point loads from e.g. stone edges, to oppose them through the local alignment of the fibers that then occur and thus to provide a protective function for example to take over the functional position.

The design of the first and / or second geosynthetic layer as a nonwoven layer particularly favors needling because fiber bundles from nonwoven layers can be locally deflected and taken along by means of the needling process in order to anchor them in the respective other geosynthetic layer. In particular, the arrangement of a nonwoven layer on both sides of the functional layer can bring about a favorable integration and cross-linking of the fiber bundles both with the first geosynthetic layer and with the second geosynthetic layer. The functional layer is preferably produced from multifilament strands, in particular to take on a reinforcement function. The multifilament strands suitable for absorbing tensile force are ideally arranged as straight as possible in the direction of the intended direction of stress (s), the direction of stress (s) preferably being arranged in the longitudinal direction of the production and unwinding direction and perpendicular thereto in the transverse direction of the production and unwinding direction. The direction of production and unwinding typically corresponds to the longest direction in which the geosynthetic sheet extends.

According to a preferred embodiment, the arranged multifilament strands are made up of oriented fibers and are preferably twisted in such a way that they form individual bundles and, as a result of the twisting, build up an increased internal friction bond under tensile stress. This twist corresponds to a twist around the longitudinal axis of each multifilament strand and is particularly suitable, under tensile stress, to build up an increased frictional bond to the second quantity of fibers of the upper and / or lower geosynthetic layers, which run perpendicular to the plane of the multifilament bundles, and thus to prevent displacement among one another. In addition, this rotation achieves a better fixation of the fiber bundles which run through the multifilament strand against displacement in the longitudinal direction of the multifilament strand. The geosynthetic sheet according to the invention is basically suitable for stabilizing soil layers and for other uses described at the beginning. In particular, it can be used to reinforce soil layers, to record physical measured variables and / or to record chemical measured variables. Furthermore, because of its porosity, the geosynthetic sheet according to the invention can be used to introduce liquids into soils or to lead them out of soils by guiding them along the geosynthetic layer. Even further, the multi-filament bundles can be completely or partially replaced by lines, measuring sensors, hoses or combinations thereof, in which case only the first set of the fiber bundles running perpendicular to the plane of the functional layer creates a position assurance, and the second set of fiber bundles is reduced or reduced to zero is set if there is a risk of damage to the lines and hoses. The invention therefore also includes the specific use of the geosynthetic sheet explained above for these purposes mentioned at the outset and above. According to a first preferred embodiment it is provided that the first multifilament strands extend in the longitudinal direction. According to this development, the first multifilament strands run in the longitudinal direction of the geosynthetic sheet, that is, in the direction in which the geosynthetic sheet extends the furthest after its production and, as a rule, also after assembly. This is the direction along the circumference in which such a geosynthetic sheet is rolled up around an axis in order to make it transportable as rolled goods and to be able to be laid out at the installation site by unrolling. By aligning the first multifilament strands in this longitudinal direction, reinforcement is achieved in the direction in which a geosynthetic sheet should also have high strength and low elongation in many applications, for example when used in the base of a dam on a soft subsoil where the geosynthetic sheet is laid transversely to the longitudinal direction of the dike in a horizontal surface orientation and the dam flanks are prevented from slipping apart by absorbing tensile forces.

According to a further preferred embodiment, the geosynthetic sheet is formed by a second functional layer, which consists of a plurality of parallel second multifilament strands that extend in the transverse direction, the multifilament strands being arranged perpendicular to or at a defined angle to the first multifilament layer and each Multifilament strand made from a second variety of Filaments. According to this embodiment, a second functional layer is arranged between the first and second geosynthetic layers. This second functional layer can be completely above or completely below the first functional layer.

In the prior art, on the other hand, the multifilament layers are laid undulating in the manner of a woven fabric or crosswise and / or connected to one another in the manner of a knitted fabric to form a textile plane. At least one level of the multifilaments is laid undulating and is withdrawn by deflection in the direction of an acting force, whereby additional deformations occur in an uncontrolled manner or can only be reduced by slow or special production processes such as straight warping or knitting. This is disadvantageous because it creates additional production costs and optimal alignments and properties of the functional layer are not achieved.

The technique according to the invention enables the multifilament strands to be laid in the functional plane without deflection and the bond between the layers is produced by a first and a second quantity of fiber bundles perpendicular to the functional plane. Laying in two or more separate functional levels allows the use of an economically advantageous production technique and the avoidance of the functional disadvantages described above due to undulating or deflected laying of the multifilament strands. The second multifilament strands of the second functional layer extend transversely to the first multifilament strands, that is, they run perpendicularly or at a defined angle which is typically between 90 and 15 degrees to the longitudinal extent of the first multifilament strands. In special individual cases, however, the angle between the first and second multifilament strands can also be more acute than 15 degrees. The second functional layer achieves reinforcement transversely to the longitudinal extension of the geosynthetic sheet. On the one hand, this reinforcement achieves greater stability and less stretching of the geosynthetic sheet transversely to its longitudinal extension, which is advantageous for many purposes in which the main load runs in the direction of the transverse extension. The second functional layer also makes it possible to lay the geosynthetic sheet in such a direction that the main load is introduced transversely to its longitudinal extent. This main load can then be absorbed by the second functional layer and consequently a geosynthetic sheet can be provided which enables a laying direction that deviates from the previous procedure. For example, when using a stabilization of a dam structure the geosynthetic sheet can be laid with its longitudinal extent parallel to the longitudinal direction of the dam structure on soft ground at its base and absorb the main forces occurring transversely to the longitudinal direction of the dam structure with the second functional layer. This possibility of a different laying direction opens up an advantageous, faster laying in many applications.

The first and second multifilament strands can be designed in the same way. Depending on the desired load-bearing capacity in the longitudinal direction and transverse direction of the geosynthetic sheet, the first multifilament strands can also be designed with a smaller or greater thickness than the second multifilament strands. It is even further preferred if a third quantity of the fiber bundles extend from the first to the second nonwoven layer and run through the second multifilament strands of the functional layer. According to this embodiment, a third quantity of the fiber bundles which form the needling is passed through the second multifilament strands, so that at least one of the fiber bundles passes through each of the second multifilament strands and therefore grips them in a form-fitting manner. As a result of this arrangement of the needling with direct penetration of the second multifilament strands by a third quantity of the fiber bundles of the needling, the second multifilament strands are fixed in their longitudinal direction in the geosynthetic sheet, so that also by forces acting transversely to the longitudinal direction of the geosynthetic sheet on the second multifilament strands, these cannot be shifted or pulled in their longitudinal direction. By providing the first, second and third amount of fiber bundles for needling, an ideal fixation of the multifilament strands of the first and second functional layer in the geosynthetic sheet is achieved for all loading directions and a pulling out or displacement of these multifilament strands is reliably prevented.

It is even further preferred that the density of the fiber bundles in the longitudinal direction is greater than the density of the second multifilament strands in the longitudinal direction. According to this embodiment, a greater density of the fiber bundles than the density of the second multifilament strands in this direction is achieved in the longitudinal direction of the geosynthetic sheet. Here, density is to be understood as the horizontal area covered by the fiber bundles along the longitudinal direction or by the second multifilament strands along the longitudinal direction. This means that the totaled route sections covered by the fiber bundles along a line in the longitudinal direction are longer than the totaled Route sections which are covered by the second multifilament strands along the same line. With the same thickness of the multifilament strands and the fiber bundles, this means at the same time that more fiber bundles per centimeter are arranged in the longitudinal direction than multifilament strands per centimeter. Due to this dense setting of the fiber bundles, with a corresponding distance between the fiber bundles and the distance between the multifilament strands, a sufficient amount of fiber bundles of the first amount, which pass through the first and second multifilament strands through the first and second functional layer and a third amount of fiber bundles that penetrate through the second multifilament strands can be achieved and thereby a secure mechanical anchoring can be achieved. In a simplified embodiment, the ratio of the densities can also be designed such that the number of fiber bundles per centimeter in the longitudinal direction is greater than the number of second multifilament strands per centimeter in the longitudinal direction. With the same thickness of the fiber bundles and the multifilament strands, this configuration corresponds to the aforementioned configuration and can therefore be used as an approximation for a simplified consideration and conceptualization.

It is even further preferred if the density of the fiber bundles in the transverse direction is greater than the density of the first multifilament strands in the transverse direction. According to this embodiment, the same increased density of the fiber bundles of the needling is provided in the transverse direction in relation to the density of the first multifilament strands. In turn, this relatively higher density of the fiber bundles enables secure anchoring of the first multifilament strands by a corresponding number of fiber bundles of the first set and number of fiber bundles of the second set with a correspondingly selected spacing, thereby achieving secure anchoring. The definition of the density takes place in accordance with the density of the embodiment explained above. Here, too, a simplified consideration of the density ratios can take place in such a way that the number of fiber bundles per centimeter in the transverse direction is greater than the number of the first multifilament strands per centimeter in the transverse direction.

It is even further preferred if the first geosynthetic layer is thicker than the second geosynthetic layer. According to this embodiment, a geosynthetic sheet with an asymmetrical cross-section is provided, which has a thicker geosynthetic layer on a first side and a geosynthetic layer that is thinner by comparison on a second side. With this arrangement, compared to many applications that require a special surface load capacity on one side or require special protection of the functional layers against point loads from one side, a more favorable one Layer structure can be achieved which meets these requirements with a low weight per unit area of the entire geosynthetic sheet. The geosynthetic layer on the other hand, which is thicker than this, fulfills a protective function of the first and optionally the second functional layer and enables effective needling. According to a further preferred embodiment it is provided that the first and / or second geosynthetic layer is formed from a nonwoven fabric, from a fabric, from a fabric / nonwoven combination, or from a textile flat product that allows a connection by needling. According to this embodiment, a material structure is selected for the first or second geosynthetic layer or both geosynthetic layers, which particularly favorably withstands the penetration of foreign bodies exerting a point load and transfers such point loads to the functional layers and can absorb them in a favorable manner. At the same time, these types of textile surface materials are well suited for needling, i.e. they are suitable for forming a fiber bundle when pierced with a barbed needle, which is pulled out of the first or the second geosynthetic layer, through the functional layer ( n) and is anchored in the other, opposite geosynthetic layer in order to achieve the connection perpendicular to the surface extension in the layer composite. Products that allow such a connection for needling are regularly products that are formed from longer fibers or continuous fibers or woven or knitted fabrics and in which these fibers are anchored in a textile composite and do not have a cohesive bond that would prevent them from being pulled out in the course of the Prevented needling.

It is even more preferred if the functional layers are arranged in multiple layers in one or more directions in different planes. The geosynthetic sheet is modified by the arrangement of, for example, multifilament layers in such a way that it can absorb tensile forces multiaxially, ie in more than two preferred main axes. A possible preferred embodiment is also a combination of, for example, two or more multifilament layers, each with a preferred laying and pulling direction and one or more functional levels, each of which has a different function, for example as a measuring level, as a conductor level or as a drainage level. According to a further preferred embodiment, the invention comprises a geosynthetic sheet arrangement with a first and a second geosynthetic sheet of the type described above. These two geosynthetic sheets are connected to one another in the geosynthetic sheet arrangement by the second functional layer by a number of second multifilament strands is formed, the second multifilament strands running parallel to one another in the middle area of the geotextile web and spaced apart by a distance a in the transverse direction, the second multifilament strands being formed by a number of n endless multifilament strands which are attached to the two longitudinal edges of the geosynthetic web via a Length, which corresponds to n times the distance a, run in the longitudinal direction and thereby form an edge-side bundle strand of second multifilament strands, wherein an edge-side bundle strand of the first geosynthetic sheet is connected, in particular sewn, to an edge-side bundle strand of the second geotextile sheet. According to this embodiment, the second functional layer is created by introducing multifilament strands in the transverse direction of the geosynthetic sheet and using endless multifilament strands, which each run at the edges of the geosynthetic sheet over a certain distance in the longitudinal direction, in order to then extend in the transverse direction over the geosynthetic sheet. In terms of manufacturing technology, this can be implemented in such a way that a certain number, for example n = 5, multifilament strands are laid in the transverse direction over the geosynthetic sheet using a multifilament laying device, then a relative longitudinal advance in the longitudinal direction of the geosynthetic sheet between this laying device and the geosynthetic sheet takes place over the length nxa, whereby the five multifilament strands are laid at the edge of the geosynthetic sheet over the length nxa in the longitudinal direction, in order to be laid across the geosynthetic sheet again in a reciprocal movement after this longitudinal advance. The longitudinal feed between two such laying processes in the transverse direction corresponds to the distance between two adjacent multifilament strands multiplied by the number of simultaneously laid multifilament strands, i.e. in the above example five times the distance between two adjacent multifilament strands. The laying technique can be carried out with a single endless multifilament strand (n = 1) or with a plurality of such endless multifilament strands.

As a result of this laying system, a stable strand consisting of several multifilament strands is formed on both edges of the geosynthetic sheet, which is also firmly connected to the transverse second multifilament strands of the second functional layer or is part of this second functional layer. This enables a stable connection of two geosynthetic sheets with one another along their long sides in order to lay them out next to one another and thereby form a solid geosynthetic sheet arrangement. This connection can be made, for example, by welding or sewing or gluing the longitudinally extending sections of the multifilament strands of the second functional layer. In particular, it is possible to have two or more geosynthetic sheets in such Way to connect with each other and thereby achieve an advantageous geosynthetic sheet arrangement, which is beneficial for stabilizing the base of a dam, for example, if the geosynthetic sheets are laid in the longitudinal direction of the dam, but the forces are preferably to be absorbed in the transverse direction of the dam. Another aspect of the invention is a geosynthetic sheet arrangement comprising a first geosynthetic sheet and a second geosynthetic sheet of the type described above, the first geosynthetic sheet having a hook or mushroom head strip of a Velcro fastener along a longitudinal edge and the first and second geosynthetic sheet with each other by means of this hook or Mushroom strips are connected. According to this embodiment, the connection between two adjacent geosynthetic sheets is achieved by a Velcro fastener effect, which is made possible by a hook or mushroom head strip of a Velcro fastener being formed on one of the two geosynthetic sheets and this hook or mushroom head layer can be connected to the geosynthetic layer of the other geosynthetic sheet. This type of connection requires an overlap of the two geosynthetic sheets corresponding to the width of the hook or mushroom strip and, depending on the degree of overlap and consequently the width of the Velcro fastener connection, can achieve a force transmission between the two geosynthetic sheets that is sufficient to absorb the forces occurring in the ground. This aspect of the invention can be used advantageously in geosynthetic sheets which are laid out in the longitudinal direction of a structure, such as a dam, but in which the force is preferably transmitted in the transverse direction of the structure. The use in the direction of laying and overlapping in the longitudinal direction is also advantageous in order to achieve small overlapping lengths, so that the web does not have to be pulled and compressed and, thus, folds are not required or are not to be feared. This adder laying of the webs is also advantageous if the geosynthetic webs are arranged with their preferred longitudinal direction in the transverse direction to the building, and the overlaps in the longitudinal direction of the building can be used for load transfer using the connection technology described above and the overlap widths can be kept small. The above variants allow an advantageous laying technique and load transfer, which enables a lower consumption of geosynthetic sheets compared to today's systems and an easier laying, since the sheets do not have to be sewn or long anchoring lengths do not have to be carried out. A weakening of the geosynthetic sheet by sewing, as is necessary for fabric, is also avoided. According to a further preferred embodiment, the geosynthetic sheet is developed by a plurality of lines, hoses, measuring devices or combinations thereof, which run in the longitudinal or transverse direction, the needling not being formed in the area of the hoses. According to this embodiment, for example, hoses are introduced into the geosynthetic sheet. A tube is to be understood here as a longitudinally extending cavity which, according to the invention, is not perforated by the needling, but on the other hand is fixed in position by the first set of fiber bundles. Such a hose can be used to guide liquid within the geosynthetic sheet, for example for cooling or heating purposes. The hose can also be specifically perforated at certain points in order to release liquid and thus distribute it over the surface of the geosynthetic sheet in order to stabilize and stiffen the geosynthetic sheet, for example as a result of hardening of an introduced liquid as a result of reversible or irreversible physical and / or chemical processes / or to improve the bond between the geosynthetic sheet and one or both of the adjacent soil layers, or to absorb liquid and thereby enable drainage by means of suction from the surface of the geosynthetic sheet. According to the invention, this function can also be achieved through increased permeability in the plane of the functional layer compared to the geoplastic layers, in that the functional plane itself serves to supply or discharge liquids. In this case, for example, the hose itself cannot initially be designed for supply or discharge, but the functional layer is specifically processed after installation, e.g. locally perforated (drilled) and the increased permeability of the sheet compared to the existing floors or layers is used to add grout or to distribute other liquids in a targeted manner over a large area. In this case, targeted pressure can be built up to a limited extent, although a pressure-tight connection to the functional layer is not possible. The functional layer is used to distribute a liquid due to its increased permeability compared to the environment. This makes it possible for the geosynthetic sheet to be used, for example, first as a drainage level by means of the functional layer, and for the geosynthetic sheet to be used as a sealing level after drainage has taken place so that no water can penetrate through it is introduced directly into the functional level and, after hardening, causes a seal in the level of the geosynthetic sheet. This also makes it possible to specifically influence the contact of one of the two geosynthetic layers with the surrounding soil by adding grouting agents or, for example, adhesives and / or lubricants, in which the supplied liquid e.g. by hardening the surrounding soil in the vicinity of the geosynthetic layer on the geosynthetic sheet binds or specifically reduces the contact by adding lubricants Furthermore, an inserted hose can also be used to carry out measurements on liquids or soil air, which are drawn off the surface of the geosynthetic sheet via the hose. If a line is inserted instead of the hose, measuring transducers can be activated or a line itself can serve as a measuring instrument.

The functions described above can be supported in that the permeability of one or both geosynthetic layers is reduced, so that an escape of fluids or an inflow of fluids preferably takes place via the first or the second geosynthetic sheet. The reduction in permeability can be achieved through chemical or thermal treatment of the geosynthetic layers or through the introduction or subsequent application of e.g. polymeric coatings. This treatment can already take place on the fibers from which the geosynthetic sheet is made, but it can also take place as post-treatment in the manufacturing process of the geosynthetic sheet on the fibers that have already been processed into a layer of the geosynthetic sheet or on the finished geosynthetic sheet itself. Finally, for certain purposes it is preferred to carry out the treatment as an aftertreatment on the geosynthetic sheet that has already been placed in the ground, in order to subsequently reduce or completely eliminate a permeability initially desired, for example for drainage purposes. Another aspect of the invention is a method for producing a geosynthetic sheet according to one of the preceding claims, comprising the steps:

Laying a first geosynthetic sheet along a longitudinal direction

Laying a functional layer of several first multifilament strands running parallel to one another in the longitudinal direction on the first geosynthetic layer,

Laying a second geosynthetic layer on top of the functional layer,

Needling the first geosynthetic layer, the functional layer and the second geosynthetic layer by means of a plurality of fiber bundles, a first quantity of which extend from the first to the second geosynthetic layer and run alongside the multifilament strands and a second quantity run through each multifilament strand of the first multifilament strands.

The method can be developed in that the laying of the functional layer comprises laying down second multifilament strands running transversely to the longitudinal direction and that Needling takes place with a third quantity of fiber bundles which run through each multifilament strand of the second multifilament strand and / or the first multifilament strand.

The method can be developed further by arranging a first functional layer in a first direction in the first step, then a second functional layer with a second direction, followed by a third functional layer in the direction of the first functional layer, the change of functional layers being repeated as required can be, the direction in the levels of the functional layers can be rotated against each other as desired. The method can be further developed in that a first and a second geosynthetic sheet are produced and connected to one another by connecting the first longitudinal edge of the first geosynthetic sheet to the second longitudinal edge of the second geosynthetic sheet by adding second transverse filament strands of the first geosynthetic sheet, which in the area of the first longitudinal edge in Run longitudinally, with second transverse filament strands of the second geosynthetic sheet, which run in the region of the second longitudinal edge, are sewn, or by connecting a hook or mushroom head layer of a Velcro fastener to the first geosynthetic sheet and connecting the hook layer to the first nonwoven layer of the second geosynthetic sheet , or in that the first longitudinal filament strands of the first or second geosynthetic sheet are not arranged in the area of the Velcro fastener.

Another aspect of the invention is a method for laying out a geotextile layer from several geosynthetic sheets to stabilize a longitudinal structure that extends in a longitudinal direction, characterized in that several geosynthetic sheets extending in a longitudinal direction are rolled out in the longitudinal direction, so that the longitudinal direction of the geosynthetic sheets and the longitudinal direction of the longitudinal structure run parallel to each other, with each geosynthetic sheet being reinforced by a functional layer which has several multifilament strands running transversely to the longitudinal direction of the sheet and the longitudinal edges of the geosynthetic sheets are connected to one another, preferably by means of a previously explained method of connecting edge-side second multifilament strands or the connection by means of Velcro fastened together. The arrangement of the Longitudinal filament strands in both geosynthetic sheets, but in such a way that the longitudinal filament strands in one of the two geosynthetic sheets are not arranged in the area of the Velcro fastener, the result is that these longitudinal filament strands are not laid twice in the area of the overlap of the two geosynthetic sheets, which on the one hand saves material without impairment the strength values of the overall layer is achieved, on the other hand, undesirable stiffening in the area of the overlap is economically and technically sensible avoided.

Preferred embodiments of the invention are explained with reference to the attached figures. 1 shows a schematic top view of a geosynthetic sheet arrangement with two geosynthetic sheets sewn together,

FIG. 2 shows a detailed view of the connection area of the geosynthetic sheet arrangement according to FIG. 1,

3 shows a vertical cross section along the longitudinal direction of a geosynthetic sheet arrangement according to the invention,

4 shows a schematic representation of an installation position of a geosynthetic sheet arrangement for the base support of a dike, and

5 shows a schematic perspective detailed view of a connection between two geosynthetic sheets in a geosynthetic sheet arrangement. 1 shows a section of a geosynthetic sheet arrangement with a first geosynthetic sheet 10 and a second geosynthetic sheet 20. Each of the two geosynthetic sheets has first multifilament strands 11a, b, c, 21a, b, c which run in the longitudinal direction L. The multifilament strands form a first functional layer and reinforce the geosynthetic sheets in the longitudinal direction. The multifilament strands are arranged parallel to one another and are evenly spaced from one another.

Furthermore, second multifilament strands 12a, b, c, 22a, b, c are arranged in each of the two geosynthetic sheets 10, 20. These second multifilament strands form a second functional layer in each of the two geosynthetic sheets. The second multifilament strands extend transversely to the longitudinal direction L and are also parallel and uniform Distance to each other. The second multifilament strands reinforce the geosynthetic sheets in their transverse direction.

At the points of intersection between the first multifilament strands and the second multifilament strands, the first and second multifilament strands are not connected to one another, but rather lie one above the other. In terms of production technology, they can therefore be introduced using a fiber bending technique.

The first and second multifilament strands are arranged between a lower geosynthetic layer 13, 23 and an upper geosynthetic layer (not shown for better visibility of the multifilament strands). The geosynthetic sheets therefore represent a sandwich composite of four layers, which are formed by the lower geosynthetic layer, the first functional layer, the second functional layer and the upper geosynthetic layer.

FIG. 2 shows a section from FIG. 1 in greater detail. In this section, the connection area between the first geosynthetic sheet 10 and the second geosynthetic sheet 20 is shown.

As can be seen from Fig. 2, the second multifilament strands are laid in such a way that they are deflected from their transverse course over the entire width of the geosynthetic sheet at the edge of the geosynthetic sheet, then run in the longitudinal direction over a certain section on this edge, and then again in the transverse direction to run along the opposite edge of the geosynthetic sheet. The second multifilament strands can therefore be introduced into the geosynthetic sheet as an endless multifilament strand in a meandering course. In particular, several second endless multifilament strands can be laid during production so that the predetermined distance which these multifilament strands run in the longitudinal direction at the edge is the distance between two directly adjacent second multifilament strands multiplied by the number of simultaneously laid endless multifilament strands corresponds to.

The fiber strand bundles of the second multifilament strands formed at the edge, which run in the longitudinal direction, are sewn to one another with a seam 30, whereby a firm connection of the two geosynthetic sheets 10, 20 is achieved along their adjacent longitudinal edges. Forces that penetrate across the geosynthetic can be brought can be effectively taken up by the second multifilament strands and effectively transferred from the first to the second geosynthetic sheet and vice versa by means of this connection by means of sewing technology.

FIG. 2 also shows the arrangement of a plurality of fiber bundles, which represent a needling of the geosynthetic sheets. The fiber bundles are arranged in such a way that they form a first, second and third quantity. A first quantity 41 of the fiber bundles is arranged in the spaces between the first and second multifilament strands and consequently runs next to the first and second multifilament strands from the first geosynthetic layer to the second geosynthetic layer. A second set 42 of the fiber bundles is aligned parallel to the first set of fiber bundles and runs through the first multifilament strands so that they are fixed directly and also against forces in the longitudinal direction L. A third set 43 of the fiber bundles also runs parallel to the fiber bundles of the first and second sets and is positioned such that it passes through the second multifilament strands. This third set of fiber bundles thus fixes the second multifilament strands along their longitudinal direction, that is, in the transverse direction of the geosynthetic sheets.

Fig. 3 shows a cross section through a geosynthetic sheet. The geosynthetic sheet can be seen in this cross-sectional view in its vertically staggered structure. Starting from an upper geosynthetic layer 50, which can be embodied as a nonwoven, a first functional layer with first multifilament strands 11 adjoins it at the bottom. A second functional layer is arranged adjacent to and parallel to this first functional layer, which lies below the first functional layer and comprises second multifilament strands 12. This second functional layer is followed by a second geosynthetic layer 60 at the bottom, which can also be designed as a nonwoven layer and can be the same or different in thickness, as shown in FIG. 3, namely thicker than the first geosynthetic layer 50 in this example.

The first and second geosynthetic layers 50, 60, the first and second functional layers formed by the first multifilament strands 11 and the second multifilament strands 12 are connected to one another by means of needling. This needling is formed by fiber bundles 41, 42, 43 which extend perpendicular to the plane of these layers through all layers. The fiber bundles of this needling are produced by piercing the layer composite in a vertical direction of movement with vertically aligned needles with barbs, this movement of the needles being carried out in a back and forth movement and the barbs thereby removing the fiber bundle from the The upper geosynthetic layer is pulled through the two functional layers into the lower geosynthetic layer and, conversely, fiber bundles of the lower geosynthetic layer are pulled through the two functional layers into the upper geosynthetic layer. The fiber bundles of the needling are located in such a way that this includes fiber bundles that run through the functional layers in addition to the first and second multifilament strands, furthermore fiber bundles are included that run through the first multifilament strands and fiber bundles are included that run through the second multifilament strands.

Fig. 4 shows a dike that can be used, for example, for bank reinforcement of an inland waterway or for coastal protection. The dike is stabilized at its base with a geosynthetic sheet arrangement which is intended to prevent the dike from slipping transversely to its longitudinal direction L by providing a base which is stable in this transverse direction and on which the dike rests.

The geosynthetic sheet arrangement is formed from a total of four geosynthetic sheets 110, 120, 130, 140. The geosynthetic sheets are laid along the longitudinal direction L of the dike, so that the longitudinal edges of the geosynthetic sheets run parallel to one another and parallel to the longitudinal direction of the dike.

The geosynthetic sheets 110, 140 are connected to one another along their longitudinal edges. This connection is shown in Fig. 5 in a detail. As can be seen, the geosynthetic sheets 110, 120 overlap over a small portion along their longitudinal edges. Here, a hook strip 125 of a Velcro fastener is attached to the geosynthetic sheet 120 lying below in the overlap area, which can be done by welding, gluing, sewing or the like. The lower geosynthetic layer of the geosynthetic sheet 110, which comes to lie in the overlapping area on the geosynthetic sheet 120, is formed by a nonwoven layer and can be mechanically firmly anchored in this hook layer. The two-dimensional connection paired with the earth load that is exerted on the geosynthetic sheets by the dyke results in a heavy-duty connection between the two geosynthetic sheets by means of a Velcro fastener. In the area of the hook strip 125, that is to say where the two geosynthetic webs 110, 120 overlap, no multifilament strands are arranged in the longitudinal direction in the geosynthetic web 110. This creates a homogeneous stiffness behavior of the composition of the first and second geosynthetic sheet in the longitudinal direction and avoids undesired stiffening along this overlapping area.

Claims

Expectations

Geosynthetic sheet for the stabilization and / or reinforcement and / or acquisition of physical and / or chemical measured quantities of soil layers and / or for the introduction or acquisition of liquids and / or physical quantities in or out of soils, with a longitudinal direction and a transverse direction, which in a Geosynthetic sheet level, comprising: a first geosynthetic layer, a second geosynthetic layer, a first functional layer arranged between the first and second geosynthetic layers, which preferably consists of a plurality of parallel first multifilament strands, wherein each multifilament strand consists of a first plurality of filaments, the first The geosynthetic layer preferably consists of a nonwoven and / or fabric or comprises a fabric and / or a nonwoven, and the second geosynthetic layer preferably consists of a nonwoven and / or fabric or comprises a fabric and / or a nonwoven, characterized in that the first e geosynthetic layer, the functional layer and the second geosynthetic layer are connected to one another by needling, which comprises a plurality of fiber bundles running perpendicular to the geosynthetic sheet plane, in which fibers of the first geosynthetic layer and / or fibers of the second geosynthetic layer are drawn through the functional layer, a first Amount of fiber bundles extends between the first and second geosynthetic layers and runs alongside the multifilament strands through the functional layer and a second amount of fiber bundles extends between the first and second geosynthetic layers and runs through each multifilament strand of the first multifilament strands of the functional fiber layer.

Geosynthetic sheet according to claim 1, characterized in that the first multifilament strands extend in the longitudinal direction or in the transverse direction. 3. geosynthetic sheet according to claim 1 or 2, characterized by a second functional layer, which consists of a plurality of parallel second multifilament strands which extend in the transverse direction or longitudinal direction, the multifilament strands being arranged perpendicular to or at a defined angle to the direction of the first multifilament layer, each multifilament strand consisting of a second plurality of Filaments,

4. geosynthetic sheet according to claim 3, characterized in that a third quantity of the fiber bundles extend from the first to the second geosynthetic layer and run through the second multifilament strands of the functional layer. 5. Geosynthetic sheet according to claim 4, characterized in that the density of the first multifilament strands in the longitudinal direction is greater than the density of the second multifilament strands in the transverse direction, or the density of the second multifilament strands in the transverse direction is greater than the density of the first multifilament strands in the longitudinal direction, or the The density of the first multifilament strands in the longitudinal direction is equal to the density of the second multifilament strands in the transverse direction.

6. geosynthetic sheet according to any one of the preceding claims, characterized in that the thickness of the first geosynthetic layer is different from the thickness of the second geosynthetic layer.

7. geosynthetic sheet according to one of the preceding claims, characterized in that the first and / or second geosynthetic layer made of a nonwoven fabric, a fabric, - a fabric / nonwoven combination, or a textile surface product that allows a connection by needling, or

- from a flat preliminary product with an independent function, in particular one Sealing foil, a root protection membrane or a conductive foil that allows a connection by needling.

8. geosynthetic sheet according to any one of the preceding claims, characterized in that the functional layers are arranged in multiple layers in one or more directions in different planes.

9. Geosynthetic sheet according to one of the preceding claims, characterized by a plurality of functional elements selected from:

Hoses, sensors, polymeric or metallic wires or filaments cables or

Combinations can consist of these, which run in the longitudinal direction, wherein the needling is not formed in the area of the functional elements.

10. geosynthetic sheet according to any one of the preceding claims, characterized by a plurality of functional elements selected from

Hoses,

Encoders, - polymeric or metallic wires or filaments,

Cables or

Combinations can consist of these, which run in the transverse direction, wherein the needling is not formed in the area of the functional elements. 11. geosynthetic sheet according to any one of the preceding claims, characterized in that the permeability to Liquids or gases of the first and / or the second geosynthetic sheet perpendicular to their plane of extension is reduced by a chemical or thermal aftertreatment or by the subsequent application of a coating compared to the functional layer.

12. geosynthetic sheet arrangement, comprising a first geosynthetic sheet according to one of the preceding claims 3-11 and a second geosynthetic sheet according to one of the preceding claims 3-11, characterized in that the second functional layer is formed by a number of second multifilament strands, the second multifilament strands in the The middle area of the geotextile sheet run parallel to one another and spaced a distance a in the transverse direction, the second multifilament strands being formed by a number of n endless multifilament strands which are attached to the two longitudinal edges of the geosynthetic sheet over a length which is n times the distance a corresponds, run in the longitudinal direction and thereby an edge-side

Form bundle strand from second multifilament strands, wherein an edge-side bundle strand of the first geosynthetic sheet is connected, in particular sewn, to an edge-side bundle strand of the second geotextile sheet. 13. geosynthetic sheet arrangement, comprising a first geosynthetic sheet according to any one of the preceding claims 1-11 and a second geosynthetic sheet according to any one of the preceding claims 1-11, characterized in that the first geosynthetic sheet has a hook or mushroom head strip of a Velcro fastener along a longitudinal edge and the first and second geosynthetic sheet with each other by means of this hook or

Mushroom head strips are connected, wherein the first geosynthetic sheet serves as a fleece, in particular in that the first geosynthetic sheet consists of a nonwoven or comprises a nonwoven.

14. A method for producing a geosynthetic sheet according to any one of the preceding claims, characterized by the steps: Laying a first geosynthetic sheet along a longitudinal direction

Laying a functional layer of several first multifilament strands running parallel to one another in the longitudinal direction on the first geosynthetic layer, - Laying a second geosynthetic layer on the functional layer,

15. The method according to claim 14, characterized in that the laying of the functional layer comprises laying down second multifilament strands running transversely to the longitudinal direction and the needling takes place with a third quantity of fiber bundles which either run through the multifilament strands of a second functional layer or through the multifilament strands of the first functional position or both.

16. The method according to claim 14 or 15, characterized in that in the first step a first functional layer is arranged in a first direction, then a second functional layer with a second direction, followed by a third functional layer in the direction of the first

Functional layer, whereby the change of the functional layers can still be repeated as desired, whereby the direction in the planes of the functional layers can be rotated against each other as desired. 17. The method according to any one of the preceding claims 14-16, wherein a first and a second geosynthetic sheet are produced and connected to one another by the first longitudinal edge of the first geosynthetic sheet is connected to the second longitudinal edge of the second geosynthetic sheet by second transverse filament strands of the first geosynthetic sheet, which in Area of the first longitudinal edge run in the longitudinal direction, with second transverse filament strands the second geosynthetic sheet, which run in the longitudinal direction in the area of the second longitudinal edge, are sewn, or by attaching a hook or mushroom head layer of a Velcro fastener to the first geosynthetic sheet and the hook or mushroom head layer with the first geosynthetic layer of the second geosynthetic sheet as a fleece layer of the

Velcro fastener is connected, in particular in that the first geosynthetic layer of the second geosynthetic sheet comprises a nonwoven layer or consists of a nonwoven layer, in that the two geosynthetic sheets are butted against each other and this joint area by an overlap sheet according to one of the preceding claims, fully equipped with a hook or mushroom head layer a Velcro fastener, is underlaid or covered and thereby a connection of the first and second geosynthetic sheet is achieved, or - by the two geosynthetic sheets are butted against each other and the geosynthetic sheets are equipped in the edge area with a hook or mushroom head layer of a Velcro fastener, and this joint area through a strip of a geosynthetic sheet according to one of the preceding claims is underlaid or covered and thereby a connection of the first and second geosynthetic sheet is achieved.

18. A method for laying out a geotextile layer from several geosynthetic sheets to stabilize a longitudinal structure that extends in a longitudinal direction, characterized in that several geosynthetic sheets extending in a longitudinal direction are rolled out in the longitudinal direction, so that the longitudinal direction of the geosynthetic sheets and the longitudinal direction of the

Longitudinal structures run parallel to each other, with each geosynthetic sheet being reinforced by one or more functional layers which have several multifilament strands running transversely to the longitudinal direction of the sheet and wherein the longitudinal edges of the geosynthetic sheets are connected to one another, preferably by means of a method according to claim 19.

19. The method according to any one of the preceding claims, characterized in that the geosynthetic sheet has a first permeability for fluids and hoses included in the functional layer, the geosynthetic sheet is installed and remains installed for a first period of time with the first permeability, and that a liquid is introduced through the hoses into the geosynthetic sheet and, if applicable, the soil adjacent to the geosynthetic sheet, the liquid subsequently hardens or a hardening process of the geosynthetic material and / or causes the adjacent soil, and the geosynthetic sheet subsequently has a second permeability for fluids, which is less than the first permeability.