EP2712374A1

EP2712374A1 - Method and arrangement for providing effect of polymer on soil

Info

Publication number: EP2712374A1
Application number: EP12782777.2A
Authority: EP
Inventors: Tuomas Lievonen; Kalle Antniemi
Original assignee: Uretek Worldwide Oy
Current assignee: Uretek Worldwide Oy
Priority date: 2011-05-10
Filing date: 2012-05-08
Publication date: 2014-04-02
Anticipated expiration: 2032-05-08
Also published as: TWI579431B; FI20115449A; FI126080B; TW201313990A; FI20115449A0; EP2712374B1; AU2012252277A1; AU2012252277B2; EP2712374A4; FI20115449L; WO2012152999A1; AR086331A1

Abstract

The invention relates to a method and arrangement for providing effect of a polymer on soil. The disclosed solution provides an injection structure (4) for arranging the effect of the polymer on the soil. The injection structure (4) comprises at least two injection elements (5). The injection element (5) comprises a frame pipe (6) through which the polymer is injected, and means for conveying the effect of polymer on the soil. The frame pipe (6) includes connection means (9) for connecting the injection element (5) as a part of the injection structure (4). The injection structure (4) comprises at least two injection elements (5) interconnected on site in such a manner that the injection elements (5) included in the injection structure (4) are separately transportable to the working site.

Description

Method and arrangement for providing effect of polymer on soil

Background of the invention

[0001] The invention relates to an arrangement for providing effect of a polymer on soil.

[0002] The invention also relates to a method for providing effect of a polymer on soil.

[0003] The soil is improved, for instance, to increase the bearing capacity of soil or to fill voids in the soil. Further, soil improvement is needed, if it is desired that vibrations transmitted through soil are dampened or soil liquefaction occurring in connection with earthquakes is prevented in advance. Lifting of structures, in turn, refers to lifting and balancing damaged, subsided or off-the-position buildings or foundations or floors of buildings. Lifting of structures further comprises that, for instance, subsided, paved roads or fields, such as concrete and asphalt roads or runways, or railroads are lifted and balanced.

[0004] Deterioration of soil or subsidence of structures may be caused, for instance, by poorly consolidated soil, water-induced erosion, wrong soil type in the stage of construction, weakening of friction forces in the soil or variations in temperature or moisture conditions. Further, deterioration of soil may be caused by changes in conditions due to a mechanical damage, such as breakage in water or sewage pipes. Furthermore, soil conditions may change by the effect of dynamical forces.

[0005] For improving the soil, the soil of poor bearing capacity is replaced by a material of better bearing capacity. So-called soil exchange of this kind is extremely laborious and expensive. Further, it is known to use conventional techniques, such as friction piles, which support to the soil by means of friction, or bottom piles, which support to the hard bottomset bed. Equipment required for conventional piling are heavy and complicated, and they cause noise and other disturbance in the environment.

[0006] Publication EP 0851064 discloses a solution for improving bearing capacity of soil. In said solution, holes are drilled in the soil and a substance expanding as a consequence of a chemical reaction is injected in the hole. Publication EP 1314824 discloses a corresponding solution, in which a pressure exceeding 500 kPa is to be achieved with the material.

[0007] Publication US 7789591 discloses a solution for improving soil and/or for lifting structures. According to the publication, the soil or struc- ture is provided with a hole, and an injecting pipe having a fillable expansion element provided in connection therewith is arranged in the hole. A substance that expands as a consequence of a chemical reaction is injected into the expansion element.

Brief description of the invention

[0008] It is an object of the present invention to provide a solution of new type.

[0009] The solution of the invention is characterized by what is disclosed in the independent claims.

[0010] The disclosed solution provides an injection structure for arranging the effect of a polymer on the soil. The injection structure comprises at least two injection elements. The injection element, in turn, comprises a frame pipe through which the polymer is injected, and means for conveying the effect of polymer on the soil. The fact that the injection element includes means for conveying the effect of polymer on the soil or that the injection element causes the polymer to act on the soil means that from the injection element the polymer is guided at least for a portion of the injection element length in a direction differing from the axial direction of the injection element. The frame pipe includes connection means for connecting the injection element as a part of the injection structure. Thus, the injection structure comprises at least two injection elements interconnected on site in such a manner that the injection elements included in the injection structure are separately transportable to the working site. The logistics of such a structure is simple and thus achievable at reasonable costs, since storage and transport of even long injection structures does not require manipulation of long elements, because the injection structure need not be assembled to its final dimensions until on the working site. On the other hand, there is no need to provide a large number of structures of different sizes, because the final dimensions of the injection structure may be defined on the basis of whether two or more, if necessary, injection elements are connected thereto. This makes it also easier that as the final need is established, it is possible to form an injection structure of desired length and it need not be formed in advance. When the length of the injection structure is determined on the working site, in the same way, it is also possible not to determine until on the working site the distance within which the effect is arranged. So, it is possible to supply an injection structure of correct measurements to the working site without an advance order or long-term storage of various optional compo- nents. Further, controllability of polymer injection is very good. For instance, in a very simple manner it is possible to determine the points in the injection structure where the polymer is injected in a given order, i.e. the polymer may be injected into different injection elements consecutively. Controllability of injection in a single-piece injection structure is considerably more challenging than in the present solution, where the polymer may be injected first into one injection element in the injection structure and thereafter into the second injection element in the injection structure, etc.

[0011] The idea of an embodiment is that at least one injection element comprises a frame pipe and an expansion element arranged outside it. The structure of an injection element of this kind is robust and, on the other, it allows the polymer to be very reliably placed also in a loose, fractured or otherwise demanding soil. If so desired, this solution also allows a polymeric pillar to be provided in the soil, for instance.

[0012] The idea of a second embodiment is that inside the frame pipe there is arranged an injecting pipe along which a polymer is conveyed into an injection element. In that case polymer injection will be particularly well controlled. For instance, by moving the injecting pipe it is possible to define accurately in which injection element the polymer is injected and even the accurate point where in said injection element the polymer is injected.

[0013] The idea of yet another embodiment is that the expansion element is provided to have such dimensions and arrangement that in the consecutively arranged injection elements the outer surfaces of the expansion elements are set to support one another, when they contain reacted polymer. Thus, the obtained structure will be very strong and, when necessary, the structure may serve as a pillar, for instance.

Brief description of figures

[0014] Figure 1 shows schematically an injection structure arranged in soil,

Figure 2 is a schematic cross-sectional side view of an injection element,

Figure 3 is a schematic cross-sectional side view of a second injection element,

Figure 4 shows schematically a second injection structure arranged in soil, and Figure 5 shows schematically a third injection structure arranged in soil.

[0015] In the figures, some embodiments of the invention are shown simplified for the sake of clarity. Like reference numerals refer to like parts in the figures.

Detailed description of the invention

[0016] Figure 1 shows an apparatus 1 by which a polymer is injected in such a manner that the polymer causes an effect on the soil 2. The apparatus 1 includes an injection device 3 by which the material to be injected is supplied to an injection structure 4. The injection device 3 generates a sufficient hydraulic pressure so that the material to be injected can be supplied through the injection structure 4 to act on a desired location in the soil 2. For the sake of clarity, the injection device 3, which supplies the material to be injected to the injection structure 4, is shown only schematically, because its structure and operation are known per se to a person skilled in the art.

[0017] The polymer to be injected may be, for example, a mixture mainly consisting of two components. In that case, the first component may contain polyether polyol and/or polyester polyol, for example. The second component may contain isocyanate, for instance. The volumetric ratios of the first component to the second component may vary between 0.8 to 1.2 : 0.8 to 1.8, for example. The polymer may further contain catalysts and water and, if desired, also other components, such as silica, rock dust, sand, grit, expand- ed-clay aggregate, fibre reinforcements, and other possible additional and/or auxiliary agents. The use of a single-component polymer is also possible in connection with the solutions disclosed in this description.

[0018] The polymer 3 may be non-expanding, in which case its -chemical reaction typically comprises solidification and/or hardening. The polymer may also be material expanding as a consequence of a chemical reac- tiqn,,whereby the polymer, when reacting, expands and, in addition to expansion, also solidifies and/or hardens as well. The polymer expands to a volume that is e.g. 1 to 120 times the original volume. When a polymer that expands is used, the expansion coefficient of the substance, i.e. the volume of the substance at the end of the reaction as compared with the volume of the substance at the beginning of the reaction, may be of the order of 1.1 to 120, for instance. Advantageously, the polymer 3 may be arranged to expand, for in- stance, 1.5 to 20 times the original volume. The material expanding as a consequence of a chemical reaction need not be fed into the ground 2 at so high hydraulic pressure as a non-expanding polymer. Thus the polymer feeding equipment may be provided simpler. Relatively low feed pressure is also advantageous in view of the work safety.

[0019] The injection structure 4 comprises a plurality of injection elements 5. In the embodiment of Figure 1 , the injection structure 4 comprises three interconnected injection elements 5. The injection element 5 comprises a frame pipe 6 through which the polymer is injected, as illustrated in Figure 2, for instance. In the embodiment of Figure 2, outside the frame pipe 6 there is arranged an expansion element 7. Holes 8a to 8c in the frame pipe 6 and the expansion element 7 serve as means for conveying the effect of the polymer on the soil 2.

[0020] The frame pipe 6 of each injection element 5 comprises connection means 9 for connecting one injection element 5 to another injection element 5 or in some other manner to form part of the injection structure 4.

[0021] The connection means 9 may consist of an external thread 10a at the lower end of the injection element 5 and a corresponding internal thread 10b at the upper end of the injection element 5, as indicated in Figure 2. In addition to or in place of said threaded connection, the connection means 9 may be a compressing ring, a bayonet joint or the like, which allows the injection element 5 to be connected from the frame pipe 6 to be part of the injection structure 4.

[0022] With the connection means 9 the injection elements 5 can be interconnected on the site. So, the injection elements 5 included in the injection structure 4 are separately transportable to the working site.

[0023] The expansion element 7 is, for instance, a folded bag, inside which the polymer is injected. In that case the polymer reacts in the soil 2, inside the expansion element 7. Thus, the expansion element 7 restricts the migration of the polymer in the soil 2.

[0024] The expansion element 7 is of material permeable to air or impermeable to air and of substantially inelastic material. An example of the material suitable for providing the expansion element 7 is a geotextile. It is also possible to use some other flexible and durable material.

[0025] As the material of the expansion element 7 it is possible to use a plastic, such as polyester or polypropylene, or artificial fibre or natural fi- bre. The material may also be rubber or some other elastomer. The wall of the expansion element 7 may thus be permeable to air or impermeable to air. The wall of the expansion element 7 may also be flexible or non-flexible. The wall of the expansion element 7 may also include metallic reinforcement material or glass fibre, or some other suitable reinforcement material. The expansion element may be provided either with seams or without seams. The seam may be made, for instance, by sewing, gluing, using an attachment element, riveting, welding, soldering, melting, or by some other mechanical, chemical, thermal or electrotechnical method or a combination thereof. The wall of the expansion element 7 may also be made such that it lets some of the material injected therein penetrate out through the wall. The wall thickness in the expansion element 7 may vary between 0.02mm and 5mm, for instance, depending on the material, size of the expansion element 7, expansion pressure, etc. The expansion element 7 may be attached to the frame pipe 6 with a clamp or a bushing. The embodiment of Figure 2 shows a lower bushing 11a and an upper bushing 11 b as attachment elements.

[0026] The attachment elements, such as the lower bushing 1 a and the upper bushing 11 b, may be hose clamps, for instance. Further, said attachments may be metal sleeves, which are produced by cutting a piece of pipe. The metal sleeve may be attached to place by press-fitting, for instance.

[0027] The attachment elements, such as the lower bushing 1 a or the upper bushing b, may also be provided movable, and thus, as the expansion element 7 fills up, they slide to a proper position. With respect to the stationary attachments, this solution has an advantage that it makes possible to avoid distortion in the frame pipe 6 and even eventual breakage. The attachment element may be made movable, for instance, by forming in a part of the frame pipe a solid portion, and a movable sleeve is arranged thereon. The wall of the expansion element 7 is arranged on the movable sleeve and the at- tachment bushing is arranged around it, whereby the wall of the expansion element 7 is fixedly between the attachment bushing and the movable sleeve. Thus, when the movable sleeve is able to slide along the surface of the frame pipe, the attachment moves while the expansion element 7 fills up.

[0028] The outer diameter of the expansion element 7 is preferably provided to be as small as possible. The expansion element 7 is folded outside the frame pipe 6 and preferably it is compacted as tightly as possible against the frame pipe 6 with a compactor, for instance. To reduce the outer diameter of the expansion element 7 it is also possible to utilize heat, compressed air, moisture, suction and/or compression with a roller press, for instance. To make sure that the expansion element 7 stays tightly against the frame pipe 6 it is possible to arrange a plastic membrane thereon. The plastic membrane may be arranged on the expansion element 7, by pulling or wrapping, for instance.

[0029] At the lower end of the injection element 5 it is possible to arrange a percussion tip 12, for instance, by a threaded joint. Correspondingly, at the upper end of the injection element 5 it is possible to arrange a striking piece 13, for instance, by a threaded joint. Thus, the injection element 5 can be thrusted or driven into the soil. In that case, the percussion tip 12 provides a penetration path for the injection element, and the upper end of the injection element 5 is subjected to a downwardly pushing force through the striking piece 13. In this manner the upper end of the frame pipe 6 of the injection element 5 will not be damaged. When a sufficient portion of the injection element 5 has been driven into the soil 2, the striking piece 13 is removed and a second injection element 5, for instance, is arranged at the upper end of the injection element 5. Thereafter, the striking piece 13 is arranged at the upper end of the upper injection element 5, and the injection elements 5 are driven again deeper in the soil, and again, a next injection element 5 is attached to the upper end of the upper injection element, etc. In addition, at the upper end of the uppermost injection element 5 it is possible to attach a frame pipe having a wall without holes, for instance, if there is no need to provide an effect of polymer on the upper surface of the soil.

[0030] The polymer to be injected may be fed from the apparatus 1 directly into the frame pipe, whereby the polymer is arranged to flow inside the frame pipe and further through the holes 8a to 8c into the expansion element. On the other hand, the polymer may also be fed along a separate injecting pipe 14. The injecting pipe 14 is arranged inside the frame pipe 6 with appropriately tight-fitting dimensions. For instance, if the inner diameter of the frame pipe 6 is 12.5mm, the outer diameter of the injecting pipe 14 may be 12mm. Hence, it is relatively easy to move the injecting..pipe 14 inside the frame pipe 6, because their mutual sliding friction is relatively small. The outer diameter of the injecting pipe 14 varies thus according to the inner diameter of the frame pipe 6, and it may be between 3 and 20mm, for instance. The clearance between the injecting pipe 14 and the frame pipe 6 is selected such that the polymer has substantially no access between them and their mutual sliding fric- tion will be suitable. The injecting pipe 14 may be made of metal, such as steel.

[0031] The injecting pipe 14 may also be made of some other material, such as plastic, e.g. polyethylene PE. Also, the injecting pipe 14 need not necessarily be rigid. The injecting pipe 14 may thus be a plastic hose or pipe, for example. Furthermore, if the injecting pipe 14 is a hose, its wall may be provided with textile reinforcement fabrics or metal or other similar reinforcements.

[0032] The polymer is arranged to flow through the lower end of the injecting pipe 14. Typically, the injection element 5 is filled from below upwards. The injecting pipe 14 is thus arranged inside the injection element 5 in such a manner that the lower end of the injecting pipe 14 is between the lowest hole 8a and the middle hole 8b. In that case the polymer flows from the lower end of the injecting pipe 14, through the hole 8a, into the expansion element 7. Thereafter the injecting pipe 14 is retracted upwardly, whereby it will be above the hole 8b. Thus, polymer starts flowing also through the hole 8b into the expansion element 7, and the expansion element 7 is filled with the polymer from below upwards. Thereafter, the injecting pipe 14 is further retracted upwards, whereby its lower end will be placed above the hole 8c, and the polymer is able to flow into the expansion element 7 also through the uppermost hole 8c. On the other hand, the polymer may also be fed in such a manner that initially the lower end of the injecting pipe 14 is arranged above the uppermost hole 8c, whereby the polymer will be able to flow into the expansion element 7 through all holes 8a to 8c mainly at the same time.

[0033] If desired, the polymer may also be injected in an order that differs from what is described above, for instance, in such a way that first the injecting pipe 14 is arranged above the uppermost hole 8c, whereby the main part of the polymer flows through the uppermost hole 8c into the expansion element 7, and thereafter the injecting pipe 14 is lowered downwardly, whereby the main part of the polymer will flow through the desired lower hole 8a or 8b. .Further, typically the polymer is injected first into the lowermost injection element 5 and thereafter into the injection element 5 thereabove, etc. Also the injection elements may be filled in some other order, e.g. from above downwards, or otherwise differently than from below upwards.

[0034] The injection structure 4 of Figure 1 is thus obtained, for instance, by interconnecting three injection elements of Figure 2. Figure 3 shows a second injection element 5. The most essential difference in the injection element of Figure 3 over the injection element of Figure 2 is that the expansion element 7 of Figure 3 is longer than the expansion element 7 of Figure 2. In that case, when the polymer reacts inside the expansion element 7, the expansion element 7 takes such a shape that in the consecutively arranged injection elements 5 the outer surfaces of the expansion elements 7 are set to support one another when they contain reacted polymer. Thus will be obtained the injection structure 4 illustrated in Figure 4, for instance.

[0035] As illustrated in Figure 3, an injection element 5 of this kind is provided by arranging the outer surface of the expansion element 7 against the outer surface of the upper part of the frame pipe 6 and arranging an upper bushing 11 b at said point against the inner surface of the expansion element 7. Thereafter, the expansion element 7 is reversed such that its outer surface will mainly be outwards and the inner surface of the lower end of the expansion element 7 is arranged in the lower part of the frame pipe 6 to be against the outer surface of the frame pipe 6. Thereafter, a lower bushing 11a is arranged on the outer surface of the expansion element 7. Because the length of the expansion element 7 is clearly longer than the mutual distance between the upper bushing 11 b and the lower bushing 11a, a fold 7a is formed at the upper end of the expansion element 7.

[0036] When the injection element 5 of Figure 2 is filled with polymer, typically, the injection element 5 becomes mainly cylindrical in form. Typically, the injection element 5 is, however, slightly tapered at the upper and lower ends, and in the middle the diameter is larger, as illustrated in Figure 1. All in all, typically, the final length of the expansion element 7 in the axial direction is slightly shorter than the length of the frame pipe 6 of the injection element 5.

[0037] In the embodiment of Figure 3, instead, the expansion element 7 filled with the polymer is substantially as long as the frame pipe 6 of the injection element 5. Thus the outer surfaces of the expansion elements 7 in the successively arranged injection elements 5 are set to support one another.

[0038] When the expansion element 7 is full of solid material, its outer diameter may vary between 20cm and 1 m, for instance. The length of the injection element 5, in turn, is selected on the basis of the requirements set by the application for a minimum length, on one hand, and as to maximum length, considering what is sensible in view of storage and transportation, on the other hand. Thus, the length of the injection element 5 may vary between 20cm and 3m, for instance. The idea of an embodiment is that the length of. the injection element 5 is about 1 m. In that case, the final length of the injectior¾.structure 4 may be selected on site approximately at 1 -metre intervals. Thus, it is determined on the working site the distance within which the effect of the polymer is to be arranged. The length of the injection structure 4, in turn, is arranged to correspond therewith and the injection structure 4 is provided by interconnecting a necessary number of injection elements 5.

[0039] In Figures 2 and 3, the wall of the expansion element 7 is depicted slightly off the frame pipe 6. In practice, the wall of the expansion element 7 is to be arranged as close as possible to the frame pipe 6, i.e. as closely as possible against it. Further, typically, in the embodiment of Figure 2 the length of the wall of the expansion element 7 is substantially the same as that of the injection element 5, when the polymer is not arranged inside the expansion element 7. When the expansion element 7 is made of geotextile, for instance, its wall stretches slightly when reacted polymer is arranged inside the expansion element 7. Consequently, when the reacted polymer is inside the expansion element 7, the wall length of the expansion element 7 is for the amount of the final outer diameter of the expansion element longer than the length of the injection element 5. By way of example, it may be set forth that if in the embodiment of Figure 2 the length of the injection element 5 is 1 m and the outer diameter is 30cm, when it is full of polymer, the length of the wall of the expansion element 7 is 1.3m. Thus, typically at the upper and lower ends of the injection element 5 a small portion of the frame pipe 6 will remain visible. Thus, the interconnected injection elements 5 may provide a structure as shown in Figure 1 , for instance.

[0040] In the embodiment of Figure 3, in turn, because of the fold 7a, the wall length of the expansion element 7, prior to feeding the polymer inside the expansion element 7, is typically longer than the length of the injection element 5. Again, by way of example, it may be set forth that if in the embodiment of Figure 3 the length of the injection element 5 is 1m and the outer di- ameter is 30cm, when it is full of polymer, the wall length of the expansion element 7 is 1.2m when there is no reacted polymer inside the expansion element 7, and the wall length of the expansion element 7 is 1.5m when there is reacted polymer inside it. Typically, when the injection element of Figure 3 is full of reacted polymer, the lower bushing 11a and part of the frame pipe 6 will remain visible in a direct side view. Instead, because of the fold 7a, the expansion element 7 is shaped such that, in a side view, the frame pipe 6 will not be visible at the upper end of the injection element 5. Thus, the embodiments of Figure 3 allow the injection structure of Figure 4 to be provided, for instance.

[0041] In particular, in the embodiment of Figure 3, the upper bushing 1 1 b may especially be provided slidable in the earlier described manner. In that case, the expansion element 7 will be shaped in a desired manner to provide a structure supporting to another injection element 5.

[0042] In the embodiment of Figure 3 it is described that at the lower end of the frame pipe 6 there is an internal thread 10b and at the upper end an external thread 10a. Naturally, the external thread 10a and the internal thread 10b may also be arranged as shown in Figure 2. Further, naturally also in this case the injection elements 5 may be connected to one another in some other manner.

[0043] Figure 3 further illustrates a solution, in which the holes 8a, 8b and 8c in the frame pipe 6 are arranged to orientate in different directions. In Figure 3, the middle hole 8b is arranged at an angle of about 45 degrees in a different direction from the lowermost hole 8a. Further, the uppermost hole 8c is arranged at an angle of about 45 degrees in a different direction from the middle hole 8b. Further, the uppermost hole 8c is arranged at an angle of about 90 degrees in a different direction from the lowermost hole 8a. Further, the injecting pipe 4 is provided such that its lower end is closed and its sides comprise holes 15a to 15c corresponding to holes 8a to 8c.

[0044] When, in the embodiment of Figure 3, the injecting pipe 14 is arranged inside the frame pipe 6 in the position shown in Figure 3, the lowermost holes 8a and 15a will be in alignment and when the polymer is injected, it flows into the expansion element 7 via the holes 15a and 8a thus filling the expansion element 7 in the lower part. Instead, the holes 15b and 8b and 15c and 8c, respectively, are hot in alignment, whereby polymer does not flow therethrough. When the injecting pipe 14 is subsequently turned 45 degrees, the holes 8b and 15b will be in alignment, whereby the polymer flows via the holes 8b and 15b into the expansion element 7. Whereas, in that case the holes 8a and 15a and 8c and 15c are not in alignment, and the polymer does not flow therethrough.

[0045] When the injecting pipe 14 is subsequently further turned 45 degrees in the same direction, the holes 8c and 15c will be in alignment, whereby the polymer flows therethrough into the expansion element 7. Whereas, in that case the holes 8a and 15a and 8b and 15b are not in alignment, and the polymer does not flow therethrough.

[0046] Thus is provided an operation similar to that described above, i.e. the expansion element 7 is consecutively filled at a desired point without having to draw or push the injecting pipe 14 inside the frame pipe 6. It will be sufficient that the injecting pipe 14 is turned in a suitable direction in such a manner that the desired holes 8a to 8c and 15a and 15c, respectively, are in alignment. Further, the same principle may be utilized in such a manner that in one injection element 5 the holes 8a to 8c are provided to orientate in the same direction, whereas in consecutive injection elements 5 said holes orientate in a different direction. Thus, by turning the injecting pipe 14 it is possible to select in which injection element 5 polymer is injected.

[0047] The holes 8a to 8c and 5a to 5c may further be utilized in the feed of polymer in such a way that the injecting pipe 14 is retracted and/or pushed inside the frame pipe 6 for arranging the holes in alignment, and correspondingly, by arranging the holes in non-alignment to prevent the polymer flow through the holes. Thus, by utilizing the turning of the injecting pipe as well as the moving in the up and down direction it is possible to select in an extremely versatile manner the point where polymer is injected.

[0048] The holes 8a to 8c and/or the holes 15a to 15c need not necessarily be round. For instance, the holes may be elongated apertures in the longitudinal direction of the tube or the pipe. To align the elongated apertures in the longitudinal direction of the tube or the pipe is easier than to align the round holes. Further, the holes 15a to 15c in the injecting pipe 14 may be so elongated, for instance, that through one aperture the polymer is able to flow into two or more holes 8a to 8c. If both the holes 8a to 8c and the holes 15a to 15c are elongated apertures, for instance, it is possible to reliably ensure the polymer flow from inside the injecting pipe 14 outside the frame pipe 6.

[0049] One embodiment is such that a plurality of injection structures are arranged side by side in the soil. In that case the injection may be carried out in stages, for instance, in such a manner that first material is injected into the lowermost injection element of the first injection structure and thereafter into the lowermost injection element of an adjacent injection structure etcetera, until polymer is injected into the lowermost injection element of each injection structure. Thereafter, polymer is injected in the second lowest injection element of the first injection structure and thereafter into the second lowest injection element of its adjacent injection structure etcetera. Naturally, the injecting order into the injection elements of the injection structure may also be selected in another, desired manner, for instance, on the basis of the soil or a structure to be supported thereabove.

[0050] Further, inside the frame pipe 6 it is possible to provide various compartments, each of which communicates with a different hole 8a to 8c, and by arranging the injecting pipe 14 in said compartment, or by arranging each compartment to have a specific injecting pipe 14, it is also possible to select at which location in the expansion element 7 or in which one of the injection elements 5 the polymer is injected.

[0051] Further, the provided compartment may be used as such as an injection passage without using the injecting pipe 14.

[0052] Figure 5 shows an embodiment, in which the lowermost injection element 5 of the injection structure 4 consists of a frame pipe having holes in the walls, but on the exterior of the frame pipe 6 there is not arranged an expansion element 7. Consequently, said injection element 5 passes the polymer 16 freely into the soil 2.

[0053] Further, in the embodiment of Figure 5, the structure of the two uppermost injection elements 5 is similar to the injection elements shown in Figures 1 and 2. Between the uppermost injection elements 5 there is arranged a tube having a continuous wall, i.e. a frame pipe 6 with no holes, for instance. Thus, the injection structure 4 is such that from its lowermost part it passes the polymer 16 to act on the soil 2 directly, and for the upper injection elements, the effect of the polymer 8 on soil is arranged to take place through the wall of the expansion element 7. Between the uppermost injection elements, no effect is substantially arranged on the soil with the injection structure 4. A mere closed frame pipe is thus not an injection element, because it does not have means to convey the effect of polymer on the soil, but in that case for the entire length of the frame pipe the polymer only flows in the axial direction of the pipe. The embodiment of Figure 5 is particularly well suited for anchoring solutions, for instance. In that case the injection structure 4 is attached to a structure which is to be prevented from moving.

[0054] The effect of polymer on soil may comprise e.g. consolidating, filling or replacing the soil. Further, the effect of polymer on soil may in- volve that the injection structure is to be made adhere to the soil 2 as well as possible by means of cohesion or adhesion, for instance. So, the disclosed solution may be used for consolidating, filling or replacing the soil, 2. Further, the disclosed solution may be used for lifting or balancing structures. Yet another application may be to support structures or to prevent them from moving.

[0055] The frame pipe 6 need not necessarily be so long as the entire injection element 5. The frame pipe 6 may, for instance, consist of two parts, of which the upper one is in the upper part of the injection element 5 and the lower one is in the lower part of the lower injection element 5. Further, if the injection element 5 is arranged lowermost in the injection structure, it will suffice that the frame pipe 6 is arranged in the upper part thereof.

[0056] Further, instead of the percussion tip 12, it is possible to arrange a drill bit, for instance, in the injection structure 4. In that case, the injection structure 4 makes it possible to provide a hole therefor by drilling. In this embodiment the liquid utilized in drilling may be conveyed inside the frame pipe 6.

[0057] For installing the injection structure 4 in the soil it is possible to provide in advance a hole, in which the injection structure is arranged. On the other hand, as stated above, the injection structure may be installed directly in the soil, if so desired, without separately providing a hole in advance. Further, the injection structure 4 may be installed in the soil, surrounded by a protective sleeve. In that case, when the injection structure 4 is driven in the soil, the protective sleeve is retracted therefrom prior to polymer injection.

[0058] In some cases, the features disclosed in this application may be used as such, irrespective of other features. On the other hand, when necessary, the features disclosed in this application may be combined to provide different combinations.

[0059] The drawings and the related description are only intended to illustrate the idea of the invention. The details of the invention may vary within the scope of the claims.

[0060] So, also the injection element 5 may be flexible. In that case the frame pipe 6 may be made of flexible material. On the other hand* the injection element 5 may be provided flexible also in such a manner that the frame pipe 6 does not extend throughout the entire length of the injection element. In connection with the flexible injection element it is possible to use also a flexible injecting pipe, whereby the injection structure 4 may be arranged such that it is not completely in the vertical direction, but it may be arranged to make a bend> i.er after a vertical portion to extend at least to some extent in the horizontal direction.^; The flexible injection structure may be arranged in an existing hole or one provided therefor, or it may be installed in the soil, surrounded by a protective sleeve.

[0061] At the upper end of the injection structure it is possible to provide a connection part, in which is arranged, when necessary, a haul piece in place of the striking piece shown in Figure 2, for instance. The haul piece comprises gripping members which permit the haul piece to be gripped for pulling it upwardly. The haul piece is secured to the upper end of the injection structure 4 such that by pulling the haul piece the injection structure may be retracted upwardly, when so needed.

[0062] The frame pipe of the injection structure may be arranged to consist of a plurality of pipes within one another, which in a telescopic manner are drawn from within one another to form a longer pipe. At the ends of the pipes within one another there may be a cone joint or a threaded joint or a bayonet joint or the like, by which the successive pipe sections, constituting the telescopic pipe, can be interlocked to form the final frame pipe structure.

Claims

1. An arrangement for providing an effect of a polymer on soil, c h a ra cte rized in that the arrangement includes an injection structure (4) for providing the effect of the polymer on the soil, the injection structure (4) comprising at least two injection elements (5), the injection element (5) comprising a frame pipe (6), through which the polymer is injected, and means for conveying the effect of the polymer on the soil (2), the frame pipe (6) including connection means (9) for connecting the injection element (5) to be part of the injection structure (4), whereby the injection structure (4) comprises at least two injection elements (5) interconnected on site in such a manner that the injection elements (5) included in the injection structure (4) are separately transportable to the working site.

2. The arrangement of claim 1 , c h a ra cte ri zed in that the wall of the frame pipe (6) has holes (8a to 8c), through which the polymer is able to flow.

3. The arrangement of claim 1 or 2, c h a ra cte ri ze d in that at least one injection element (5) comprises an expansion element (7) into which the polymer is injected.

4. The arrangement of any one of the preceding claims, c h a ra cte ri z ed in that the injection structure (4) comprises at least two consecutively arranged injection elements (5), each comprising an expansion element (7) into which the polymer is injected, and that the expansion elements (7) are provided to have such dimensions and arrangement that in the consecutively arranged injection elements (5) the outer surfaces of the expansion elements (7) are set to support one another, when they contain reacted polymer.

5. The arrangement of any one of the preceding claims, ch a ra cte ri zed in that the arrangement includes an injecting pipe (14) which is ar- rangeable inside the frame pipe (6) and along which the polymer is conveyable into the injection element (5).

6. The arrangement of claim 5, c h a ra cte ri ze d in that the injecting pipe (14) is closed in its lower part and holes (15a to 15c) are arranged in its walls and in the wall of the frame pipe (6) there are corresponding holes (8a to 8c), and by arranging the hole (15a to 15c) in the injecting pipe (14) in alignment with the corresponding hole (8a to 8c) in the frame pipe (6) the polymer is able to flow through said holes.

7. A method for providing an effect of a polymer on soil, c h a ra cte rized by forming a required number of injection elements (5), the injection element (5) comprising a frame pipe (6), through which the polymer is injected, and means for conveying the effect of the polymer on the soil (2), transporting the injection elements (5) to a working site, determining the length of a required injection structure (4) and assembling the injection structure (4) by interconnecting at least two injection elements on the working site and injecting the polymer through the injection structure (4) to act on the soil.

8. The method of claim 7, c h a ra cte ri zed in that the wall of the frame pipe (6) has holes (8a to 8c), through which the polymer is arranged to flow.

9. The method of claim 7 or 8, ch a ra cte ri ze d in that at least one injection element (5) comprises an expansion element (7) into which polymer is injected.

10. The method of any one of claims 7 to 9, c h a ra cte rized by conveying the polymer into the injection element (5) with the injecting pipe (14) arranged inside the frame pipe (6).