Drug injection method

Abstract

To set a direction in which a large amount of chemical is injected into the ground.SOLUTION: A chemical injection method comprises: a casing pipe process of drilling a hole in the ground G and erecting a casing pipe 50; a filling process of filling a grout material 54 into the casing pipe 50; an injection pipe process of erecting an injection pipe 100 in the casing pipe 50; a pulling-out process of pulling out the casing pipe 50 after filling with the grout material 54; and an injection process of inserting an injection packer 150 into the injection pipe 100, spraying chemical from an injection hole 112 between packer materials 152 above and below the injection packer 150 in the injection pipe 100, and fracturing one side of a grout portion 180 formed by hardening of the grout material 54 to inject the chemical 90 into the ground G.SELECTED DRAWING: Figure 1

Description

Technical Field

[0004] ,

[0001] The present invention relates to a method for injecting a chemical solution.

Background Art

[0002] In Cited Document 1, when constructing a structure below a laid track, techniques related to a ground improvement method for preventing deformation of the track and an underpass method for constructing an underground structure after implementing the ground improvement method are disclosed. In this prior art, the ground above which the track is constructed is improved. When the ground to be improved is cohesive soil, a steel pipe for cohesive soil is inserted into the ground to be improved in a substantially horizontal direction at a predetermined interval for ground improvement. When the ground to be improved is sandy soil, a directional injection steel pipe provided with injection holes capable of injecting an improving chemical solution into a predetermined range in the circumferential direction is inserted into the ground to be improved in a substantially horizontal direction at a predetermined interval, the orientation of the directional injection steel pipe is adjusted so that the injection holes are in a desired injection direction, and the improving chemical solution is injected from inside the directional injection steel pipe into the ground to be improved.

[0003] In Cited Document 2, a technique for improving the ground by injecting a ground injection material (injection chemical solution, cement milk, etc.) into the ground to be improved is disclosed. In this prior art, the ground injection device includes an injection pipe, an elastic profile covering the outer peripheral portion thereof, and a heat-shrinkable member covering the outer peripheral portion of the elastic profile. The injection pipe is provided with through holes, the elastic profile is covered from each of both ends of the injection pipe and covers the through holes, a groove extending in the longitudinal direction is formed in the outer peripheral portion of the elastic profile, and a slit is formed in the heat-shrinkable member.

[0004] Reference 3 discloses a chemical grouting device and a ground reinforcement method using the same. In this prior art, the chemical grouting device consists of an injection outer tube equipped with multiple permeable bags that bulge larger than the bore diameter at axial intervals, and an injection inner tube that can be inserted into the injection outer tube. A solidifying agent is filled into the bags from the injection inner tube to expand the bags, consolidating the surrounding ground and forming packers, and the solidifying agent is injected between these packers to inject and solidify a predetermined area. In addition, the injection ports formed in the injection outer tubes between adjacent bags are covered with flexible sleeves that have vertical slits. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2011-256611 [Patent Document 2] Japanese Patent Publication No. 2014-234671 [Patent Document 3] Japanese Patent Publication No. 2005-314938 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The injection of chemical solutions into the ground is affected by the heterogeneity of the ground and does not necessarily spread uniformly. Therefore, for example, if a large amount of chemical solution penetrates the ground on the opposite side from the side where ground improvement is desired, the amount of chemical solution injected on the one side will decrease, and the ground on that side may not be sufficiently improved. For this reason, for example, in order to ensure that the amount of chemical solution injected on one side is reliably secured, it may be necessary to increase the amount of chemical solution injected more than necessary.

[0007] In view of the above facts, the present invention aims to provide a chemical injection method that allows for setting the direction in which a large amount of chemical solution is injected into the ground. [Means for solving the problem]

[0008] The first embodiment is a chemical injection method comprising: a casing pipe step of drilling a hole in the ground and installing a casing pipe; a filling step of filling the casing pipe with grout material; an injection pipe step of installing an injection pipe in the casing pipe; an extraction step of pulling out the casing pipe after filling with grout material; and an injection step of inserting an injection packer into the injection pipe, spraying a chemical solution from an ejection hole between the upper and lower packer materials constituting the injection packer in the injection pipe, crushing one side of the grout portion formed by the hardening of the grout material, and injecting the chemical solution into the ground.

[0009] In the first embodiment of the chemical injection method, one side of the grout section formed by the hardening of the grout material is crushed and the chemical is injected into the ground, so that a larger amount of chemical is injected on one side.

[0010] The second embodiment is the ground improvement method according to the first embodiment, wherein in the injection step, the chemical solution is ejected from the ejection hole provided only on one side between the upper and lower packer materials in the injection pipe.

[0011] In the second embodiment of the chemical injection method, the chemical is injected by ejecting the chemical from an ejection hole provided only on one side between the upper and lower packer materials constituting the injection packer in the injection pipe, thereby crushing one side of the grout section.

[0012] The third embodiment is a ground improvement method according to the first or second embodiment, wherein the injection pipes are installed in series parallel to the wall surface of the underground exterior wall, and a watertight wall is constructed with one side of the grout section facing the wall surface.

[0013] In the third embodiment of the chemical injection method, a large amount of chemical solution is injected into the underground structure, thus preventing or suppressing the formation of a gap between the watertight wall and the underground exterior wall. [Effects of the Invention]

[0014] According to the present invention, it is possible to set the direction in which a large amount of chemical solution is injected into the ground. [Brief explanation of the drawing]

[0015] [Figure 1] It is a process diagram showing the process of injecting a chemical solution. [Figure 2] It is a longitudinal sectional view schematically showing a state in which the grout material in Fig. 1(E) has hardened and the grout portion has been constructed. [Figure 3] (A) schematically showing the main part of the first embodiment is a longitudinal sectional view along the axial direction, and (B) is a horizontal sectional view orthogonal to the axial direction. [Figure 4] It is a longitudinal sectional view for explaining a method of fixing a rubber material. [Figure 5] It is a longitudinal sectional view along the axial direction corresponding to Fig. 3(A) schematically showing the main part of the second embodiment. [Figure 6] It is a horizontal sectional view schematically showing the construction of the water barrier of the first embodiment. [Figure 7] It is a horizontal sectional view schematically showing the construction of the water barrier of the second embodiment. [Figure 8] It is a horizontal sectional view schematically showing the construction of the water barrier of the third embodiment. [Figure 9] It is a horizontal sectional view schematically showing a method of filling the joint portion between the existing water barrier and the newly constructed water barrier of the fourth embodiment. [Figure 10] (A) is a horizontal sectional view schematically showing the construction of the water barrier of the fifth embodiment, and (B) is a longitudinal sectional view. [Figure 11] (A) is a horizontal sectional view schematically showing the construction of the water barrier of the sixth embodiment, and (B) is a longitudinal sectional view. [Figure 12] (A) is a longitudinal sectional view schematically showing the construction of the water barrier of the seventh embodiment, (B) is a horizontal sectional view along line 12B - 12B of (A), and (C) is a horizontal sectional view along line 12C - 12C of (A). [Figure 13] It is an explanatory diagram for explaining a state in which two injection pipes are crossed and built in. [Figure 14] It is a horizontal sectional view of a grout portion in which a thin portion is formed. [Figure 15] In the case of using a general injection pipe, (A) is a longitudinal sectional view, and (B) is a horizontal sectional view of (A). [Figure 16] This is an explanatory diagram illustrating one side of the grouted area. [Modes for carrying out the invention]

[0016] <First Embodiment> A first embodiment of the present invention, a method for injecting a drug solution, will be described.

[0017] [Injection tube] The structure of the injection pipe in this embodiment will now be described. Except for the part where the ejection hole is provided (described later), the injection pipe has the same configuration as a typical commercially available injection pipe.

[0018] As shown in Figures 3(A) and 3(B), the injection pipe 100 (see also Figures 1(C) to 1(G) and Figure 2) has multiple ejection holes 112 in its peripheral wall 110. The ejection holes 112 are provided only on one side (the left side in the figure) when viewed in the axial direction.

[0019] Specifically, as shown in Figure 3(B), two ejection holes 112 are provided at an angle of approximately 90° in a cross-section perpendicular to the axial direction. Also, as shown in Figure 3(A), multiple ejection holes 112 are provided in a row with intervals in the axial direction. Although Figure 3(A) shows two locations, in reality, three or more ejection holes 112 are formed with predetermined intervals in the axial direction.

[0020] A cylindrical rubber material 120 is wrapped around the outside of the portion of the circumferential wall 110 of the injection pipe 100 where the ejection holes 112 are provided. The rubber material 120 is attached in a way that prevents it from falling off the circumferential wall 110. The attachment structure for the rubber material 120 to the circumferential wall 110 is the same as that of a typical injection pipe. In this embodiment, as shown in Figure 4, the rubber material 120 is attached by fitting it into a groove 111 formed in the circumferential wall 110, but it is not limited to this. Although not shown in the figures, for example, a structure in which the rubber material 120 is attached to the circumferential wall 110 by joining ring materials to the top and bottom of the rubber material 120 to prevent slippage, or a structure in which the upper end of the rubber material 120 is sandwiched between ring materials for attachment, may also be used.

[0021] Here, as shown in Figures 15(A) and 15(B), the peripheral wall 110 of a commercially available general injection pipe 900 has four ejection holes 112 provided at equal intervals of 90° in a cross section perpendicular to the axial direction.

[0022] In contrast, as shown in Figure 3(B), the injection pipe 100 of this embodiment has two ejection holes 112 at an angle of approximately 90°, as described above. In this embodiment, of the four ejection holes 112 formed in the peripheral wall 110 of a commercially available general injection pipe 900 shown in Figure 15(B), two adjacent holes (the two on the right in this example) are blocked by a plug member 115 as shown in Figure 3(B), but the embodiment is not limited to this. For example, a structure in which only two ejection holes 112 are formed from the beginning is also possible.

[0023] In this embodiment, the injection pipe 100 is adjusted so that the combined opening area of ​​the two ejection holes 112 is the same as the combined opening area of ​​the four ejection holes 112 of the injection pipe 900, but it is not limited to this.

[0024] As mentioned above, the injection pipe 100 of this embodiment shown in Figure 3 has an ejection hole 112 on only one side (the left side in the figure). "One side" refers to the semicircular portion on side A or B of the center line C in a cross-section perpendicular to the axial direction, as shown in Figure 16.

[0025] [Method of drug injection] Next, an example of the chemical injection method according to this embodiment will be described. Note that it is not necessary to perform the procedure in the order described below. Modifications may be made as appropriate depending on the circumstances.

[0026] As shown in Figure 1(A), the drilling device 10 drills into the ground G while installing the casing pipe 50 into the ground G. Reference numeral 20 denotes the drilled hole. As shown in Figure 1(B), grout material 54 such as cement bentonite (see Figure 2) is injected into the casing pipe 50.

[0027] As shown in Figure 1(C), an injection pipe 100 (see also Figures 2 and 3) is installed inside a casing pipe 50 filled with grout material 54 (see Figure 2). As shown in Figure 1(D), the casing pipe 50 is withdrawn while leaving the injection pipe 100 in place before the grout material 54 has finished hardening.

[0028] As shown in Figure 1(E), after the grout material 54 has hardened, the injection packer 150 is inserted into the injection pipe 100. The state in which the grout material 54 has hardened and become cylindrical is referred to as the grout section 180 (see also Figures 2 and 3).

[0029] As shown in Figures 1(F) and 1(G), the chemical solution 90 is supplied from a supply device (not shown) while the injection packer 150 is being raised, and the chemical solution 90 is injected into the ground G. The chemical solution 90 is ejected from the ejection holes 112 (see Figure 3) provided in the peripheral wall 110 of the injection pipe 100, crushing the grout section 180 (see Figures 2(D) and 3) and being injected into the ground G. Reference numeral 92 in Figure 1(G) indicates the area where the chemical solution 90 has permeated. The chemical solution 90 may also be injected while the injection packer 150 is being inserted.

[0030] The chemical solution 90 in this embodiment is an injection material that is injected into the ground G and then solidifies to improve the ground. Specifically, it is a grout classified into chemical-based grouts such as water glass and non-chemical-based grouts such as cement and clay. Note that even if "chemical solution 90" is mentioned in the following description, the reference numeral 90 may not be assigned to it in the drawings. In other words, there are drawings in which the reference numeral 90 is omitted.

[0031] Furthermore, Figure 1(F) shows the primary injection, and Figure 1(G) shows the secondary injection. In the primary injection, cement bentonite and other materials may also be injected in addition to chemical solution 90. Generally, the ground is heterogeneous because it is composed of layers with different particle sizes and permeability. Therefore, in the primary injection shown in Figure 1(F), chemical solution 90 and bentonite are injected to roughly fill the water channels and voids in the ground. This prevents the leakage of chemical solution 90 during the secondary injection shown in Figure 1(G).

[0032] The injection packer 150 in this embodiment has the same structure as existing ones. The injection packer 150 uses a double packer structure in which the chemical solution 90 is injected into the ground G from between the upper and lower packer materials 152 of the injection packer 150 (see Figure 2).

[0033] Simply put, by keeping the packer material 152 in a deflated state, it can be moved inside the injection pipe 100. On the other hand, by keeping the packer material 152 in an expanded state, it adheres tightly to the inner wall 100A of the injection pipe 100 (see Figure 2).

[0034] Then, by injecting the chemical solution 90 between the upper and lower packer materials 152 in this state, the chemical solution 90 is ejected from the ejection hole 112 of the injection pipe 100 located between the upper and lower packer materials 152, as shown in Figure 3(A). At this time, as indicated by arrow K2, the chemical solution 90 is ejected from both the top and bottom of the rubber material 120. Note that in Figure 3(A), for clarity, only the packer material 152 of the injection packer 150 is shown with dashed lines (double-dotted lines).

[0035] As shown in Figures 3(A) and 3(B), the injection pipe 100 in this embodiment has an ejection hole 112 on only one side (the left side in the figure). Therefore, when the chemical solution 90 is ejected from the ejection hole 112 and crushes the grout section 180, one side of the grout section 180 (the left side in the figure) is crushed, and the chemical solution 90 is mainly injected into the ground G on that side (the left side in the figure). In other words, a large amount of the chemical solution 90 is injected in the direction of K1.

[0036] In Figure 3(B), the symbol 95 indicates a crack formed by fracture. In the figure, only one crack 95 is formed for each ejection hole 112, but in reality, multiple cracks 95 are often formed.

[0037] Furthermore, even if only one side of the grout section 180 (the left side in the diagram) is crushed, the chemical solution 90 will also penetrate in the opposite direction to the one side (K1 direction) as it is injected into and permeates the ground G (see Figure 6).

[0038] [Effect] Next, the operation of this embodiment will be described.

[0039] As mentioned above, the injection pipe 100 in this embodiment has an ejection hole 112 on only one side. Therefore, when the chemical solution 90 is ejected from the ejection hole 112 of the injection pipe 100 and crushes the grout section 180, one side of the grout section 180 is crushed, and the chemical solution 90 is mainly injected into the ground on that side.

[0040] In other words, it is possible to set a direction (arrow K1) for injecting a large amount of chemical solution 90 into the ground G. From another perspective, it is possible to give directionality to the injection of chemical solution 90.

[0041] <Second Embodiment> A second embodiment of the present invention, a method for injecting a drug solution, will now be described. Note that components similar to those in the first embodiment are denoted by the same reference numerals, and redundant explanations are omitted or simplified.

[0042] [Injection tube] The structure of the injection pipe in this embodiment will now be described. The injection pipe has the same configuration as in the first embodiment, except for the portion where the ejection port is provided.

[0043] As shown in Figure 5, the injection holes 112 of the injection pipe 200 are formed in a row with spacing in the axial direction. A cylindrical rubber material 120 is wrapped around the outside of the peripheral wall 110 of the injection pipe 100 where the injection holes 112 are formed.

[0044] In this embodiment, the injection pipe 200 has portions where the ejection holes 112 are provided only on one side (the left side in Figure 5) (the portion where the lower ejection holes 112 are provided in Figure 5) and portions where the ejection holes 112 are formed only on the other side (the right side in Figure 5) (the portion where the upper ejection holes 112 are provided in Figure 5), which are alternately provided in the axial direction.

[0045] [Method of drug injection] Next, an example of the chemical injection method in this embodiment will be described. Note that, as in this embodiment, the procedure is carried out according to the construction procedure shown in Figure 2, so only the essential parts will be explained.

[0046] When the chemical solution 90 is ejected from the ejection hole 112 of the injection pipe 200 and crushes the grout section 180 (see Figures 2(D) and 3), the grout section 180 is crushed and the chemical solution 90 is injected into the ground G.

[0047] At this time, by positioning the injection pipe 200 so that the ejection hole 112 is formed only on one side (the left side in Figure 5) between the upper and lower packer materials 152 of the injection packer 150, one side of the grout section 180 is crushed, and the chemical solution 90 is mainly injected into the ground G on that side.

[0048] Furthermore, by positioning the space between the upper and lower packer materials 152 of the injection packer 150 to the area where the ejection hole 112 of the injection pipe 200 is formed only on the other side, the other side of the grout section 180 is crushed, and the chemical solution 90 is mainly injected into the ground G on the other side.

[0049] Therefore, by adjusting the depth of the injection packer 150, it is possible to select whether to inject the drug solution 90 to one side or to inject the drug solution 90 to the other side.

[0050] [Effect] Next, the operation of this embodiment will be described.

[0051] The injection pipe 200 of this embodiment has both a portion where the ejection hole 112 is formed on one side and a portion where the ejection hole 112 is formed on the other side. Therefore, the direction in which the grout portion 180 is crushed and the chemical solution 90 is injected into the ground G can be selected from one side or the other.

[0052] In other words, it is possible to select a direction (arrow K1) that allows for a larger injection of the chemical solution 90 into the ground G. From another perspective, it is possible to select a direction that provides directionality.

[0053] In this embodiment, for the sake of clarity, we have used the terms "one side" and "the other side" in our explanation. However, even in the case of "the other side," the process is "an injection process in which the chemical solution is ejected from the ejection hole between the upper and lower packer materials in the injection pipe to crush one side of the grout section and inject the chemical solution into the ground."

[0054] <Examples> Next, we will describe an example in which construction is carried out by setting a direction to inject a large amount of chemical solution 90 into the ground G using either the chemical solution injection method of the first embodiment or the chemical solution injection method of the second embodiment. In the first, second, third, and fourth embodiments described later, either the injection pipe 100 of the injection method of the first embodiment or the injection pipe 200 of the injection method of the second embodiment may be used, but for convenience, we will describe using the injection pipe 100 of the first embodiment.

[0055] Furthermore, in the embodiments described later, the same reference numerals are used for parts identical to those described earlier, and redundant explanations are omitted or simplified.

[0056] [First Example] This section describes a first embodiment of constructing a watertight wall by injecting a chemical solution into the ground at intervals.

[0057] As shown in Figure 6, a watertight wall 500 is constructed by injecting chemical solution 90 from injection pipes 900 installed in series and injection pipes 100 of the first embodiment's chemical injection method installed in series, and allowing them to harden. The row of injection pipes 900 is designated as row 400, and the row of injection pipes 100 is designated as row 300. In Figure 6, other components besides injection pipes 100 and 900, such as the grout section 180, are not shown.

[0058] In a plan view, the injection tube 900 in row 400 and the injection tube 100 in row 300 are arranged alternately. The direction K1, from which a large amount of drug solution 90 is injected from the injection tube 100 in row 300, is directed between the two injection tubes 900 in row 400.

[0059] In row 400, due to the non-uniformity of the ground G, there is a risk that the injection range 92 of the chemical solution 90 will vary randomly. Therefore, in the example in Figure 7, gaps 503 are created. Note that in Figure 7 and Figure 8 described later, the thick lines extending from the injection pipe 900 in the area 92 where the chemical solution 90 has penetrated represent the parts of the ground G where the chemical solution 90 is more likely to penetrate.

[0060] In this embodiment, in the first embodiment of the drug injection method in row 300, the direction K1, where a large amount of drug solution 90 is injected, is oriented between the injection tubes 900 in row 400. Therefore, the drug solution 90 is injected into the gap 503.

[0061] Therefore, no gaps are formed or are unlikely to form in the area 92 into which the chemical solution 90 is injected; in other words, no gaps are formed or are unlikely to form in the constructed watertight wall 500.

[0062] In this case, if a watertight wall is constructed using only the injection pipe 900, a large amount of chemical solution 90 needs to be injected to prevent the formation of gaps 503 or to fill any gaps 503. However, as described above, by using the chemical solution injection method of the first embodiment, it is possible to construct a watertight wall 500 while reducing the amount of chemical solution 90 injected.

[0063] [Second Example] A second embodiment will be described, in which a watertight wall is constructed by injecting a chemical solution into the ground at intervals.

[0064] As shown in Figure 7, rows 300 of injection tubes 100 for the drug injection method of the first embodiment are arranged on both sides of row 400 of injection tubes 900.

[0065] The injection tube 900 in row 400 and the injection tube 100 in row 300 are arranged alternately. Also, the direction K1, from which a large amount of drug solution 90 is injected from the injection tube 100 in row 300, is directed between the two injection tubes 900 in row 400.

[0066] Therefore, compared to the first embodiment, no gaps are formed or are less likely to form in the area where the chemical solution 90 is injected; in other words, no gaps are formed or are less likely to form in the constructed watertight wall 510.

[0067] [Third Example] A third embodiment will be described, in which a watertight wall is constructed by injecting a chemical solution into the ground at intervals.

[0068] As shown in Figure 8, a watertight wall 520 is constructed in one row of the row 302 of injection pipes 100 in the first embodiment of the chemical injection method. The K1 direction, in which a large amount of chemical solution 90 is injected into the injection pipe 100, is directed toward the adjacent injection pipe 100 and is in the same direction.

[0069] Therefore, no gaps are created or are unlikely to be created in the area 92 into which the chemical solution 90 is injected; in other words, no gaps are formed in the constructed impermeable wall 520 or gaps are unlikely to be formed. From another perspective, the impermeable wall 520 can be constructed while reducing the amount of chemical solution 90 injected.

[0070] [Fourth Example] This section describes an example of injecting a chemical solution into the joint between an existing watertight wall constructed adjacent to the underground structure and a newly constructed watertight wall that was added as an extension.

[0071] As shown in Figure 9, the existing impermeable wall 700, constructed adjacent to the underground outer wall 602 of the underground structure 600, and the newly added impermeable wall 702 are constructed using a soil-cement column-type continuous wall construction method. Reference numeral 710 denotes an H-shaped steel beam, and reference numeral 712 denotes a soil-cement column 712.

[0072] In the first embodiment of the chemical injection method, the injection pipe 100 is installed on the outside of the joint 704 between the existing impermeable wall 700 and the newly constructed impermeable wall 702, and the chemical solution 90 is injected toward the joint 704. Therefore, the chemical solution 90 is effectively injected into and fills the joint 704 between the two walls. From another perspective, the joint 704 between the two walls can be filled while reducing the amount of chemical solution 90 injected.

[0073] [Fifth Example] A fifth embodiment will be described in which a watertight wall is constructed adjacent to the underground exterior wall of the underground structure.

[0074] As shown in Figure 10(A), the injection pipes 200 of the second embodiment of the chemical injection method are installed in series parallel to the wall surface 602A of the underground outer wall 602 of the underground structure 600 to construct the watertight wall 530.

[0075] As shown in Figure 10(B), the lower end of the injection pipe 200 is embedded in the poorly permeable layer GA, such as a clay layer, in the ground G. Below the injection pipe 200, the chemical solution 90 is injected into the ground G on both sides (left side in the figure and right side in the figure). The symbol S indicates the groundwater level.

[0076] Then, in the injection pipe 200, from the vicinity of the base slab 604 of the underground structure 600 upwards, the chemical solution 90 is injected into the ground G only on the other side (right side in the diagram). By injecting in this manner, a gap is not formed between the underground outer wall 602 and the impermeable wall 530, or a gap is less likely to form. To explain from another perspective, the amount of chemical solution 90 injected can be reduced while constructing an impermeable wall 530 that fills the gap between the underground outer wall 602 and the impermeable wall 530.

[0077] [Sixth Embodiment] A sixth embodiment will be described in which a watertight wall is constructed on the lower side of the underground outer wall and base of the underground structure.

[0078] As shown in Figures 11(A) and 11(B), the watertight wall 632 is constructed by a row 300 of injection pipes 200 of the second embodiment of the chemical injection method, which are installed in series parallel to the underground outer wall 602 of the underground structure 600, and a row 302 of injection pipes 302 that are inserted and installed through insertion holes 603 formed in the base plate 604. Note that the symbol L is a parallel line located at a predetermined distance from the underground outer wall 602.

[0079] The lower end of each injection pipe 200 is embedded in a poorly permeable layer GA, such as a clay layer. Then, the chemical solution 90 is injected into the ground G from the injection pipe 200 of row 300 to the other side (right side in the diagram), and the chemical solution 90 is injected into the ground G from the injection pipe 100 of row 302 to one side (left side in the diagram).

[0080] By injecting in this manner, no gaps are formed in the impermeable wall 632, or gaps are less likely to be formed, and no gaps are formed between the underground structure 600 and the impermeable wall 632, or gaps are less likely to be formed. From another perspective, it is possible to construct an impermeable wall 532 that fills the gap between the underground structure 600 and the impermeable wall 632 while reducing the amount of chemical solution 90 injected.

[0081] [Seventh Example] A seventh embodiment, in which a watertight wall is constructed by injecting a chemical solution into the ground at intervals, will be described.

[0082] As shown in Figure 12, a watertight wall 502 is constructed by injecting and curing chemical solution 90 from a row 400 constructed with injection pipes 900 and a row 300 of injection pipes 200 according to the chemical solution injection method of the second embodiment.

[0083] First, measure the inclination of injection pipe 900 and injection pipe 200. Any method can be used to measure the inclination. For example, one method is to measure the inclination of the casing pipe 50 using an inclinometer before installing injection pipes 100 and 900, or to measure the inclination of injection pipes 200 and 900 using a geomagnetic meter.

[0084] In this example, as shown in Figure 13, the injection pipe 900 is installed at an angle, the injection pipe 100 is installed vertically, and the injection pipes 900 and 200 intersect. "Intersection" refers to a side view in the direction of the rows 300 and 302. The point where they intersect is referred to as the intersection 910. In the example shown, below the intersection 910 of the injection pipe 200, the injection pipe 900 is on the left side of the figure, and above the intersection 910, the injection pipe 900 is on the right side of the figure.

[0085] Therefore, as shown in Figures 12(A) and 12(C), the chemical solution 90 is injected from the lower side of the injection pipe 200 toward the left side of the figure, and from the upper side of the injection pipe 100 toward the right side of the injection pipe 200 in the figure. In addition, at depths near the intersection 910, the chemical solution 90 may be sprayed alternately to the left and right sides.

[0086] Any method can be used to determine the depth of the intersection 910 where the injection pipe 900 and the injection pipe 200 intersect, that is, the depth at which the direction of directivity is switched. For example, the relationship between the amount of misalignment between the injection pipe 900 and the injection pipe 200 and the depth can be determined from the inclination angles of the injection pipes 900 and 200, and the point where this amount of misalignment becomes 0 can be defined as the intersection 910.

[0087] By injecting in this manner, even if the injection pipe 900 and the injection pipe 200 intersect, no gaps are created or are unlikely to be created in the area 92 into which the chemical solution 90 is injected; in other words, no gaps are formed or are unlikely to be formed in the constructed impermeable wall 502. To explain from another perspective, the impermeable wall 502 can be constructed while reducing the amount of chemical solution 90 injected.

[0088] <Other> The present invention is not limited to the embodiments and examples described above.

[0089] For example, in the above embodiment, the chemical solution 90 was injected into the ground G by ejecting the chemical solution 90 from an ejection hole 112 provided only on one side between the upper and lower packer materials 152 of the injection packer 150 in the injection pipes 100 and 200, thereby crushing one side of the grout section 180 formed by the hardening of the grout material 54. However, the embodiment is not limited to this.

[0090] For example, as shown in Figure 14, the grout material 54 may be hardened with the casing pipe 50 (see Figure 1) and the injection pipe 900 close together to form a thin-walled section 182 and a thick-walled section 184 in the grout section 180, so that the thin-walled section 182 side (one side) is crushed and the chemical solution 90 is injected into the ground G. In this case, the injection pipe 900 may be installed before filling the casing pipe 50 with the grout material 54.

[0091] Furthermore, in the second embodiment described above, for example, the two directions in which the drug solution 90 can be injected with directionality are alternately provided in the axial direction, but the invention is not limited to this. For example, the direction in which the drug solution 90 is injected may be changed between the upper half and the lower half of the injection tube.

[0092] Furthermore, for example, in the second embodiment described above, the two directions from which the liquid drug 90 can be injected with directionality were opposite to each other, meaning the angle between the two directions was 180°, but this is not limited to this. For example, the angle between the two directions from which the liquid drug 90 can be injected with directionality may be 90°. Specifically, a section with only the two ejection holes 112 on the left side of Figure 15(B) and a section with only the two ejection holes 112 on the upper side of the figure may be provided.

[0093] Furthermore, for example, in the above embodiment, there were two ejection holes 112 between the upper and lower packer materials 152 in the injection pipes 100 and 200, but this is not limited to this. There may be two or more ejection holes 112 between the upper and lower packer materials 152, or there may be just one.

[0094] Furthermore, while the above embodiment was applied to the construction of watertight walls 500, 502, 510, 520, 530, and 532 or to the filling of the chemical solution 90 into the joint portion 704, the invention is not limited to these applications. For example, the present invention can also be applied to watertight reinforcement of cracked portions of retaining walls. [Explanation of Symbols]

[0095] 50 Casing pipes 54 Grout material 90 chemical solutions 100 injection tube 112 Spout hole 150 Injection Packers 152 Packer material 180 Grout section 200 injection tube 602 Underground outer wall 602A Wall 530 Impermeable wall 900 injection tube G Ground

Claims

1. The casing pipe process involves drilling holes in the ground and installing casing pipes, A filling step of filling the casing pipe with grout material, The injection pipe process involves installing an injection pipe inside the casing pipe, The extraction process involves removing the casing pipe, An injection step comprising: inserting an injection packer into the injection pipe; ejecting a chemical solution from an ejection hole between the upper and lower packer materials constituting the injection packer in the injection pipe; crushing one side in the circumferential direction of the cylindrical grout portion formed by the hardening of the grout material and injecting the chemical solution into the ground; A drug injection method comprising the following features.

2. A casing pipe process in which a hole is drilled in the ground and a casing pipe is erected, The injection pipe process involves installing an injection pipe inside the casing pipe, A filling step of filling the casing pipe with grout material, The extraction process involves removing the casing pipe, An injection step comprising: inserting an injection packer into the injection pipe; ejecting a chemical solution from an ejection hole between the upper and lower packer materials constituting the injection packer in the injection pipe; crushing one side in the circumferential direction of the cylindrical grout portion formed by the hardening of the grout material and injecting the chemical solution into the ground; A drug injection method comprising the following features.

3. In the injection step, the chemical solution is ejected from the ejection hole provided only on one side between the upper and lower packer materials in the injection pipe. A drug injection method according to claim 1 or claim 2.

4. The injection pipes are installed in series parallel to the wall surface of the underground exterior wall, and a watertight wall is constructed with one side of the grout section facing the wall surface. A drug injection method according to claim 1 or claim 2.

5. The injection pipe is installed at an eccentric position with respect to the center of the casing pipe, By hardening the grout material, the grout portion is formed with a thin-walled portion where the thickness between the injection pipe and the outer surface of the grout portion is small, and a thick-walled portion where the thickness between the injection pipe and the outer surface of the grout portion is large. In the injection step, the thin-walled portion is crushed and the chemical solution is injected into the ground. A drug injection method according to claim 1 or claim 2.

6. The injection pipe is the first injection pipe, The injection pipe that ejects the chemical solution from multiple ejection holes provided in multiple directions, including one side and the other side, between the upper and lower packer materials is designated as the second injection pipe. In a plan view, the second injection pipes are installed in series, and the first injection pipes are installed in series alternately with the second injection pipes. A watertight barrier is constructed between adjacent second injection pipes so that the direction in which a large amount of the chemical solution is injected from the first injection pipe is directed. A drug injection method according to claim 1 or claim 2.

7. The injection pipe alternately has in the axial direction a first portion in which the ejection holes are provided only on the first direction side in the circumferential direction, and a second portion in which the ejection holes are provided only on the second direction side opposite to the first direction side in the circumferential direction, By moving the injection packer in the axial direction, it is possible to select between the ejection of the liquid chemical from the ejection hole of the first part and the ejection of the liquid chemical from the ejection hole of the second part. With the first direction side facing the wall surface of the underground outer wall of the underground structure, the injection pipes are installed in series parallel to the wall surface. In the injection process, In the injection pipe, below the base of the underground structure, the chemical solution is ejected from the ejection holes of the first section and the ejection holes of the second section, respectively. In the upper part of the base plate portion of the injection tube, the liquid chemical is ejected from the ejection hole of the first portion. A drug injection method according to claim 1 or claim 2.

8. The injection pipe alternately has in the axial direction a first portion in which the ejection holes are provided only on the first direction side in the circumferential direction, and a second portion in which the ejection holes are provided only on the second direction side opposite to the first direction side in the circumferential direction, By moving the injection packer in the axial direction, it is possible to select between the ejection of the liquid chemical from the ejection hole of the first part and the ejection of the liquid chemical from the ejection hole of the second part. With the aforementioned first direction side facing the wall surface of the underground outer wall of the underground structure, the injection pipes are installed in series parallel to the wall surface to form the first row. The injection pipe is inserted through an insertion hole formed in the base of the underground structure, and the injection pipe is erected with the first row side facing the second direction side to form a second row. In the injection process, With respect to the injection tubes in the first row, the liquid chemical is ejected from the ejection holes in the first portion. With respect to the injection tubes in the second row, the liquid chemical is ejected from the ejection holes in the second portion. A drug injection method according to claim 1 or claim 2.

Images