JP2024037500A - Chemical injection method - Google Patents

Abstract

[Problem] To set the direction in which a large amount of chemical solution is injected into the ground.
[Solution] A chemical injection method includes a casing pipe step in which a hole is drilled in the ground G and a casing pipe 50 is built in, a filling step in which grout material 54 is filled in the casing pipe 50, and an injection pipe 100 in the casing pipe 50. an injection pipe step in which the casing pipe 50 is pulled out after being filled with the grout material 54; and an injection pipe step in which the injection packer 150 is inserted into the injection pipe 100 to cause ejection between the packer materials 152 above and below the injection packer 150 in the injection pipe 100. The method includes an injection step of spouting the chemical liquid from the hole 112, crushing one side of the grout portion 180 formed by hardening the grout material 54, and injecting the chemical liquid 90 into the ground G.
[Selection diagram] Figure 1

Description

The present invention relates to a liquid drug injection method.

Cited document 1 describes a ground improvement method to prevent deformation of the track when constructing a structure below the laid track, and an underground structure in which an underground structure is constructed after implementing the ground improvement method. Technology related to the path construction method is disclosed. This prior art improves the ground on which the tracks are built. If the ground to be improved is cohesive soil, steel pipes for cohesive soil are inserted into the ground to be improved approximately horizontally at predetermined intervals to improve the ground, and if the ground to be improved is sandy soil, steel pipes for cohesive soil are inserted into the ground to be improved in a predetermined range in the circumferential direction. A steel pipe for directional injection equipped with an injection hole through which an improvement chemical can be injected is inserted into the ground to be improved approximately horizontally at a predetermined interval, so that the injection hole is in the desired injection direction. Adjust the direction of the directional injection steel pipe and inject the improvement chemical solution from inside the directional injection steel pipe into the ground to be improved.

Cited Document 2 discloses a technique for improving the ground by injecting a ground injection material (injection chemical solution, cement milk, etc.) into the ground to be improved. In this prior art, the ground injection device includes an injection pipe, an elastic profile covering the outer periphery of the injection pipe, and a heat-shrinkable member covering the outer periphery of the elastic profile. The injection tube is provided with a through hole, and the elastic material is placed over each end of the injection tube and covers the through hole, and the elastic material has a groove extending in the longitudinal direction on its outer periphery. A slit is formed in the heat-shrinkable member.

Cited Document 3 discloses a technology regarding a chemical liquid injection device and a ground strengthening method using the same. In this prior art, the chemical liquid injection device includes an injection outer tube that is equipped with a plurality of water-permeable bags that are spaced apart in the axial direction and bulges larger than the diameter of the drilled hole, and an injection inner tube that can be inserted into the injection outer tube. The solidifying material is filled into the bag from this inner injection pipe, and the bag is expanded to consolidate the surrounding ground and form a packer, and the solidifying material is injected between the packers to inject the specified area. solidify. Furthermore, the injection port formed in the outer injection tube between adjacent bags is covered with a flexible sleeve provided with a vertical slit.

Japanese Patent Application Publication No. 2011-256611 Japanese Patent Application Publication No. 2014-234671 Japanese Patent Application Publication No. 2005-314938

Injection of chemical solutions into the ground depends on the heterogeneity of the ground and may not necessarily spread uniformly. Therefore, for example, if a large amount of chemical solution permeates into the ground on the other side opposite to the desired one side where the ground improvement is desired, the amount of chemical solution injected on one side will decrease, and there is a risk that the ground on the same side will not be sufficiently improved. There is. Therefore, for example, in order to reliably secure the amount of medical fluid injected in one direction, it is necessary to take measures such as increasing the amount of chemical fluid injected more than necessary.

In view of the above-mentioned facts, it is an object of the present invention to provide a chemical liquid injection method that can set the direction in which a large amount of chemical liquid is injected into the ground.

A first aspect includes a casing pipe step of drilling a hole in the ground and erecting a casing pipe, a filling step of filling the casing pipe with grout material, an injection pipe step of erecting an injection pipe into the casing pipe, and the above-mentioned. After filling the grout material, a drawing step of pulling out the casing pipe, inserting an injection packer into the injection pipe, and spouting a chemical solution from an injection hole between upper and lower packer materials forming the injection packer in the injection pipe, This chemical injection method includes an injection step of crushing one side of a grout portion formed by hardening the grout material and injecting the chemical into the ground.

In the chemical liquid injection method of the first aspect, one side of the grout portion formed by hardening the grout material is crushed and the chemical liquid is injected into the ground, so that a large amount of the chemical liquid is injected into one side.

A second aspect is the ground improvement method according to the first aspect, wherein in the injection step, the chemical solution is jetted from the jet hole provided only on one side between the upper and lower packer materials in the injection pipe. .

In the chemical injection method of the second aspect, by spouting the chemical from the injection hole provided only on one side between the upper and lower packer materials that constitute the injection packer in the injection pipe, one side of the grout portion is crushed and the chemical is injected. is injected.

A third aspect is the method according to the first aspect or the second aspect, in which the injection pipe is built in series in parallel with the wall surface of the underground outer wall, and a water-shielding wall is constructed with one side of the grout portion facing the wall surface. This is a ground improvement method.

In the chemical liquid injection method of the third aspect, since a large amount of the chemical liquid is injected into the underground framework side, the formation of a gap between the water-blocking wall and the underground outer wall is prevented or suppressed.

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.

FIG. 3 is a process diagram showing a step of injecting a chemical solution. FIG. 2 is a vertical cross-sectional view schematically showing a state in which the grout material in FIG. 1(E) is hardened and a grout part is constructed. (A) schematically showing main parts of the first embodiment is a vertical cross-sectional view along the axial direction, and (B) is a horizontal cross-sectional view perpendicular to the axial direction. FIG. 3 is a longitudinal cross-sectional view for explaining a method of fixing a rubber material. FIG. 4 is a vertical cross-sectional view along the axial direction corresponding to FIG. 3(A) schematically showing main parts of the second embodiment. FIG. 3 is a horizontal cross-sectional view schematically showing construction of a water-blocking wall according to the first embodiment. FIG. 7 is a horizontal cross-sectional view schematically showing construction of a water-blocking wall according to a second embodiment. FIG. 7 is a horizontal cross-sectional view schematically showing construction of a water-blocking wall according to a third embodiment. FIG. 7 is a horizontal sectional view schematically showing a method of filling the joint between an existing impermeable wall and a newly installed impermeable wall in the fourth embodiment. (A) is a horizontal cross-sectional view schematically showing construction of a water-blocking wall according to the fifth embodiment, and (B) is a vertical cross-sectional view. (A) is a horizontal cross-sectional view schematically showing construction of a water-blocking wall according to the sixth embodiment, and (B) is a vertical cross-sectional view. (A) is a vertical cross-sectional view schematically showing construction of a water-shielding wall according to the seventh embodiment, (B) is a horizontal cross-sectional view taken along line 12B-12B in (A), and (C) is a horizontal cross-sectional view along line 12B-12B of (A). FIG. 3 is a horizontal cross-sectional view taken along line 12C-12C in (A). It is an explanatory view explaining a state where two injection pipes are built in such a way that they intersect. FIG. 3 is a horizontal cross-sectional view of a grout portion in which a thin wall portion is formed. (A) is a longitudinal sectional view when a general injection tube is used, and (B) is a horizontal sectional view of (A). It is an explanatory view for explaining one side of a grout part.

<First embodiment>
A liquid medicine injection method according to the first embodiment of the present invention will be described.

[Injection tube]
The structure of the injection tube of this embodiment will be explained. The injection tube has the same structure as a commercially available general injection tube except for a portion where a jet hole, which will be described later, is provided.

As shown in FIGS. 3(A) and 3(B), the injection pipe 100 (see also FIGS. 1(C) to 1(G) and FIG. 2) has a plurality of ejection holes 112 provided in the peripheral wall 110. ing. The ejection hole 112 is provided only on one side (left side in the figure) when viewed in the axial direction.

Specifically, as shown in FIG. 3(B), two ejection holes 112 are provided at an angle of about 90° in a cross section perpendicular to the axial direction. Further, as shown in FIG. 3(A), a plurality of the ejection holes 112 are arranged in a row at intervals in the axial direction. Although there are two injection holes 112 in FIG. 3(A), three or more injection holes 112 are actually formed at predetermined intervals in the axial direction.

A cylindrical rubber material 120 is wrapped around the outside of a portion of the peripheral wall 110 of the injection tube 100 where the ejection hole 112 is provided. The rubber material 120 is attached so as not to fall off the peripheral wall 110. The mounting structure for attaching the rubber material 120 to the peripheral wall 110 is similar to a general injection pipe. In this embodiment, as shown in FIG. 4, the rubber material 120 is fitted and attached to a groove 111 formed in the peripheral wall 110, but the structure is not limited to this. Although not shown in the drawings, for example, the rubber material 120 may be mounted on the peripheral wall 110 by using ring materials joined to the top and bottom of the rubber material 120 to prevent displacement, or may be mounted by sandwiching the upper end of the rubber material 120 with ring materials. .

Here, as shown in FIGS. 15(A) and 15(B), in the peripheral wall 110 of a commercially available general injection tube 900, four ejection holes 112 are formed at 90 mm in a cross section perpendicular to the axial direction. They are placed at equal intervals of °.

On the other hand, as shown in FIG. 3(B), the injection tube 100 of this embodiment has two ejection holes 112 provided at an angle of about 90 degrees, as described above. In this embodiment, two of the four ejection holes 112 formed in the peripheral wall 110 of a commercially available general injection pipe 900 shown in FIG. 15(B) (in this example, the two on the right side of the figure) 3) is closed with a plug member 115, as shown in FIG. 3(B), but the present invention is not limited to this. For example, a structure in which only two ejection holes 112 are formed from the beginning may be used.

In the injection pipe 100 of this embodiment, the total opening area of the two jet holes 112 is adjusted to be the same as the total opening area of the four jet holes 112 of the injection pipe 900, but the invention is not limited to this. It's not something you can do.

As described above, the injection tube 100 of this embodiment shown in FIG. 3 is provided with the ejection hole 112 only on one side (the left side in the figure). Note that, as shown in FIG. 16, "one side" is a semicircular portion on the A side or B side of the center line C in a cross section perpendicular to the axial direction.

[Method of drug injection]
Next, an example of the drug solution injection method of this embodiment will be described. Note that construction does not necessarily have to be carried out in the order listed below. It may be modified as appropriate depending on the situation.

As shown in FIG. 1(A), a hole is drilled in the ground G while a casing pipe 50 is being built into the ground G using a drilling device 10. In addition, the code|symbol 20 is a drilled hole. As shown in FIG. 1(B), a grout material 54 (see FIG. 2) such as cement bentonite material is injected into the casing pipe 50.

As shown in FIG. 1(C), the injection pipe 100 (see also FIGS. 2 and 3) is built into the casing pipe 50 filled with the grout material 54 (see FIG. 2). As shown in FIG. 1(D), the casing pipe 50 is pulled out while the injection pipe 100 is left in place before the hardening of the grout material 54 is completed.

As shown in FIG. 1(E), after the grout material 54 has hardened, the injection packer 150 is inserted into the injection pipe 100. Note that the grout portion 180 is defined as a cylindrical state in which the grout material 54 is hardened (see also FIGS. 2 and 3).

As shown in FIGS. 1(F) and 1(G), while pulling up the injection packer 150, the chemical solution 90 is supplied from a supply device (not shown), and the chemical solution 90 is injected into the ground G. The chemical solution 90 is ejected from the ejection hole 112 (see FIG. 3) provided in the peripheral wall 110 of the injection pipe 100 to crush the grout portion 180 (see FIGS. 2(D) and 3), and is injected into the ground G. be done. Reference numeral 92 in FIG. 1(G) represents a region into which the chemical solution 90 has penetrated. Note that the drug solution 90 may be injected while the injection packer 150 is inserted.

The chemical solution 90 of this embodiment is an injection material that is injected into the ground G and solidifies to improve the ground. Specifically, it is classified into chemical solutions such as water glass, and non-chemical solutions such as cement and clay. grouting. Note that even if "chemical solution 90" is described in the following description, the reference numeral 90 may not be indicated in the drawings. In other words, there are figures in which the reference numeral 90 is omitted.

Further, FIG. 1(F) shows the primary injection, and FIG. 1(G) shows the secondary injection. In the primary injection, cement bentonite or the like may be injected in addition to the chemical solution 90. In general, the ground is heterogeneous because it is composed of layers with different grain sizes and permeability. Therefore, in the primary injection shown in FIG. 1(F), by injecting the chemical solution 90, bentonite, etc., the water paths and voids in the ground are roughly filled. This prevents the chemical solution 90 from escaping during the secondary injection shown in FIG. 1(G).

The injection packer 150 of this embodiment has a similar structure to existing ones. The injection packer 150 has a double packer structure in which the chemical solution 90 is injected into the ground G from between the packer materials 152 above and below the injection packer 150 (see FIG. 2).

Briefly, the packer material 152 can be moved inside the injection tube 100 by being in a deflated state. On the other hand, by bringing the packer material 152 into an expanded state, the packer material 152 comes into close contact with the inner wall 100A of the injection pipe 100 (see FIG. 2).

Then, by injecting the chemical liquid 90 between the upper and lower packer materials 152 in this state, as shown in FIG. gushes out. At this time, the chemical liquid 90 is ejected from above and below the rubber material 120, as shown by arrow K2. In addition, in FIG. 3(A), in order to make it easy to understand, only the packer material 152 of the injection packer 150 is illustrated with an imaginary line (two-dot chain line).

As shown in FIGS. 3(A) and 3(B), the injection tube 100 of this embodiment is provided with a jet hole 112 only on one side (left side in the figure). Therefore, when the chemical liquid 90 is ejected from the spout hole 112 and crushes the grout portion 180, one side (the left side in the figure) of the grout part 180 is crushed, and the chemical liquid 90 mainly flows into the ground on one side (the left side in the figure). Injected into G. In other words, a large amount of the chemical liquid 90 is injected in the K1 direction.

Reference numeral 95 in FIG. 3(B) indicates a crack formed by crushing. In the figure, only one crack 95 is formed for each ejection hole 112, but in reality, a plurality of cracks 95 are often formed.

Note that even if only one side (the left side in the figure) of the grout portion 180 is crushed, in the process in which the chemical solution 90 is injected into the ground G and permeates, it will also permeate in the opposite direction to the one side (K1 direction). (See Figure 6).

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

As described above, the injection tube 100 of this embodiment is provided with the ejection hole 112 only on one side. Therefore, when the chemical liquid 90 is ejected from the injection hole 112 of the injection pipe 100 to crush the grout portion 180, one side of the grout portion 180 is crushed, and the chemical liquid 90 is mainly injected into the ground on one side.

That is, the direction (arrow K1) in which a large amount of the chemical solution 90 is injected into the ground G can be set. To explain from another point of view, the injection of the drug solution 90 can be directed.

<Second embodiment>
A liquid medicine injection method according to a second embodiment of the present invention will be described. Note that members similar to those in the first embodiment are given the same reference numerals, and overlapping explanations will be omitted or simplified.

[Injection tube]
The structure of the injection tube of this embodiment will be explained. Note that the injection pipe has the same configuration as the first embodiment except for the portion where the ejection hole is provided.

As shown in FIG. 5, a plurality of the injection holes 112 of the injection pipe 200 are formed side by side at intervals in the axial direction. A cylindrical rubber material 120 is wrapped around the outer side of the peripheral wall 110 of the injection pipe 100 in which the ejection hole 112 is formed.

The injection pipe 200 of this embodiment has a part where the jet hole 112 is provided only on one side (the left side in FIG. 5) (a part where the jet hole 112 is provided on the lower side in FIG. are formed only on the other side (the right side in FIG. 5) (the portion where the ejection holes 112 on the upper side in FIG. 5 are provided) are provided alternately in the axial direction.

[Method of drug injection]
Next, an example of the drug solution injection method of this embodiment will be described. Note that this embodiment is also performed according to the construction procedure shown in FIG. 2, so only the main parts will be explained.

When the chemical liquid 90 is ejected from the injection hole 112 of the injection pipe 200 to crush the grout part 180 (see FIGS. 2(D) and 3), the grout part 180 is crushed and the chemical liquid 90 is injected into the ground G. Ru.

At this time, by locating the space between the upper and lower packer materials 152 of the injection packer 150 at a portion where the injection hole 112 of the injection pipe 200 is formed only on one side (the left side in FIG. 5), one side of the grout portion 180 is The side is crushed, and the chemical solution 90 is injected into the ground G mainly on one side.

Furthermore, by locating the space between the upper and lower packer materials 152 of the injection packer 150 at a portion where the injection hole 112 of the injection pipe 200 is formed only on the other side, the other side of the grout portion 180 is crushed, and the other side is mainly crushed. A chemical solution 90 is injected into the ground G on the side.

Therefore, by adjusting the depth of the injection packer 150, injection of the chemical liquid 90 to one side and injection of the chemical liquid 90 to the other side can be selected.

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

The injection pipe 200 of this embodiment has both a portion where the ejection hole 112 is formed only on one side and a portion where the ejection hole 112 is formed only on the other side. The direction of crushing and injecting the chemical solution 90 into the ground G can be selected from one side and the other side.

That is, the direction (arrow K1) in which a large amount of the chemical solution 90 is injected into the ground G can be selected. To explain from another point of view, it is possible to select a direction in which directivity is provided.

Here, in this embodiment, for the sake of clarity, the terms "one side" and "the other side" have been described. However, in the case of "the other side", it is also "an injection process in which a chemical solution is ejected from the injection hole between the upper and lower packer materials in the injection pipe, one side of the grout portion is crushed, and the chemical solution is injected into the ground."

<Example>
Next, an example will be described in which a direction in which a large amount of the chemical solution 90 is injected into the ground G is set and construction is performed using the chemical solution injection method of the first embodiment or the chemical solution injection method of the second embodiment. In addition, in the first example, second example, third example, and fourth example described later, the injection pipe 100 of the injection method of the first embodiment and the injection pipe 200 of the injection method of the second embodiment are Although either may be used, the injection tube 100 of the first embodiment will be described for convenience.

Further, in the embodiments to be described later, the same components as those in the embodiments described previously are given the same reference numerals, and redundant explanations will be omitted or simplified.

[First example]
A first embodiment will be described in which a water-blocking wall is constructed by injecting a chemical into the ground at intervals.

As shown in FIG. 6, the chemical liquid 90 is injected and hardened through the injection pipe 900 built in series and the injection pipe 100 of the chemical liquid injection method of the first embodiment built in series, respectively, thereby blocking water. Build wall 500. Note that the row of injection tubes 900 is referred to as row 400, and the row of injection tubes 100 is referred to as row 300. Further, in FIG. 6, illustrations of members other than the injection pipe 100 and the injection pipe 900, such as the grout portion 180, are omitted.

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

In the row 400, due to the non-uniformity of the ground G, the injection range 92 of the chemical solution 90 may vary randomly. Therefore, in the example of FIG. 7, a gap 503 is created. Note that a thick line extending from the injection pipe 900 in a region 92 where the chemical solution 90 has permeated in FIG. 7 and FIG. 8 described later represents a portion of the ground G where the chemical solution 90 easily permeates.

In this example, in the first embodiment of the chemical liquid injection method in the row 300, the K1 direction in which a large amount of the chemical liquid 90 is injected is oriented between the injection tubes 900 in the row 400. Therefore, the chemical solution 90 is injected into the gap 503.

Therefore, a gap is not formed or hardly formed in the range 92 where the chemical solution 90 is injected, that is, a gap is not formed or hardly formed in the water-blocking wall 500 that has been constructed.

Here, when constructing a water-shielding wall using only the injection pipe 900, it is necessary to inject a large amount of the chemical solution 90 in order to prevent the formation of the gap 503 or to fill the gap 503. However, as described above, by using the chemical injection method of the first embodiment, the water-blocking wall 500 can be constructed while reducing the injection amount of the chemical liquid 90.

[Second example]
A second embodiment will be described in which a water-blocking wall is constructed by injecting a chemical into the ground at intervals.

As shown in FIG. 7, rows 300 of injection tubes 100 of the liquid medicine injection method of the first embodiment are arranged on both sides of row 400 of injection tubes 900, respectively.

Injection tubes 900 in row 400 and injection tubes 100 in row 300 are arranged alternately. Further, the K1 direction in which a large amount of the drug solution 90 is injected from the injection tubes 100 in the row 300 is directed between the injection tubes 900 in the row 400.

Therefore, gaps are not formed or are less likely to be formed in the range where the chemical solution 90 is injected than in the first embodiment, that is, gaps are not formed or are less likely to be formed in the constructed water-blocking wall 510.

[Third Example]
A third embodiment will be described in which a water-blocking wall is constructed by injecting a chemical into the ground at intervals.

As shown in FIG. 8, a water-blocking wall 520 is constructed in one row of the rows 302 of the injection tubes 100 in the liquid medicine injection method of the first embodiment. The K1 direction in which a large amount of the chemical solution 90 is injected into the injection tube 100 is toward the adjacent injection tube 100 and in the same direction.

Therefore, a gap is not formed or hardly formed in the range 92 where the chemical solution 90 is injected, that is, a gap is not formed or hardly formed in the constructed water-blocking wall 520. To explain from another perspective, the water-blocking wall 520 can be constructed while reducing the injection amount of the chemical solution 90.

[Fourth example]
An example will be described in which a chemical solution is injected into the joint between an existing impermeable wall constructed adjacent to an underground framework and a newly constructed impermeable wall.

As shown in FIG. 9, the existing impermeable wall 700 constructed adjacent to the underground outer wall 602 of the underground framework 600 and the newly constructed impermeable wall 702 are constructed by the soil-cement column type continuous wall construction method. Note that the reference numeral 710 is an H-shaped steel, and the reference numeral 712 is a soil cement column 712.

The injection pipe 100 of the chemical liquid injection method of the first embodiment is built outside the joint part 704 between the existing impermeable wall 700 and the new impermeable wall 702, and the chemical liquid 90 is injected with the joint part 704 facing. Therefore, the chemical solution 90 is effectively injected and filled in the contact portion 704 between the two. To explain from another point of view, it is possible to fill in the contact area 704 between the two while reducing the injection amount of the chemical solution 90.

[Fifth example]
A fifth embodiment will be described in which a water-blocking wall is constructed adjacent to the underground outer wall of an underground framework.

As shown in FIG. 10(A), the injection pipe 200 of the chemical liquid injection method of the second embodiment is built in series parallel to the wall surface 602A of the underground outer wall 602 of the underground structure 600 to construct a water-blocking wall 530.

As shown in FIG. 10(B), the lower end of the injection pipe 200 is installed so as to be embedded in the impervious water layer GA such as a clay layer in the ground G. At the bottom of the injection pipe 200, the chemical solution 90 is injected into the ground G on both one side (left side in the figure) and the other side (right side in the figure). Note that the symbol S indicates the groundwater level.

Then, the chemical solution 90 is injected into the ground G only from the vicinity of the bottom plate 604 of the underground framework 600 to the upper side of the injection pipe 200 on the other side (the right side in the figure). By injecting in this manner, no gap is formed between the underground outer wall 602 and the water-blocking wall 530, or a gap is hardly formed. To explain from another point of view, it is possible to construct the water-blocking wall 530 that fills the gap with the underground outer wall 602 while reducing the injection amount of the chemical solution 90.

[Sixth Example]
A sixth embodiment will be described in which a water-blocking wall is constructed below the underground outer wall and bottom plate of an underground framework.

As shown in FIGS. 11(A) and 11(B), a row 300 in which the injection pipes 200 of the chemical liquid injection method of the second embodiment are built in series parallel to the underground outer wall 602 of the underground framework 600, and a bottom panel A water-shielding wall 632 is constructed with the rows 302 inserted through the insertion holes 603 formed in the holes 604 and built in. Note that the symbol L is a parallel line separated from the underground outer wall 602 by a predetermined distance.

The lower end of each injection pipe 200 is installed so as to be embedded in an impermeable layer GA such as a clay layer. Then, the chemical solution 90 is injected into the ground G from the injection pipe 200 in the row 300 on the other side (the right side in the figure), and the chemical solution 90 is injected into the ground G on the other side (the left side in the figure) from the injection pipe 100 in the column 302. do.

By injecting in this manner, a gap is not formed or is difficult to form in the water-shielding wall 632, and a gap is not formed or a gap is difficult to be formed between the underground framework 600 and the water-shielding wall 632. To explain from another point of view, it is possible to construct the water-blocking wall 532 that fills the space between the underground structure 600 and the underground structure 600 while reducing the amount of the chemical solution 90 to be injected.

[Seventh Example]
A seventh embodiment will be described in which a water-blocking wall is constructed by injecting a chemical into the ground at intervals.

As shown in FIG. 12, by injecting and hardening the chemical liquid 90 from the row 400 constructed with injection pipes 900 and the row 300 of the injection pipes 200 of the chemical liquid injection method of the second embodiment, the water-blocking wall is created. Construct 502.

First, the inclinations of the injection tube 900 and the injection tube 200 are measured. Any method may be used to measure the slope. For example, there is a method of measuring the inclination of the casing pipe 50 before the injection pipes 100, 900 are installed using an inclinometer, a method of measuring the inclination of the injection pipes 200, 900 using a geomagnetometer, etc.

In this example, as shown in FIG. 13, it is assumed that the injection pipe 900 is installed diagonally, the injection pipe 100 is installed vertically, and the injection pipe 900 and the injection pipe 200 intersect. "Intersection" refers to a side view of the rows 300 and 302 in the row direction. Further, the portion where the two intersect is defined as an intersection portion 910. In the illustrated example, below the intersection 910 in the injection tube 200, the injection tube 900 is on the left side of the figure, and above the intersection 910, the injection tube 900 is on the right side of the figure.

Therefore, as shown in FIGS. 12(A) and 12(C), on the lower side of the injection tube 200, the drug solution 90 is injected toward the left side of the figure, and on the upper side of the injection tube 100, the drug solution 90 is injected toward the left side of the injection tube 200 in the figure. The chemical solution 90 is injected toward. In addition, at the depth near the intersection 910, the chemical liquid 90 may be ejected alternately on the left side and the right side.

Any method may be used to determine the depth of the intersection 910 where the injection tube 900 and the injection tube 200 intersect, that is, the depth at which the direction of directivity is switched. For example, the relationship between the amount of misalignment of the injection tube 900 and the injection tube 200 and the depth may be determined from the inclination angles of the injection tube 900 and the injection tube 200, and the portion where the amount of misalignment becomes 0 may be defined as the intersection 910.

By injecting in this way, even if the injection pipe 900 and the injection pipe 200 intersect, a gap does not or is difficult to form in the range 92 where the chemical solution 90 is injected, that is, in the constructed impermeable wall 502. No gaps are formed or gaps are difficult to form. To explain from another point of view, the water-blocking wall 502 can be constructed while reducing the injection amount of the chemical solution 90.

<Others>
The present invention is not limited to the above embodiments and examples.

For example, in the embodiment described above, the grout material 54 is hardened by ejecting the chemical solution 90 from the 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, 200. Although one side of the grout portion 180 formed by the above method was crushed and the chemical solution 90 was injected into the ground G, the present invention is not limited thereto.

For example, as shown in FIG. 14, the grout material 54 is hardened while the casing pipe 50 (see FIG. 1) and the injection pipe 900 are brought close together to form a thin wall portion 182 and a thick wall portion 184 in the grout portion 180. By doing so, the thin part 182 side (one side) may be crushed and the chemical solution 90 may be injected into the ground G. In this case, the injection pipe 900 may be installed before filling the grout material 54 into the casing pipe 50.

Further, for example, in the second embodiment, the two directions in which the chemical solution 90 can be directionally injected are provided alternately 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.

Further, for example, in the second embodiment, the two directions in which the drug solution 90 can be directionally injected are opposite to each other, that is, the angle between the two directions is 180°, but this is not limitative. It's not something you can do. For example, the angle between two directions in which the chemical solution 90 can be injected directionally may be 90°. Specifically, a region on the left side of FIG. 15(B) where only the two ejection holes 112 are opened, and a region on the upper side of the figure where only the two ejection holes 112 are opened may be provided.

Further, for example, in the above embodiment, there are two ejection holes 112 between the upper and lower packer materials 152 in the injection pipes 100, 200, but the number 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 one.

Further, for example, in the above embodiments, the present invention is applied to constructing the water-shielding walls 500, 502, 510, 520, 530, and 532 or filling the connecting portion 704 with the chemical solution 90, but the present invention is not limited thereto. For example, the present invention can be applied to waterproof reinforcement of cracked portions of retaining walls.

50 Casing pipe 54 Grout material 90 Chemical solution 100 Injection pipe 112 Blowout hole 150 Injection packer 152 Packer material 180 Grout part 200 Injection pipe 602 Underground outer wall 602A Wall surface 530 Impermeable wall 900 Injection pipe
G ground

Claims (3)

A casing pipe process in which a hole is drilled in the ground and a casing pipe is built,
a filling step of filling grout material into the casing pipe;
an injection pipe step of building an injection pipe into the casing pipe;
a drawing step of pulling out the casing pipe after filling the grout material;
An injection packer is inserted into the injection pipe, and a chemical solution is ejected from the injection hole between the upper and lower packer materials constituting the injection packer in the injection pipe, and one side of a grout portion formed by hardening the grout material. an injection step of crushing and injecting the chemical solution into the ground;
A drug solution injection method comprising: 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.
The liquid drug injection method according to claim 1. building the injection pipe in series parallel to the wall surface of the underground outer wall, and constructing a water-shielding wall with one side of the grout section facing the wall surface;
The liquid drug injection method according to claim 1 or claim 2.