JP7129052B2 - Injection outer tube and chemical injection method - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to an injection outer tube and a chemical injection method.

Conventionally, a chemical solution injection method for the purpose of ground improvement is known (see Patent Document 1). The chemical injection method includes the strainer method and the double packer method. Furthermore, the double packer method includes the seal grout method and the ground packer method.

In the chemical injection method, first, a hole is drilled in the ground, and an injection outer pipe is inserted into the drilled hole. Furthermore, the inner injection tube is inserted into the outer injection tube. An injection port is formed in the injection outer tube. The injection inner tube pumps the drug solution to the injection port. The pumped chemical solution is discharged from the injection port of the injection outer pipe and permeates the ground. The ground is improved by solidifying the chemical solution that has permeated the ground and forming an improved body.

If there is a gap between the outer injection pipe and the ground, the liquid medicine discharged from the injection port of the outer injection pipe escapes through this gap. Therefore, in the double packer construction method of the ground packer method, a plurality of packers are attached to the outside of the injection outer pipe. Before injecting the chemical solution, the packer is filled with a filler to swell and adhere to the ground. This packer can suppress escape of the chemical solution.

Japanese Patent No. 3313351

The packer can be attached to the outer injection tube by crimping the end of the packer to the main body of the outer injection tube using a crimping member. In this case, if the filling pressure of the filler in the packer is high, the caulking member may come off.

An object of one aspect of the present disclosure is to provide an injection outer pipe and a chemical injection method that can prevent the caulking member from coming off.

One aspect of the present disclosure is provided between a tubular body portion, a plurality of packers attached to the outer peripheral surface of the body portion, and the adjacent packers of the body portion, and the inside of the body portion a filling port provided in a portion of the main body to which the packer is attached and communicating between the inside and the outside of the main body; and an end of the packer connected to the main body and a crimping unit for crimping the first crimping member, the crimping unit being positioned closer to the center in the axial direction of the packer than the first crimping member and the first crimping member. and a second crimping member having a width narrower than the width of the crimping outer tube, wherein a gap exists between the first crimping member and the second crimping member.

An injection outer tube that is one aspect of the present disclosure includes a crimping unit that crimps an end of a packer to a main body. The crimping unit comprises a first crimping member and a second crimping member. The second crimping member is positioned closer to the center in the axial direction of the packer than the first crimping member and is narrower than the first crimping member. Also, a gap exists between the first crimping member and the second crimping member. With the above configuration, even if the packing pressure of the packer is high, the first crimping member and the second crimping member are less likely to come off from the main body.

Another aspect of the present disclosure is a tubular main body, a plurality of packers attached to the outer peripheral surface of the main body, and provided between the adjacent packers of the main body, an injection port that communicates between the inside and the outside; a filling port that is provided in a portion of the main body to which the packer is attached and communicates between the inside and the outside of the main body; and a crimping unit for crimping a main body, and a chemical injection method using an outer injection pipe, wherein the outer injection pipe is inserted into a drilled hole formed in the ground, and the packer is filled with the filler through the filling port. By doing so, the packer is expanded, the packer is brought into close contact with the inner wall of the drilled hole, the chemical solution is discharged from the injection port and injected into the ground, and the crimping unit includes a first crimping member and the a second crimping member positioned closer to the center in the axial direction of the packer than the first crimping member and having a narrower width than the first crimping member, wherein the first crimping member and the second crimping member This is a chemical solution injection method in which there is a gap between the caulking member and the caulking member.

The injection outer tube used in the chemical injection method, which is another aspect of the present disclosure, includes a crimping unit that crimps the end of the packer to the main body. The crimping unit comprises a first crimping member and a second crimping member. The second crimping member is positioned closer to the center in the axial direction of the packer than the first crimping member and is narrower than the first crimping member. Also, a gap exists between the first crimping member and the second crimping member. With the above configuration, even if the packing pressure of the packer is high, the first crimping member and the second crimping member are less likely to come off from the main body.

1 is an explanatory diagram showing the overall configuration of an outer injection tube 1. FIG. It is explanatory drawing showing the structure of the packer 5 and its periphery. FIG. 3 is a cross-sectional view along the line III-III in FIG. 2; FIG. 3 is an explanatory diagram showing the configuration of an end portion 13 and caulking members 15 and 17; It is explanatory drawing showing a chemical|medical solution injection construction method. 4 is an explanatory diagram showing the relationship between the shape of the end portion 13 and the limit filling pressure; FIG.

Embodiments of the present disclosure will be described based on the drawings.
1. Configuration of outer injection tube 1 The configuration of the outer injection tube 1 will be described with reference to FIGS. 1 to 4. FIG. As shown in FIG. 1 , the injection outer tube 1 includes a body portion 3 and a plurality of packers 5 .

The body portion 3 has a tubular shape. The body portion 3 has a filling port 7 as shown in FIG. Further, the body portion 3 includes an injection port 9 as shown in FIG. The filling port 7 is a hole that communicates between the inside and the outside of the body portion 3 . The position of the filling port 7 is a portion of the body portion 3 to which the packer 5 is attached. A plurality of filling ports 7 are provided along the circumferential direction of the body portion 3 .

A sleeve 11 is attached to a portion of the body portion 3 where the filling port 7 is provided. The sleeve 11 has an annular shape and is attached to the main body 3 from the outer peripheral side. The sleeve 11 normally covers the filling port 7 from the outside. The sleeve 11 is made of an elastically deformable material such as rubber. As will be described later, when the packing material is filled into the packer 5 through the filling port 7 , the pressure of the filling material pushes the sleeve 11 outward, creating a gap between the filling port 7 and the sleeve 11 . As a result, the filler passes through the filling port 7 and further through the above-described gap, and is filled into the packer 5 .

The injection port 9 is a hole that communicates between the inside and the outside of the body portion 3 . The location of the inlet 9 is between adjacent packers 5 . A plurality of inlets 9 are provided. The plurality of injection ports 9 are arranged at predetermined intervals along the axial direction of the body portion 3 . The interval between adjacent injection ports 9 is, for example, preferably 20 to 40 cm, more preferably 25 to 35 cm, and particularly preferably 30 cm.

As shown in FIGS. 2 and 3 , the packer 5 has a tubular basic shape with a diameter one size larger than that of the body portion 3 . The body part 3 passes through the inside of the packer 5 . The axial direction of the body portion 3 and the axial direction of the packer 5 match. The axial length of the packer 5 is smaller than the axial length of the body portion 3 .

Both ends 13 of the packer 5 in the axial direction are reduced in diameter and are in contact with the outer peripheral surface of the main body 3 . The end portion 13 is crimped to the body portion 3 by a pair of crimping members 15 and 17 . As shown in FIGS. 2 to 4, the caulking members 15 and 17 each have an annular shape. The caulking members 15 and 17 are each in contact with the end portion 13 from the outer peripheral side. The crimping member 15 is located closer to the center C in the axial direction of the packer 5 than the crimping member 17 is. A gap 19 exists between the crimping member 15 and the crimping member 17 .

As shown in FIG. 4, the width of the caulking member 17 in the axial direction of the main body 3 is W1. Further, the width of the caulking member 15 in the axial direction of the body portion 3 is W2. W1 is greater than W2. W1 is preferably 1.1 times or more of W2. The crimping member 17 corresponds to the first crimping member. The crimping member 15 corresponds to the second crimping member. A pair of crimping members 15, 17 correspond to a crimping unit.

As shown in FIG. 3 , the packer 5 has a layered structure comprising a first layer 21 and a second layer 23 . The first layer 21 is made of rubber. The first layer 21 is elastically deformable, and bulges outward in the radial direction of the body portion 3 when the packer 5 is filled with the filler. The first layer 21 is impermeable to the filler and has airtightness.

The second layer 23 is positioned outside the first layer 21 and is in contact with the first layer 21 . The second layer 23 consists of cloth. When the packer 5 is filled with the filler, the second layer 23 bulges outward in the radial direction of the body portion 3 until it reaches a predetermined shape. After reaching a predetermined shape, it is difficult to bulge further compared to the first layer 21 . The above predetermined shape is a cylindrical shape centered on the central axis of the body portion 3 .

2. Chemical Injection Method The chemical injection method will be described with reference to FIG. In STEP-1, a drilling hole 101 is formed in the ground 100, an injection outer pipe 1 is inserted into the drilling hole 101, and a sealant 107 is filled between the hole wall 105 of the drilling hole 101 and the injection outer pipe 1. state.

For example, the situation shown in STEP-1 can be realized by forming a drilled hole 101, then filling the drilled hole 101 with a sealant 107, and then inserting the injection outer tube 1 into the drilled hole 101.
The sealant 107 contains aluminum hydroxide gel, has a specific gravity within the range of 1.05 to 1.30, and has a pH within the range of 4 to 11.1. Examples of the sealing agent 107 include S1 to S14 shown in Table 1. The sealants S1 to S8 and S11 to S14 are obtained by preparing the liquids A and B shown in Table 1 in advance and mixing them immediately before use. The sealing agents S9 and S10 are obtained by preparing the A liquid, the B liquid, and the C liquid shown in Table 1 in advance and mixing them immediately before use.

表１における配合量の単位は質量部である。表１における「Al₂(SO₄)₃」は、硫酸アルミニウム (北陸化成(株)製、Al₂O₃：12%)を意味する。表１における「活性剤」は、界面活性剤を意味する。Ｓ１１のＡ液に配合されている界面活性剤はカルボキシメチルセルロース(信越化学工業(株)製、製品名:アスカクリーン)である。Ｓ１２のＡ液に配合されている界面活性剤はアルキルアリルスルホン酸塩である。Ｓ１３のＡ液に配合されている界面活性剤はアルキルアンモニウム塩である。Ｓ１４のＡ液に配合されている界面活性剤は、アルキルアリルスルホン酸塩(花王(株)、製品名:ビスコトップ100A)と、アルキルアンモニウム塩(花王(株)、製品名:ビスコトップ100B)とを質量比１：１で混合したものである。

The unit of the compounding amount in Table 1 is parts by mass. "Al2 _{( SO4} ) ₃ " in Table 1 means aluminum sulfate (manufactured by Hokuriku Kasei Co., Ltd. _{, Al2O3} : 12%). "Activator" in Table 1 means surfactant. The surfactant contained in solution A of S11 is carboxymethyl cellulose (manufactured by Shin-Etsu Chemical Co., Ltd., product name: Asuka Clean). The surfactant blended in the A liquid of S12 is an alkylallyl sulfonate. The surfactant blended in the A liquid of S13 is an alkylammonium salt. The surfactants blended in the A liquid of S14 are alkyl allyl sulfonate (Kao Corporation, product name: Visco Top 100A) and alkyl ammonium salt (Kao Corporation, product name: Visco Top 100B). and are mixed at a mass ratio of 1:1.

“NaAlO ₂ ” in Table 1 means sodium aluminate (manufactured by Hokuriku Kasei Co., Ltd., product name: AS17, Al ₂ O ₃ : 19%). "No. 5" in Table 1 means No. 5 sodium silicate (manufactured by Fuji Chemical Co., Ltd., _SiO2 : 25.5%, _Na2O : 7%).

The outer injection tube 1 is the one described in the section "1. Configuration of the outer injection tube 1", and includes an injection port 9 and a plurality of packers 5, as shown in FIG.
In STEP- 2 , an inner injection tube (not shown) is inserted into the outer injection tube 1 , and the packing material is filled into the packer 5 through the inner injection tube and the filling port 7 . The packer 5 expands outward and adheres to the hole wall 105 .

In STEP- 3 , an inner injection tube (not shown) is inserted into the outer injection tube 1 , the drug solution 113 is sent through the inner injection tube, and the drug solution 113 is discharged from the injection port 9 . The chemical liquid 113 discharged from the injection port 9 dissolves the sealing agent 107 near the injection port 9 . The chemical solution 113 is a mixture of the following components.

Colloidal silica: 44g
No. 5 sodium silicate: 274g
Dilute sulfuric acid for industrial use: about 40g
Water: 736g
The pH of the chemical solution 113 was adjusted to 4 or less or 9 or more by adjusting the amount of industrial dilute sulfuric acid.

In STEP-4, the chemical solution 113 in which the sealing agent 107 is dissolved penetrates the ground 100. As shown in FIG. In STEP-5, the chemical solution 113 spreads sufficiently on the ground 100 and solidifies to form an improved body 115. FIG.

3. Effects of Injection Outer Tube 1 and Chemical Solution Injection Method (1A) The packer 5 includes a first layer 21 made of rubber. Therefore, exudation of the filler from the packer 5 can be suppressed, and contraction of the packer 5 can be suppressed. As a result, the packer 5 can be maintained in close contact with the hole wall 105 .

(1B) The packer 5 comprises a second layer 23 of fabric. After reaching a predetermined shape by swelling, the second layer 23 hardly expands further and maintains the predetermined shape. Therefore, the second layer 23 can suppress the packer 5 from partially excessively swelling and becoming distorted.

(1C) In the chemical injection method, a sealant 107 is injected into the drilled hole 101 before the packer 5 is expanded. Therefore, even if there is a gap between the bulging packer 5 and the hole wall 105 , the gap can be closed with the sealant 107 .

(1D) The sealing agent 107 contains aluminum hydroxide gel, has a specific gravity within the range of 1.05 to 1.30, and has a pH within the range of 4 to 11.1. Also, the pH of the chemical liquid 113 is 4 or less or 9 or more. Therefore, the chemical solution 113 discharged from the injection port 9 dissolves the sealant 107 near the injection port 9 . When the sealant 107 dissolves, the chemical solution 113 can permeate the ground over a wide area. As a result, the penetration source can be expanded.

It was confirmed by a dissolution test that the chemical solution 113 dissolved the sealant 107 . A dissolution test is a test in which the chemical solution 113 and the sealing agent 107 are mixed and the dissolved portion of the sealing agent 107 is quantified. As a result of the dissolution test, 60% by mass or more of the sealing agent 107 was dissolved.

( 1 E) In the injection outer tube 1 , the crimping members 15 and 17 crimp the end portion 13 and the body portion 3 . The crimping member 15 is located closer to the center C in the axial direction of the packer 5 than the crimping member 17 is. A gap 19 exists between the crimping member 15 and the crimping member 17 . The width W2 of the crimping member 15 is narrower than the width W1 of the crimping member 17. - 特許庁With the above configuration, even if the packing pressure of the packer 5 is high, the caulking members 15 and 17 are less likely to come off from the body portion 3 .

This was confirmed by the following tests. As shown in FIG. 6, cases 1 to 5 were produced as the form of the end portion 13 . Case 1 corresponds to the embodiment described above, where W1 is 1.1 times or greater than W2. A gap 19 exists.

In case 2, W1 and W2 are equal. W1 and W2 in case 2 are equal to W2 in case 1. A gap 19 exists.
The case 3 does not have the caulking member 17 . Width W2 of crimping member 15 is equal to W2 in case 1 .

In case 4, the gap 19 does not exist. Also, W1 and W2 are equal. W1 and W2 in case 4 are equal to W2 in case 1.
In Case 5, W2 is greater than or equal to 1.1 times W1. W1 in case 5 is equal to W2 in case 1. W2 in case 5 is equal to W1 in case 1; A gap 19 exists.

For each of Cases 1 to 5, the filling pressure of the packer 5 was gradually increased, and the filling pressure when the caulking member came off (hereinafter referred to as the limit filling pressure) was measured. The results are shown in FIG. In Case 1, the limit filling pressure was 1.0 MPa or more. On the other hand, in Cases 2 to 5, the limit filling pressure was 0.5 MPa or less.

4. Other Embodiments Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications can be made.

(1) The number of injection ports 9 provided between a pair of packers 5 may be singular.
(2) The injection outer tube 1 may be used in construction methods other than the construction method described above. For example, the injection outer tube 1 may be used in a construction method that does not use a sealant.

(3) The sealant used in the chemical injection method may be, for example, a sealant containing superabsorbent resin and water (hereinafter referred to as a sealant containing superabsorbent polymer). At least part of the superabsorbent polymer is in a swollen state after absorbing water.

The superabsorbent resin-containing sealant has a high effect of suppressing collapse of the hole wall of the excavation hole. In addition, when the chemical liquid is discharged from the injection tube, the superabsorbent resin-containing sealant tends to shrink. When the superabsorbent polymer-containing sealant shrinks, the chemical solution discharged from the injection pipe can permeate the ground over a wide area. As a result, the penetration source can be enlarged.

A synthetic polymer-based super absorbent resin is preferable as the super absorbent resin. As the synthetic polymer-based super absorbent resin, a polyacrylate-based super absorbent resin is preferred. A partially sodium salt cross-linked product of an acrylic acid polymer is preferable as the polyacrylate-based super absorbent resin.

When the superabsorbent resin-containing sealant contains a synthetic polymer-based superabsorbent resin, the effect of suppressing collapse of the hole wall of the excavation hole is further enhanced. Further, in the case where the superabsorbent resin-containing sealing agent contains a synthetic polymer-based superabsorbent resin, the superabsorbent polymer-containing sealing agent shrinks more easily when the chemical liquid is discharged from the injection tube.

When the superabsorbent resin-containing sealant contains a polyacrylate-based superabsorbent resin, the effect of suppressing collapse of the hole wall of the excavation hole is further enhanced. Further, when the superabsorbent resin-containing sealing agent contains a polyacrylate-based superabsorbent resin, the superabsorbent polymer-containing sealing agent shrinks more easily when the chemical liquid is discharged from the injection tube.

When the superabsorbent polymer-containing sealant contains the acrylic acid polymer partial sodium salt crosslinked product, the effect of suppressing collapse of the hole wall of the borehole is particularly high. Further, in the case where the superabsorbent polymer-containing sealing agent contains an acrylic acid polymer partial sodium salt cross-linked product, the superabsorbent polymer-containing sealing agent is particularly likely to shrink when the chemical liquid is discharged from the injection tube.

The superabsorbent resin-containing sealant preferably contains 1000 parts by mass of water and 1 to 100 parts by mass of the superabsorbent polymer. More preferably, the superabsorbent resin-containing sealant contains 1000 parts by mass of water and 1.5 to 20 parts by mass of the superabsorbent resin.

When the superabsorbent polymer-containing sealant contains 1 part by mass or more of the superabsorbent polymer with respect to 1000 parts by mass of water, it is highly effective in suppressing collapse of the hole wall of the excavation hole.
When the superabsorbent polymer-containing sealant contains 1.5 parts by mass or more of the superabsorbent polymer with respect to 1000 parts by mass of water, the effect of suppressing collapse of the hole wall of the excavation hole is further enhanced.

When the superabsorbent polymer-containing sealing compound contains 100 parts by mass or less of the superabsorbent polymer per 1000 parts by mass of water, the manufacturing cost of the superabsorbent polymer-containing sealing compound can be reduced.
When the superabsorbent polymer-containing sealing compound contains 20 parts by mass or less of the superabsorbent polymer per 1000 parts by mass of water, the manufacturing cost of the superabsorbent polymer-containing sealing compound can be further reduced.

The dosage form of the superabsorbent polymer-containing sealant is, for example, liquid, slurry, suspension, or the like. The superabsorbent polymer-containing sealant may further contain components other than water and the superabsorbent polymer.
(4) A plurality of functions possessed by one component in the above embodiment may be realized by a plurality of components, or a function possessed by one component may be realized by a plurality of components. . Also, a plurality of functions possessed by a plurality of components may be realized by a single component, or a function realized by a plurality of components may be realized by a single component. Also, part of the configuration of the above embodiment may be omitted. Moreover, at least part of the configuration of the above embodiment may be added or replaced with respect to the configuration of the other above embodiment. It should be noted that all aspects included in the technical idea specified by the wording described in the claims are embodiments of the present disclosure.

(5) In addition to the above-described injection outer pipe and chemical injection method, the present disclosure can be realized in various forms such as a product having the injection outer pipe as a component, a ground improvement method, and the like.

DESCRIPTION OF SYMBOLS 1... Injection outer pipe, 3... Main body part, 5... Packer, 7... Filling port, 9... Injection port, 11... Sleeve, 13... End part, 15, 17... Crimping member, 19... Gap, 21... First layer , 23... Second layer, 100... Ground, 101... Drilling, 105... Hole wall, 107... Sealing agent, 113... Chemical liquid, 115... Improvement body

Claims (3)

a cylindrical main body;
a plurality of packers attached to the outer peripheral surface of the main body;
an injection port provided between the adjacent packers in the main body and communicating between the inside and the outside of the main body;
A filling port provided in a portion of the main body to which the packer is attached and communicating between the inside and the outside of the main body;
a crimping unit for crimping the end of the packer to the main body;
with
The crimping unit is
a first crimping member;
a second crimping member located closer to the center in the axial direction of the packer than the first crimping member and having a narrower width than the first crimping member;
with
a gap exists between the first crimping member and the second crimping member;
The crimping unit is configured to detach from the main body when the packing pressure of the packer is gradually increased.
Injection outer tube. a cylindrical main body;
a plurality of packers attached to the outer peripheral surface of the main body;
an injection port provided between the adjacent packers in the main body and communicating between the inside and the outside of the main body;
A filling port provided in a portion of the main body to which the packer is attached and communicating between the inside and the outside of the main body;
a crimping unit for crimping the end of the packer to the main body;
A chemical injection method using an injection outer tube comprising
inserting the injection outer pipe into a drilled hole formed in the ground;
Filling the packer with a filler through the filling port swells the packer and brings the packer into close contact with the inner wall of the drilled hole,
discharging a chemical solution from the injection port and injecting it into the ground;
The crimping unit is
a first crimping member;
a second crimping member located closer to the center in the axial direction of the packer than the first crimping member and having a narrower width than the first crimping member;
with
a gap exists between the first crimping member and the second crimping member;
The crimping unit is configured to detach from the main body when the packing pressure of the packer is gradually increased.
Chemical injection method. The chemical injection method according to claim 2,
A chemical injection method of injecting a sealant into the drilled hole prior to swelling the packer.

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