Stabilization system and method

Abstract

The invention relates to a stabilization system for an embankment, in particular in the form of a dam, dike or a sloped traffic route boundary, with a terrain section having a soil body forming an embankment and having a hypothetical embankment failure body which extends at least over part of the soil body and which is delimited by a hypothetical sliding surface, characterized by at least one rod-shaped element which is arranged and aligned in the soil body such that the rod-shaped element extends at least partially within the hypothetical embankment failure body, and that a hypothetical cutting surface is formed between the rod-shaped element and the hypothetical sliding surface, wherein the hypothetical cutting surface runs at an angle to the longitudinal axis of the rod-shaped element.Furthermore, the invention relates to a method for stabilizing an embankment, in particular by forming the stabilization system according to the invention.

Description

[0001] The invention relates to a stabilization system for an embankment, in particular in the form of a dam, a dike, or a sloped road barrier. Furthermore, the invention relates to a method for stabilizing an embankment, in particular by forming a stabilization system according to the invention.

[0002] A slope is a natural or artificial, relatively steep transition between horizontal or gently sloping surfaces of a piece of land. Natural slopes are formed by geomorphological processes such as erosion, soil uplift, or sedimentation. Artificial slopes are created by the construction of embankments and the excavation of cuttings with unpaved edges during road construction. The slope is formed by a portion of the larger soil body of the piece of land, which encompasses the surfaces of the piece of land and extends from it in depth. A slope itself usually consists of at least one slope surface, which is formed by an inclined surface of the piece of land, and an embankment body that adjoins the embankment surface at least partially in depth. The embankment body forms part of the soil body of the piece of land.The stability of a slope is determined, among other things, by the slope angle and depends on several factors. If a slope is not designed to be stable, it can fail.

[0003] Factors that influence the stability of a slope include, in particular, the properties of the underlying soil types, such as cohesion and the angle of internal friction. Furthermore, water conditions (groundwater, surface water, pore water pressure, hydrodynamic effects of water) as well as constantly acting loads and traffic loads favor slope failure.

[0004] A slope failure can therefore also occur as a result of environmental influences, such as the impact of wind and / or water on the slope body.

[0005] In order to improve the stability of an embankment, it is therefore known from the state of the art to select certain materials from which the embankment surface and / or embankment body are formed, depending on the nature of the subsoil and the requirements for stability, especially in the case of artificial embankments.

[0006] Furthermore, to improve the stability of an existing slope, it is known from the state of the art to flatten an existing slope by changing the original slope angle. This can be achieved, for example, by adding additional slope material. However, this requires an increased amount of space, which is not always available due to spatial constraints.

[0007] Nevertheless, beyond the measures known in the state of the art, there is a vital commercial and, in the case of traffic routes, also public interest in improving the stability of existing embankments, regardless of soil conditions, embankment material and slope angle, particularly with regard to external influences, and in doing so avoiding major interventions in the existing structure, such as replacing the embankment material or flattening the embankment.

[0008] The invention is therefore based on Task The aim is to specify measures that can be used to improve the stability of an embankment and prevent embankment failures.

[0009] To SolutionTo achieve this aim, the invention proposes a stabilization system for a slope as mentioned at the outset, comprising a terrain section having a soil body forming a slope and having a hypothetical slope failure body which extends at least over part of the soil body and which is delimited by a hypothetical sliding surface, which is characterized by at least one rod-shaped element which is arranged and aligned in the soil body in such a way that the rod-shaped element extends at least partially within the hypothetical slope failure body, and that a hypothetical cutting surface is formed between the rod-shaped element and the hypothetical sliding surface, wherein the hypothetical cutting surface runs at an angle to the longitudinal axis of the rod-shaped element.

[0010] The invention takes advantage of the fact that the nature and extent of potential slope failures can be predicted with some degree of probability using suitable computational methods. By utilizing certain computational parameters, such as the slope failure body and / or the slip line, it is possible for the first time to stabilize the slope body against a slope failure by specifically arranging the at least one rod-shaped element relative to these parameters. This allows the at least one rod-shaped element to absorb failure-driving forces acting on the rod-shaped element and / or the slope body at an angle, in particular transversely, to the longitudinal extent of the rod-shaped element.It has been shown that the integration of a rod-shaped element according to the invention into the soil body, in particular the embankment body and / or the areas of the soil body that are preferably directly adjacent to the embankment body and are delimited by the sliding surface, significantly increases the stability of the embankment against embankment failures in general and its structural stability in particular. This makes it possible to construct embankments with steeper angles of repose than is possible with methods known from the prior art. Furthermore, the flexibility with regard to the required embankment material is advantageously increased. Furthermore, the system according to the invention offers the possibility of incorporating the rod-shaped elements according to the invention into an existing embankment, in order to subsequently stabilize embankments that are particularly at risk of embankment failure.As a result, the safety of slopes is improved and the risk of property damage and / or personal injury resulting from slope failures is minimized. The advantageously increased stability also reduces the maintenance and rehabilitation costs of slopes.

[0011] The term "rod-shaped element" in the sense of the invention refers to an elongated shaped body whose axial extent exceeds its radial extent by a multiple, in particular by a factor of 5 to a factor of 100. It is in particular solid, i.e., formed as a solid body. The cross-section is preferably round. It is preferred that the at least one rod-shaped element has a diameter of 15 cm to 60 cm, in particular 20 to 40 cm. Such dimensions have proven particularly advantageous in terms of their mechanical stability and production with regard to the slopes to be stabilized and the associated forces acting on the slope body and the rod-shaped elements. In particular, it is provided that the rod-shaped element extends, with respect to its axial longitudinal extent, in the vertical direction, i.e., along the height direction of the slope body, within the slope failure body.

[0012] The term "angular to the longitudinal axis" means in the sense of the invention that between the hypothetical cutting surface formed between the hypothetical sliding surface and the at least one rod-shaped element and / or an elongated hole to receive the rod-shaped element and the longitudinal axis of the at least one rod-shaped element and / or the elongated hole, an angle α ≠ 0° and α # 180°, in particular an angle α between 15° and 165°, preferably between 30° and 150°, preferably between 45° and 135°, particularly preferably between 65° and 115°, is formed.

[0013] The term "terrain section" within the meaning of the invention encompasses a slope as well as adjacent horizontal surfaces or surfaces that are less steeply inclined relative to the slope, as well as the three-dimensional soil sections extending below the surfaces in the depth direction. The totality of all surfaces and associated soil sections of the terrain section is referred to as the "soil body" within the meaning of the invention. The slope forms part of the soil body and is therefore formed entirely by part of the soil body. In addition to the soil body, the terrain section can include objects arranged on the surfaces.

[0014] The invention makes use of hypothetical parameters that can be calculated to determine the position and orientation of the at least one rod-shaped element or, in the process, of elongated holes to be introduced into the soil body. These parameters are the slope failure body and the sliding surface. They can be determined using various calculation models, such as in particular the sliding circle method. The slope failure body is spatially delimited by the sliding surface. The sliding surface extends at least through part of the soil body, in particular at least through part of the slope body. The sliding surface often also runs through regions of the soil body that are directly adjacent to the slope body in the vertical and / or horizontal direction. The slope failure body thus extends at least over part of the soil body, in particular over part of the slope body.Furthermore, it can also extend to those areas of the soil body that directly adjoin the slope body in the vertical and / or horizontal direction. The parameters defining the above characteristics depend on slope-specific properties, such as slope angle, slope material, and forces acting on the slope.

[0015] According to a preferred feature of the invention, the at least one rod-shaped element is formed from an expanded plastic. Preferably, the plastic is expanded polyurethane resin. Firstly, the construction from plastic is advantageous because, in contrast to steel, for example, plastic has a favorable ratio of weight to transverse resistance. Furthermore, in contrast to metal, plastic offers the advantage that it can be introduced in flowable form into the soil body, in particular into the embankment body and / or into at least one region of the soil body which is preferably directly adjacent to the embankment body and which is delimited by the sliding surface, and can then be hardened to form the rod-shaped element while compacting the soil body, in particular through expansion.This has both process-related advantages and, on the other hand, leads to additional mechanical stabilization of the soil body in the area of the slope affected by the slope failure body through compaction. In this regard, the use of a polyurethane resin has proven particularly advantageous due to its exceptional mechanical stability, reaction mechanics, and the easy handling of its reactants.

[0016] According to a preferred feature of the invention, the at least one rod-shaped element is arranged in a casing made of a textile material, in particular a geotextile or Kevlar. On the one hand, this serves to protect the rod-shaped element. On the other hand, it ensures that, during any reaction of the plastic in the casing, the expansion of the polyurethane resin is limited to a certain diameter and a compaction of the surrounding embankment material occurs in the radial direction of the rod-shaped element. Geotextiles are flat or three-dimensional textiles that are particularly permeable to water. They are preferably made of natural (such as reed, jute and / or coconut) fibers or synthetic (such as polypropylene, polyamide, polyester and polyethylene) materials and are used for separation, drainage, filtering, reinforcement, protection, packaging and erosion control.They are used in the form of woven fabrics, nonwovens, and composites. Due to their limited durability, geotextiles made of jute or coconut fibers are only used when subsequent decomposition is desired. Kevlar generally refers to p-aramid fibers, which are known for their exceptional mechanical properties, particularly weight and tensile strength. In addition to the rod-shaped element according to the invention, a textile covering, in particular a covering made of a Kevlar textile, further enhances and improves its mechanical resistance to transverse loading, thereby synergistically improving the stability of the embankment.

[0017] According to a preferred embodiment of the invention, further rod-shaped elements are provided. In particular, a plurality of regularly and / or irregularly distributed, similar rod-shaped elements are arranged in the soil body, in particular in the embankment body and / or in at least one region of the soil body that is preferably directly adjacent to the embankment body and is delimited by the sliding surface. The further rod-shaped elements extend within the hypothetical embankment failure body, wherein they are designed to absorb forces that act at an angle to the longitudinal extent of the rod-shaped elements in order to stabilize the embankment or the embankment body. In particular, it is provided that the rod-shaped elements extend parallel to one another with respect to their longitudinal axis.This further stabilizes the resistance of the embankment body and thus the embankment as a whole against various influences, further improves the stability of the embankment and prevents embankment failures.

[0018] To Solution In order to achieve this object, the invention further proposes a method, in particular by forming a stabilization system according to the invention, for stabilizing an embankment, in particular against a slope failure, in which for a section of terrain which has a soil body forming a slope, a hypothetical slope failure body and a hypothetical sliding surface delimiting the slope failure body are determined mathematically; at least one elongated hole open at one end and of adjustable length is introduced into the soil body, in particular by means of a ramming displacement method, such that the elongated hole extends at least partially within the hypothetical slope failure body, and that a hypothetical cutting surface is formed between the elongated hole and the hypothetical sliding surface, wherein the hypothetical cutting surface runs at an angle to the longitudinal axis of the elongated hole; a multi-component flowable composition is injected into the hole; the components of the composition are mixed during the injection;As a result of the mixing, the composition is cured with spatial expansion beyond the previous radius of the hole, forming a plastic in the form of a rod-shaped element; the soil body is radially displaced and compacted by the curing and expansion of the composition.

[0019] The method according to the invention allows for the simple integration of rod-shaped elements into the soil body, in particular into the embankment body and / or into at least one region of the soil body that is preferably directly adjacent to the embankment body and is delimited by the sliding surface, in order to stabilize the embankment and improve its stability. A particularly advantageous process is the formation of the rod-shaped element directly in the embankment body by curing a multi-component composition, in particular a composition that forms a polyurethane foam. This eliminates the need to pre-produce, store, and transport a large number of prefabricated elements in different sizes to the installation site. Rather, it is only necessary to maintain a composition that is the same for all sizes.The required dimensions of the rod-shaped element can be adapted directly on-site to the local conditions, in particular the dimensions of the embankment body and its material. The final size of the rod-shaped element is controlled and adjusted by the hole size and the amount of compound filled in. With regard to the stabilization system to be formed, the process according to the invention has the advantage that the expansion of the compound during curing causes compaction of the soil body material. This synergistically leads to further stabilization of the embankment body, which would not be achievable with the mere introduction of a prefabricated rod-shaped element due to the lack of expansion.

[0020] According to the invention, at least one elongated hole of adjustable length, open at one end, is drilled into a soil body, in particular into the embankment of an embankment, in particular a dam or a road boundary, and / or into at least one region of the soil body directly adjacent to the embankment and delimited by the sliding surface. In principle, the hole can be drilled using drilling methods such as dry drilling, flush drilling, ram drilling, grab drilling, percussion drilling, or auger drilling. A ram displacement method is preferably used. Here, a soil displacement hammer is driven forward using compressed air, in particular from a construction site compressor, or hydraulics, in particular with a hydraulic unit. The elongated hole according to the invention is excavated in the form of an underground cavity. According to a preferred feature of the invention, the elongated hole is formed with a diameter of 45 mm to 80 mm.This allows for process-economical filling with the flowable composition and, if necessary, process-economical arrangement of the casing.

[0021] The multi-component, flowable composition, in particular a resin, is preferably one that forms a thermosetting plastic after curing. Compositions that form an epoxy resin, a phenolic resin, or a polyurethane resin are suitable. A composition that forms a polyurethane resin upon spatial expansion is preferred. For this purpose, the composition preferably comprises at least one polyol and at least one polyisocyanate.

[0022] According to a preferred feature of the invention, the multi-component, flowable resin composition is filled evenly by means of a filling device, starting from the end of the hole remote from the opening toward the opening of the hole, up to a predeterminable fill level and / or fill quantity. For this purpose, the filling device preferably has a correspondingly long filling probe.

[0023] It is preferably provided that before the multi-component flowable composition is injected into the elongated hole, a textile sleeve open at one end is inserted through the opening of the hole. The opening of the sleeve is aligned in the direction of the opening of the hole. Preferably, the sleeve is made of a textile material, in particular a geotextile or Kevlar, i.e. p-aramid fibers. The diameter of the sleeve corresponds to or preferably corresponds to the diameter of the rod-shaped element that it is intended to form after expansion and curing. Preferably, the materials used for the sleeve have a certain degree of elasticity, which allows stretching in the radial direction. In particular, the sleeve is so elastic that rod-shaped elements of up to 60 cm in diameter can be formed after curing and expansion. Alternatively, the sleeve is not elastic or only elastic to a limited extent.In this case, it is intended that the diameter of the sleeve in the adjusted state corresponds to the later diameter of the rod-shaped element, but is preferably packed so compactly that it fits into the elongated hole with a comparatively small diameter.

[0024] If a casing is provided, it is preferred that the multi-component, flowable composition is poured into the casing arranged in the hole. On the one hand, this serves to protect the rod-shaped element. On the other hand, this ensures that during any reaction of the plastic in the casing, the expansion of the polyurethane resin is limited to a certain diameter and compaction of the surrounding embankment material occurs in the radial direction of the rod-shaped element. Furthermore, this ensures that during a reaction of the plastic in the casing, the expansion direction can be controlled and the compaction of the surrounding embankment material can be evened out. In addition, the casing serves to contain the preferably flowable starting materials of the plastic, in particular the polyurethane resin, ensuring that the starting materials are not contaminated by the surrounding embankment material.

[0025] According to a preferred feature of the invention, the hole is made through an embankment surface into the embankment body. This is particularly relevant when rehabilitating embankments where the embankment surface and embankment body are made of different materials. For example, an embankment body made of earth and gravel on the one hand and a green embankment surface made of lawn. To form the elongated hole, the embankment surface is first pierced in order to gain access to the embankment body. After expansion and curing of the composition are complete, i.e. after formation of the rod-shaped element, it is preferred that the hole open on the embankment surface side is closed to create a continuous embankment surface.

[0026] The invention is explained below using an exemplary embodiment. Figure 1: A stabilization system according to the invention in a sectional view of the slope from the side; Figure 2: A stabilization system according to the invention in a sectional view of the slope from above.

[0027] Figure 1 shows a stabilization system 1 according to the invention. The stabilization system 1 comprises a terrain section 2, which in the sectional view shown extends between the dashed lines A and B. The terrain section 2 has an embankment 3 and a horizontal surface 4 which adjoins the embankment 3 to the right with respect to the image plane. The embankment has an embankment body 5. The embankment body 5 is part of the soil body 6, which forms the entire subsoil of the terrain section 2. In the present case, the soil body 6 also comprises the soil section 7, which is located directly below the embankment body 5, and the soil section 8, which is located below the surface 4.

[0028] Using the slip circle method, parameters were determined depending on slope-specific properties. These parameters define characteristics that provide information about the likely behavior of slope 3 in the event of a slope failure. This characteristic is, firstly, the hypothetical slip surface 9, which is depicted as a circular slip line in the sectional view shown. Another characteristic is the hypothetical slope failure body 10, spatially delimited by the slip surface 9.

[0029] In this case, the sliding surface 9 runs through the soil body 6. In particular, the sliding surface 9 runs through the slope body 5, the soil section 7 and the soil section 8. The slope failure body 10 thus extends at least partially onto the slope body 5, the soil section 7 and the soil section 8.

[0030] To stabilize the slope against acting forces, i.e., to prevent a possible slope failure, rod-shaped elements 11 are arranged in the soil body 6, in particular in the slope body, the soil section 7, and the soil section 8, in such a way that they are positioned horizontally spaced from one another on the sliding surface 9 and partially extend into the slope failure body 10. This achieves effective stabilization of the slope.

[0031] The illustration of the rod-shaped elements 11 shows two different states. The inner, gray-shaded contour 12 with a smaller cross-sectional diameter shows the expansion of a multi-component, flowable composition before its curing to form the rod-shaped element 11. The outer contour 13 of the rod-shaped element 11, in contrast, shows the cross-sectional expansion of the rod-shaped element 11 after its formation from the flowable composition during curing and expansion. In this case, the rod-shaped element 11 is formed from a thermosetting plastic by curing a polyurethane resin.

[0032] The rod-shaped elements 11 are arranged at a distance from one another on the sliding surface 9. They are aligned relative to one another in such a way that their respective longitudinal axes run parallel to one another.

[0033] It can also be seen in this illustration that the sliding surface 9 intersects the rod-shaped elements. In doing so, a hypothetical cutting surface is formed in each case, which is shown in cross-section here as a cutting line. The shape follows the shape of the sliding surface. It is evident that the cutting surface or the cutting line is circular arc-shaped. The cutting surface and the longitudinal axis of the rod-shaped elements 11 are at an angle α ≠ 0° and α ≠ 180°, in particular at an angle α between 15° and 165°, to one another. Due to the circular arc shape of the sliding surface 9 or the illustrated sliding line, the angle α is dynamic relative to the longitudinal axis of the respective rod-shaped element.

[0034] Figure 2 shows a stabilization system 1 according to the invention, which is shown in another view in Figure 1 is shown.

[0035] Looking from above at the slope 3, it can be seen that the rod-shaped elements 11 are arranged evenly distributed in the horizontal direction over the hypothetical sliding surface 9.

[0036] The two different diameters of the rod-shaped elements and their educts before and after curing and expansion can also be seen again. List of reference symbols

[0037] 1Stabilization system 2Terrain section 3Slope 4Horizontal surface 5Slope body 6Soil body 7Soil section 8Soil section 9Slip surface 10Slope failure body 11Rod-shaped element 12Inner contour 13Outer contour

Claims

1. Stabilisation system for an embankment, in particular in the form of a dam, dike or a sloped road boundary, with a terrain section comprising a soil body forming an embankment and comprising a hypothetical embankment failure body which extends at least over a part of the soil body and which is delimited by a hypothetical sliding surface, characterized by at least one rod-shaped element which is arranged and oriented in the soil body such that the rod-shaped element extends at least partially within the hypothetical slope failure body, and that a hypothetical cutting surface is formed between the rod-shaped element and the hypothetical sliding surface, wherein the hypothetical cutting surface extends at an angle to the longitudinal axis of the rod-shaped element.

2. Stabilization system according to claim 1, characterized in thatthe parameters defining the hypothetical slope failure body and / or the hypothetical sliding surface are determined by applying the sliding circle method, whereby the hypothetical sliding surface has a circular arc shape in cross-section.

3. Stabilization system according to one of claims 1 or 2, characterized in that the at least one rod-shaped element is formed from an expanded polyurethane resin.

4. Stabilization system according to one of claims 1 to 3, characterized in that the at least one rod-shaped element has a diameter of 15 cm to 60 cm, in particular 20 cm to 40 cm.

5. Stabilization system according to one of claims 1 to 4, characterized in that the at least one rod-shaped element is arranged in a sheath made of a textile material, in particular a geotextile or Kevlar.

6. Stabilization system according to one of claims 1 to 5, characterized byfurther rod-shaped elements which are arranged and aligned in the soil body in such a way that the further rod-shaped elements each extend at least partially within the hypothetical slope failure body, and that a hypothetical cutting surface is formed between a respective further rod-shaped element and the hypothetical sliding surface, wherein the respective hypothetical cutting surface extends at an angle to the respective longitudinal axis of the further rod-shaped element.

7. Stabilization system according to claim 6, characterized in that the individual rod-shaped elements are arranged horizontally spaced from each other on the hypothetical sliding surface.

8. Stabilization system according to one of claims 6 or 7, characterized in that the rod-shaped elements are aligned relative to each other in such a way that their respective longitudinal axes run parallel to each other.

9. Stabilization system according to one of claims 1 to 8, characterized in that an angle α ≠ 0° and α ≠ 180°, in particular an angle α between 15° and 165°, preferably between 30° and 150°, is formed between the hypothetical cutting surface and the longitudinal axis of the at least one rod-shaped element.

10. A method for stabilizing a slope, in particular against slope failure, in particular by forming a stabilization system according to one of claims 1 to 9, in which a. a hypothetical slope failure body and a hypothetical sliding surface delimiting the slope failure body are mathematically determined for a section of terrain which has a soil body forming a slope; b. at least one elongated hole open at one end and of adjustable length is introduced into the soil body, in particular by means of a ramming displacement method, such that the elongated hole extends at least partially within the hypothetical slope failure body, and that a hypothetical cutting surface is formed between the elongated hole and the hypothetical sliding surface, wherein the hypothetical cutting surface runs at an angle to the longitudinal axis of the elongated hole; c.a multi-component flowable composition is injected into the hole; d. the components of the composition are mixed during injection; e. the composition is cured as a result of the mixing, expanding spatially beyond the previous radius of the hole to form a plastic in the form of a rod-shaped element; f. the soil body is radially displaced and compacted by the curing and expansion of the composition.

11. Method according to claim 10, characterized in that the multi-component flowable composition is filled by means of a filling device starting from the end of the hole remote from the opening towards the opening of the hole evenly up to a predeterminable filling level and / or filling quantity.

12. Method according to one of claims 10 or 11, characterized in thatBefore the multi-component flowable composition is injected into the elongated hole, a textile sheath, in particular one open at one end, is inserted through the opening.

13. Method according to claim 12, characterized in that the shell is made of a geotextile or Kevlar.

14. Method according to one of claims 12 or 13, characterized in that the multi-component flowable composition is poured into the casing arranged in the hole.

15. Method according to one of claims 10 to 14, characterized in that the hole is formed in the soil body with a diameter of 45 mm to 80 mm.

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