Geotextile web having biodegradable properties

Abstract

The invention relates to a geotechnical material web comprising an organic first structural material and a second structural material different from the organic first structural material, the second structural material being connected to the first structural material to form a planar material composite web extending in two mutually perpendicular directions. The invention is characterized in that the first and second structural materials are organic materials, the first structural material having a first biodegradability to some extent, while the second structural material has a second biodegradability different from the first biodegradability, in particular lower than the first biodegradability.

Description

TECHNICAL FIELD

[0001] The present invention relates to a geomaterial web, to a method for soil stabilization by means of a geomaterial web and to the use of a geomaterial web for soil stabilization. BACKGROUND

[0002] Geowebbing, also referred to as geotextile (or classic geosynthetic), is used in a multitude of ways for stabilizing soil layers. These different possibilities of use of geowebbing are typical examples in the reinforcement of slopes, in the construction of embankments, in the protection of embankments of rivers and lakes, in the slope stabilization in landfills or for the stabilization of carriageways in road and railway construction. Geowebbing is in this case usually installed in a predetermined depth, i.e. covered by a soil layer, but in individual cases can also be installed on the surface.

[0003] Geowebbing in this case assumes the task of stabilizing the soil layer and the layer boundaries between the soils, that is to say, of preventing erosion or the rearrangement and mixing of the soil material and of inhibiting or reducing the transfer of soil material, for example, caused by erosion and redeposition of the soil material restricted by the flow, and of preventing the overall slippage of the soil layer. Geowebbing in this case can be used as a lasting solution, especially in cases where stabilization of the soil layer or the layer boundaries cannot be achieved due to natural processes such as root penetration or other soil consolidation mechanisms. In many applications, geowebbing is constructed in order to achieve a transitional, temporary mechanical stabilization effect which stabilizes the soil layer in such a way that the growth of plants is enabled and additional stabilization of the soil layer can be achieved in the long term by means of root penetration of these growing plants. A geowebbing for use as a fiber-reinforced mat is known from EP 2 439 342 A1.

[0004] One problem associated with such geowebbing is that the artificial material introduced into the soil is a potential environmental risk, which arises at the installation site itself or at other sites if the geowebbing is separated into smaller sections by mechanical influences or other effects and is carried away from the installation site. In order to overcome these disadvantages, it is generally proposed to manufacture the geowebbing from biodegradable materials. For example, a cover layer consisting of a material which can consist of natural fibers is known from DE 29 51 679 U1. A geotextile having a nonwoven structure is known from US 2013 / 0344759 A1, which is manufactured using plant fibers. For this purpose, it is proposed to use hemp fibers as an alternative to the known jute fibers or coconut fibers.

[0005] A fiber structure material designed for an increased water absorption capacity is known from EP 3 385 426 A1. The fiber structure of this known material is designed as a three-dimensional fiber skeleton of a coarse fiber section and a fine fiber partial section connected to each other, which is manufactured from a lyocell solution. This fiber structure material has the disadvantage that due to the three-dimensional direct connection of the fiber sections to each other, the fiber structure material has a uniform biodegradability and thus does not comprise two structural materials with different biodegradability.

[0006] A textile sealing membrane consisting of lyocell fibers is known from US 2009 / 0317583 A1. This sealing membrane does not have two structural materials with different biodegradability.

[0007] However, the disadvantage of biodegradable geotextiles presented in this way is that in many applications it cannot be ensured within the required period of time that the desired mechanical soil stabilization loses the mechanical protection due to biodegradation and can cause undesired soil movements, such as slope slippage, dike damage, etc. While a fiber coating is presented in order to avoid these problems, this runs counter to the actual goal of achieving biodegradation and creates an environmental risk from the coating. Therefore, the use of biodegradable geotextiles made of the above-mentioned known natural fibers cannot lead to satisfactory results in many applications or is not effective with regard to the time requirement for the mechanical reinforcement. Therefore, for geosynthetics, DIN EN 12225 gives a test standard in order to prove general resistance to microbial degradation. SUMMARY

[0008] It is therefore the object of the present invention to present a geotextile web, a method for stabilizing a soil layer by means of a geotextile web and a use of a geotextile web for stabilizing a soil layer, which ensure a reliable mechanical stabilization within the necessary period of use, while at the same time reducing environmental pollution.

[0009] According to the invention, this object is achieved according to a first aspect of the invention by a geotextile web comprising an organic first structural material and a second structural material different from the first structural material, which are connected to each other to form a planar material composite web extending in two mutually perpendicular directions, wherein the first structural material and the second structural material are organic materials, the first structural material having a first biodegradability of the following degree:

[0010] - in a composting test with the following parameters:

[0011] o a sample having a length of 10 cm, a width of 10 cm and an initial material thickness,

[0012] o 50°C + / - 5°C,

[0013] o high temperature conditions according to ISO 16929,

[0014] o the solids are sieved after six months in a sieve with a mesh size of 2 mm (sieve 8.75),

[0015] less than 80 wt.%, in particular less than 50 wt.%, less than 25 wt.% or less than 10 wt.% of the dry matter of the initial material remains in the sieve at the sieving,

[0016] - in the marine incubation test with the following parameters:

[0017] o samples with a length of 2 cm, a width of 2 cm and the thickness of the initial material,

[0018] o 30°C + / - 2°C,

[0019] o aerobic conditions in sea water with a salinity of 3.5 wt.% + / - 1 wt.%,

[0020] o the solids are sieved after 4, 8 and 12 weeks in a sieve with a mesh size of 2 mm (sieve 8.75),

[0021] less than 80 wt.%, in particular less than 50 wt.%, less than 25 wt.% or less than 10 wt.% of the dry matter of the initial material remains in the sieve at the sieving after 12 weeks,

[0022] - and the second structural material has a second biodegradability which is different from the first biodegradability, in particular lower than the first biodegradability.

[0023] According to the present application, a geotextile web is proposed, which is composed of or comprises a first structural material and a second structural material. The first structural material and the second structural material are connected to each other as a planar material composite web, i.e. as a geotextile, mat, etc. This connection can be achieved by weaving, knitting, needling, nonwoven processing or other methods which systematically connect the first and second structural material to each other. Preferably, the first and second structural material can be a fibrous material, wherein this is to be understood as short fibers, long fibers, yarns, continuous fibers, etc. The connection between the first and second structural material can also be constituted in the manner of a nonwoven material by randomly arranging the fibers to create a tangling and hooking effect between the fibers.

[0024] According to the application, the first structural material is an organic structural material, i.e. for example wood, wood-like material or plastic. The second structural material can be an organic or inorganic material. The functionality and the effect of the geotextile web are achieved by the interaction of the two structural materials.

[0025] Both the first and the second structural material have biodegradability. Here, the biodegradability is defined according to the principles of the ISO 16929 standard or according to the marine degradation test developed by the Austrian Belgian consortium according to the application. The material according to the application must meet at least one of these two conditions, preferably both.

[0026] According to ISO 16929, the compostability of a material is proven if it meets three criteria. One of these criteria is defined such that in a controlled composting under high-temperature composting conditions according to ISO 16929 after 84 days, not more than 10% of the material remain on a 2 mm sieve when the material or its components are sieved. According to this systematics and adapted to the requirements for geotextiles, the first structural material has a first biodegradability, wherein in a controlled composting according to ISO 16929 under high-temperature composting conditions within six months, not more than 50% by weight of the dry matter of the first structural material remain on the sieve after sieving through a 2 mm sieve. Thus, the first material does not necessarily meet the compostability criteria in the sense of ISO 16929. However, it can be compostable or can achieve a degradation of 90% by weight of the particles < 2 mm over a period of more than six months.

[0027] The degradation test under marine conditions simulates the degradation of standardized samples under accelerated simulation in seawater. Here, the degree of degradation is also determined by the final sieving according to the dry weight remaining on the sieve. However, after 4 and 8 weeks, a stronger mobility of the material is simulated by two intermediate sievings.

[0028] Both degradation tests are carried out with test samples having defined dimensions. The length and the width are defined here, the thickness is oriented to the original material, i.e. the thickness of the material in the produced configuration. This can be the thickness of the material in the respective ply in the case of a layer composite in which the first structural material and the second structural material are arranged in plies separated from one another, one above the other, and are connected to one another. If the original material is produced as a composite ply, for example as a nonwoven or as a ply woven, knitted or otherwise connected from two different fibers, for the purpose of the degradation test a sample in the original material thickness of the ply must be used which is made only of the material to be examined.

[0029] ​The second structural material has a second biodegradability which is different, in particular smaller, than the first biodegradability of the first structural material, i.e. a second weight percentage fraction of the second structural material remains in the 2 mm sieve after six months or twelve weeks, which is different, in particular higher, than the first weight percentage fraction of the first structural material. That is, if for example 70 wt% of the first structural material is degraded to particles of < 2 mm within six months in a compost test, then a weight percentage fraction of 60% of the second structural material can be degraded to particles of < 2 mm within the same time period under the same conditions.

[0030] By the present application, therefore, a geotextile web is provided which undergoes a material conversion into carbon dioxide in a defined manner by biodegradation, wherein one of the two structural materials included in the geotextile web or used for the construction of the geotextile web biodegrades faster than the other structural material. Thus, both the geometric and mechanical properties of the geotextile web are influenced in a targeted manner by the biodegradation. For example, by the faster degradation of the first structural material in the geotextile web, the formation of openings or holes can be achieved, which is advantageous for the root penetration process in such a way that the increasing spatial requirement of the plant roots with increasing root penetration is provided by the biodegradation of the first structural material, while the mechanical stability still required is maintained by the second structural material. Furthermore, in a woven or knitted fabric or nonwoven or composite material composed of the first and second structural material, the mechanical properties in a first direction are reduced to a greater extent than the mechanical properties in a second direction different from the first direction, wherein the first structural material essentially stretches in the geotextile web in the first direction and the second structural material essentially stretches in the geotextile web in the second direction. Thus, for example in the reinforcement of slopes, the stability transverse to the slope direction is reduced faster than the stability in the slope direction, thereby achieving a slight mobility of the geotextile web desired for plant growth, while at the same time preventing a slip along the slope direction. The difference between the two structural materials can for example lie in the fact that the first structural material is composed of a different material than the second structural material or contains a different material than the second structural material. The difference can also lie in the fact that the first structural material and the second structural material are of the same material, but the material of the first structural material is subjected to a different material treatment than the material of the second structural material. Preferably, the first structural material and the second structural material do not differ in specific properties such as fiber thickness and / or fiber length.

[0031] In principle, in addition to influencing the geometric and mechanical properties by specifically setting the first and second structural material in the geotextile web, it is also possible to influence the mechanical properties as a whole over the degradation period of the geotextile web by the selection and share ratio of the first and second structural material. This advantageously enables that the biodegradation rate and the reduction of the mechanical / geometric properties can be matched to the local conditions at the installation site of the geotextile web. The standardized biodegradability is determined under standardized conditions, whereas at the installation site there can be different influencing parameters for the biodegradability. Thus, for example, an increased oxygen content would lead to a faster biodegradation, and vice versa, a reduced oxygen content would lead to a slower biodegradation. In addition, influencing factors such as increased UV radiation, or high or low pH values, increased nutrient supply, increased bacterial share, increased fungal share, etc. influence the speed of biodegradation. By the possibility of varying the mixing ratio of the first and second structural material in the geotextile web according to the application, it is thus possible, for example, to increase the share of the second structural material if an increased biodegradation speed is expected due to local influencing factors at the installation site, or vice versa, if influencing factors are expected at the installation site that reduce the biodegradation speed, this can be countered by increasing the share of the second structural material in order to obtain in this way a geotextile web with a customized biodegradation speed that matches the local conditions.

[0032] It is preferably proposed that the first biodegradability is greater than the second biodegradability. According to this embodiment, the second structural material has a lower biodegradability than the first structural material, that is to say, the second structural material degrades more slowly than the first structural material. In principle, for example, the first structural material can have a degradability in which at least 90% by weight of the first structural material is broken down into particles smaller than 2 mm after six months or twelve weeks, whereas in the second structural material only 80% by weight or less. This means that in the first material less than 10% by weight of the material remains on the 2 mm sieve, whereas in the second material more than 20% by weight remains on the sieve. Preferably, the second structural material has a biodegradability in which less than 50% is broken down into particles smaller than 2 mm after six months.

[0033] It is further preferred that the first structural material is arranged in the geotextile web in such a way that, after partial or complete biodegradation of the first structural material in the geotextile web, an opening through the geotextile web is constituted. According to this embodiment, the faster degradation of the first structural material changes the geometric appearance of the geotextile web in such a way that an opening through the geotextile web is created. The first structural material is thus arranged in the geotextile web in such a way that it closes said opening in the initial state and opens said opening or creates said opening by its degradation. The geotextile web is thus perforated or perforated to a greater extent in order to match the root penetration process, which, with increasing root penetration, on the one hand requires a greater degree of permeability of the geotextile web and, on the other hand, also requires a lower mechanical strength of the geotextile web. The desired effect can be achieved in the case of the constitution of an opening by the degradation of the first structural material, for example, by the way that the first and second structural materials are processed together into a nonwoven fabric.

[0034] It is further preferred that the first structural material partially or completely penetrates the second structural material. By means of this penetration, on the one hand, a specific, oriented or non-oriented mechanical destabilization of the geotextile web can be achieved by the biodegradation of the first structural material. On the other hand, specific, oriented or non-oriented channels and openings can be created in the second structural material by the biodegradation of the first structural material, which channels and openings run along the penetration.

[0035] It is further preferred that the first structural material and the second structural material are connected to one another as a layer composite, the second structural material has a plurality of second perforations, and the first structural material has no perforations or a plurality of first perforations that are smaller than the second perforations. By this design, it is achieved that, due to the faster degradation of the first structural material, a larger opening through the geotextile web as a whole can be created.

[0036] Another aspect of the application is a method for soil stabilization in a site-related manner by means of a geotextile web, the method comprising the following steps:

[0037] determining the intensity of an influencing parameter at the installation site, wherein the intensity of the influencing parameter is selected from the group consisting of:

[0038] - the intensity of the radiation effect of electromagnetic radiation,

[0039] - the height of the temperature,

[0040] - the concentration of substances that chemically and / or biochemically react with the geotextile web,

[0041] - the concentration of bacteria in a certain concentration, and / or

[0042] - the concentration of fungi,

[0043] determining one or more of the influencing parameters at a transfer site spaced apart from the installation site,

[0044] installing the geotextile web at the installation site, wherein the geotextile web comprises a structural material, which structural material

[0045] o has a degree of biodegradability under the strength of the influencing parameters at the transfer site, that if the material or its constituents are sieved, a transfer site residual fraction remains in the 2 mm sieve within six months,

[0046] o wherein the transfer site residual fraction is less than 30% by weight of the material,

[0047] o has a degree of biodegradability under the strength of the influencing parameters at the installation site, that if the material or its constituents are sieved, an installation site residual fraction of the material remains in the 2 mm sieve within six months,

[0048] o wherein the installation site residual fraction is greater than the transfer site residual fraction.

[0049] According to this aspect of the application, the site-related soil stabilization is achieved by means of the geotextile web. It is understood that the geotextile web has a duration of biodegradation at the installation site and a different biodegradability at the transfer site, which biodegradability is as before, for example, similar to the standardization of the degradability according to ISO 16929 or the marine degradation test - but can be defined by means of the sought parameters at the installation site or at the transfer site. Depending on the conditions present at the installation site, more than 10% by weight, in particular more than 25% by weight or more than 80% by weight of the structural material can remain as particles in the 2 mm sieve after a period of six months or twelve weeks. Thereby a reduced biodegradation rate at the installation site is achieved, which is sufficient for soil stabilization applications and leads to a reliable degradation of the geotextile web. This biodegradability is achieved under the conditions at the installation site, in particular the mentioned influencing parameters, i.e. temperature, radiation, oxygen concentration, bacterial concentration and / or fungal concentration, etc. In contrast thereto, in the method according to the application, the material has a higher biodegradability at the transfer site. That is, under the conditions there, the particles of the material remaining in the 2 mm sieve after six months or twelve weeks are less compared to the conditions at the installation site. This can achieve a preferably less than 80% by weight, in particular less than 25% by weight or less than 10% by weight of the structural material within six months or twelve weeks under the conditions present there at the transfer site, which have a higher degradation rate.

[0050] The transfer site can in this case be a site to which the geotextile web is transferred after being removed at the installation site, for example deposited there, and which differs from the installation site in one of the influencing parameters. Thus, a higher oxygen concentration and / or stronger ultraviolet radiation and / or bacterial and / or fungal concentration, which is planned to be established, can for example be present at the deposition site and cause an accelerated biodegradation of the geotextile web. If the geotextile web is exposed to environmental influences or other influences, subjected to mechanical action so as to be exposed, for example, transported in a floating manner or for other influences, the transfer site can also be a site to which the geotextile web arrives completely or in fragments. In this case, the transfer site can also be understood as meaning that the original installation of the geotextile web at the installation site under a soil layer is changed such that the soil layer is stripped off so that the geotextile web is exposed. This is the case, for example, in many marine applications for coastal protection and erosion protection, in which, due to water movement and wave movement, a separation of the material and a transfer from the installation site to the transfer site can take place. At the transfer site, the geotextile web degrades acceleratedly and thus does not represent a relevant environmental pollution.

[0051] It is preferred here that the installation site has an environment which has a lower temperature and / or a lower oxygen content and / or a lower bacterial and / or fungal concentration compared to the transfer site. These influencing parameters are particularly suitable for geotextile webs based on a fiber glue, such as lyocell, in order to achieve a different biodegradation rate at the installation site than at the transfer site.

[0052] Here, in particular, the installation site can be located on the seabed, and the geotextile web can float up due to currents and / or density differences or reach the surface due to human influences. The transfer site is thus characterized by a higher oxygen concentration and temperature in the upper water layer and an increased ultraviolet radiation and ensures an accelerated degradation.

[0053] It is further preferred that the structural material is a material based on a fiber glue, in particular lyocell. Such a structural material has proven to be particularly suitable for a selectively accelerated biodegradation rate at the transfer site compared to the installation site.

[0054] According to this aspect of the application, the geotextile web is thus used in such a way that it comprises a structural material which

[0055] - has a biodegradability in a first strength of the influencing parameters at the installation site in such an extent that

[0056] - in a composting test with the following parameters

[0057] o a sample having a length of 10 cm, a width of 10 cm and an initial material thickness,

[0058] o 50°C + / - 5°C,

[0059] o high temperature conditions according to ISO 16929, as long as these conditions are not limited by specific intensities of specific influencing parameters at the installation site,

[0060] o the solids are sieved after six months in a sieve with a mesh size of 2 mm (sieve 8.75), more than 50 dry weight-% of the initial material remaining in the sieve at the time of sieving, or

[0061] - in the marine incubation test, with the following parameters:

[0062] o a sample having a length of 2 cm, a width of 2 cm and the thickness of the initial material,

[0063] o 30°C + / - 2°C,

[0064] o aerobic conditions in seawater with a salinity of 3.5 wt.-% + / - 1 wt.-%, as long as these conditions are not limited by specific intensities of specific influencing parameters at the installation site,

[0065] o the solids are sieved after 4, 8 and 12 weeks in a sieve with a mesh size of 2 mm (sieve 8.75),

[0066] more than 10 dry weight-%, in particular more than 25 dry weight-% or more than 80 dry weight-% of the initial material remaining in the sieve at the time of sieving after 12 weeks and the first structural material has a biodegradability to the following extent at a second intensity of influencing parameters at the transfer site: within six months in the composting test or within twelve weeks in the marine incubation test and less than 80 wt.-%, in particular less than 25 wt.-% or less than 10 wt.-% of the dry matter of the first structural material remaining in the sieve after sieving through the 2 mm sieve, wherein the intensity of the influencing parameters is selected from:

[0067] - the intensity of the radiation of the electromagnetic radiation,

[0068] - the height of the temperature,

[0069] - the concentration of substances that chemically and / or biochemically react with the geotextile web,

[0070] - the concentration of bacteria at a certain concentration,

[0071] - the concentration of fungi,

[0072] in such a way that the geotextile web is installed at the installation site at the installation time point and the geotextile web is transported to the transfer site at a time point after the installation time point.

[0073] According to the use, the geotextile web is used in such a way that it has a predetermined rate of degradation of not more than a certain biodegradation rate at the installation site, which is achieved by the above-mentioned influencing parameters present there. In contrast, the geotextile web is used in such a way that, if it is transported from the installation site to a transfer site, where this can take place by planned transport or unplanned delivery, the geotextile web has a higher rate of degradation and thus biodegrades more rapidly at the transfer site than at the installation site. This accelerated degradation is achieved by the correlation of the rate of degradation with the different intensity of the influencing parameters there - optionally also by a plurality of different influencing parameters, which are present at the installation site and at the transfer site in different intensities and are used as influencing parameters instead of preset parameters in the previously defined material tests with regard to compostability or marine degradation. According to a further aspect of the present application, the initially stated object is achieved by a geotextile web comprising a first fiber material based on viscose, in particular lyocell.

[0074] According to this aspect of the present application, the geotextile web comprises a fiber material based on viscose. Such a fiber material based on viscose can be used as a first structural material or as a second structural material in the geotextile web. In principle, according to the present application, cellulose regenerated fibers such as lyocell are very suitable as a material or component part of the geotextile web.

[0075] The geotextile web can consist exclusively of the first fiber material based on viscose or can comprise further structural materials, in particular further fiber materials. The fiber material based on viscose can in particular be a mass consisting of viscose fibers, i.e. a mass consisting of synthetic fibers usually made of regenerated cellulose. In this case, the cellulose is usually processed into filament yarn or staple fibers, for example in a wet spinning process. According to the inventors' knowledge, viscose fibers have proven to be particularly suitable for providing the targeted biodegradation required for the geotextile web. Thus, by varying the fiber length, crimp and by different fineness, i.e. fiber thickness, the viscose fibers can be adapted to the desired rate of biodegradation under the predetermined environmental conditions at the installation site. Viscose fibers can furthermore be metabolized by many organisms and can thus be classified as environmentally friendly.

[0076] The fiber material based on viscose, such as lyocell, can in particular also be used as a first and / or second structural material according to the first aspect of the present application.

[0077] The inventors have recognized that viscose fibers of the Lyocell genus are particularly suitable. These fibers are of the type of viscose fibers which are manufactured by means of a solvent spinning process, in which cellulose is dissolved directly in an organic solvent without forming a derivative, and the solution is spun. This manufacturing process, particularly when using the organic solvent NMNO (N-methylmorpholine-N-oxide), is environmentally friendly both in production and in the manufactured product. According to the invention, wood pulp can preferably be used as the cellulose starting material. According to the inventors' knowledge, Lyocell has proven to be biodegradable under typical environmental conditions in the soil layer, and in this case with a degradation rate which can act in conjunction with the rate of root penetration in newly planted roots, so that the degree of biodegradation of the geotextile web also progresses to such an extent that the root penetration is neither significantly impeded nor does any significant residual amount of the geotextile web exist in further time courses, when a degree of root penetration is reached which is sufficient for mechanical stabilization of the slope. Furthermore, according to the inventors' knowledge, Lyocell is very suitable for differentiated biodegradation. Thus, Lyocell biodegrades more quickly under conditions in which the oxygen concentration, the bacterial and / or fungal concentration and the UV radiation in the environment are increased, compared to conditions in which the oxygen concentration, the bacterial and / or fungal concentration and the UV radiation are low. This allows the geotextile web to be structured in such a way as to be planned for soil layer stabilization, to also provide the mechanical properties which are necessary for soil stabilization at the installation site for the desired period of time, however, when transferred to another site, either intentionally or unintentionally, the geotextile web degrades more quickly, at the other site there are then other conditions, such as increased oxygen concentration, bacterial and / or fungal concentration or UV radiation. This selectivity of the degradation rate is advantageous, for example, for use at the seabed with low oxygen concentration, bacterial and fungal concentration and low temperature and low UV radiation, because Lyocell which unintentionally drifts or is transferred to a site with different environmental conditions then degrades more quickly. Likewise, this can be advantageous in coastal protection and dike reinforcement measures, in which Lyocell then degrades more quickly due to the increased UV radiation and the increased concentration of bacteria and / or fungi, in the exposed case.

[0078] According to one preferred embodiment it is proposed for this purpose that the first fibrous material is configured as a nonwoven or as a woven or as a textile and is processed into a textile planar fabric in the geotextile web by mechanical consolidation, braiding, knitting or weaving. By such a connection of the first fibrous material a loadable geotextile web is achieved, which is very suitable for bearing mechanical loads for soil layer stabilization. At the same time, by the described method approach, an advantageous degradation behavior is achieved by means of the provision of perforations or enlarged openings and a mechanical property reduction. The first fibrous material can in this case be connected to one or more identical fibrous materials into a nonwoven product or a woven or a textile. Furthermore, the first fibrous material can be configured with a second fibrous material into a nonwoven product or a woven or a textile, which differs from the first fibrous material in terms of material or in terms of a modification of the fibers. In particular, it is thereby possible to connect a first structural material and a second structural material into a geotextile web.

[0079] According to another preferred embodiment it is proposed that the first fibrous material is processed into a textile planar fabric with a second fibrous material which differs from the first fibrous material. This textile planar fabric is composed of two different fibrous materials or more than two different fibrous materials. The textile planar fabric can be configured as a nonwoven, as a woven or as a textile or as a combination thereof.

[0080] It is further preferred that the first fibrous material differs from the second fibrous material in terms of a different fiber thickness, a different chemical composition, a different surface roughness, a different degree of stretching, a different opening or mesh size or a different tensile-elongation behavior or a different breaking strength or a combination of two or more of these properties. According to this embodiment, the first and the second fibrous material differ in one or more of the seven properties which influence the mechanical properties and the biodegradation speed of the fibrous material. By this configuration of the textile planar fabric, a biodegradation speed and a mechanical performance of the first fibrous material during the entire service life is achieved which differs from the second fibrous material, which is possible due to different material properties (chemical properties) and due to a modification of the fibers of the material uniformity.

[0081] According to the present application, the above-mentioned geotextile web is used for installation into a soil layer for the purpose of soil stabilization. As mentioned above, such soil stabilization can be used for slope reinforcement, embankment reinforcement, dike reinforcement in coastal protection, sea floor reinforcement to prevent scouring effects and reinforcement of soil layers along traffic routes. These applications are characterized in that, on the one hand, biodegradation of the geotextile web at the installation site itself is advantageous and desirable in order to dissolve the geotextile web after a certain degree of root penetration has been achieved or in other ways the reinforcement of the soil layer has been achieved. On the other hand, in these applications the following properties of the geotextile web are desirable, which accelerate degradation at a location other than the installation site, for example, due to mechanical disintegration, being transported by the wind, floating or being transported to another location by other flows, at which location accelerated degradation and / or metabolism by plants and animals compared to conventional products is possible.

[0082] Another aspect of the present application relates to the use of a geotextile web for stabilizing a soil layer in flood protection or scour protection, the geotextile web comprising a structural material

[0083] - having a degree of biodegradability at a predetermined intensity of influencing parameters at the installation site of:

[0084] - in a composting test with the following parameters:

[0085] o a sample having a length of 10 cm, a width of 10 cm and an initial material thickness,

[0086] o 50°C + / - 5°C,

[0087] o high-temperature conditions according to ISO 16929, as long as these conditions are not limited by a specific intensity of specific influencing parameters at the installation site,

[0088] o the solids are sieved after six months in a sieve with a mesh size of 2 mm (sieve mesh 8.75),

[0089] less than 50 dry weight-% of the initial material remains in the sieve when sieving, or

[0090] - in a marine incubation test with the following parameters:

[0091] o a sample having a length of 2 cm, a width of 2 cm and an initial material thickness,

[0092] o 30°C + / - 2°C

[0093] o aerobic conditions in seawater with a salinity of 3.5 wt.-% + / - 1 wt.-%, as long as these conditions are not limited by a specific intensity of specific influencing parameters at the installation site,

[0094] o the solids are sieved after 4, 8 and 12 weeks in a sieve with a mesh size of 2 mm (sieve 8.75),

[0095] In the sieving after 12 weeks, less than 20 dry weight-% of the initial material remain in the sieve, wherein the predetermined intensity of the influencing parameter is selected from the group consisting of:

[0096] - the intensity of the radiation of the electromagnetic radiation,

[0097] - the height of the temperature,

[0098] - the concentration of substances which chemically and / or biochemically react with the geotextile web,

[0099] - the concentration of bacteria in a certain concentration,

[0100] - the concentration of fungi.

[0101] According to this aspect of the application, the geotextile web, in particular of the type described above, is used for achieving soil stabilization in connection with erosion protection or in flood protection. As flood protection, in this case any type of bank reinforcement can be carried out at the coast, at the banks of flowing and standing waters and lakes, wherein the geotextile web can be arranged in the area below or above the water surface in the respective optimum dry or wet condition. In this case, the geotextile web is used for river bed stabilization, slope stabilization or dike stabilization and can be used permanently or temporarily during the construction work until a sufficient root penetration of plants is achieved. In this case, the erosion protection is understood as the prevention of the soil material being transferred by the flow. Here, a permanent or temporary protection of the soil can also be carried out by the geotextile web. In particular, such an erosion protection can be achieved, for example, by flexible containers filled with a granular material, such as sand or the like, which are manufactured from the geotextile web laid on the soil layer to be stabilized.

[0102] Here, the geotextile web is used in such a way that a targeted biodegradation is achieved. On the one hand, this targeted biodegradation can consist in that, unlike in known applications, the biodegradability occurs at the installation site itself so that the geotextile web dissolves as planned within a certain period of time. The biodegradability can also be carried out in such a way that the geotextile web has a higher biodegradability at the transfer site than at the installation site. In this case, it is achieved that if the geotextile web is intentionally or unintentionally removed from the installation site, it biodegrades more quickly at the transfer site with the other influencing parameters so that there is no environmental pollution of any kind.

[0103] It is preferred to propose that the geotextile web is used for the production of fillable containers and that these containers are used in such a way that the containers are placed on the seabed in a filled manner in order to provide scour protection at locations which are subject to flow loads. With this improved form, particularly effective scour protection can be achieved.

[0104] The use can be further improved in such a way that the geotextile web is installed in a dike or shore protection at an installation site which is occasionally dry or occasionally wet, wherein the geotextile web preferably has a lower density than water. Especially in the case of occasional drying or wetting, the particular property of unintentional release of the geotextile web in such a securing measure works to the advantage of the biodegradation.

[0105] A further aspect of the present application is a method for soil reinforcement by means of a geotextile web, comprising the following steps: a) determining soil parameter values which indicate soil properties at the installation site, b) determining degradation values which indicate properties of the biodegradation speed, c) selecting a mixing ratio of a first and a second structural material having different biodegradability depending on the soil parameter values and the degradation values, d) connecting the first and the second structural material into a geotextile web in the mixing ratio, e) providing the geotextile web at the installation site for installation.

[0106] According to this aspect of the present application, the soil reinforcement at the installation site is carried out by providing the geotextile web there in order to install it in the soil layer at the installation site. For this purpose, the soil properties must be known. This means that at least one property of the soil is assumed or measured which influences the biodegradability in a relevant manner. Thus, for example, the moisture content, the pH value, the nutrient concentration, the presence of bacteria and fungi of the soil, and / or the soil temperature as an average temperature within a day, a week, a month or a year can be assumed or determined. Furthermore, the intensity of the ultraviolet radiation at the installation site can be measured.

[0107] These installation site-specific parameters take into account influencing parameters of the biodegradation process which exists at the installation site. From these parameters, characteristic values can be determined, for example as dimensionless factors or as empirical values from tables. Thus, the compostability or the soil degradation under marine conditions defined according to ISO 16929, which was set forth before, can be used as a standard reference value, and the degradation value can be defined depending on this reference value, for example by the following way: a lower percentage of the degradation property is characterized by the respective percentage below 100% by the soil-inherent properties, or a higher biodegradation speed at the installation site is characterized by the degradation value, wherein values greater than 100% are taken as degradation values.

[0108] Furthermore, a degradation value is determined, which defines in which time period a certain degree of biodegradation of the geotextile web or of a component of the geotextile web should be achieved.

[0109] A mixing ratio of the first and second structural material is then selected depending on the soil parameter value and the degradation value. The first and second structural material have different biodegradability or degradation rates in the soil parameter value here. Here, by means of the mixing ratio, the biodegradation rate achieved overall by the geotextile web constructed from the first and second structural material can be provided. This biodegradation rate is here related to the soil parameter value assumed or measured at the installation site so that it should be selected such that the desired degradation value is achieved, which describes the rate of biodegradation of the geotextile web.

[0110] After the mixing ratio has been selected, the first and second structural material are joined into a geotextile web. This joining can take place as a nonwoven, woven, knitted or in another form and should join the first and second fibrous material to one another in a way that is loadable mechanically. The geotextile web woven in this way is thus tailored to the use and targeted biodegradation under the conditions prevailing at the installation site.

[0111] By this solution, a biodegradation of the geotextile web that is neither too fast nor too slow is achieved in such a way that the soil parameters influencing the biodegradation are included in the design of the geotextile web. In this case, the targeted degradation behavior characterized by the degradation value is set by the mixing ratio of the two fibrous materials.

[0112] The method can be improved by the soil parameter value being: the soil moisture content of the soil at the installation site, for example between 3 and 300 percent by weight; the soil pH value of the soil at the installation site, for example between 1 and 13; the enzyme concentration in the soil at the installation site; the temperature between 4 and 50°C; or a soil characteristic value formed from a plurality of the soil parameter values. By means of these soil parameter values, influencing variables that have a significant influence on the biodegradation rate of typical fibrous materials, for example viscose fibers such as lyocell, are determined and can thus be used to construct a geotextile web with a biodegradability that is individually designed for the installation site.

[0113] It is particularly preferred here that the degradation value is a strength quotient, which is formed from the ratio of the mechanical strength value with respect to the installation duration of the geotextile web to the initial value, is a permeability quotient, which is formed from the ratio of the porosity with respect to the installation duration of the geotextile web to the initial value, or is a degradation characteristic value formed from a plurality of these degradation values. According to this embodiment, the degradation value is defined as a strength quotient or as a permeability quotient or as a degradation characteristic value calculated from the strength quotient and the permeability quotient. The strength quotient in this case indicates a characteristic of the reduction in mechanical strength of the geotextile web over the residence time of the geotextile web in the soil. This strength quotient is formed from the ratio of the mechanical strength value at the installation time point, i.e. at the time when no biological degradation has yet occurred, to the mechanical strength value after a predetermined residence time, which can be standardized, for example, to three or six months, and indicates the mechanical strength after biological degradation has proceeded to a certain extent. The permeability quotient is analogously determined by setting the porosity at the start, i.e. at the installation time point, in relation to the porosity after biological degradation over a predetermined period of time. By this characterization of the degradation value, it is possible to determine, by selection of the respective material, to influence the desired properties in a targeted manner. The strength quotient is in the order of magnitude of 1.0 to 0, typically 0.25, that is to say, the strength at the defined time point is reduced to a quarter after biological degradation compared to the initial value. A typical permeability quotient is in the order of magnitude of 1 to 4 powers of 10, ideally greater than 10, that is to say, the permeability is increased to 10 times the initial value at the specific time point after biological degradation.

[0114] The geotextile web described above, the specific use of the geotextile web described above and the method using it can be improved in that the geotextile web has a polymer group, which comprises a molecule provided with an isotopic label, in particular 13 C or 18 O isotopic label. According to this improved form, the geotextile web is provided with an isotopic label so that it can also be clearly identified in the form of a possible fragmentation that exists later. Thus, the method in this way can unambiguously attribute or exclude the occurrence of environmental pollution and can quickly and reliably find the cause of such environmental pollution.

[0115] Furthermore, the method, use and geotextile web can be improved in that the geotextile web comprises or consists of one or more metabolisable structural materials. This reintegration of the geotextile web into the biological cycle by means of metabolism by organisms, such as mammals, fish or microorganisms, such as microorganisms, leads to an environmentally friendly disposal. The metabolism is preferably able to take place on the fragmented fibre residues, such as the pulverised fibre residues of the geotextile web. In this case, the metabolism is understood on the one hand as the biologically harmless compatibility of the geotextile web with the organisms and, on the other hand, as the ability of the geotextile web to be chemically changed and degraded under the metabolic processes of the organisms during digestion.

[0116] Furthermore, preferably, the geotextile web is formed from a single layer or a plurality of layers of a filter nonwoven fabric which is manufactured from at least two different structural materials which are connected to one another into a nonwoven fabric, wherein

[0117] - the first structural material has a biodegradability of the following extent at a predetermined intensity of the influencing parameter at the installation site:

[0118] - in a composting test with the following parameters:

[0119] o a sample having a length of 10 cm, a width of 10 cm and an initial material thickness,

[0120] o 50°C + / - 5°C,

[0121] o high-temperature conditions according to ISO 16929, as long as these conditions are not limited by a specific intensity of a specific influencing parameter at the installation site,

[0122] o the solids are sieved after six months in a sieve with a mesh size of 2 mm (sieve mesh 8.75),

[0123] - less than 80% by weight, in particular less than 25% by weight or less than 10% by weight of the dry matter of the first structural material remains in the sieve after twelve weeks when sieving, or

[0124] - in a marine incubation test with the following parameters:

[0125] o a sample having a length of 2 cm, a width of 2 cm and an initial material thickness,

[0126] o 30°C + / - 2°C

[0127] o aerobic conditions in seawater with a salinity of 3.5% by weight + / - 1% by weight, as long as these conditions are not limited by a specific intensity of a specific influencing parameter at the installation site,

[0128] o the solids are sieved after 4, 8 and 12 weeks in a sieve with a mesh size of 2 mm (sieve 8.75),

[0129] In the sieving after 12 weeks, less than 80 wt.-%, in particular less than 25 wt.-% or less than 10 wt.-% of the dry matter of the first structural material remains in the sieve after twelve weeks, wherein the predetermined intensity of the influencing parameter is selected from the group consisting of:

[0130] - the intensity of the radiation action of electromagnetic radiation,

[0131] - the height of the temperature,

[0132] - the concentration of substances which chemically and / or biochemically react with the geotextile web,

[0133] - the concentration of bacteria in a certain concentration,

[0134] - the concentration of fungi,

[0135] and the second structural material is connected to the first structural material as a filter nonwoven, wherein the second structural material has a lower biodegradability to the same predetermined intensity of the influencing parameter at the same installation site in the following extent: in comparison to the first structural material under the same conditions, a greater weight-% portion of the dry matter of the second structural material remains in the sieve after six months or 12 weeks when sieved through a sieve of 2 mm. According to this refinement, the geotextile web is configured as a nonwoven which consists of two different structural materials which have different biodegradation speeds under the given predetermined parameters. Thereby, the nonwoven can on the one hand be subjected to a targeted mechanical structural weakening by the biodegradation process and on the other hand to a geometric change, for example by pore formation, perforation formation, etc., for example in order to facilitate the root penetration process.

[0136] A further refinement proposes that the geotextile web, the method for its production or its installation and the use thereof are refined in such a way that the geotextile web is installed as an element in a construction for influencing an air flow, so that the air flow speed is reduced, in particular locally, for the purpose of depositing particles which are transported, jump or roll in the air floatingly in the absence of a reduction in air speed. Thus, the geotextile web, the use and the method are used for mineral substances, in particular sand, for example for deposition at a coast section which is endangered by sand erosion. Thereby, the reduction in air speed leads to sand deposition, preferably at the lee side of the construction. The construction is here partially or completely embedded in sand. Thus, the geotextile web according to the invention becomes an integral part of the sand deposition and can be degraded according to the invention at the installation site or at a transfer site as soon as the construction according to the invention is removed within the sand deposition or if the construction is exposed again due to a change in the erosion conditions. Attached Figure Description

[0137] Preferred embodiments are illustrated with reference to the accompanying drawings. The drawings show:

[0138] Figure 1 Schematic diagrams illustrating the use of geotextile webs according to the invention for coastal protection in three different configurations.

[0139] Figure 2a Figure b illustrates the use of the geotextile web according to the invention for slope reinforcement at two different root penetration time points.

[0140] Figure 3 A schematic diagram of a first embodiment of the geotextile web according to the present invention is shown.

[0141] Figure 4 A schematic diagram of a second embodiment of the geotextile web according to the present invention is shown.

[0142] Figure 5 A schematic diagram showing a third embodiment of the geotextile web according to the present invention is provided.

[0143] Figure 6 A schematic diagram showing a fourth embodiment of the geotextile web according to the present invention is shown. Detailed Implementation

[0144] The geotextile sheet according to the invention can, in principle, be installed in three different installation scenarios concerning water contact in a levee area. Starting with a natural levee area 2, adjacent to the waterline or, in the case of tidal-related waters, the average water level and which is optionally protected against flooding by an artificial dike 3, the geotextile sheet can initially be used in installation location A to stabilize the underwater topography of the natural seabed orientation, where soil stabilization with vegetation is insufficient. In installation location A, the geotextile sheet is typically underwater and may dry out under special circumstances due to low water levels or strong wave undulations.

[0145] In the second installation position B, geotextile sheets for reinforcing natural embankment slopes and / or artificial dikes are installed on the water side. In this installation position, the geotextile sheets stabilize the normally dry slope portion of a natural embankment and optionally the artificial slope portion. Therefore, the geotextile sheets are typically dry, but may be underwater in flood conditions or under strong wave conditions.

[0146] In the third installation position C, the geotextile web is used in areas, for example the backside of a dike, in which the geotextile web is not exposed to the water body itself and only in exceptional cases, such as overflows, is subjected to stress. In this installation position, the geotextile web is thus always dry and only moistened by rainfall as in each installation position.

[0147] Each of the three installation positions requires a different matching behavior of the geotextile web in order to achieve an ecologically advantageous behavior. Thus, in the installation position A, the stability of the geotextile web in the aqueous environment is required, but if parts of this geotextile web separate due to a wear event so that they are no longer located at the place required for the fulfillment of its function, the degradation of these dissolved geotextile web parts is desirable. According to the present application, this can be achieved in that, for example, the geotextile web consists of a material which degrades quickly under the influence of ultraviolet radiation. Thereby it is achieved that torn parts of the geotextile web which float or have been washed ashore are subjected to a quick degradation, while at the installation site a mechanical stability is maintained when no ultraviolet radiation falls onto the geotextile web. Instead of specifying the geotextile web for ultraviolet radiation, it is also possible to specify a biodegradability depending on the oxygen content and / or the bacterial concentration and / or the fungal concentration of the water in the particular application. This is especially suitable when using the geotextile web in the depths of the sea, where there is, in particular, a low concentration of the above-mentioned influencing parameters. In this case, the material of the geotextile web can be designed in such a way that the material is mechanically stable in the planned installation situation and in the surrounding water body and biodegrades as soon as the concentration of the influencing parameters in the surrounding water body or at the transfer site increases.

[0148] The installation situation according to C, for example with respect to root penetration and the matching of the geotextile web to the root penetration process, is important to the present application. Figure 2a and b show two temporally successive root penetration situations, in which the geotextile web 10 is structured in a certain depth of the soil to stabilize the soil layer 20. As can be seen from Figure 2a the geotextile web 10 has a high density with only small openings in the early phase, shortly after the planting of the stabilizing soil plants, to provide a high mechanical stability of the soil. The planted plants can grow unhindered with small root sprouts through the geotextile web. In this early phase, an effective mechanical composite of the geotextile web and the plants has already been achieved.

[0149] Figure 2bThe same installation situation after a few weeks of plant growth is shown. The geotextile web has been partially mechanically disintegrated by biodegradation. The geotextile web has larger openings and a lower mechanical stability. Due to the larger openings, the root penetration and the root diameter enlargement of the growing plants are not hindered and can assume the mechanical stabilization function. By means of the geotextile web according to the application, therefore, a continuous transfer of the mechanical stability of the soil layer composed of the geotextile web onto the plants is achieved, wherein at the same time a good mechanical connection between the plants and the geotextile web is maintained, and the geotextile web also optionally has different mechanical properties in the direction and assumes the function of stabilizing the soil.

[0150] Figures 3 to 6 An exemplary embodiment of a geotextile web is shown. In principle, the geotextile web according to the application can be provided in different widths and lengths. In this case, typical widths are greater than 1 m, 1.5 m or 2 m and less than 4 m, 5 m or 6 m, and in this case, typical lengths are greater than 2 m, 5 m, 10 m, 50 m, wherein the geotextile web is preferably transportable in a rolled-up state and is unrolled upon installation. The thickness of the geotextile web can be greater than 1 mm; a thickness of greater than 5 mm, 10 mm or greater than 20 mm is preferred. The geotextile web can have a weight per unit area of greater than 150 g / m 2 , greater than 300 g / m 2 or greater than 500 g / m 2 . The weight per unit area can be less than 1500 g / m 2 , less than 2000 g / m 2 or less than 2500 g / m 2 .

[0151] Figure 3 A first embodiment with a cover layer 110, a carrier layer 120 and an intermediate layer 130 arranged between the cover layer 110 and the carrier layer 120 is shown. The cover and carrier layers 110 and 120 can be composed of different or uniform materials, and the intermediate layer 130 can be composed of different materials or uniformly with the cover and carrier layers.

[0152] The cover and carrier layers are connected to one another by means of needling or sewing or braiding; for this purpose, a plurality of needling portions 140a, b, c are introduced into the geotextile web, which connect the cover layer through the intermediate layer 130 with the carrier layer. For example, in this design of the geotextile web, the cover layer can be composed of a material which biodegrades more quickly than the carrier layer 120. Thereby, after partial or complete biodegradation of the needling or sewing or braiding portions of the geotextile web, passages are created which extend from the upper side of the geotextile web towards the lower side and provide space, for example, for root penetration or a drainage effect.

[0153] Figure 4 A second embodiment of a geotextile web is shown, which has an upper mesh layer 210 and a nonwoven layer 220 below it. The mesh layer 210 is composed of a mesh formed by the intersection of firm monofilaments or monopoles, which mesh forms mesh openings of a certain size, for example 10 x 10 mm to 40 x 40 mm. The nonwoven layer is composed of compact, randomly oriented fibers of a different material compared to the layer 210. Overall, this nonwoven layer causes the openings of the mesh layer 210 to be closed, so that a geotextile web is produced which is impermeable overall to coarser particles, which has permeability for liquids and gases. The nonwoven layer 220 is constructed of a material such as lyocell and biodegrades more quickly than the mesh layer 210. Thereby, the mechanical strength of the geotextile web is reduced within the short biodegradation time of the nonwoven layer 220, and the geotextile web reduces to the remaining mesh layer 210 with openings formed therein after the degradation of the nonwoven layer 220, which in turn provides the corresponding space for advantageous root penetration.

[0154] Figure 5 A third embodiment is shown, which is constructed in principle as a single-layer geotextile web. In the geotextile web, fibers 310 of a first material are arranged along a first direction, while fibers 320 are arranged along a second direction transverse to the first direction, thereby forming fiber layers, respectively. The fibers 310 and 320 can be connected to one another, for example by welding, bonding, looping, needling, textile or braiding techniques and / or by means of a cover layer and a carrier layer above and below the fibers 310 and 320. The fibers 310 are composed of a different material than the fibers 320, wherein the material of which the fibers 320 are composed biodegrades more quickly than the material of which the fibers 310 are composed. Due to this biodegradation behavior of the geotextile web, the geotextile web initially has load capacity in longitudinal and transverse directions corresponding to the course of the fibers 310, 320. With increasing biodegradation of the fibers 320, the strength and load capacity in the longitudinal direction along the course of the fibers 320 decreases, so that an anisotropic mechanical load behavior of the geotextile web is produced.

[0155] Figure 6 A fourth embodiment is shown, in which two different materials are processed into a nonwoven layer, which is a geotextile web or can be a ply of a geotextile web. The two different materials 410, 420 are processed into a nonwoven without orientation as short fibers or long fibers or continuous fibers and are connected to one another. The material 420 biodegrades more quickly than the material 410, whereby the density of the geotextile web decreases with increasing biodegradation in the installed state, and the geotextile web becomes more permeable and / or its mechanical properties change.

[0156] It is understood in principle that the four embodiments can also be combined with one another in such a way that a multi-layered geotextile web having the combined properties of these embodiments is produced therefrom. Furthermore, it is understood that the four embodiments can also be combined in such a way that their properties are combined in one unique ply of the geotextile web, in that the grid structure 210 of the second embodiment is composed of the anisotropically biodegradable fibers 310, 320 of the third embodiment.

[0157] The biodegradation behavior can in principle be set at the installation site and in a way that is adapted to the conditions prevailing there. Thus, in all embodiments, the share of one material relative to the share of another material can be increased or reduced in matching the biodegradation properties in order to obtain the desired biodegradation behavior that matches the conditions prevailing. Furthermore, the biodegradation properties can be influenced by external influences such as UV radiation and / or oxygen content and / or the concentration of bacteria, fungi in the environment or chemical influences, or even triggered, whereby if the geotextile web is transferred from one site to another site, where the specific environmental conditions change, a specific behavior of the geotextile web with regard to biodegradation occurs.

Claims

1. Use of a geotechnical material web comprising a structural material, the geotechnical material web having a biodegradability and a biodegradation duration at a site of installation and a higher biodegradability at a site of transfer, wherein the structural material has a biodegradability at a first intensity of an influencing parameter at the site of installation to the following extent: - in a composting test with the following parameters: ° a sample having a length of 10 cm, a width of 10 cm and an initial material thickness, ° high temperature conditions according to ISO 16929, as long as these conditions are not limited by a specific intensity of a specific influencing parameter at the site of installation, ° sieving of the solids in a sieve with a mesh size of 2 mm after six months, - more than 80 dry weight-% of the initial material remain in the sieve at the time of sieving, or - in a marine incubation test with the following parameters: ° a sample having a length of 2 cm, a width of 2 cm and an initial material thickness, ° aerobic conditions in seawater with a salinity of 3.5 wt.-% + / - 1 wt.-%, as long as these conditions are not limited by a specific intensity of a specific influencing parameter at the site of installation, ° sieving of the solids in a sieve with a mesh size of 2 mm after 4, 8 and 12 weeks, - more than 80 dry weight-% of the initial material remain in the sieve at the time of sieving after 12 weeks, and - a biodegradability at a second intensity of an influencing parameter at the site of transfer to the following extent: less than 80 wt.-% of the dry matter of the first structural material remain in the sieve after sieving through a sieve of 2 mm within six months in the composting test or within twelve weeks in the marine incubation test, wherein the second intensity of the influencing parameter is greater than the first intensity of the influencing parameter, and the intensity of the influencing parameter is selected from: - the intensity of the radiation action of electromagnetic radiation, - the height of the temperature, - the concentration of a substance that chemically and / or biochemically reacts with the geotechnical material web, - the concentration of a concentration of bacteria of a certain concentration, - the concentration of fungi, - the expected mechanical stress, in a manner that the geotechnical material web is installed at the site of installation at a point in time of installation and is transferred to the site of transfer at a point in time after the point in time of installation.

2. The use according to claim 1, characterized in that, in the composting test, more than 25 dry weight-% of the initial material remain in the sieve at the time of sieving, the second intensity of the influencing parameter at the site of transfer is to the following extent: less than 25 wt.-% of the dry matter of the first structural material remain in the sieve after sieving through a sieve of 2 mm within six months in the composting test or within twelve weeks in the marine incubation test.

3. The use according to claim 1, characterized in that, in the composting test, more than 10 dry weight-% of the initial material remain in the sieve at the time of sieving, ​ °50℃+ / -5℃， ​ ​ ​ ​ ​ °30℃+ / -2℃， ​ ​ ​ ​ ​ wherein ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ has a biodegradability in the second intensity of the influencing parameters at the site of transfer in such a degree that less than 10 weight-% of the dry matter of the first structural material remains on a sieve of 2 mm after sieving in the compost test within six months or in the marine incubation test within twelve weeks.

4. Use according to claim 1, characterized in that more than 25 dry weight-% of the initial material remain on the sieve after sieving after 12 weeks in the marine incubation test, has a biodegradability in the second intensity of the influencing parameters at the site of transfer in such a degree that less than 25 weight-% of the dry matter of the first structural material remains on a sieve of 2 mm after sieving in the compost test within six months or in the marine incubation test within twelve weeks.

5. Use according to claim 1, characterized in that more than 10 dry weight-% of the initial material remain on the sieve after sieving after 12 weeks in the marine incubation test, has a biodegradability in the second intensity of the influencing parameters at the site of transfer in such a degree that less than 10 weight-% of the dry matter of the first structural material remains on a sieve of 2 mm after sieving in the compost test within six months or in the marine incubation test within twelve weeks.

6. Use according to claim 1, wherein the geotextile web comprises a first fibrous material based on a fiber glue.

7. Use according to claim 6, characterized in that the geotextile web comprises lyocell.

8. Use according to claim 6, characterized in that the first fibrous material is configured as a nonwoven, a knitted or a woven fabric and is formed into a textile planar fabric in the geotextile web by a consolidation, a braiding, a knitting or a weaving process, respectively.

9. Use according to claim 6, characterized in that the first fibrous material is processed into a textile planar fabric with a second fibrous material different from the first fibrous material.

10. Use according to claim 9, characterized in that the first fibrous material differs from the second fibrous material in that: - different fiber thicknesses, - different chemical properties, - different surface roughnesses, - different degrees of stretch, - different opening or mesh sizes, - different stretch force-elongation behavior, or - different breaking strengths, or a combination of two or more of these properties.

11. Use of a geotextile web according to any one of claims 1 to 10 for installation into a soil layer for the purpose of soil stabilization.

12. Use of a geotextile web according to any one of claims 1 to 10 for the purpose of stabilizing a soil layer piece in a flood protection or erosion protection.

13. Use according to claim 12, characterized in that - the geotextile web is used to manufacture a fillable container and the container is used in such a way that it is placed on the seabed in a filled manner to provide erosion protection at a site subjected to flow loads, or - the geotextile web is installed at an installation site which is either intermittently drying or intermittently wetting.

14. Use according to claim 13, characterized in that the geotextile web has a lower density than water.

15. Use according to any one of claims 1 to 10, a method for reinforcing soil by means of the geotextile web, the method comprising the following steps: a) determining a soil parameter value which is indicative of a soil property at the installation site, b) determining a degradation value which is indicative of a characteristic of the speed of biodegradation, c) selecting a mixing ratio of a first structural material and a second structural material having different biodegradability from the soil parameter value and the degradation value, d) connecting the first and second structural materials into a geotextile web in the mixing ratio, e) providing the geotextile web at the installation site for installation.

16. Use according to claim 15, characterized in that the soil parameter value is - a soil moisture content of the soil at the installation site in the range from 0 nFK to 100 nFK, - a soil pH value of the soil at the installation site in the range from pH 1 to 13, - an enzyme concentration in the soil at the installation site, - a fungal concentration at the installation site, - a bacterial concentration at the installation site, - a temperature between 4°C and 50°C or a soil property value formed from a plurality of these soil parameter values.

17. Use according to claim 15, characterized in that the degradation value is - a strength quotient in the range from 0 to 1, the strength quotient being formed from the ratio of a first mechanical strength value at the time of installation of the geotextile web to a second mechanical strength after a predetermined residence time, or - a penetrability quotient in the range from 0 to 1, the penetrability quotient being formed from the ratio of a first porosity at the time of installation of the geotextile web to a second porosity after a predetermined residence time, or a degradation characteristic value formed from these degradation values.

18. Use according to any one of claims 1 to 10, characterized in that - the geotextile web has polymeric groups which comprise molecules provided with an isotopic label, and / or - the geotextile web comprises or consists of one or more metabolizable structural materials.

19. Use according to claim 18, characterized in that The polymer group comprises a 13 C or 18 O isotopically labeled molecule.

20. Use according to any one of claims 2 to 5, characterized in that the geotextile web is formed from a single layer or a plurality of layers of a filter nonwoven fabric which is manufactured from at least two different structural materials which are connected to one another into a nonwoven fabric, wherein - at a predetermined strength of the influencing parameter at the installation site, the first structural material has a biodegradability to the extent that more than 50% of the weight percentage fraction of the structural material is converted into carbon dioxide in an aqueous medium within six months, - and a second structural material is connected to said first structural material to form a filter nonwoven, wherein said second structural material has a degree of biodegradability at the same installation site at the same predetermined strength of the influencing parameter as follows: - in a composting test with the following parameters: ° a sample with a length of 10 cm, a width of 10 cm and an initial material thickness, °50℃+ / -5℃， ° high temperature conditions according to ISO 16929, ° after six months the solids are sieved in a sieve with a mesh size of 2 mm, - less than 50 dry weight-% of the initial material remains in said sieve at the time of sieving, or - in a marine incubation test with the following parameters: ° a sample with a length of 2 cm, a width of 2 cm and an initial material thickness, °30℃+ / -2℃， ° aerobic conditions in seawater with a salinity of 3.5 wt.-% + / - 1 wt.-%, ° after 4, 8 and 12 weeks the solids are sieved in a sieve with a mesh size of 2 mm, - less than 20 dry weight-% of the initial material remains in said sieve after 12 weeks.

21. Use according to claim 20, characterized in that said first structural material has a degree of biodegradability at the predetermined strength of the influencing parameter at the installation site as follows: within six months in an aqueous medium more than 75 percent by weight fraction of said structural material is converted into carbon dioxide.

22. Use according to any one of claims 1 to 10, characterized in that said geotextile web is installed as an element in a construction for influencing an air flow such that the air flow velocity is reduced for the purpose of depositing particles which are transported floating in the air, jumping or rolling without reduction of the air velocity.

23. Use according to any one of claims 1 to 10, wherein said geotextile web comprises - an organic first structural material and an organic second structural material different from said first structural material, said second structural material being connected to said first structural material to form a planar material composite web extending in two mutually perpendicular directions, characterized in that said first structural material and said second structural material are organic materials, - said first structural material has a first degree of biodegradability as follows: - in a composting test with the following parameters: ° a sample with a length of 10 cm, a width of 10 cm and an initial material thickness, °50℃+ / -5℃， ° high temperature conditions according to ISO 16929, ° after six months the solids are sieved in a sieve with a mesh size of 2 mm, - less than 80 wt.-% of dry matter of the initial material remains in said sieve at the time of sieving, or - in a marine incubation test with the following parameters: ° a sample with a length of 2 cm, a width of 2 cm and an initial material thickness, °30℃+ / -2℃， ° aerobic conditions in seawater with a salinity of 3.5 wt.-% + / - 1 wt.-%, ° after 4, 8 and 12 weeks the solids are sieved in a sieve with a mesh size of 2 mm, - less than 80 wt.-% of dry matter of the initial material remains in said sieve after 12 weeks, and said second structural material has a second degree of biodegradability which is less than said first degree of biodegradability.

24. Use according to any one of claims 1 to 23, wherein said geotextile web is installed as an element in a construction for influencing an air flow such that the air flow velocity is reduced for the purpose of depositing particles which are transported floating in the air, jumping or rolling without reduction of the air velocity.

25. Use according to any one of claims 1 to 23, wherein said geotextile web is installed as an element in a construction for influencing a water flow such that the water flow velocity is reduced for the purpose of depositing particles which are transported floating in the water, jumping or rolling without reduction of the water velocity.

24. Use according to claim 23, characterized in that in the composting test, less than 50 wt.% of the dry matter of the initial material remains in the sieve at sieving.

25. Use according to claim 23, characterized in that in the composting test, less than 25 wt.% of the dry matter of the initial material remains in the sieve at sieving.

26. Use according to claim 23, characterized in that in the composting test, less than 10 wt.% of the dry matter of the initial material remains in the sieve at sieving.

27. Use according to claim 23, characterized in that in the marine incubation test, less than 50 wt.% of the dry matter of the initial material remains in the sieve at sieving after 12 weeks.

28. Use according to claim 23, characterized in that in the marine incubation test, less than 25 wt.% of the dry matter of the initial material remains in the sieve at sieving after 12 weeks.

29. Use according to claim 23, characterized in that in the marine incubation test, less than 10 wt.% of the dry matter of the initial material remains in the sieve at sieving after 12 weeks.

30. Use according to claim 23, characterized in that the first structural material is arranged in the geotextile web such that, after partial or complete biodegradation of the first structural material in the geotextile web, an opening is formed through the geotextile web.

31. Use according to claim 30, characterized in that - the first structural material partially or completely penetrates the second structural material, or - the first structural material and the second structural material are connected to each other as a layer composite, the second structural material having a plurality of second perforations and the first structural material having no perforations or a plurality of first perforations that is less than the plurality of second perforations.

32. Use according to any one of claims 1 to 10 for a method for site-related soil stabilization by means of a geotextile web, the method having the following steps: designing the product according to influencing parameters for the durability of the geotextile at the installation site, wherein the influencing parameters are selected from: - the intensity of the radiation effect of electromagnetic radiation, - the height of the temperature, - the concentration of substances that chemically and / or biochemically react with the geotextile web, - the concentration of bacteria in a certain concentration, - the concentration of fungi, determining one or more of the influencing parameters at a transfer site that is spaced apart from the installation site, - installing the geotextile web at the installation site, wherein the geotextile web comprises a structural material, the structural material ° having a degree of biodegradability at the intensity of the influencing parameters at the transfer site that, if the material or its constituents are sieved, leaves a transfer site residual fraction in a 2 mm sieve within six months, ° wherein the transfer site residual fraction is less than 80 wt.% of the material, ° a degree of biodegradability at the intensity of the influencing parameters at the installation site, which is such that if the material or its components are sieved, an installation site residual fraction of the material remains in the 2 mm sieve within six months, ° wherein the installation site residual fraction is greater than the transfer site residual fraction.

33. The use according to claim 32, characterized in that the transfer site residual fraction is less than 25% by weight of the material.

34. The use according to claim 32, characterized in that the transfer site residual fraction is less than 10% by weight of the material.

35. The use according to claim 32, characterized in that the installation site has an environment with lower temperatures, radiation, oxygen concentration, bacterial and / or fungal concentration relative to the transfer site.

36. The use according to claim 32, characterized in that the installation site is at the seabed and the geotextile web floats or is transferred in seawater due to currents and / or density differences.

37. The use according to claim 32, characterized in that the structural material is a fiber cement-based material.

38. The use according to claim 32, characterized in that the structural material is lyocell.

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