Ground consolidation and waterproofing method

Abstract

To provide a consolidation water-stop method capable of preventing an injection pressure of an injection pipe through which a two-component mixture flows from increasing even when a two-component mixture type urethane-based injection material is used.SOLUTION: An injection device comprises: an insertion pipe 12 in which a plurality of through holes 14 are drilled in a longitudinal direction on a side wall and which is inserted into the ground; a plurality of junction pipes 18 in which each of a plurality of A liquid flows from an A liquid delivery portion of A liquid containing polyol and each of a plurality of B liquid flows from a B liquid delivery portion of B liquid containing an isocyanate compound are joined; and a plurality of injection pipes 16 which have a discharge port for mixed liquid obtained by mixing the joined liquid from the junction pipes 18 with a mixer member, wherein respective injection pipes 16 of the same length are inserted into the insertion pipe 12 so that the discharge port is at a different position along a longitudinal direction of the insertion pipe 12. A consolidation water-stop method adjusts so that a feeding amount of the A liquid and a feeding amount of the B liquid are to be equal, using the injection device. A mixture from each discharge port of the injection pipe 16 flows out into the ground and hardens to form a consolidated water-stop material.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a consolidation and water stop construction method in which a urethane-based grouting material is injected into ground to be consolidated and / or water-stopped to achieve consolidation and / or water stop of the ground.

Background Art

[0002] In mountain tunnel construction and the like, consolidation and water stop construction, in which a grouting material is injected into the ground to be consolidated and / or water-stopped to consolidate the ground and / or stop water, is performed to prevent loosening of the natural ground to be constructed and water gushing out, so as to ensure construction safety. In this consolidation and water stop construction, the grouting material is discharged from an injection pipe inserted into an insertion pipe which is inserted into the ground to be constructed and has a through hole formed in a side wall thereof, and the grouting material diffuses into the ground through the through hole of the insertion pipe to form a consolidation area and / or a water stop area.

[0003] As a grouting material, a consolidation and water stop construction method using a urethane-based grouting material is proposed in the following Patent Document 1. In the proposed consolidation and water stop construction method, as shown in Fig. 5, an insertion pipe 102 is inserted slightly obliquely into the ground 100 to be consolidated and water-stopped. A plurality of through holes 104 are formed in the insertion pipe 102 along the longitudinal direction of the side wall thereof. Three injection pipes 106a, 106b, 106c are inserted into the insertion pipe 102. Static mixers 108a, 108b, 108c serving as mixer members are attached to the respective tip ends of these injection pipes 106a, 106b, 106c, and a discharge port for discharging the grouting material is formed on each tip end face. The respective discharge ports of the injection pipes 106a, 106b, 106c are located at different positions in the longitudinal direction of the insertion pipe 102 so as to be positioned in the planned injection zone of the ground 100. In addition, the respective rear ends of the injection pipes 106a, 106b, 106c are located outside the inlet of the insertion pipe 102, and merging pipes 110a, 110b, 110c are attached thereto. The grouting material is fed into each of the merging pipes 110a, 110b, 110c from a first pump, a second pump and a third pump provided corresponding to the connected injection pipes respectively. Note that the inlet portion of the insertion pipe 102 is closed by a closing layer 112 made of a closing member such as rubber.

[0004] The injection material supplied to each of the confluence pipes 110a, 110b, and 110c consists of liquid A, which contains a sodium silicate solution, a catalyst, and an additive as a reaction accelerator, and liquid B, which contains isocyanate and an additive. Liquid A and liquid B are supplied separately from the first, second, and third pumps corresponding to each injection pipe and are combined in the confluence pipes 110a, 110b, and 110c. The combined liquid flows through the injection pipes 106a, 106b, and 106c and is mixed by the static mixers 108a, 108b, and 108c. The mixed liquid is discharged from the outlet to the location in the insertion pipe 102 corresponding to the injection zone, where it hardens and flows out through multiple through-holes 104 in the insertion pipe 102 into the injection zone of the ground 100, where it diffuses and hardens, forming a solidified region and / or a watertight region. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2011-106133 [Overview of the project] [Problems that the invention aims to solve]

[0006] According to the inventors' studies, the combined liquid of liquid A and liquid B, which are joined by a confluence pipe immediately before being supplied to the injection pipe, begins to react to some extent immediately after joining. As a result, the viscosity of the combined liquid increases and the injection pressure increases as the length of the injection pipe increases. Furthermore, in ground where groundwater seepage occurs, there is a possibility that the injection material may escape due to the seepage, and it is desirable to prevent this from happening. For this reason, it is preferable that the viscosity of the combined liquid of liquid A and liquid B increases immediately after joining so that it does not escape due to seepage. Also, in ground where groundwater seepage does not occur, it is preferable that the combined liquid be similar to that in ground where seepage occurs, as the viscosity of the combined liquid increases immediately after joining, allowing the combined liquid to come into contact with the target ground, remain in place, and not escape, thus enabling strong solidification. Based on these findings, it was found that, among the injection pipes 106a, 106b, and 106c shown in Figure 5, the longest injection pipe 106c has a high viscosity of the combined liquid and therefore the injection pressure is high, requiring the use of special pressure-resistant pipes for injection pipe 106c and the liquid supply pipe to injection pipe 106c. Furthermore, it was found that when a urethane raw material composition with a fast curing rate is used, the viscosity of the combined liquid becomes high, and the injection pressure of the longest injection pipe 106c may exceed the pressure resistance of the liquid supply pipe to injection pipe 106c and combined pipe 110c, potentially leading to the termination of injection.

[0007] The present invention was made to solve the aforementioned problems, and aims to provide a solidification waterproofing method that can prevent the injection pressure of the injection pipe through which the two-component mixture flows from increasing, even when a two-component urethane-based injection material is used.

[0008] To achieve the above objective, the ground solidification and waterproofing method according to the present invention comprises: an insertion pipe inserted into the ground to be solidified and / or waterproofed, having a plurality of through holes drilled along the longitudinal direction of its side wall; an A liquid delivery section for delivering A liquid containing a polyol, an amine compound, and a viscosity modifier; a B liquid delivery section for delivering B liquid containing an isocyanate compound; a plurality of confluence pipes for confluence the plurality of A liquid flows delivered by the A liquid delivery section and the B liquid flows delivered by the B liquid delivery section corresponding to each of the A liquid flows; and an injection pipe connected to each of the confluence pipes, having a discharge port formed therein for discharging a mixed liquid obtained by mixing the combined liquid of the A liquid flows and the B liquid flows that have been combined in the confluence pipes using a mixer member equipped with such a pipe, wherein each of the injection pipes has the same length from the connection end to the confluence pipe to the discharge port. there The insertion tube is inserted such that the position of the discharge port is different along the longitudinal direction of the insertion tube. Furthermore, of the multiple confluence pipes and injection pipes, at least a portion of them, or the entire confluence pipe and injection pipe, are inserted into the insertion pipe. Using the injection device, The amount of liquid A supplied from the liquid A supply unit is adjusted so that the amount of liquid A supplied to each of the confluence pipes is equal, and the amount of liquid B supplied from the liquid B supply unit is adjusted so that the amount of liquid B supplied to each of the confluence pipes is equal. The amount of liquid delivered is adjusted and discharged from each outlet of the injection pipe. The aforementioned mixed liquid The invention is characterized by the fact that, as it hardens, it flows out into the ground from each of the through-holes of the insertion pipe, and the hardened material solidifies the ground and / or stops water from entering.

[0009] Each of the injection pipes is inserted into the insertion pipe such that the position of its discharge port corresponds to the planned injection zone of the ground, thereby ensuring that the injection material is reliably injected into the area of ​​the ground where it is to be injected.

[0010] The length of the injection pipe is preferably 3.5 to 6 m.

[0011] It is preferable to adjust the viscosity of both liquid A and liquid B to 300 mPa·sec or less at 25°C, as this allows for a lower injection pressure.

[0012] By attaching the mixer member to the tip of the injection pipe and forming the discharge port on the tip surface of the injection pipe, the mixer member can be made smaller and the combined liquid can be mixed easily and thoroughly.

[0013] The pressure at which liquid A is supplied to each of the confluence pipes and the pressure at which liquid B is supplied to each of the confluence pipes Gauge pressure By adjusting the pressure to 8 MPa or less, general-purpose products can be used as the injection pipe and the liquid delivery pipe to the injection pipe.

[0014] The aforementioned solution A preferably contains propylene glycol or a glycerin-initiated polyether polyol as a polyol, and an alicyclic diamine having a primary amino group as an amine compound.

[0015] As the alicyclic diamine, 4,4'-diaminodicyclohexylmethane or 1,3-bis(aminomethyl)cyclohexane can be preferably used.

[0016] Polyoxyalkylene alkyl ethers or castor oil fatty acid esters can be suitably used as the viscosity adjusting agent.

[0017] It is preferable to blend the viscosity modifier into liquid A at a concentration of 5 to 15%.

[0018] Since neither liquid A nor liquid B contains a foaming agent, foaming can be suppressed, resin strength can be increased, and a high water-stopping effect can be obtained with the injection material, which is preferable.

[0019] The aforementioned solution B preferably contains polymeric MDI. [Effects of the Invention]

[0020] According to the consolidated water stopping method of the present invention, each of the plurality of injection pipes connected to a merging pipe that can be inserted into an insertion pipe inserted into the ground to be consolidated and / or water stopping, in which a plurality of through holes are formed along the longitudinal direction of the side wall, has the same length from the connection end with the merging pipe to the discharge port, and can be inserted into the insertion pipe such that the positions of the discharge ports are different along the longitudinal direction of the insertion pipe. Therefore, after the liquid A and liquid B merge in each insertion pipe, the viscosity increase due to the reaction from merging to discharging from the discharge port is at the same level, and the injection pressure of each injection pipe can be made substantially the same. For this reason, by adjusting the length from the connection end of the injection pipe to the merging pipe to the discharge port according to the reaction rate when liquid A and liquid B, which are used as urethane-based injection materials, merge, it is possible to prevent the injection pressure of each injection pipe from becoming high due to the viscosity increase of the merged liquid, prevent the situation where injection is stopped due to high injection pressure, and use general-purpose products for the injection pipes and the liquid feed pipes to the injection pipes. [BRIEF DESCRIPTION OF THE DRAWINGS]

[0021] [Figure 1] It is a schematic diagram explaining the consolidated water stopping method to which the present invention is applied. [Figure 2] Figure 2(a) is a cross-sectional view explaining an example of a state where a plurality of injection pipes are inserted into an insertion pipe to which the present invention is applied, and Figure 2(b) is a front view of an injection pipe connected with a merging pipe. Figure 2(c) and Figure 2(d) are front views of injection pipes connected with other merging pipes. [Figure 3] It is a cross-sectional view explaining another example of a state where a plurality of injection pipes are inserted into an insertion pipe to which the present invention is applied. [Figure 4] It is a schematic diagram explaining a model experiment device using one injection pipe among the plurality of injection pipes inserted into the insertion pipe shown in Figure 1. [Figure 5] It is a cross-sectional view of an insertion pipe inserted with a plurality of injection pipes explaining a conventional consolidated water stopping method. [MODE FOR CARRYING OUT THE INVENTION]

[0022] The following describes in detail the ground consolidation and watertightness method according to the present invention, but the scope of the present invention is not limited to these.

[0023] Figure 1 shows an example of an injection device used in the ground solidification and waterproofing method according to the present invention. In the ground solidification and waterproofing method shown in Figure 1, an insertion pipe 12 is inserted slightly diagonally into the ground 10 to be solidified and waterproofed. Multiple through holes 14 are drilled in a staggered pattern along the longitudinal direction of the side wall of the insertion pipe 12. Three injection pipes 16a, 16b, and 16c are inserted into the insertion pipe 12 as shown in Figure 2(a), and Y-shaped confluence pipes 18a, 18b, and 18c are connected to the rear ends of the injection pipes 16a, 16b, and 16c. The inlet of the insertion pipe 12 is closed with a sealing layer 15. The rear end of the injection pipe 16a shown in Figure 1 protrudes outward from the insertion pipe 12, and the confluence pipe 18a is connected to its rear end. Liquid A, which contains a polyol, an amine compound, and a viscosity modifier, is supplied from the liquid A supply section to one of the bifurcated pipes of the confluence pipe 18a. As shown in Figure 2(a), the injection tubes 16b and 16c, including the merging tubes 18b and 18c connected to their respective rear ends, are entirely inserted into the insertion tube 12.

[0024] As shown in Figure 1, the liquid A supply section is equipped with liquid supply pumps 22a, 22b, and 22c that supply liquid A from the liquid A tank 20 in which liquid A is stored. A valve 24a is provided on the liquid supply pipe 22a side and a valve 30a is provided on the confluence pipe 18a side of the confluence pipe 18a in the liquid supply pipe 26a from the liquid supply pump 22a. A pressure gauge 23a is provided between the liquid supply pump 22a and the valve 24a, and a pressure gauge 32a is provided between the confluence pipe 18a and the valve 30a. In addition, a valve 24b is provided on the liquid supply pipe 22b side and a valve 30b is provided on the inlet side of the insertion pipe 12 in the liquid supply pipe 26b from the liquid supply pump 22b side and a valve 30b is provided on the inlet side of the insertion pipe 12 in the liquid supply pipe 26b that leads to one of the confluence pipes 18b in the confluence pipe 16b inserted into the insertion pipe 12. A pressure gauge 23b is provided between the liquid transfer pump 22b and the valve 24b, and a pressure gauge 32b is provided between the inlet side of the insertion pipe 12 and the valve 30b. Furthermore, in the liquid transfer pipe 26c that runs from the liquid transfer pump 22c to one of the bifurcated pipes of the confluence pipe 18c of the injection pipe 16c inserted into the insertion pipe 12, a valve 24c is provided on the liquid transfer pump 22c side, and a valve 30c is provided on the inlet side of the insertion pipe 12. A pressure gauge 23c is provided between the liquid transfer pump 22c and the valve 24c, and a pressure gauge 32b is provided between the inlet side of the insertion pipe 12 and the valve 30c.

[0025] As shown in Figures 1 and 2(a), liquid B containing an isocyanate compound is supplied from the liquid B supply unit to the other end of the bifurcated pipes of the confluence pipes 18a, 18b, and 18c. The liquid B supply unit is equipped with liquid supply pumps 41a, 41b, and 41c that supply liquid B from the liquid B tank 40 in which liquid B is stored, as shown in Figure 1. A valve 45a is provided on the liquid supply pump 41a side and a valve 40a is provided on the confluence pipe 18a side in the liquid supply pipe 46a from the liquid supply pump 41a to the other end of the bifurcated pipe of the confluence pipe 18a of the injection pipe 16a. A pressure gauge 43a is provided between the liquid supply pump 41a and the valve 45a, and a pressure gauge 42a is provided between the other end of the bifurcated pipe of the confluence pipe 18a and the valve 40a. Furthermore, in the liquid delivery pipe 46b from the liquid delivery pump 41b to the other branch of the bifurcated pipe 18b of the junction pipe 18b of the injection pipe 16b inserted into the insertion pipe 12, a valve 45b is provided on the liquid delivery pump 41b side, and a valve 40b is provided on the inlet side of the insertion pipe 12. A pressure gauge 43b is provided between the liquid delivery pump 41b and the valve 45b, and a pressure gauge 43b is provided between the inlet side of the insertion pipe 12a and the valve 40b. In addition, in the liquid delivery pipe 26c from the liquid delivery pump 41c to the other branch of the bifurcated pipe 18c of the junction pipe 16c inserted into the insertion pipe 12, a valve 45c is provided on the liquid delivery pump 41c side, and a valve 40c is provided on the inlet side of the insertion pipe 12. A pressure gauge 43c is provided between the liquid delivery pump 41c and the valve 45c, and a pressure gauge 42c is provided between the inlet side of the insertion pipe 12 and the valve 40c.

[0026] An injection pipe 16, shown in Figure 2(b), is inserted into the insertion pipe 12 shown in Figure 1. A static mixer 17, acting as a mixer component, is housed inside the tip of the injection pipe 16, with a discharge port opening on its tip surface. A Y-shaped confluence pipe 18 is connected to the rear end of the injection pipe 16. As shown in Figure 2(a), injection pipes 16a, 16b, and 16c, all of the same length and shown in Figure 2(b), are inserted into the insertion pipe 12 shown in Figure 1, with their respective discharge ports located at different positions along the longitudinal direction of the insertion pipe 12. The positions of the discharge ports of injection pipes 16a, 16b, and 16c correspond to the injection zones of the ground 10 (Figure 1). In addition to the Y-shape shown in Figure 2(b), the confluence pipe 18 can also be of known shapes such as the T-shape shown in Figure 2(c), the U-shape shown in Figure 2(d), or the U-shape shown in Figure 2(e).

[0027] An injection pipe 16a, whose discharge port is located at the position of the insertion pipe 12 corresponding to the planned injection zone in the shallow layer of the ground 10, has its rear end protruding outward through the sealing layer 15 that seals the inlet of the insertion pipe 12, and its rear end is connected to a confluence pipe 18a. Liquid A is supplied from the liquid A supply section to one of the bifurcated pipes of the confluence pipe 18a, and liquid B is supplied from the liquid B supply section to the other bifurcated pipe of the confluence pipe 18a. In addition, an injection pipe 16b, whose discharge port is located at the position of the insertion pipe 12 corresponding to the planned injection zone in the middle layer of the ground 10, is inserted into the insertion pipe 12, including its confluence pipe 18b. A liquid delivery pipe for supplying liquid A from the liquid A supply section is connected to one of the bifurcated sections of the confluence pipe 18b, passing through the sealing layer 15. Similarly, a liquid delivery pipe for supplying liquid B from the liquid B supply section is connected to the other bifurcated section of the confluence pipe 18b, also passing through the sealing layer 15. Furthermore, an injection pipe 16c, whose discharge port is located at the position of the insertion pipe 12 corresponding to the planned injection zone in the deep part of the ground 10, is inserted into the insertion pipe 12, including its confluence pipe 18c. A liquid delivery pipe for supplying liquid A from the liquid A supply section is connected to one of the bifurcated sections of the confluence pipe 18c, passing through the sealing layer 15. Similarly, a liquid delivery pipe for supplying liquid B from the liquid B supply section is connected to the other bifurcated section of the confluence pipe 18c, also passing through the sealing layer 15 made of rubber or the like.

[0028] The lengths of these injection tubes 16a, 16b, and 16c can be changed according to the length of the insertion tube 12, but since the length of the insertion tube 12 is approximately 10m, it is preferable to set the lengths to 3.5 to 6m. With injection tubes shorter than 3.5m, the distance over which the combined liquid of solution A and solution B flows is short, and the increase in viscosity of the combined liquid flowing through the injection tube does not need to be a concern. Although this broadens the range of choices for the compositions of solution A and solution B, it tends to increase the number of injection tubes inserted into the insertion tube 12, forcing the insertion tube 12 to have a larger diameter. On the other hand, with injection tubes longer than 6m, the number of injection tubes inserted into the insertion tube 12 can be reduced, and a smaller diameter insertion tube 12 can be used. However, since the distance over which the combined liquid of solution A and solution B flows is longer, it becomes necessary to select compositions of solution A and solution B that can suppress the increase in viscosity of the combined liquid, which tends to narrow the range of choices for the compositions of solution A and solution B.

[0029] The liquid A stored in the liquid A tank 20 of the injection device shown in Figures 1 and 2 contains a polyol, an amine compound, and a viscosity modifier. The polyol can be propylene glycol or a glycerin-initiated polyether polyol. This propylene glycol or glycerin-initiated polyether polyol is a 2-3 functional with propylene glycol or glycerin as the initiator, has a propylene skeleton or a glycerin skeleton, and contains propylene oxide addition. These polyether polyols may be used individually or in combination of two types. The weight-average molecular weight (Mw) of this polyether polyol is preferably 1000 or less, more preferably 700 or less, and even more preferably 600 or less, from the viewpoint of maintaining workability and the compressive strength of the cured product. If the molecular weight exceeds 1000, the viscosity tends to be too high, which tends to lead to a decrease in compatibility and activity, an increase in discharge pressure, and a tendency for injection to stop. It may also adversely affect the strength of the resulting cured product. The polyether polyol content in solution A is preferably 70% by mass or more, and more preferably 80% by mass or more. Below 70% by mass, the compressive strength of the cured product tends to decrease.

[0030] As for the amine compound, an amine compound having a primary amino group is preferable because it can promote the gelation of the mixture of solution A and solution B and prevent elution into water, and alicyclic diamines are preferred. Examples of alicyclic diamines include 4,4'-diaminodicyclohexylmethane and 1,3-bis(aminomethyl)cyclohexane. Such alicyclic diamines may be used alone, but it is preferable to use them in combination with an amine compound having a tertiary amino group because it can improve the degree of curing of the cured product of solution A and solution B. As amine compounds having a tertiary amino group, known compounds can be used without particular limitation, for example, N,N-dimethyloctylamine, N,N-dimethyllaurylamine, N,N,N',N'-tetramethylhexamethylenediamine, N,N,N',N'-tetramethylpropylenediamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N',N''-pentamethyldiethylenetriamine, trimethylaminoethylpiperazine, bis-(dimethylaminoethyl) ether, hexahydro-S-triazine, triethanolamine, triethylenediamine, 2-methyltriethylenediamine, N,N-dimethylaminoethylmorpholine, dimethylaminopropylimidazole, hexamethyltriethylenetetramine, hexamethyltripropylenetetramine, N,N,N-tris(3-dimethylaminopropyl)amine, and the like.

[0031] These amine compounds are preferably present in solution A at a concentration of 10.0% by mass or less, and more preferably at 5.0% by mass or less. Below 2.0% by mass, it tends to be difficult to suppress turbidity, and above 10.0% by mass, initial thickening during application tends to increase. The ratio (by weight) of the amine compound having a primary amino group to the amine compound having a tertiary amino group is preferably 50:10 to 10:50.

[0032] Viscosity modifiers are used to adjust the viscosity of liquid A and to ensure stable injection and curing properties. Known viscosity modifiers can be used without particular limitations, and examples include phthalate esters such as dibutyl phthalate, dioctyl phthalate, and diisononyl phthalate; adipate esters such as dibutyl adipate, dioctyl adipate, diisononyl adipate, and bis(2-(2-butoxyethoxy)ethyl) adipate; trimellitate esters such as tri(2-ethylhexyl) trimellitate; castor oil fatty acid esters; and polyoxyalkylene alkyl ethers. Of these, polyoxyalkylene alkyl ethers and castor oil fatty acid esters are preferred because they have little impact on the environment and are highly safe.

[0033] Viscosity modifiers can be used alone or in a mixture of two or more. The viscosity modifier content in liquid A is preferably 30% by mass or less, and more preferably 10% by mass or less. If it exceeds 30% by mass, the compressive strength tends to decrease.

[0034] In addition to the components described above, known additives such as silicone-based foam stabilizers, diluents, anticorrosion agents, pigments, inorganic fillers, crosslinking agents, and coupling agents may be added to Solution A as needed, within a range that does not impair the objective of the present invention (in a ratio (by weight) of 100:0.5 to 100:10 relative to the polyol).

[0035] The silicone-based foam stabilizer is not particularly limited, and examples include polyoxyalkylene dimethylpolysiloxane copolymer, which is commonly used in rigid polyurethane foam resins.

[0036] Examples of scorch inhibitors include organic acids such as phthalic anhydride, salicylic acid, benzoic acid, and malic acid; nitroso compounds such as N-nitrosodiphenylamine, N-nitrosophenyl-β-naphthylamine, and N-nitroso-2,2,4-trimethyl-1,2-dihydroquinoline; tin compounds such as N-cyclohexylthiophthalimide; and amine compounds such as styrene-diphenylamine.

[0037] From the viewpoint of workability, the viscosity of liquid A used in the present invention is preferably 300 mPa·sec or less at 25°C, more preferably 250 mPa·sec or less, and even more preferably 200 mPa·sec or less.

[0038] In the present invention, solution B, used together with solution A as described above, contains an isocyanate compound. The isocyanate compound is not particularly limited and includes, for example, polyisocyanates such as diphenylmethane diisocyanate and its isomers, polymethylene polyphenyl polyisocyanate (polymeric MDI), xylylene diisocyanate, isophorone diisocyanate, naphthalene diisocyanate, hydrogenated diphenylmethane diisocyanate, trimethylene xylylene diisocyanate, etc., either alone or in mixtures, carbodiimide modified versions of these polyisocyanates, or dimers or trimers obtained by adding a catalyst, either alone or in mixtures. The content of the isocyanate compound in solution B is preferably 28 to 34% by mass, and more preferably 29 to 33% by mass.

[0039] Among these, polymethylene polyphenyl polyisocyanate (polymeric MDI) and its isocyanate-terminated urethane prepolymer are preferred from the viewpoint of being less prone to clouding. These isocyanate compounds can be used alone or in combination of two or more.

[0040] In the present invention, liquid B may, if necessary, be mixed with liquid A to provide a ground-consolidating or water-stopping injection material with self-extinguishing properties. A flame retardant may be added to the liquid B in a ratio (by weight) of 100:5 to 100:20 relative to the isocyanate compound. For example, additive-type flame retardants can be used. Examples of additive-type flame retardants include phosphorus-containing non-halogen compounds such as trimethyl phosphate, triethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, and cresyl diphenyl phosphate; phosphorus-containing halogen compounds such as trischloropropyl phosphate; and halogen-containing compounds such as chlorinated paraffin, pentabromoethylbenzene, and decabromodiphenyl ether. Note that using chlorinated phosphate esters as flame retardants tends to make it difficult to suppress the leaching of components into water.

[0041] In the present invention, solution B may contain, as necessary, conventionally known additives as described in the description of solution A, within a range that does not impair the objective of the present invention (in a ratio (by weight) of 100:0.5 to 100:10 relative to the isocyanate compound).

[0042] From the viewpoint of workability, the viscosity of liquid B used in the present invention is preferably 300 mPa·sec or less at 25°C, more preferably 250 mPa·sec or less, and even more preferably 200 mPa·sec or less.

[0043] In this invention, the ground can be solidified and / or waterproofed by a hardened material obtained by injecting the aforementioned liquid A and liquid B into the ground using the injection device shown in Figures 1 and 2 and allowing it to harden. To obtain such a ground solidification and waterproofing material, it is preferable that the mixing ratio of liquid A and liquid B described above, the reaction equivalent ratio of the OH groups and NH2 groups of the polyol in liquid A to the NCO groups in liquid B, i.e., ((OH+NH2) / NCO), be in the range of 1 / 5 to 5 / 1, and more preferably 1 / 3 to 2 / 1. If this reaction equivalent ratio ((OH+NH2) / NCO) exceeds 5 / 1, the hardened material tends to be soft and have low strength, and if it is less than 1 / 5, the hardening time becomes longer and the hardened material tends to be weak and brittle.

[0044] In this invention, the liquids A and B used are preferably mixed after adjusting each liquid to 20°C, with a rise time of 30 to 90 seconds. More preferably, it is 30 to 60 seconds. If the rise time is less than 30 seconds, workability tends to deteriorate, while if it exceeds 90 seconds, the water present, such as spring water, tends to become cloudy. To achieve a short rise time, it is preferable not to add water as a foaming agent to liquids A and B. This is because a mixture of liquids A and B without added water as a foaming agent hardens before incorporating water, resulting in a high-density hardened product with few voids. The rise time refers to the time from the completion of mixing of liquids A and B until hardening occurs (i.e., the time until gelation progresses and hardening occurs).

[0045] The A and B liquids used in this process are chosen to minimize the environmental impact when the hardened material, formed within the ground, leaks out due to water seepage or groundwater seepage, while ensuring sufficient strength and long-term durability. Therefore, it is preferable that the free expansion ratio of the resulting hardened material be low, for example, 3.0 times or less, more preferably 2.0 times or less, and even more preferably 1.5 times or less. This expansion ratio is calculated by dividing the volume of the hardened material after the hardening reaction by the total volume of the raw materials, A and B. If the free expansion ratio is within the aforementioned range, during injection, within the enclosed ground, the expansion ratio will be 3.0 times or less, preferably 2.0 times or less, due to fluidity and internal pressure, thus ensuring sufficient strength and long-term durability.

[0046] The liquids A and B used in the present invention described above are injected into the ground 10 using the injection device shown in Figure 1. First, one end of the injection pipe 16 to be inserted into the insertion pipe 12 inserted into the ground 10 is directly connected to the liquid A supply pipes 26a, 26b, and 26c shown in Figure 1, and the other end of the injection pipe 16 is inserted into the liquid A tank 20 in which the liquid A is stored. Using the liquid supply pumps 22a, 22b, and 22c respectively, the liquid A in the liquid A tank 20 is circulated, and the amount of liquid supplied from the liquid supply pipes 26a, 26b, and 26c to the injection pipe 16 is adjusted using valves 24a, 24b, 24c and valves 30a, 30b, and 30c respectively so that the amount of liquid supplied to the injection pipe 16 is a predetermined value. Similarly, one end of the injection pipe 16 to be inserted into the insertion pipe 12 is directly connected to the liquid B supply pipes 46a, 46b, and 46c shown in Figure 1, and the other end of the injection pipe 16 is inserted into the liquid B tank 40 where the liquid B is stored. Using the liquid supply pumps 41a, 41b, and 41c respectively, the liquid B in the liquid B tank 40 is circulated, and the amount of liquid supplied from the liquid supply pipes 46a, 46b, and 46c to the injection pipe 16 is adjusted using valves 45a, 45b, 45c and valves 40a, 40b, and 40c to set the amount of liquid supplied to each of the injection pipes 46a, 46b, and 46c to a predetermined value. The amount of liquid A and liquid B supplied to the injection pipe 16 is adjusted so that the reaction equivalent ratio ((OH+NH2) / NCO) between the OH groups and NH2 groups of the polyol in liquid A and the NCO groups in liquid B is in the range of 1 / 5 to 5 / 1, more preferably 1 / 3 to 2 / 1. Next, liquid delivery pipes 26a, 26b, and 26c for liquid A are connected to one of the two branches of the confluence pipes 18a, 18b, and 18c, which are connected to one end of each of the three injection pipes 16 of the same length. Additionally, liquid delivery pipes 46a, 46b, and 46c for liquid B are connected to the other branch of the confluence pipes 18a, 18b, and 18c. Subsequently, each of the three injection pipes 16 is inserted into a predetermined position within the insertion pipe 12 inserted into the ground 10, as shown in Figure 2(a). After sealing the inlet of the insertion pipe 12 with the sealing layer 15, the liquid transfer pumps 22a, 22b, 22c and 41a, 41b, 41c are driven to start the transfer of liquids A and B.

[0047] The injection pressure into the injection pipes 16a, 16b, and 16c, which are connected to the respective confluence pipes 18a, 18b, and 18c, largely depends on the pressure loss due to the increase in viscosity caused by the reaction of the combined liquid of liquid A and liquid B as it flows through the injection pipe, and the pressure loss due to the mixer member attached to the tip. In this respect, since the injection pipes 16a, 16b, and 16c are of the same length and are equipped with the same mixer member, the injection pressure of liquid A into each of the injection pipes 16a, 16b, and 16c can be made approximately the same, and the injection pressure of liquid B can also be made approximately the same.

[0048] Liquids A and B, supplied to the respective confluence pipes 18a, 18b, and 18c, merge and flow through the respective injection pipes 16a, 16b, and 16c. The mixed liquid, mixed by the static mixers 17a, 17b, and 17c, which are mixer components housed in the tips of the pipes, is discharged from the discharge ports on the tip surfaces of the respective injection pipes 16a, 16b, and 16c to positions within the insertion pipe 12 corresponding to the planned injection zone into the ground 10. The mixed liquid discharged into the insertion pipe 12 hardens and flows out into the ground through the through-holes 14 of the insertion pipe 12, where it hardens and forms a solidifying and watertight material within the ground around the entire circumference of the insertion pipe 12.

[0049] When a predetermined time has elapsed since starting the liquid transfer pumps 22a, 22b, 22c and 41a, 41b, 41c and the injection of a predetermined amount of liquid A and liquid B is complete, the liquid transfer pumps 22a, 22b, 22c and 41a, 41b, 41c are stopped. Even before the injection of a predetermined amount of liquid A and liquid B is complete, if the liquid transfer pressure of any of the pressure gauges 32a, 32b, 32c indicating the injection pressure of liquid A or 42a, 42b, 42c indicating the injection pressure of liquid B rises sharply, the liquid transfer pump supplying liquid A and liquid B to the corresponding injection pipe is stopped, and the corresponding valve is closed. This is because the injection zone of the injection pipe where the liquid transfer pressure rose sharply may be complete, or there may be a blockage in the injection pipe. In this case as well, the supply of liquid A and liquid B to other injection pipes where the injection pressure of liquid A and liquid B is maintaining a predetermined pressure is continued, and the predetermined amount of liquid A and liquid B is injected. It is preferable to set the upper limit of the liquid delivery pressure at which the liquid delivery pump is stopped to 8 MPa. This is because general-purpose products can be used as the injection pipe and liquid delivery pipe. However, if the pressure gauges 23a, 23b, 23c on the liquid delivery pumps 22a, 22b, 22c or 43a, 43b, 43c on the liquid delivery pumps 41a, 41b, 41c exceed 8 MPa, it is preferable to stop the corresponding liquid delivery pump in case of blockage of the corresponding liquid delivery pipe.

[0050] When the injection of liquids A and B into all injection tubes is complete, in order to disconnect the insertion tube 12 from the liquid A and liquid B supply sections, the portion of injection tube 16a protruding from the inlet of insertion tube 12 and the liquid A and liquid B supply tubes to injection tubes 16b and 16c, which are fully inserted into insertion tube 12, are cut near the inlet of insertion tube 12, as shown in Figure 1. To facilitate this disconnection, the connection between injection tube 16a and junction tube 18a, and the connection between the liquid A and liquid B supply tubes to injection tubes 16b and 16c, which are fully inserted into insertion tube 12, and the liquid A and liquid B supply sections may be made using one-touch connectors that can be connected and disconnected with a single touch.

[0051] The insertion pipe 12 shown in Figure 1 may be one in which partition plates 19a and 19b are installed at predetermined positions inside, as shown in Figure 3. Furthermore, although the insertion pipes 12 shown in Figures 1 to 3 are inserted diagonally into the ground 10, the insertion angle of the insertion pipe 12 into the ground 10 is arbitrary. [Examples]

[0052] The following describes in detail some embodiments of the present invention, but the scope of the present invention is not limited to these embodiments.

[0053] Example 1 (1) Composition of liquid A and liquid B, and physical properties of the cured product thereof (I) Raw materials used for liquid A (i) Polyol • Polyol (a1-1): A polyether polyol with an average hydroxyl value of 240 mgKOH / g, obtained by addition polymerization of propylene oxide to glycerin (product name: Sannix GP-700, manufactured by Sanyo Chemical Industries, Ltd.) • Polyol (a1-2): A polyether polyol with an average hydroxyl value of 281 mgKOH / g, obtained by addition polymerization of propylene oxide to glycerin (product name: Sannix GP-600, manufactured by Sanyo Chemical Industries, Ltd.) • Polyol (a1-3): A polyether polyol with an average hydroxyl value of 337 mgKOH / g, obtained by addition polymerization of propylene oxide to glycerin (product name: Puranol 305, manufactured by Kagaku Chemical Co., Ltd.) • Polyol (a1-4): A polyether polyol with an average hydroxyl value of 421 mgKOH / g, obtained by addition polymerization of propylene oxide to glycerin (product name: Sannix GP-400, manufactured by Sanyo Chemical Industries, Ltd.) • Polyol (a1-5): A polyether polyol with an average hydroxyl value of 561 mgKOH / g, obtained by addition polymerization of propylene oxide to glycerin (product name: Sannix GP-3000, manufactured by Sanyo Chemical Industries, Ltd.) • Polyol (a1-6): A polyether polyol with an average hydroxyl value of 112 mgKOH / g, obtained by addition polymerization of propylene oxide to propylene glycol (product name: Sannix PP-1000, manufactured by Sanyo Chemical Industries, Ltd.) • Polyol (a1-7): A polyether polyol with an average hydroxyl value of 281 mgKOH / g, obtained by addition polymerization of propylene oxide to propylene glycol (product name: Sannix PP-400, manufactured by Sanyo Chemical Industries, Ltd.)

[0054] (ii) Amine compounds Amine compounds having a primary amino group (b1) • Amine compound (b1-1): 1,3-bis(aminomethyl)cyclohexane (trade name: 1,3-BAC, manufactured by Mitsubishi Gas Chemical Company) • Amine compound (b1-2): 4,4′-diaminocyclohexylmethane (Trade name: JA-69I02, manufactured by Nippon Emulsifier Co., Ltd.)

[0055] Amine compounds having a tertiary amino group (b2) • Amine compound (b2-1): Bis(2-dimethylaminoethyl) ether (product name: TOYOCAT-ET, manufactured by Tosoh Corporation) • Amine compound (b2-2): Triethylenediamine (trade name: TEDA-L33, manufactured by Tosoh Corporation).

[0056] (iii) Viscosity modifiers • Viscosity modifier (c1-1): Polyethylene glycol dimethyl ether (product name: Highsolve MPM, manufactured by Toho Chemical Industry Co., Ltd.) • Viscosity modifier (c1-2): Castor oil fatty acid ester (product name: Ricksizer C-88, manufactured by Ito Oil Co., Ltd.)

[0057] (II) Raw materials used for solution B Isocyanate compounds • Isocyanate compound 1: A mixture of polymeric MDI (trade name: MR-200, manufactured by Tosoh Corporation) and tris(chloropropyl) phosphate (trade name: Phyrol PCF, manufactured by ICL JAPAN). • Isocyanate compound 2: A mixture of polymeric MDI (trade name: C-1567, manufactured by Tosoh Corporation) and tris(chloropropyl) phosphate (trade name: Phyrol PCF, manufactured by ICL JAPAN). (2) Preparation of Agent A and Agent B Solution A and Solution B were prepared by mixing the raw materials for Solution A and Solution B according to the formulations shown in Tables 1 and 2 below.

[0058] (3) Physical properties <Viscosity> The viscosity of the prepared solutions A and B was measured at 25°C using a Type B viscometer (manufactured by Toki Sangyo Co., Ltd.) in accordance with JIS K-7117-1. The results are shown in Tables 1 and 2 below.

[0059] <Evaluation of reactivity and cured product> (Rise time) The above-mentioned liquids A and B, whose temperature was adjusted to 20°C, were mixed in the mixing ratios (by weight) shown in Tables 1 and 2 below to a total volume of 100 mL. The mixture was then hand-mixed for 3 seconds, and the rise time (time until foaming and hardening) was measured. The measured rise times are shown in Tables 1 and 2 below.

[0060] (Expansion ratio) After adjusting the temperature of liquid A and liquid B to 20°C, a total volume of 100 mL was prepared using the mixing ratios (by weight) shown in Tables 1 and 2 below. The mixture was then hand-mixed for 3 seconds to allow free foaming. After the curing reaction was complete, the foaming ratio was calculated by dividing the volume of the cured product by the initial volumes of liquids A and B. The measured foaming ratios are shown in Tables 1 and 2 below.

[0061] (Compressive strength) After adjusting the temperature of liquid A and liquid B to 20°C, a total volume of 100 mL was prepared using the mixing ratios (by weight) shown in Tables 1 and 2 below. The mixture was then hand-mixed for 3 seconds, and the cured material was hardened to a foaming ratio of 1 in a test specimen shape of 50 mmφ × 100 mm. The hardened material was then measured using a precision universal testing machine (manufactured by Shimadzu Corporation) in accordance with JIS-A-9511. From the viewpoint of obtaining sufficient strength and long-term durability, a compressive strength of 60 MPa or higher at 1x foaming is considered good. The measured compressive strengths of the hardened material are shown in Tables 1 and 2 below.

[0062] <Water Pollution Assessment (Turbidity and Defoaming Time)> After adjusting the temperature of liquids A and B to 20°C, a total volume of 100 mL was prepared using the mixing ratios (by weight) shown in Tables 1 and 2 below. The mixture was then hand-mixed for 3 seconds, and the mixture was quickly poured into a 1 L container containing 500 mL of water. The mixture was stirred in the container until foaming began and the resin reached the water surface. After foaming was complete, water was collected from the container, and the turbidity was measured using a turbidimeter (HACH) in accordance with UL1262. A turbidity of 20 degrees or less was considered good. In addition, 100 mL of the water from the foaming container was collected into a separate 250 mL container, and the sealed container was vigorously shaken by hand for 10 seconds. The time until the foam disappeared was visually measured. A defoaming time of 30 seconds or less was considered good. The measured turbidity and defoaming time are shown in Tables 1 and 2 below.

[0063] <Effective Oxygen Index> After adjusting the temperature of liquid A and liquid B to 20°C, a total volume of 100 mL was prepared using the mixing ratios (by weight) shown in Tables 1 and 2 below. The mixture was then hand-mixed for 3 seconds, and the cured product was allowed to harden. Test pieces measuring (80 mm to 150 mm) × 10 mm × 10 mm were cut from the cured product in accordance with JIS-K-7201-2, and measured using a flammability tester ON-2M (manufactured by Suga Test Instruments Co., Ltd.). An effective oxygen index of 22 or higher is considered good. The measured effective oxygen index is shown in Tables 1 and 2 below.

[0064] <Workability> Liquids A and B were mixed and stirred in an insert hose installed inside a 114.3 mmφ steel pipe at the mixing ratio (by weight) shown in Tables 1 and 2 below, and then discharged. A circle (○) indicated successful discharge, while a cross (×) indicated nozzle clogging during discharge. The measured workability is also shown in Tables 1 and 2 below.

[0065] <Waterproofing> The above-mentioned liquids A and B were mixed and stirred in an insert hose installed inside a 114.3 mmφ steel pipe at the mixing ratio (by weight) shown in Tables 1 and 2 below, and then discharged into the flowing water inside the steel pipe, simulating groundwater. Samples that stopped the flow were marked with ○. The measured water-stopping properties are also shown in Tables 1 and 2 below.

[0066] [Table 1]

[0067] [Table 2]

[0068] Liquids A and B, numbered No. 1 to No. 13 in Tables 1 and 2, can be used for ground consolidation and / or waterproofing.

[0069] (4) Experimental apparatus The experiment was conducted using the experimental apparatus shown in Figure 4(a) with liquids A and B shown in No. 3 of Table 1. The experimental apparatus shown in Figure 4(a) is a model apparatus for conducting an experiment corresponding to the injection pipe 16a shown in Figure 2. It comprises a liquid A supply section consisting of a liquid A tank 60 storing liquid A, a liquid supply pump 62, a pressure gauge 64c, a liquid A supply pipe 66, and a valve 68, and a liquid B supply section consisting of a liquid B tank 70 storing liquid B, a liquid supply pump 72, a pressure gauge 74c, a liquid B supply pipe 76, and a valve 78. The liquid A supply pipe 66 is connected to one of the bifurcated pipes of a Y-shaped confluence pipe 88, and the liquid B supply pipe 76 is connected to the other bifurcated pipe of the confluence pipe 88. The confluence pipe 88 is connected to one end of the injection pipe 86 by a one-touch coupler (not shown). The injection pipe 86, as shown in Figure 4(b), has a length L of 3.5m and a pressure resistance of 8MPa (gauge pressure), and a static mixer 87 is attached to the other end. The length from the liquid transfer pump 62 to one branch of the confluence pipe 88 and the length from the liquid transfer pump 72 to the other branch of the confluence pipe 88 are both 3.5m.

[0070] (5) Experiment 1 (Example 1) The individual liquid delivery pressures were measured when liquids A and B, shown in No. 3 of Table 1, stored in liquid tank A 60 and liquid tank B 70 as shown in Figure 4, were delivered to the injection pipe 86 individually while maintaining the liquid temperature of liquids A and B at 30°C. (i) Separate liquid delivery pressure of solution A Liquid A was directly supplied from a liquid supply pump 62 to the other end of an injection pipe 86, one end of which was inserted into the liquid A tank 60. While circulating liquid A in the liquid A tank 60, the pressure of liquid A supplied alone, as shown on the pressure gauge 64a, was measured. The pressure of liquid A supplied alone was 0.23 MPa (gauge pressure). (ii) Separate delivery pressure of solution B The injection pipe 86, with one end inserted into the B liquid tank 70, was used to supply only B liquid directly from the liquid supply pump 72 to the other end. While circulating B liquid in the B liquid tank 70, the pressure of the standalone supply of B liquid, as shown on the pressure gauge 64c, was measured. The standalone supply pressure of B liquid was 0.36 MPa (gauge pressure).

[0071] Next, as shown in Figure 4(a), when liquid A from liquid A tank 60 and liquid B from liquid B tank 70 were simultaneously supplied to the junction pipe 88 connected to the injection pipe 86, the supply pressures of liquid A and liquid B (pressures measured by pressure gauges 64c and 74c) were measured. The supply pressure of liquid A measured by pressure gauge 64c was 1.69 MPa (gauge pressure), and the supply pressure of liquid B measured by pressure gauge 74c was 1.68 MPa (gauge pressure). The supply pressures of liquid A and liquid B were approximately the same.

[0072] (6) Experiment 2 (Example 2) The liquid temperatures of liquids A and B stored in liquid tank 60 and liquid tank 70 were maintained at 20°C, and the individual pumping pressures of liquids A and B were measured in the same manner as in Experiment 1. The individual pumping pressure of liquid A was 0.46 MPa (gauge pressure), and the individual pumping pressure of liquid B was 0.55 MPa (gauge pressure). Furthermore, when liquids A and B were simultaneously pumped into the junction pipe 88, the pumping pressure of liquid A was 2.10 MPa (gauge pressure), and the pumping pressure of liquid B was 2.30 MPa (gauge pressure). The pumping pressures of liquid A and liquid B were approximately the same.

[0073] (7) Experiment 3 (Example 3) The liquid temperatures of liquids A and B stored in liquid tank 60 and liquid tank 70 were maintained at 10°C, and the individual pumping pressures of liquids A and B were measured in the same manner as in Experiment 1. The individual pumping pressure of liquid A was 0.93 MPa (gauge pressure), and the individual pumping pressure of liquid B was 1.41 MPa (gauge pressure). Furthermore, when liquids A and B were simultaneously pumped into the junction pipe 88, the pumping pressure of liquid A was 3.96 MPa (gauge pressure), and the pumping pressure of liquid B was 4.89 MPa (gauge pressure). The pumping pressures of liquid A and liquid B were approximately the same.

[0074] Comparative Example 1 In Experiment 1 of Example 1, the procedure was the same as in Experiment 2, except that the length of the injection pipe 86 was set to 12 m. The liquid temperatures of liquids A and B stored in liquid A tank 60 and liquid B tank 70 were maintained at 30°C, and liquids A and B were simultaneously supplied to the junction pipe 88 connected to the injection pipe 86. The supply pressure of liquid A was 3.69 MPa (gauge pressure), and the supply pressure of liquid B was 3.80 MPa (gauge pressure). These supply pressures were higher than those of the liquid injection in Experiment 1.

[0075] Comparative Example 2 In Comparative Example 1, while maintaining the liquid temperatures of liquids A and B stored in liquid A tank 60 and liquid B tank 70 at 20°C, liquids A and B were simultaneously supplied to a junction pipe 88 connected to an injection pipe 86. The supply pressure of liquid A was 5.40 MPa (gauge pressure), and the supply pressure of liquid B was 5.60 MPa (gauge pressure). These supply pressures were higher than those used for the liquid injection in Experiment 2.

[0076] Comparative Example 3 In Comparative Example 1, while maintaining the liquid temperatures of liquids A and B stored in liquid A tank 60 and liquid B tank 70 at 10°C, liquids A and B were simultaneously supplied to a confluence pipe 88 connected to an injection pipe 86. The supply pressure of liquid A was 7.04 MPa (gauge pressure), but the supply pressure of liquid B reached 8.12 MPa (gauge pressure), exceeding the pressure resistance of the injection pipe 86 (8 MPa), so the supply pumps 62 and 72 were immediately stopped. [Industrial applicability]

[0077] The consolidation and water-stopping method according to the present invention can be used in ground without inflowing water such as groundwater, as well as in ground with inflowing water such as groundwater, and can be applied to civil engineering works such as tunnel construction. [Explanation of Symbols]

[0078] 10,100: Ground, 12,102: Insertion pipe, 14,104: Through hole, 15,112: Sealing layer, 16,16a,16b,16c,86,106a,106b,106c: Injection pipe, 17,17a,17b,17c,87,108a,108b,108c: Static mixer, 18,18a,18b,18c,88,110a,110b,110c: Confluence pipe, 19a,19b: Partition plate, 20,60: Liquid A tank, 22a,22b,22c,41a,41b,41c,62,72: Liquid transfer pumps: 23a, 23b, 23c, 32a, 32b, 32c, 42a, 42b, 42c, 43a, 43b, 43c, 64a, 64c, 74c; Pressure gauges: 24a, 24b, 24c, 30a, 30b, 30c, 40a, 40b, 40c, 45a, 45b, 45c, 68, 78; Valves: 26a, 26b, 26c, 46a, 46b, 46c, 66, 76; Liquid transfer pipes: 40, 70; Liquid B tanks

Claims

1. An insertion pipe is inserted into the ground to be solidified and / or waterproofed, and has multiple through holes drilled along the longitudinal direction of its side wall, A liquid delivery unit delivers liquid A containing a polyol, an amine compound, and a viscosity modifier. A liquid B supply unit that delivers liquid B containing an isocyanate compound, Multiple confluence pipes that merge each of the multiple A liquid flows delivered by the A liquid delivery unit and the B liquid flows delivered by the B liquid delivery unit corresponding to each of the A liquid flows, Each of the aforementioned confluence pipes is connected to an injection pipe, which has a discharge port formed therein for discharging a mixed liquid obtained by mixing the combined liquid of liquid flow A and liquid flow B, which are combined in the confluence pipe, with a mixer member attached. Each of the injection pipes has the same length from the connection end to the junction pipe to the discharge port, and is inserted into the insertion pipe such that the position of the discharge port is at a different position along the longitudinal direction of the insertion pipe, and an injection device is used in which at least some of the multiple junction pipes and injection pipes are inserted into the insertion pipe, The amount of liquid A supplied from the liquid A supply unit is adjusted so that the amount of liquid A supplied to each of the confluence pipes is equal, and the amount of liquid B supplied from the liquid B supply unit is adjusted so that the amount of liquid B supplied to each of the confluence pipes is equal. A ground solidification and watertight construction method characterized in that the mixed liquid discharged from each outlet of the injection pipe hardens and flows out into the ground through each of the through holes of the insertion pipe, and the hardened material solidifies and / or stops water from entering the ground.

2. The ground solidification and watertight construction method according to claim 1, characterized in that each of the injection pipes is inserted into the insertion pipe such that the position of its discharge port corresponds to the planned injection zone of the ground.

3. The ground consolidation and watertight construction method according to Claim 1, characterized in that the length of the injection pipe is 3.5 to 6 m.

4. The ground solidification and watertight construction method according to claim 1, characterized in that the viscosity of both liquid A and liquid B is adjusted to 300 mPa·sec or less at 25°C.

5. The ground solidification and watertight construction method according to claim 1, characterized in that the mixer member is attached to the tip of the injection pipe and the discharge port is formed on the tip surface of the injection pipe.

6. The ground consolidation and watertight sealing method according to claim 1, characterized in that the liquid supply pressure of liquid A to each of the confluence pipes and the liquid supply pressure of liquid B to each of the confluence pipes are adjusted to 8 MPa or less by gauge pressure.

7. The ground consolidation and waterproofing method according to claim 1, characterized in that the aforementioned liquid A contains propylene glycol or a glycerin-starting polyether polyol as a polyol, and an alicyclic diamine having a primary amino group as an amine compound.

8. The ground consolidation and waterproofing method according to claim 7, characterized in that 4,4'-diaminodicyclohexylmethane or 1,3-bis(aminomethyl)cyclohexane is used as the alicyclic diamine.

9. The ground solidification and waterproofing method according to claim 1, characterized in that polyoxyalkylene alkyl ether or castor oil fatty acid ester is used as the viscosity adjusting agent.

10. The ground solidification and watertight construction method according to claim 1 or 9, characterized in that the viscosity modifier is blended into liquid A at an amount of 5 to 15%.

11. The ground consolidation and watertight construction method according to claim 1, characterized in that the aforementioned liquid A and liquid B do not contain a foaming agent.

12. The ground consolidation and waterproofing method according to claim 1, characterized in that the aforementioned liquid B contains polymeric MDI.

Images