JP2021113433A - Ground consolidation agent and ground consolidation method using the same - Google Patents

Abstract

To provide a ground consolidation agent capable of foaming and hardening the ground to develop sufficient strength without intentionally leaving diphenylmethane diisocyanate.SOLUTION: A ground consolidation agent comprises a component (A) containing an active hydrogen compound, a catalyst and water, and a component (B) containing an isocyanate compound. The active hydrogen compound contains an aromatic amine compound. The isocyanate compound contains an isocyanate group-terminated prepolymer obtained by reacting diphenylmethane diisocyanate and a polyether polyol so that the equivalent ratio of NCO group and OH group (NCO group/OH group) is 1.5 to 2.0.SELECTED DRAWING: None

Description

The present invention relates to a ground consolidation agent and a method of ground consolidation using the same.

Conventionally, inorganic or organic grout has been injected to stabilize and strengthen unstable rocks and ground. Inorganic cement milk, which is commonly used, has a slow solidification rate and a slow onset of strength. Therefore, the purpose of quickly stabilizing and strengthening the unstable ground during excavation of a tunnel, which is required to consolidate in a short time and develop strength, could not be achieved.

On the other hand, rigid foamed polyurethane containing polyol and polyisocyanate as main components has been usefully used because it has a high consolidation rate and can consolidate the ground in a short time to develop strength. Patent Document 1 discloses a ground consolidation agent containing a polyoxyalkylene diol and an isocyanate. Diphenylmethane diisocyanate has usually been used as an isocyanate component in these ground-caking agents in order to exhibit good curability and sufficient strength. Even when the isocyanate component is prepolymerized, a partially modified product is used from the viewpoint of suppressing the increase in viscosity, and the design is such that unreacted diphenylmethane diisocyanate is intentionally left.

Japanese Patent No. 3944878

By the way, in "Pharmaceutical Drug Trial No. 1225 No. 1" issued by the Ministry of Health, Labor and Welfare on December 25, 2018, bis (4-isocyanatophenyl) methane (that is, 4,4'-diphenylmethane diisocyanate) is a toxic substance. Based on the judgment, there is a demand for a ground-caking agent that intentionally does not leave diphenylmethane diisocyanate.

On the other hand, when the isocyanate component is prepolymerized, if it is intentionally designed so that diphenylmethane diisocyanate does not remain, it may not be foam-cured or may not exhibit sufficient strength.

An object of the present invention is to provide a ground consolidation agent capable of foaming and hardening to exhibit sufficient strength without intentionally leaving diphenylmethane diisocyanate.

The ground binder according to the embodiment of the present invention comprises a component (A) containing an active hydrogen compound, a catalyst and water, and a component (B) containing an isocyanate compound, and the active hydrogen compound. However, the isocyanate compound contains an aromatic amine compound so that the equivalent ratio (NCO group / OH group) of diphenylmethane diisocyanate and polyether polyol to NCO group and OH group is 1.5 to 2.0. It contains an isocyanate group-terminated prepolymer and xylylene diisocyanate obtained by reacting with.

The method for solidifying the ground according to the embodiment of the present invention includes a step of drilling a plurality of holes in the bedrock or the ground at predetermined intervals, a step of inserting a hollow bolt into the hole, and an opening of the bolt. This includes a step of injecting the above-mentioned ground consolidation agent into the bedrock or the ground and consolidating it.

According to the embodiment of the present invention, a ground consolidation agent capable of consolidating the ground in a short time and exhibiting strength without intentionally leaving diphenylmethane diisocyanate, and a ground consolidation method using the same. Can be provided.

The ground consolidation agent according to the present embodiment comprises a component (A) containing an active hydrogen compound, a catalyst and water, and a component (B) containing an isocyanate compound, and usually contains the component (A). Is a liquid A, and the component (B) is a liquid B, which is a two-component curing type ground consolidation agent. In addition to the component (A) and the component (B), a third component as an optional component may be provided.

[(A) component]
(Active hydrogen compound)
The component (A) contains an active hydrogen compound. The active hydrogen compound is a compound having one or more active hydrogen groups in the molecule (however, water is excluded). Examples of the active hydrogen compound include amine compounds having a primary or secondary amino group and hydroxyl group-containing compounds such as polyols.

In this embodiment, the active hydrogen compound comprises an aromatic amine compound (a1) having a primary or secondary amino group. The amount of the aromatic amine compound (a1) is preferably 15 parts by mass or more with respect to 100 parts by mass of the total amount of the components (A) and (B) from the viewpoint of increasing the compressive strength of the cured product. It is preferably 18 parts by mass or more, and more preferably 20 parts by mass or more. When the content of the aromatic amine compound (a1) is 15 parts by mass or more, the effect of increasing the compressive strength of the cured product is excellent. The upper limit of the content of the aromatic amine compound (a1) is not particularly limited, and may be, for example, 60 parts by mass or less, or 50 parts by mass, based on 100 parts by mass of the total amount of the components (A) and (B). It may be less than or equal to 30 parts by mass or less.

Further, the amount of the aromatic amine compound (a1) is preferably 70 parts by mass or more with respect to 100 parts by mass of the amount of the active hydrogen compound in the component (A) from the viewpoint of increasing the compressive strength of the cured product. It is more preferably 75 parts by mass or more, further preferably 80 parts by mass or more, further preferably 90 parts by mass or more, and may be 100 parts by mass.

Examples of the aromatic amine compound (a1) include aromatic monoamines such as N-methylbenzylamine, dibenzylamine, benzylamine, and p-methylbenzylamine; diaminodiphenylmethane, diaminodiphenyl ether, xylylene diamine, phenylenediamine, diethyl. Aromatic diamines such as toluenediamine and dimethylthiotoluenediamine; aromatic triamines such as 1,3,5-tris (aminomethyl) benzene can be mentioned. These aromatic amine compounds (a1) can be used alone or in combination of two or more.

As the aromatic amine compound (a1), among the above compounds, a bifunctional or higher functional aromatic amine compound is preferable, and diethyltoluenediamine and dimethylthiotoluenediamine are more preferable, from the viewpoint of further improving the compressive strength of the cured product. It is at least one selected from the group consisting of.

As the active hydrogen compound of the component (A), in addition to the above aromatic amine compound (a1), for example, a chain aliphatic amine compound and / or an alicyclic amine compound, a polyether polyol, and a polyester are used. A polyol such as a polyol may be used in combination. In that case, the blending amount of the chain aliphatic amine compound and / or the alicyclic amine compound is not particularly limited, and is, for example, 1 to 30 parts by mass with respect to 100 parts by mass of the active hydrogen compound of the component (A). It may be 3 to 20 parts by mass. Further, the blending amount of the polyol such as the polyether polyol and / or the polyester polyol is not particularly limited, and may be, for example, 1 to 30 parts by mass with respect to 100 parts by mass of the active hydrogen compound of the component (A). It may be up to 20 parts by mass.

(catalyst)
The component (A) contains a catalyst. Examples of the catalyst include tertiary amine compounds.

Examples of the tertiary amine compound include triethylenediamine, 2-methyltriethylenediamine, N, N, N', N'-tetramethylhexamethylenediamine, N, N, N', N'-tetramethylpropylenediamine and N. , N, N', N'-tetramethylethylenediamine, N, N, N', N'-pentamethyldiethylenetriamine, trimethylaminoethylpiperazine, bis- (dimethylaminoethyl) ether, N, N', N''- Tris (dialkylaminoalkyl) -s-hexahydrotriazine, N, N-dimethylaminoethylmorpholine, dimethylaminopropylimidazole, hexamethyltriethylenetetramine, hexamethyltripropylenetetramine, N, N, N-tris (3-dimethyl) Aminopropyl) amines and the like can be mentioned, and these can be used alone or in combination of two or more. Among these, triethylenediamine is preferable from the viewpoint of good foam curability. Further, a triazine-based tertiary amine compound may be used, for example, N, N', N''-tris such as N, N', N''-tris (dimethylaminopropyl) -s-hexahydrotriazine. (Dialkylaminoalkyl) -s-hexahydrotriazine and the like can be mentioned.

The amount of the catalyst is not particularly limited, but is preferably 0.1 to 5.0 parts by mass, more preferably 0.5 to 4.0 parts by mass with respect to 100 parts by mass of the amount of the component (A). be.

(water)
The component (A) contains water. Water acts as a foaming agent because it reacts with the isocyanate compound of the component (B) to generate carbon dioxide gas. The amount of water is preferably 0.2 to 5.0 parts by mass, more preferably 0.3 to 3.0 parts by mass, and further preferably 0 with respect to 100 parts by mass of the amount of the component (A). .5 to 2.0 parts by mass. As a result, it is possible to obtain sufficient compressive strength, long-term durability, and strength development of the cured product while having sufficient foam curability.

(Other ingredients)
In addition to the above-mentioned components, the component (A) includes known additives such as silicone-based foam stabilizers, diluents, flame retardants, pigments, inorganic fillers, cross-linking agents, and coupling agents, if necessary. Can be added as long as the object of the present embodiment is not impaired.

Examples of the silicone-based defoaming agent include polyoxyalkylene dimethyl polysiloxane copolymers usually used for rigid urethane foam resins.

Examples of the diluent include phthalates such as dibutyl phthalate, dioctyl phthalate and diisononyl phthalate, adipates such as dibutyl adipate, dioctyl adipate, diisononyl adipate and bis (2- (2-butoxyethoxy) ethyl) adipate, and tri. Examples thereof include trimellitic acid esters such as (2-ethylhexyl) trimellitate.

As the flame retardant, either an additive type or a reaction type can be used. Specific examples of the additive type include phosphorus-containing systems such as triethyl phosphate and tricresyl phosphate, and phosphorus-containing halogen-containing systems such as trismonochloroisopropyl phosphate; halogen-containing systems such as chlorinated paraffin, pentabromoethylbenzene, and decabromodiphenyl ether. Examples include those of the system.

(viscosity)
In the present embodiment, the viscosity of the component (A) is preferably 650 mPa · s or less, more preferably 600 mPa · s or less, still more preferably 500 mPa · s or less at 25 ° C. from the viewpoint of workability. Is.

[(B) component]
The component (B) contains an isocyanate compound. In the present embodiment, the isocyanate compound is obtained by reacting diphenylmethane diisocyanate and a polyether polyol so that the equivalent ratio of NCO group to OH group (NCO group / OH group) is 1.5 to 2.0. Isocyanate group-terminated prepolymer (b1) (hereinafter, also simply referred to as prepolymer (b1)), and xylylene diisocyanate (b2).

Equivalent ratio of isocyanate group to hydroxyl group When the NCO group / OH group is 1.5 or more, the viscosity of the prepolymer (b1) can be reduced and the viscosity of the component (B) can be reduced. The reason why the corresponding amount ratio NCO group / OH group is 2.0 or less is to design so that diphenylmethane diisocyanate does not remain intentionally. The corresponding amount ratio NCO group / OH group is preferably 1.6 or more, more preferably 1.7 or more, from the viewpoint of promoting low viscosity.

Examples of the polyether polyol constituting the prepolymer (b1) include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, 1,3-butanediol, 1,4-butanediol, and 1 , Diols such as 6-hexanediol; Polyols such as glycerin, trimethylolpropane, pentaerythritol, diglycerin, sorbitol, sucrose; Diols such as ethylenediamine, diethylenetriamine, triethylenetetramine; Alkanolamines such as monoethanolamine, diethanolamine, etc. It is obtained by using one or more alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, and styrene oxide in a single compound containing divalent or higher active hydrogen or a mixture thereof, and performing addition polymerization by a known method. Examples include polyols.

As the polyether polyol constituting the prepolymer (b1), propylene oxide and / or ethylene oxide is additionally polymerized with a divalent alcohol from the viewpoint of lowering the viscosity of the prepolymer (b1) and improving the compressive strength of the cured product. It is preferable to use at least one selected from the group consisting of diols having a hydroxyl value of 140 to 560 mgKOH / g.

When the hydroxyl value of the diol is 140 mgKOH / g or more, it is advantageous for foam curing to develop sufficient strength. Further, the hydroxyl value of the diol being 560 mgKOH / g or less is advantageous in promoting the lowering of the viscosity of the prepolymer (b1). The hydroxyl value of the diol is more preferably 150 mgKOH / g or more, and may be 160 mgKOH / g or more. Further, it is preferably 400 mgKOH / g or less, and more preferably 300 mgKOH / g or less. Here, the hydroxyl value is measured according to the method A of JIS K1557-1: 2007.

As the diphenylmethane diisocyanate (MDI) constituting the prepolymer (b1), 4,4'-MDI or a mixture of 4,4'-MDI and 2,4'-MDI is usually used.

The content of NCO groups in the prepolymer (b1) is not particularly limited, but the ratio of NCO groups is preferably 4.8 to 10% by mass, more preferably, with the entire prepolymer (b1) as 100% by mass. Is 5.0 to 8.0% by mass.

The component (B) contains xylylene diisocyanate (b2) as an isocyanate compound together with the prepolymer (b1). Xylylene diisocyanate (XDI, also known as 1,3-bis (isocyanatomethyl) benzene) is an aromatic aliphatic isocyanate and is a non-toxic deleterious isocyanate compound. By using xylylene diisocyanate (b2) together with the prepolymer (b1), the ratio of NCO groups in the component (B) can be increased while reducing the viscosity of the component (B), and the component (A) can be increased. It is possible to improve the reactivity with and to improve the compressive strength of the cured product.

The blending ratio of the isocyanate group-terminated prepolymer (b1) and the xylylene diisocyanate (b2) is 50/50 to 90/10 from the viewpoint of reducing the viscosity of the component (B) and improving the compressive strength of the cured product. It is preferable, and more preferably 60/40 to 80/20.

(Other ingredients)
If necessary, the conventionally known additives described in the section of the component (A) can be added to the component (B) as other components within a range that does not impair the object of the present embodiment.

(viscosity)
In the present embodiment, the viscosity of the component (B) is preferably 650 mPa · s or less, more preferably 600 mPa · s or less, still more preferably 500 mPa · s or less at 25 ° C. from the viewpoint of workability. Is.

[Mixing of component (A) and component (B)]
The component (A) and the component (B) are mixed at the time of use to form a cured product.

(mixing ratio)
The mixing ratio of the component (A) and the component (B) is not particularly limited, and for example, the active hydrogen group (NH ₂ , OH; including the active hydrogen group of water) in the component (A) and (B). The reaction equivalent ratio with the isocyanate group (NCO) in the component, that is, the NCO / active hydrogen group may be 1/3 to 3/1, 1/2 to 2/1, or 3/2 to 2/3. It may be 5/4 to 4/5.

[Consolidation method of the ground]
The ground consolidation agent according to the present embodiment is used to stabilize and strengthen rocks having a crush zone, unstable soft ground, etc. during tunnel excavation, and contains components (A) and (B). The ground can be consolidated by mixing and injecting into rock or ground.

The method of injection and consolidation is not particularly limited, and a known method can be adopted. For example, in a step of drilling a plurality of holes at predetermined intervals in a bedrock or the ground, a hollow bolt is provided in the holes. It is preferable to include a step of inserting and a step of injecting the above-mentioned ground consolidation agent into the bedrock or the ground through the opening of the bolt to consolidate the ground.

For example, using a pump that can control the injection amount, pressure, blending ratio, etc. of the components (A) and (B), the components (A) and (B) are placed in separate tanks and permeated. A perforated lock bolt or injection rod with a pre-fixed static mixer or check valve is passed through the tunnel face or top plate of difficult sandy soil, and the component (A) in the tank is inserted into this. The component (B) is injected at an injection pressure of 0.05 to 5 MPa, and the component (A) and the component (B) uniformly mixed through a static mixer are permeated into the ground and cured. As a result, the ground can be consolidated and stabilized.

With the ground consolidation agent according to the present embodiment, it is possible to consolidate the ground in a short time and develop strength without intentionally leaving diphenylmethane diisocyanate. Specifically, the equivalent ratio of NCO group to OH group when obtaining the prepolymer (b1) is set to 2.0 or less, so that diphenylmethane diisocyanate is not intentionally left in the component (B). However, by using xylylene diisocyanate (b2) in combination as the isocyanate compound and using an aromatic amine compound as the active hydrogen compound of the component (A), foam curing can be performed and sufficient strength can be exhibited. ..

Here, the fact that diphenylmethane diisocyanate is not intentionally left means that the diphenylmethane diisocyanate is not left in the component (B) by design as described above. As described above, the component (B) is formulated so that diphenylmethane diisocyanate does not remain in the design, but those containing a small amount of unreacted 4,4'-diphenylmethane diisocyanate as an impurity, for example, in an amount of 2% by mass or less are excluded. It's not a thing.

The ground consolidation agent according to the present embodiment can be made to have a low viscosity and excellent workability, and further, it can suppress white turbidity when it comes into contact with water.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples. The present invention is not limited thereto.

<Preparation of solution A>
The following raw materials were used to prepare Solution A according to the formulation shown in Table 3. The content of the aromatic amine compound (a1) in 100% by mass of the amount of the active hydrogen compound in the liquid A is shown in Table 3 as "(a1) content (%) in the active hydrogen compound".

[Aromatic amine compound (a1)]
-Aromatic amine compound 1: Diethyl toluenediamine (trade name: DETDA80, manufactured by Lonza Japan Co., Ltd.)
-Aromatic amine compound 2: Dimethylthiotoluenediamine (trade name: EtaCure 300, manufactured by Mitsui Kagaku Fine Co., Ltd.)

[Aliphatic amine compound]
Aliphatic amine compound 1: Polyoxypropylene triamine (trade name: polyetheramine T-403, manufactured by Mitsui Kagaku Fine Co., Ltd., Mw: 440)

[Polyether polyol]
-Polyel polyol 1: Polyether polyol having a hydroxyl value of 750 mgKOH / g obtained by addition polymerization of propylene oxide to ethylenediamine (trade name: Excelol 750ED, manufactured by AGC Inc.)
-Polyol polyol 2: A polyether polyol having a hydroxyl value of 450 mgKOH / g obtained by addition polymerization of ethylene oxide and propylene oxide to ethylenediamine (trade name: Excelol 450ED, manufactured by AGC Inc.).

[catalyst]
-Catalyst 1: Dipropylene glycol solution of triethylenediamine (trade name: TEDA-L33, manufactured by Tosoh Corporation, TEDA content: 33%)

[Flame retardants]
-Flame retardant 1: Tris (chloropropyl) phosphate (trade name: TMCPP, manufactured by Daihachi Chemical Industry Co., Ltd.)

<Preparation of prepolymer (b1)>
The prepolymer (b1) was synthesized using the following raw materials. Specifically, 43 parts by mass of the polyether polyol 3, 37 parts by mass of the isocyanate compound 1, and 20 parts by mass of the flame retardant 2 were mixed and reacted at 80 ° C. for 2 hours to synthesize the prepolymer 1. Similarly, prepolymers 2 to 4 were synthesized with the formulations shown in Table 1 below. Equivalent ratio of NCO group to OH group when synthesizing prepolymer (b1) "NCO / OH ratio" and content of NCO group in the obtained prepolymer (b1) "F-NCO (mass%)" Is shown in Table 1. Each component in Table 1 is as follows.

[Polyether polyol]
-Polyether polyol 3: A polyether polyol having a hydroxyl value of 187 mgKOH / g obtained by addition polymerization of ethylene oxide to diethylene glycol (trade name: PEG-600S, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
-Polyel polyol 4: Polyether polyol having a hydroxyl value of 280 mgKOH / g obtained by addition polymerization of propylene oxide to propylene glycol (trade name: Excelol 420, manufactured by AGC Co., Ltd.)

[Isocyanate compound]
-Isocyanate compound 1: Diphenylmethane diisocyanate (MDI) (trade name: Millionate NM, manufactured by Tosoh Corporation)

[Flame retardants]
-Flame retardant 2: Triethyl phosphate (trade name: TEP, manufactured by Daihachi Chemical Industry Co., Ltd.)

<Preparation of solution B>
Liquid B was prepared using the above prepolymers 1 to 4 and the following raw materials in the formulation shown in Table 2 below. Table 2 shows the NCO group content "NCO (mass%)" in 100% by mass of Liquid B.

[Foaming agent]
・ Defoamer 1: Silicone defoamer (trade name: SZ-1671, made by DOW)

[Isocyanate compound]
-Isocyanate compound 2: Xylylene diisocyanate (XDI) (trade name: Takenate 500, manufactured by Mitsui Chemicals, Inc.)

[viscosity]
The prepolymers (b1), solutions A and B prepared above were viscous at 25 ° C. (mPa. s) was measured. The results are shown in Tables 1-3.

[Evaluation of cured product]
(Rise time, foaming magnification)
Liquid A and liquid B are separately separated by the liquid ratio shown in Table 3 (mass ratio of liquid A and liquid B is A / B = 1 / x, and the value of x is shown in Table 3. The same applies hereinafter). Prepared. After the temperatures of both solutions A and B were set to 20 ° C., the solutions A and B were mixed by hand mixing, and the rise time (time from the start of stirring to the completion of foaming) was measured. After completion of the curing reaction, the foaming ratio was calculated by dividing the volume of the cured product by the initial volumes of the raw materials A and B.

Table 3 shows the reaction equivalent ratio "NCO / active hydrogen group" of the isocyanate group in the solution B and the active hydrogen group in the solution A as the mixing ratio of the solution A and the solution B. The content of the aromatic amine compound (a1) in 100% by mass of the total amount of the liquid A and the liquid B is shown in Table 3 as "(a1) content (%) in (liquid A + liquid B)".

(Compressive strength)
Solution A and solution B were prepared separately at the mixing ratios shown in Table 3. A quadruple foam was obtained by mixing and curing liquid A and liquid B using a container having a diameter of 50 mm and a height of 100 mm so as to form a quadruple foam. The compressive strength of the obtained quadruple foam having a diameter of 50 mm and a height of 100 mm was measured with a Shimadzu universal testing machine in accordance with JIS A1216.

[Underwater cloudiness test]
Solution A and solution B were prepared separately at the mixing ratios shown in Table 3. After the temperature of both solutions A and B was set to 20 ° C., a total of 100 g of these solutions A and B was mixed by hand mixing for 10 seconds, and then the mixture was immediately put into a container containing 1 L of water. After the foaming is completed, water is collected from the inside of the container, and the turbidity of the water is visually measured and measured with a spectrophotometer (Hitachi Spectrophotometer U-3900H (manufactured by Hitachi High-Technologies Corporation)). )). Those with white turbidity were evaluated as "x", and those without white turbidity were evaluated as "○". Further, the transmittance by the spectrophotometer is preferably 80% or more.

The results are shown in Table 3. As shown in Table 3, in Comparative Example 1 in which only the prepolymer 1 was used as the isocyanate compound and the liquid B (B-2) in which the xylylene diisocyanate was not used was used, the viscosity of the liquid B was high and the liquid B was mixed with the liquid A. However, it did not foam and cure. Further, in Comparative Example 2 in which the aromatic amine compound was not used in the liquid A, the foaming rate was slow and sufficient compressive strength could not be obtained, and in addition, the water became cloudy in the underwater cloudiness test. On the other hand, in Examples 1 to 10 in which the aromatic amine compound was used in the solution A and the prepolymers 1 to 4 and the xylylene diisocyanate were used in combination with the solution B, foaming and curing were performed in a short time, and the cured product was sufficient. It had a high strength and did not become cloudy when touched with water.

Although some embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments, omissions, replacements, changes, etc. thereof are included in the scope and gist of the invention, as well as in the scope of the invention described in the claims and the equivalent scope thereof.

In the present embodiment, a ground consolidation agent and a ground consolidation agent capable of exhibiting sufficient strength capable of stably strengthening unstable rocks, ground, etc. without intentionally leaving diphenylmethane diisocyanate and the like are used. It is possible to provide a method of consolidation of the existing ground.

Claims (7)

It comprises a component (A) containing an active hydrogen compound, a catalyst and water, and a component (B) containing an isocyanate compound.
The active hydrogen compound contains an aromatic amine compound and contains.
The isocyanate compound is an isocyanate group terminal obtained by reacting diphenylmethane diisocyanate and a polyether polyol so that the equivalent ratio of NCO group to OH group (NCO group / OH group) is 1.5 to 2.0. Contains prepolymers and xylylene diisocyanates,
Ground consolidation agent. The ground binder according to claim 1, wherein the polyether polyol is a diol having a hydroxyl value of 140 to 560 mgKOH / g obtained by addition polymerization of propylene oxide and / or ethylene oxide to a dihydric alcohol. The ground consolidation agent according to claim 1 or 2, wherein in the component (B), the compounding ratio of the isocyanate group-terminated prepolymer and the xylylene diisocyanate is 50/50 to 90/10 by mass ratio. .. The ground according to any one of claims 1 to 3, wherein the amount of the aromatic amine compound is 15 parts by mass or more with respect to 100 parts by mass of the total amount of the component (A) and the component (B). Mountain binder. The ground binder according to any one of claims 1 to 4, wherein the amount of the aromatic amine compound is 70 parts by mass or more with respect to 100 parts by mass of the amount of the active hydrogen compound. The ground consolidation agent according to any one of claims 1 to 5, wherein the viscosities of the component (A) and the component (B) are 650 mPa · s or less at 25 ° C., respectively. The process of drilling multiple holes in rock or ground at predetermined intervals,
The process of inserting a hollow bolt into the hole, and
A step of injecting the ground solidifying agent according to any one of claims 1 to 6 into a rock or the ground through the opening of the bolt and consolidating the ground.
How to consolidate the ground, including.