JPH04318096A - Grouting liquid composition for stabilizing soil, etc., and stabilization and reinforcement of soil using the same - Google Patents

Abstract

PURPOSE:To provide a grouting liquid composition useful for the consolidation and stabilization of an unstable part of a rock-bed, ground, artificial construction, etc., and to provide a stabilization, reinforcement and water-stopping process using the grouting composition. CONSTITUTION:The objective grouting liquid composition is composed of (A) an aqueous solution of sodium silicate and (B) a hydrophilic urethane prepolymer containing oxyethylene chain. A ground or an artificial construction can be stabilized and reinforced by injecting and solidifying the grouting composition. Since the hydrophilic urethane prepolymer (B) has high compatibility with the aqueous solution of sodium silicate (A) and high affinity to rock-bed, ground and artificial construction, the composition has improved penetration property into the rock-bed, etc., the strength of the consolidated composite is increased and the safety of the application work is improved.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is useful for solidifying and stabilizing bedrock with fracture zones, unstable soft ground, rock or ground with water leaks and springs, and also for stabilizing cracks and voids in artificial structures such as concrete. The present invention relates to a reinforcement construction method and an injection drug composition used therefor.

0002

[Prior Art and Problems to be Solved by the Invention] Conventionally, inorganic or organic grout has been injected as a method for stably strengthening unstable rock and ground, and filling cracks and voids in artificial structures. It is having some effect.

However, when these methods are examined in detail, they do not necessarily yield satisfactory results. For example, the cement milk system that is commonly used is in the form of a suspension, so it has poor permeability into cracks in rock and artificial structures, and into ground layers such as gravel, and the consolidation rate is slow, resulting in strength development. Because of the slowness of the process, it is impossible to achieve the goal of quickly stabilizing and strengthening unstable ground during tunnels and underground excavations, which require solidification and strength development in a short period of time. Furthermore, if there is spring water or water leakage, the injected cement milk will be diluted and washed away. In addition, water glass two-component system grout, which is a typical inorganic grout, has a solid strength of 3 to 10 kg/cm2.
To a lesser extent, when the solid body comes into contact with water, changes occur over time, and main components such as Na2O and SiO2 are leached out.
There are problems with alkali contamination and a significant decrease in strength.

On the other hand, organic grouts such as urea grouts also have problems such as insufficient consolidation strength and elution of curing components and auxiliary components such as sulfuric acid and formalin. Also,
JP 63-63687, JP 63-63688, JP 63-7413, JP 63-749
Publication No. 0, Publication No. 63-7491, Publication No. 63-84
Publication No. 77 and Publication No. 63-35913, etc., describe a method of solidifying rock by injecting a fast-curing rigid foam urethane system containing polyol and polyisocyanate as main components, but although the consolidation effect can be expected, It is extremely expensive and flammable, and needs to be improved in terms of economy and safety.

Further, in JP-A-61-9482 and JP-A-55-160079, using polyisocyanate and water glass (sodium silicate aqueous solution),
A liquid injection composition is described in which a specific tertiary amine or a Mannich base such as an amino alcohol is blended as a polyisocyanate trimerization catalyst on the water glass side. Although this composition is flame retardant, it requires an expensive trimerization catalyst, and it also requires dilution with a large amount of organic solvent to increase the fluidity of the polyisocyanate. There is a problem of poor compatibility. Expensive agents such as silicone polyols are required to increase compatibility.

[0006]

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned problems of the prior art. By forming a solid body, it is possible to stably strengthen rock or ground and artificial structures with high consolidation strength, stable reinforcement effect, durability, ease of injection work, safety, and economy. .

That is, the present invention provides an injection chemical composition for stabilizing soil or artificial structures, comprising (A) an aqueous sodium silicate solution and (B) a hydrophilic urethane prepolymer having an oxyethylene chain and a free isocyanate group. A first invention provides a method for drilling several holes at predetermined intervals in rock or ground, inserting a hollow injection bolt into the holes,
A second method for stably strengthening rock or ground characterized by injecting and solidifying the injection chemical composition through an opening of a bolt.
invention, and furthermore, inserting an injection pipe into an artificial structure,
A third invention provides a method for stably reinforcing an artificial structure, characterized by injecting the injection chemical composition into the injection pipe and solidifying it.

[0008]

[Example] Although the solidification reaction in the present invention is extremely complicated and not clear, when a sodium silicate aqueous solution (A) and a urethane prepolymer (B) are mixed, a solidification reaction is formed as a part of the component (A). The silanol groups in component (B) react with the isocyanate groups in component (B) to form a silicic anhydride-urethane complex, and component (B) reacts with water to generate carbon dioxide gas and bond with urea to form a multimer. or silicic anhydride
It is presumed that a urea crosslinked complex is formed, and the generated carbon dioxide gas is absorbed into the alkaline aqueous solution in component (A) and gels the sodium silicate to form an anhydrous silicic acid gel.

The injectable drug composition (hereinafter also referred to as injectable drug) of the present invention will be described below.

First, as the sodium silicate aqueous solution of component (A), as mentioned above, a commercially available sodium silicate aqueous solution is used as the main component. This sodium silicate is represented by the formula: Na2O.xSiO2.nH2O, and the molar ratio of Na2O and SiO2 is 2:1 to 1:4.
It is. The solid content concentration of the aqueous solution is usually 10 to 70.
It is preferable to adjust the amount to 20 to 40% by weight.

Component (B) is a free isocyanate obtained by reacting (a) a polyoxyalkylene mono or polyol having 5% by weight or more of oxyethylene chains in the oxyalkylene chain and (b) an organic polyisocyanate. is a hydrophilic urethane prepolymer containing groups. By introducing an oxyethylene chain into the skeleton of this urethane prepolymer, hydrophilicity can be imparted, and the compatibility with the sodium silicate aqueous solution of component (A) can be significantly improved. Therefore, there is no mixing failure in the injection equipment that often occurs at construction sites.
A uniform solid can be formed. In addition, the chemical solution has good adhesion to wet bedrock or ground or artificial structures at sites where there is a lot of water leakage, and the adhesion of the solid body to bedrock or ground or artificial structures is good.

(B) Component monool or polyol (A) includes, for example, methanol, ethanol,
Monools such as propanol, butanol, octanol, lauryl alcohol; ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-
Diols such as butanediol and 1,6-hexanediol; polyols such as glycerin, trimethylolpropane, and pentaerythritol; and mono-, di-, or triethanolamine, diglycerin, sorbitol, sucrose, etc. alone or in combination with ethylene oxide. Examples include monools or polyols obtained by addition polymerization using propylene oxide or butylene oxide in combination with known methods, and the oxyethylene chains in the oxyalkylene chains are 5% by weight or more, preferably 10 to 10% by weight.
It contains 100% by weight.

The organic polyisocyanate (b) to be reacted with the monool or polyol of component (a) is as follows:
For example, polymethylene polyphenyl polyisocyanate, liquid diphenylmethane diisocyanate, tolylene diisocyanate, crude tolylene diisocyanate,
Xylylene diisocyanate, isophorone diisocyanate, naphthalene diisocyanate, hydrogenated diphenylmethane diisocyanate and the like are preferably used alone or in mixtures.

(B) Component urethane prepolymer is:
The NCO/OH equivalent ratio of component (a) and component (b) is 1.5.
-100, preferably 2.0-50, by a known method. The resulting urethane prepolymer usually has substantially unreacted isocyanate groups at its ends.

Even when mixed with component (B) in the composition of the present invention, it does not react with isocyanate groups, and therefore (B)
It has an excellent effect on storage stability and viscosity reduction of ingredients, and on the other hand, (
A) A reactive diluent such as sodium silicate, which immediately reacts and hardens when mixed with the component and has little impact on the environment, may be blended.

[0016] Compared to the case where no reactive diluent is mixed, (B) greatly improves the permeability into rock and ground due to the lower viscosity of the component; and ■ lower volatility, which improves occupational safety, environment and health. Preferred (1) (B) The storage stability of the components is improved. (2) A composite reaction solidified structure is obtained by the reaction, and effects such as a significant improvement in the strength of the solidified body are achieved.

As mentioned above, the reactive diluent must be a liquid with low viscosity at the operating temperature (approximately -5 to 40°C) and have low volatility; (B) it must be inert to the components; )
be hydrolyzed by the components, and that the hydrolysis products are (
Preferably, those that meet the requirements of reacting with component A) and/or component (B) are preferred. The reactive groups of the hydrolysis product include hydroxyl group, carboxyl group, primary or secondary amino group, thiol group, etc.
It is preferable to have at least one.

Typical examples of reactive diluents include diesters of low molecular weight dibasic acids, acetate esters of mono- or polyhydric alcohols, alkylene carbonates, ethers, cyclic esters, acid anhydrides, and various Examples include acrylic esters and methacrylic esters.

Examples of diesters of low molecular weight dibasic acids include dimethyl esters such as glutaric acid, succinic acid, adipic acid, malonic acid, oxalic acid, and pimelic acid;
Examples include dialkyl esters such as diethyl ester.

[0020] As acetic esters of alcohols,
For example, acetates of glycol ethers such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, propylene glycol methyl ether, ethyl carbitol, and butyl carbitol; alkoxyalkyl alcohols such as 3-methoxybutyl alcohol and 3-methyl-3-methoxybutyl alcohol. and diacetates of glycols such as ethylene glycol, diethylene glycol, and triethylene glycol.

Examples of alkylene carbonates include propylene carbonate.

Ethers include tetrahydrofuran,
Examples include cyclic ethers such as dioxane and dehydrated castor oil.

Examples of the cyclic esters include lactones such as γ-butyllactone; lactams such as ε-caprolactam.

Various acrylic esters or methacrylic esters include alkyl esters of acrylic acid or methacrylic acid such as methyl, ethyl, and butyl, as well as acrylic acid or methacrylic acid and ethylene glycol, diethylene glycol, with a molecular weight of 100 to 1000.
Examples include polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol with a molecular weight of 100 to 1,000, ethylene oxide with a molecular weight of 100 to 5,000, and esters of propylene oxide with alcohols such as copolymerized diols or triols.

[0025] Examples of the acid anhydride include maleic anhydride.

[0026] Plasticizers used in general-purpose resins, such as dioctyl phthalate, dibutyl phthalate, dioctyl adipate, chlorinated paraffin, process oil, etc., may also be used in combination.

[0027] The reactive diluent and plasticizer consist of component (A) and (
B) It is preferable to mix 0 to 100% by weight of the total amount of components.

The present composition may further contain inorganic fillers such as cement, blast furnace slag, gypsum, calcium carbonate, clay, aluminum hydroxide, antimony trioxide, quicklime, slaked lime, and bentonite. These inorganic fillers have the property of curing and forming a composite compact when mixed with component (A), and as a result, the compaction strength is improved and the crack and void filling sealing effect is also improved. The blending amount of these inorganic fillers is 0 to 80% by weight based on component (B);
It is preferably 0 to 50% by weight.

[0029] A curing accelerating catalyst may be blended into the injection chemical solution to accelerate the reaction with the urethane prepolymer of component (B). From the viewpoint of catalytic activity and storage stability, such curing accelerating catalysts are particularly preferably tertiary alkylamines or cyclic amines, such as dimethyloctylamine, dimethyllaurylamine, morpholine, piperazine, and the like. Other examples include dibutyltin dilaurate, triethylenediamine, imidazole, monoethanolamine, diethanolamine, and triethanolamine. The amount of curing accelerating catalyst is as follows:
The amount is 0.1 to 20% by weight, preferably 0.5 to 15% by weight, based on component (B).

Further, if necessary, a surfactant may be used to emulsify and disperse the curing accelerating catalyst into the injection chemical solution. For example, when using a tertiary alkylamine as a curing accelerating catalyst, any anionic, nonionic, cationic, or amphoteric surfactant can be used, and specific examples include alkyl sulfates, alkylbenzene sulfonates, and ethoxyalkyl sulfates. , aqueous solutions of sodium salts such as ethoxyalkylbenzene sulfates, amine salts, ammonium salts, etc., alkyl phosphates, and nonionic surfactants prepared by addition polymerizing several moles of ethylene oxide to alcohols and alkylphenols. The amount of these surfactants ranges from 1 to 100%, preferably from 10 to 20% by weight of the curing accelerating catalyst.
It is.

In addition, a silicone foam stabilizer such as organopolysiloxane is added to component (A) and/or (B).
It may be blended into the ingredients.

In order to improve the elasticity and mechanical strength of the solid body, various polymeric materials such as solvent-type vulcanized or unvulcanized rubber such as butadiene rubber, chloroprene rubber, styrene-butadiene rubber, and ethylene can be used. −
When injecting propylene rubber, emulsions thereof, various polyacrylic resin emulsions, polyvinyl alcohol, ethylene-vinyl acid acid emulsions, polyurethane resin dispersions, polyethylene oxide, asphalt emulsions, etc., (A) component and/or (B)
It can also be added to the ingredients in the required amount.

[0033] Furthermore, if necessary, stabilizers such as various anti-aging agents, heat resistance imparting agents, antioxidants, etc. can be added to the component (B). The blending amount of these stabilizers may generally be 0 to 2% by weight in component (B).

[0034] Blending ratio of (A) component and (B) component (
(A) component/(B) component) cannot be determined unconditionally because it varies depending on the composition ratio of Na2O and Si2O contained in component (A), but it is usually 10/100 to 100 in weight ratio. /10, preferably 20/
It is desirable to adjust the ratio to 100 to 100/20. If the ratio is less than 10/100, the cost of the injected drug becomes expensive and uneconomical, and it becomes extremely difficult to control the mixing ratio with a proportional infusion pump, resulting in slow effects. Also 100/10
If it exceeds this range, the solidification will be insufficient and the product will be unhardened, and even if it hardens, it will be very weak and brittle and cannot be put to practical use.

The injection drug composition of the present invention comprises two components: a sodium silicate aqueous solution (A) and a urethane prepolymer (B).
It is preferably used in liquid form, and both components are mixed immediately before injection into rock or the like. The mixing method will be described later, or if the gelation time is long or for small-scale injection, known methods such as mixing component (A) and component (B) in advance and injecting using a one-shot method can be used. can be adopted.

(A) When using the sodium silicate aqueous solution alone, prepare the component (A) at a solid content concentration of about 10 to 10% as described above.
The amount may be 70% by weight, but when other components such as a curing accelerating catalyst are added, a surfactant may be used if necessary to sufficiently disperse them with stirring.

[0037] This is a special injection drug solution in the present invention (A
) component and (B) component is injected into soft or unstable ground with many voids and cracks, bedrock, fractured zones, and even artificial structures with cracks and voids. However, there are no particular limitations on the method of injecting and solidifying, and any known method may be employed. For example, (A) component and (B
) Using a proportional mixing pump that can control the injection amount, pressure, and mixing ratio of the ingredients, (A) and (B) are combined.
The components are placed in separate tanks, and static mixers, check valves, etc. fixed in advance are installed in predetermined locations such as rock (for example, multiple holes drilled at intervals of about 0.5 to 3 m). Each component in the tank is injected into the tank through a perforated rock bolt or injection rod at a pressure of 0.
．． Inject at 5 to 50 kg/cm2・G, pass through a static mixer, uniformly mix predetermined amounts of component (A) and component (B), inject into a predetermined unstable rock or ground location, harden and solidify. There are methods to stabilize the bond.

[0038] When injecting into the top of a tunnel, for example, holes are drilled at predetermined intervals of, for example, about 2 m using a leg auger with a 42 mmφ bit, and the holes are drilled to a depth of 2 m. An injection hole with an angle of 10 to 30 degrees is provided, and a lock bolt 1 made of a hollow carbon steel pipe with a length of 3 m is installed in the injection hole, and has a hole 4 into which a static mixer 2 and a check valve 3 as shown in FIG. 1 are inserted. Insert the opening of the lock bolt 1 to prevent backflow of the injected drug solution.
It is preferable to seal using a waste cloth, quick-setting cement, a waste cloth pre-impregnated with foamed hard urethane resin, and inject the chemical solution 5 by the method described above. The injection work is
The process ends when the injection pressure rises rapidly or when the injection amount is about 20% more than the predetermined injection volume. Generally, the chemical solution per injection hole is 30 to 200 kg.
g Just inject.

[0039] In addition, for stabilizing and reinforcing water stopping of cracks in artificial structures, for example, 20 to 50 cm away from the crack surface.
Drill holes with a diameter of 10 mm and a depth of 5 to 10 cm at intervals of 10 mm, blow away the shavings and dust in the holes with compressed air, place absorbent cotton about 5 mm thick on the drilled holes, and place about 10 mm in diameter on top of the holes.
Inject an injection pipe with a length of 20 to 30 mm and set it in a state where there is no leakage of the injected chemical solution. Also, make U- or V-shaped cuts at a pitch of about 30 cm at locations where cracks or water leaks occur, and fix the injection pipe with quick-setting cement. Next, through a Y-shaped tube or a T-shaped tube equipped with a static mixer, etc., the (A) component and (B) component of the present invention are injected at a predetermined mixing ratio using a proportional mixing pump or a hand pump at a pressure of 0. .5~20kg/cm2・G
, preferably in a predetermined amount of 0.5 to 2 kg/cm2.G. The injection volume may generally be the estimated void volume plus α.

The stable reinforcement method of the present invention has low viscosity and good penetration into unstable ground, cracks, fracture zones, etc., and stabilizes unstable rock, ground, and even artificial structures over a wide range. It is possible to aim for Also,
The formed hardened solids have high strength and durability, have excellent adhesion and adhesion to bedrock, are nonflammable or flame retardant, and are economical. Therefore, it is a practically advantageous method.

The present invention will be explained in more detail below based on production examples and examples, but the present invention is not limited only to these examples. Note that parts in the production examples are parts by weight.

Production Examples 1 to 4 Component (B), additives, and catalyst shown in Table 1 were mixed in advance, and this and component (A) were mixed using a pump with a static mixer having a length of 15 cm and a diameter of 1 cm. pressure 5~10k
g/cm2 ・G and discharged at a discharge amount of 7 kg/m2.

[0043] Time from discharge to gelation, uniformity of chemical solution, bending and compression test (JI
SR 5201), density (JIS K 5400),
Flammability test (burning time and burning distance. JIS A 951
The results of 4) are shown in Table 1.

[0044] The uniformity of the chemical liquid was examined by examining whether the discharged chemical liquid separated into layers before it hardened.

(A) Ingredients include sodium silicate No. 3 (Na
2O/SiO2 = 1/3, molar ratio) 40% aqueous solution was used.

Comparative Examples 1 and 2 (B) Compositions using only polymethylene polyphenyl polyisocyanate as a component (Comparative Example 1) and (B)
A composition (Comparative Example 2) using a polyol having no oxyethylene chain as component (a) was prepared in the same manner as Production Example 1, and its properties were investigated. The results are shown in Table 2.

[0047] The abbreviations in Tables 1 and 2 are as follows.

C-MDI polymethylene polyphenyl polyisocyanate Me70
0 ・C-MDI Urethane prepolymer G500 of monool obtained by adding 6 moles of ethylene oxide to methanol and C-MDI
0-20・C-MDI 80% by weight of oxypropylene chains and 20% of oxyethylene chains
Urethane prepolymer G3000-30 of polyoxyalkylene triol with an average molecular weight of 5000 and C-MDI consisting of 70% by weight of oxypropylene chains and 30% by weight of oxyethylene chains
Urethane prepolymer of polyoxyalkylene triol with an average molecular weight of 3000 and C-MDI N4000-50/C-MDI 50% by weight of propylene oxide in triethanolamine
and a polyoxyalkylene triol with an average molecular weight of 4000 obtained by adding 50% by weight of ethylene oxide and C
-Urethane prepolymer with MDI D2000 ・C-MDI Urethane prepolymer with polyoxypropylene glycol having an average molecular weight of 2000 and C-MDI

[0049]

[Table 1]

[0050]

[Table 2]

Example 1 Holes are drilled at 2m intervals at an angle of 25 to 35° in the top of a tunnel having a fracture zone using a leg auger with a 42mmφ bit.
Five holes were drilled at an angle to the tunnel excavation direction, and a carbon steel (JIS G 3
445, STKM 17C) injection bolt (outside diameter 27.
2 mm, inner diameter 15 mm, length 3 m, static mixer and check valve interior) was inserted, and a stockinette rag impregnated with a two-component hard urethane foam resin was pushed into the mouth part approximately 30 cm with an iron rod to seal it.

Next, the chemical solution of Production Example 1 in Table 1 was injected into each fixed injection hole at a pressure of about 20 to 50 kg/cm2.
・Approximately 80 to 120 kg was injected per hole at G.

Approximately 120 minutes after the chemical solution was injected, the state of improvement of the ground was investigated by excavation, and it was found that the consolidation area was hemispherical with a radius of 3 m, and the consolidation was stable.

[0054] Inject and solidify the part with a sampler of 5 cmφ x 1
The sample was sampled into a cylindrical shape of 0 cm, and the unconfined compressive strength was measured to be 120 kg/cm2. Note that sampling was not possible in the unimproved area due to the fractured zone. As a result, the effectiveness of the chemical solution of the present invention was fully demonstrated, and it was found that a solidified stabilizing layer was formed.

Example 2 In order to stabilize the top of a tunnel in a granite fracture zone having large voids, stabilization was carried out by injecting the chemical solution in Production Example 2 shown in Table 1. The construction method was the same as in Example 1.

That is, 10 injection holes 2 m deep were drilled at approximately 2 m intervals in the top plate using a leg auger with a 42 mmφ bit. The drilling angle was 20°. A carbon steel rock bolt (JI
SG 3455, STKM 17C) was inserted, and the mouth was sealed in the same manner as in Example 1.

[0057] 70 to 110 kg of the chemical solution of Production Example 2 in Table 1 was applied to each injection hole (injection pressure 10 to 20 kg/c).
m2 ・G) was injected. Approximately 15 minutes after injecting the drug solution
After 0 minutes, we excavated and investigated the area around the injection hole to check the stabilization status of the ground, and found that the consolidated area was hemispherical with a radius of approximately 2.5 m, and the large voids were also high. It was dense and well sealed. For reference, the single solidified part of the chemical solution of Production Example 2, which was sealed and solidified in a particularly large void area, was core sampled into a 5 cm φ x 10 cm cylindrical shape using a sampler to measure the unconfined compressive strength and conduct a combustion test. was carried out. The results are shown in Table 3.

[0058]

[Table 3]

From the results of Example 2, it was found that by injecting the chemical solution of the present invention into a granite fracture zone having a larger void than the injection bolt, the void was completely sealed and the chemical solution was able to penetrate well into the fracture zone and solidify. It has been proven to be extremely useful in tunnel excavation work, as it can stabilize the rock mass.

Example 3 Cracks occurred at the corners of the roof slab of a three-story reinforced concrete building, and water leaked downstairs during rain. For this crack, use a drill with a diameter of 10 mm and drill approximately 20
After drilling 15 holes with a depth of approximately 5 cm at a cm pitch and blowing away the shavings and dust in the holes with compressed air, place absorbent cotton approximately 5 mm thick over the drilled holes, and then place a layer of absorbent cotton on top of the holes with an outer diameter of approximately 10 m.
I hammered in the m injection pipe with a wooden hammer. A Y-shaped tube equipped with a static mixer was set in the injection pipe, and the components (A) and (B) of Production Example 1 in Table 1 were mixed with (A)/(
B) About 2 to 3 liters were injected per hole using a manual injection pump at a ratio of about 1/1.5 in volume.

After pouring, the pouring pipe was removed, a cork was inserted, and mortar was applied to finish. Approximately two weeks later, there was heavy rain, but the water leakage did not occur at all, proving that it was very effective in sealing cracks and stopping water.

[0062]

[Effects of the Invention] The injection drug composition and the stable reinforcement method using the same of the present invention exhibit the effects (1) to (4) described below.

■ The sodium silicate aqueous solution of the component (A) and the urethane prepolymer of the component (B) have very good compatibility, and are reliable urea-silicic anhydride complex, urethane-silicic anhydride complex, and anhydrous. A composite solidified body of silicic acid is formed, which has good compatibility with rock, ground, or artificial structures, and improves adhesion. Therefore, the solidification and hardening performance is very high, and it is possible to reliably stabilize and strengthen rock or the ground, and a reliable water-stopping effect can be achieved at leakage areas.

■ The mixed liquid of component (A) and component (B) has low viscosity and excellent permeability.

(A) Since an aqueous sodium silicate solution is used as a component, the cost is low and it is economical.

[0066] It has a high consolidated strength and is effective for stabilizing unstable rock or ground that requires strength.

[0067] It has excellent durability and is flame retardant or non-combustible, so there is little fear of fire. It is also excellent in terms of occupational safety and health.

[0068] As described above, the construction method of the present invention has excellent characteristics, and is more reliable and has higher strength, which is required not only for general mountain tunnels but also for large-section tunnel excavation work and deep underground civil engineering work. This method is economical, highly safe, and extremely effective for stabilizing unstable rock or ground.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of an example of a rock bolt used in the construction method of the present invention.

[Explanation of symbols]

1 Lock bolt 5 Injection drug solution

Claims (3)

[Claims] Claim 1: Reacting (A) an aqueous sodium silicate solution, and (B) (i) a polyoxyalkylene mono or polyol having 5% by weight or more of oxyethylene chains in the oxyalkylene chain, and (b) an organic polyisocyanate. An injection drug composition for stabilizing soil or artificial structures, which is made of a hydrophilic urethane prepolymer containing free isocyanate groups. 2. A plurality of holes are drilled at predetermined intervals in rock or the ground, a hollow injection bolt is inserted into the hole, and the injection drug composition according to claim 1 is applied to the rock or the ground through the opening of the bolt. A water stop method for stabilizing and strengthening rock or ground, which is characterized by injecting water into the ground and solidifying it. 3. An artificial structure characterized in that an injection pipe is inserted into the artificial structure, and the injection drug composition according to claim 1 is injected into the artificial structure through the injection pipe and solidified. Stable reinforced water stop method.