JPH04309616A - Filling chemical composition for stabilizing soil quality and method for sealing water to stabilize for reinforcement using the same - Google Patents

Abstract

PURPOSE:To increase strength of consolidation, durability, filling workability safety, and economic efficient by filling the filling chemical compound comprising specified components to form a foaming inorganic and organic complex consolidated body. CONSTITUTION:An aqueous sodium silicate solution, a hydrophilic urethane prepolymer containing free isocianate groups, which are obtained by making reaction between polyoxyalxylene monomer or polyol having oxyethylene chain of >=5wt.% in oxyalxylene chains and organic polyisocianate, and foaming diluent are mixed just before filling them into a rock-bed, etc., to prepare a filling chemical for stabilizing 5. Then a rock bolt 1 of hollow carbon steel tube with a hole 4 in which a static mixer 2 and a check valve 3 are inserted is inserted into filling hole drilled in the rock-bed or ground, and the filling chemical 5 is filled through the opening of the bolt 1 for solidification, or a pipe inserted into an artificial structure and the filling chemical 5 is inserted into the filling pipe for solidification.

Description

[Detailed description of the invention]

0001

[Industrial Application Fields] The present invention is useful for solidifying and stabilizing rock masses with fracture zones and unstable soft ground, for water-stopping rock masses or soils with water leaks and springs, and for cracks and voids in artificial structures such as concrete. The present invention relates to a stable reinforced water stop construction method such as, and an injection chemical composition used therein.

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 body, it is possible to stably strengthen and watertight rock or ground and artificial structures with high consolidation strength, stable reinforcement effect, durability, ease of injection work, safety, and economic efficiency. It is.

Specifically, the present invention provides (A) an aqueous sodium silicate solution, (B) a hydrophilic urethane prepolymer having an oxyethylene chain and a free isocyanate group, and (
C) The first invention is an injection chemical composition for stabilizing soil or artificial structures made of a foaming diluent, in which several holes are bored at predetermined intervals in bedrock or the ground, and hollow holes are formed in the holes. A second invention provides a method for stabilizing and strengthening water stoppage of rock or ground, which is characterized by inserting an injection bolt and injecting and solidifying the injection chemical composition through the opening of the bolt, and further provides an injection pipe into an artificial structure. The third invention provides a method for stably reinforcing water stoppage construction of an artificial structure, which is characterized in that the injection chemical composition is injected into the injection pipe and solidified.

[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 component (C) is volatile due to the reaction heat generated during the reaction between the component (A) and the component (B), and foams the composite formed by the above reaction to increase the volume of the solid. It is something.

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.

(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.

As mentioned above, component (C) is volatilized by the heat of reaction between component (A) and component (B), and the resulting inorganic-organic composite is foamed to increase its volume from several times to several tens of times. This causes the composite to penetrate strongly into the bedrock and ground, and the anchoring effect of the resulting solidified material increases the strength of the bedrock. Furthermore, before foaming, it serves as a diluent for components (A) and (B), contributing to lowering the viscosity and facilitating the penetration of the drug composition into rock and the like.

Examples of the component (C) include acetone, methyl ethyl ketone, methylene chloride, trichloroethane, monofluorotrichloroethane, dichlorodifluoromethane, dichlorofluoromethane, dichlorotrifluoroethane, butane, pentane, hexane, etc. 50% by weight of the total amount of component and (B) component
It is preferable to mix up to (C) Ingredients are usually (B
) Since it is inert and soluble in component (B), it may be mixed in advance with component (B).

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.

[0018] A curing accelerating catalyst for accelerating the reaction with the urethane prepolymer of component (B) can be blended into the injection chemical solution. 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 rubbers 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.

[0022] 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).

[0023] 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 is preferably used in the form of two components: an aqueous sodium silicate solution (A) and a urethane prepolymer (B) containing a foaming diluent (C). Both components are mixed immediately before injection into bedrock, etc. The mixing method will be described later, or if the gelation time is long or small-scale injection, (A) and (B) will be mixed.
), component (C) may be mixed in advance and injected using a one-shot method.

(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.

[0026] This is a special injection drug solution according to the present invention (A
) and components (B) and (C) can be 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 injection and solidification, and any known method may be employed. For example, using a proportional mixing pump that can control the injection amount, pressure, and blending ratio of component (A) and components (B) and (C),
A) component and (B) and (C) components are placed in separate tanks and placed at a predetermined location such as bedrock (e.g. 0.5 to 3 m).
A perforated lock bolt or injection rod equipped with a pre-fixed static mixer or check valve is passed through a plurality of holes drilled at regular intervals, and each component in the tank is inserted into the hole. Injection pressure 0.5~50kg/cm
2. Inject with G, uniformly mix predetermined amounts of component (A), (B) and (C) through a static mixer, inject into a predetermined unstable rock or ground location, harden and solidify. There are methods to stabilize the bond.

[0027] 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.

[0028] In addition, for stabilizing and reinforcing water stopping of cracks in artificial structures, for example, a distance of 20 to 50 cm from the surface of the crack is required.
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, the (A) component of the present invention and (B) are passed through a Y-shaped tube or a T-shaped tube equipped with a static mixer or the like.
(C) Inject the ingredients at a predetermined mixing ratio using a proportional mixing pump or hand pump at an injection pressure of 0.5 to 20 kg/cm.
2・G, preferably 0.5-2kg/cm2・
Inject the specified amount with G. The injection volume may generally be the estimated void volume plus α.

The stable reinforced water stop method of the present invention has low viscosity of the chemical solution and has good permeability into unstable ground, cracks, fractured zones, etc., and can be used over a wide range of unstable rock and ground, as well as artificial structures, etc. It is possible to stabilize water and stop water. In addition, the formed hardened solids have high strength and durability, have excellent adhesion and adhesion to bedrock, are nonflammable or flame retardant, and are economical. This 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), component (C), and catalyst shown in Table 1 were mixed in advance, and this and component (A) were mixed in a tube with a length of 15 cm and a diameter of 1 mm.
Mixed by a pump with a static mixer of cm, pressure 5 ~
It was discharged at a discharge rate of 7 kg/m2 at 10 kg/cm2 .G.

[0032] Time from discharge to gelation, uniformity of chemical solution, bending and compression test (JI
Table 1 shows the results of the foaming ratio calculated from S R 5201), density (JIS K 5400), and flammability test (burning time and burning distance, JIS A 9514).

[0033] 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.

[0036] 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

[0038]

[Table 1]

[0039]

[Table 2]

Example 1 Holes were 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 5 to 10 kg/cm2.
・Approximately 80 to 120 kg was injected per hole at G.

Approximately 120 minutes after the chemical solution was injected, the improvement state 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.

[0043] The injection solidification part is 5cmφ×1 using a sampler.
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.

[0046] For each injection hole, apply 70 to 110 kg of the chemical solution of Production Example 2 in Table 1 (injection pressure 2 to 10 kg/cm).
2・G) injected. Approximately 150 minutes after injecting the drug solution
Minutes later, we excavated around the injection hole to check the stabilization status of the ground, and found that the area had been consolidated in a hemispherical shape with a radius of approximately 2.5 m, and the large voids were also densely packed. It was well sealed. For reference, a 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 a combustion test was also conducted. was carried out. The results are shown in Table 3.

[0047]

[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 with a static mixer inside was set in the injection pipe, and the components (A), (B), and (C) of Production Example 1 in Table 1 were mixed at a volume ratio of (A)/(B) + (C). Approximately 2 to 1 per hole using a hand injection pump at a ratio of approximately 1:
Injected 3 liters.

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.

[0051]

ADVANTAGEOUS EFFECTS OF THE INVENTION The injectable liquid composition of the present invention and the stably reinforced water stop construction method using the same exhibit the effects (1) to (4) described below.

■ The sodium silicate aqueous solution (A), the urethane prepolymer (B), and the foaming diluent (C) are very compatible, and the urea
A foamed composite of a silicic anhydride composite, a urethane-silicic anhydride composite, and an anhydrous silicic acid is formed, and the foaming pressure increases the permeability and significantly improves the consolidation strength. 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.

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

■ The cost per unit volume is low due to the use of an aqueous sodium silicate solution as the component (A) and the foaming effect of the component (C), making it economical.

[0055] It has high consolidated strength and is effective for stabilizing unstable rock or ground that requires strength.

[0056] 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.

[0057] 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, deep underground civil engineering work, etc. This method is economical, highly safe, and extremely effective for stabilizing unstable rock or ground and achieving water stoppage.

[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. A hydrophilic urethane prepolymer containing free isocyanate groups obtained by the above method, and (C) a foamable diluent, for stabilizing soil or artificial structures. 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.