JP3504454B2 - Chemical composition for foaming cavity filling - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a chemical liquid composition for stabilizing ground. More specifically, the present invention relates to a chemical solution composition used for a method for stabilizing rocks by injecting them into voids or cavities around underground structures to eliminate cavities and the like and prevent collapse of the rocks. The drug solution composition of the present invention has NA
Maintaining its strength by eliminating cavities generated and grown around the tunnel constructed by the conventional method before the spread of TM
It is especially useful in the tunnel reform (tunnel repair and renewal) method for strengthening.

[0002]

2. Description of the Related Art At present, more than a quarter of the total length of tunnels in use are over 25 years after construction, and their deterioration is a problem. Many of these tunnels are NATM (New Austrian Tunnelling M
ethod) It was constructed by the so-called "conventional construction method" before the introduction.

As is well known, the NATM supports sprayed concrete and rock bolts. The waterproofing material such as a waterproof sheet is attached to the NATM, and the secondary concrete is lined up. It is finished in one structure with no gaps. On the other hand, in the conventional construction method (Fig. 1), in order to construct the tunnel 1, a steel support 3 is built, a sheet pile is hung on it to hold down the ground 2, and then the lining concrete 4 is placed. Set up. At this time, voids inevitably remain between the sheet pile and the ground and between the sheet pile and the lining concrete. Such voids cause new loosening and cracks in the ground, and grow into the cavities 6 together with the spring water from the ground.

When a hollow is formed on the back surface of the lining, the looseness of the surrounding ground becomes large and finally collapses into the hollow portion. As a result, the lining part is damaged or displaced, which further causes water leakage into the tunnel and promotes the growth of cavities, and eventually causes a large-scale collapse that leads to the destruction of the lining surface. There is a risk of causing it. In order to prevent such a situation, it is necessary to inject an appropriate filler into the cavity (backfill injection) to eliminate the cavity.

Conventionally, cement-based mortar, air mortar, urethane foam and the like have been used for filling voids.
Cement-based mortar has good workability and filling properties, but its specific gravity is as large as 2 or more, so excessive weight will be added to the lining surface depending on the size of the cavity. In addition, separation and breathing of the material are likely to occur, and it takes several hours until the fluidity disappears. For this reason, the filler may flow out or run away where there is running water or spring water. Further, it takes 2 to 3 days until the initial strength is obtained, so that traffic regulation is required when constructing a tunnel in use, which is a big limitation in practice.

Air mortar (air bubble mortar) can have a specific gravity of about half that of cement-based mortar. However, it has the same problems as cement mortar, such as runoff and runaway. Foamed urethane (two-component foamed urethane) has a small specific gravity. Further, since foaming and curing proceed simultaneously in a short time, there is no problem such as outflow. Injection is also easy. However, it is generally difficult to accurately estimate the inner volume of the cavity. For this reason, the chemical liquid injected into the cavity may be excessive as a result, but after the chemical liquid is filled, the volume expands several tens of times due to foaming, which causes unexpected pressure on the lining surface and damages or destroys it. There is also a risk of
On the contrary, if the amount of the liquid medicine is too small, the filling becomes insufficient.

[0007]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a chemical solution composition which can obtain initial strength and can safely and reliably fill a cavity.

[0008]

Means for Solving the Problems As a result of intensive studies on the solution to the above-mentioned problems, the present inventors have prepared a first chemical liquid obtained by adding a foaming agent to a polyol liquid which is the first component of a two-liquid foaming type urethane, and an isocyanate. A composition comprising a second chemical liquid containing is effective for solving the problem, specifically, the first chemical liquid is mixed with gas in advance to cause foaming, and then mixed with an isocyanate component which is a second component. Or, by mixing a gas into the two-liquid mixture to form a foamy fluid and quickly filling the cavity with the foamy fluid, the pressurization of the lining surface due to post-foaming can be minimized. Moreover, they have found that it is possible to integrate the lining surface with the ground, and have completed the present invention.

That is, the present invention provides the following drug solution composition. 1) A first liquid chemical (A liquid) containing a polyol, a foaming agent, a curing catalyst and water, and a second liquid chemical (B liquid) containing an isocyanate.
A medicinal composition for cavity filling and foaming, which comprises a mixture of air to form a foamy fluid. 2) The above-mentioned 1 consisting of a first chemical liquid (A liquid) containing a polyol, a foaming agent, a curing catalyst, and water to mix air to form a foamy fluid, and a second chemical liquid (B liquid) containing an isocyanate.
The composition according to. 3) The composition according to 1 or 2 above, wherein the foaming agent is selected from an amphoteric surfactant, a nonionic surfactant, an anionic surfactant and a cationic surfactant. 4) Liquid A is 10 to 90% by weight of polyol and 1 to 4
1 to 3, which is an aqueous solution containing 0% by weight of a foaming agent
The composition according to any one of 1. 5) The composition according to any one of 1 to 4 above, wherein the liquid B is a prepolymer containing a primary OH group. 6) The composition according to any one of 1 to 5 above, wherein the foaming fluid obtained when air is mixed has a foaming half-life of 5 minutes or more. 7) Uniaxial compressive strength of polyurethane after curing is 3 to 10
1 to 6 using the liquids A and B at a ratio of kgf / cm ²
The composition according to any one of 1.

Hereinafter, each component of the chemical liquid composition of the present invention will be described in detail. (1) Liquid A The liquid A is basically a chemical liquid containing a polyol, a foaming agent, a curing catalyst, and water. (1-1) Polyol The polyol is not particularly limited. Examples of useful polyols are ethylene glycol, propylene glycol (1,2-propanediol), 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, hexylene glycol. Examples include diols such as (hexanediol). In addition, compounds other than the usual ether-based or ester-based polyols can be used as long as they are polyols having two or more hydroxyl groups in the molecule, which react with an isocyanate component to form a polyurethane resin. Examples of such polyols include triols such as glycerin, trimethylolethane, trimethylolpropane and polyfunctional polyols such as castor oil.

Further, polyols obtained by adding ethylene oxide, propylene oxide, ethylene propylene copolymerization or the like to these compounds or saccharides such as sorbitol or sucrose can also be used. For example, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, polypropylene glycol, ethylene oxide-propylene oxide copolymer, glycerin trioxybutane, polyoxypropylene triol and the like can be mentioned. However, as the polyether polyols, compounds having an OH value of about 300 or more are preferable.

Further, a polyol containing an amino group is also preferably used. Examples of such a polyol compound include diethanolamine, monoamines such as triethanolamine, and monoethanolamine, ethylenediamine, diethanolamine, triethanolamine,
Examples thereof include adducts obtained by adding ethylene oxide or propylene oxide to amines such as triethylenediamine. The polyol content is 10 to 10% of the total amount of the liquid A.
It is preferably 90% by weight. In order to obtain sufficient strength, it is more preferably 40% by weight or more.

(1-2) Foaming Agent In the present invention, it is necessary that the liquid A contains a foaming agent. The foaming agent includes various surfactants. Any of amphoteric, nonionic, anionic and cationic types can be used, but a nonionic surfactant having two or more functional groups is preferable. Examples of such nonionic surfactant compounds include, for example, higher alcohol ethylene oxide adducts containing alkyl groups having 12 to 24 carbon atoms, alkylphenol ethylene oxide adducts, fatty acid ethylene oxide adducts, polyhydric alcohol ester ethylene oxide additions. Polyethylene glycol type nonionic surfactants such as compounds, higher alkylamine ethylene oxide adducts, fatty acid amide ethylene oxide adducts, etc .;
Glycerol fatty acid ester, pentaerythritol fatty acid ester, sorbitol and sorbitan fatty acid ester, sucrose fatty acid ester, polyhydric alcohol alkyl ether and other polyhydric alcohol ethylene oxide adduct type nonionic surfactants; and alkanolamines Examples thereof include fatty acid amides.

Bifunctional or higher functional nonionic surfactants are particularly preferred. By using the bifunctional nonionic surfactant, the foaming agent reacts with the isocyanate of the liquid B and is fixed as a solidifying component. Such a surfactant is a polyethylene glycol type nonionic surfactant containing two or more polyethylene oxide chains in one molecule and a polyhydric alcohol type nonionic surface obtained by reacting with an aliphatic alcohol or the like leaving two or more hydroxyl groups. The activator includes an alkanolamine type nonionic surfactant having two or more hydroxyl groups in one molecule. The content of the foaming agent is preferably 1 to 40% by weight of the total amount of the liquid A. If the content of the foaming agent is less than 1% by weight, sufficient foamability cannot be obtained.

(1-3) In order to smoothly proceed the reaction with the curing catalyst B liquid, it is preferable to add a curing catalyst to the A liquid. Examples of such catalysts include tertiary alkylamines and cyclic amines such as dimethyloctylamine, dimethyllaurylamine, morpholine and piperazine; dibutyltin dilaurate, triethylenediamine, imidazole, monoethanolamine, diethanolamine, triethanolamine and others. Examples thereof include water-soluble amines, betaine or imidazole type catalysts.

(1-4) Foam Retaining Agent A liquid may also be added with a foam retaining agent for maintaining the properties of the foam after the foaming until the completion of injection and curing. Examples of the foam retention agent, alcohol-based nonionic surfactant,
Examples include amphoteric surfactants, cationic surfactants, anionic surfactants and the like. The content of the foam retention agent is preferably 1 to 5% by weight of the total amount of the liquid A. If the content of the foam retention agent is less than 1% by weight, a sufficient foam retention effect cannot be obtained.

(2) Liquid B The liquid B is preferably a partial prepolymer containing, as a raw material, polymeric MDI or monomeric MDI and containing a self-emulsifying primary OH in water. As the polyisocyanate used for producing such a prepolymer, diphenylmethane diisocyanate, 1,4-butane diisocyanate, dicyclohexylmethane diisocyanate, 1,
6-hexane diisocyanate, cyclohexane diisocyanate, 1,5-bisisocyanate-1,3,3
Aliphatic diisocyanates such as trimethylcyclohexane, m-xylylene isocyanate, 1,3-bis- (isocyanatomethyl) benzene and methylcyclohexane diisocyanate, 2,4- or 2,6-tolylene diisocyanate, m- or p-phenylene Examples thereof include diisocyanate and 1,5-naphthylene diisocyanate. Diphenylmethane diisocyanate is particularly preferred. Diphenylmethane diisocyanate has various isomers, and any of them can be used.
A mixture of these may be used.

The prepolymer is obtained by reacting the above-mentioned isocyanate with a polyalkylene glycol. Such polyalkylene glycol may be polyethylene glycol or ethylene oxide (EO)-
A propylene oxide (PO) copolymer is used.
The EO content of the copolymer is usually 20% by weight or more, and the average OH value of the (co) polymer is 56 or more. NCO% in the prepolymer (=% of total number of NCO contained in isocyanate compound × NCO formula weight divided by molecular weight of isocyanate compound) is 25 to 29%
It is preferable to set it as the range. If the NCO% is less than 25%, the time until the curing reaction after mixing with the liquid A tends to be too short. On the contrary, if it exceeds 29%, the water miscibility (emulsification) of the liquid B is deteriorated. 25-29%
Within the range, the time required to reach the curing reaction after mixing with the liquid A is appropriate.

The mixing ratio of the liquid A and the liquid B depends on the composition of each liquid, but the uniaxial compressive strength after curing is 3 to 10.
It should be in the range of kgf / cm ² . Usually, the solution A: the solution B is used in the range of 1: 1 to 1: 3, preferably about 1: 2.

[Stability of Foamed Fluid] A foamed fluid prepared by mixing gas with the first chemical liquid (Liquid A) to cause foaming, and mixing this with the second chemical liquid (Liquid B) containing isocyanate, or liquid A. The foamy fluid obtained by mixing a gas with a mixed solution of the liquid B and the liquid B is required to have stability that does not defoam for a time required for construction (filling / curing). For that purpose, the half-life t _{m of} foaming (the time when V reaches 1/2 of the volume before foaming (V ₀ ) when foaming volume (V) is measured after foaming) is at least 5 minutes. Above, preferably 10 minutes or more, a stable foamy fluid can be obtained.

[Construction Method] In summary, the constitution of the chemical liquid composition of the present invention is carried out by gasifying a first chemical liquid (liquid A) containing a polyol, a foaming agent and other components optionally added. Is mixed and foamed, and this is mixed with a second chemical liquid (liquid B) containing isocyanate, or a mixed liquid of liquids A and B is mixed with gas to form an uncured urethane foam. Then, this is performed by injecting this into voids and cavities around the underground structure and curing it. Hereinafter, the entire foam-filling method will be described, including the cavity confirmation step performed as a preparatory step for foam-filling. In addition, although a tunnel will be mainly described in the present specification, the cavity filling chemical liquid of the present invention can be similarly applied to other underground structures in which water leakage may occur.

(1) Cavity Confirmation Step The cavity can be detected and confirmed by a known physical method. Examples of such methods include acoustic detection and potential measurement. Also, as mentioned above, cavities are especially generated on the back surface of the tunnel lining surface,
In a tunnel that has deteriorated to some extent, it is possible to detect and confirm cavities by observing the lining surface from the inside of the tunnel and making holes in cracks and leak points, and observing with a naked eye or a fiberscope. It is possible.

(2) Foaming Step Foaming is performed by blowing gas into the liquid A or a mixed liquid of the liquid A and the liquid B in some cases to mix them. When a mixed solution is used, the reaction of both solutions proceeds at the same time, and there is a risk of hardening during foaming or during filling into the cavities, so gas blowing into solution A is preferred. Usually, the foaming rate is about 5 to 100 times. If the foaming is less than 5 times, the efficiency is poor and the pressure generated by the post-foaming cannot be fully absorbed. If the foaming exceeds 100 times, sufficient strength cannot be obtained. Generally, about 10 to 50 times is preferable. The gas to be mixed is not particularly limited as long as it does not react with the liquid A or the liquid B and does not adversely affect the environment, but air is usually used. The method of mixing the gas is not particularly limited, but as shown in FIG. 4, it is preferable to use a foaming device 10 having a foaming chamber 12 inside a cylindrical housing 20. The foaming chamber 12 has a perforated partition wall 14
15 and 15 and wire meshes 16 and 1 attached as required.
7 separates the front and rear first and third chambers, and accommodates a large number of fillers 19. The packing 19 has a diameter of 1 to
It is a small sphere or cylinder made of glass, ceramic or plastic of about 5 mm, which complicatedly changes the gas-liquid flow path and promotes uniform mixing and foaming of both. Liquid A and air are
It is introduced into the first chamber 11 through the introduction holes 21 and 22, respectively, and is mixed with the liquid B in the third chamber 13 through the above-mentioned foam generation chamber and is discharged from the nozzle 18 as a foamy fluid.

(3) Mixing step Liquid A and liquid B are mixed after foaming of liquid A, or before foaming in some cases. It is necessary to mix well.
In general, the foamed material of the liquid A is white and the liquid B is colored (brown), so that the mixed state can be visually confirmed. The mixing method is not particularly limited, but it is preferable to continuously perform the foaming of the solution A and the addition and mixing of the solution B by the apparatus shown in FIG. In this apparatus, the B liquid is sprayed from the introduction hole 23 through the pipe 24 to the A liquid foamed from the nozzle 25 in the third chamber 13. As shown in FIG. 5, a second chemical solution introduction hole 33 is provided at the end of the first chamber, and from this introduction hole, preferably extending along the axis of the device, through the first chamber and the second chamber A pipe 34 leading to the room may be provided, and a chemical solution may be jetted from a nozzle 35 at the tip thereof. By adopting such a configuration,
The second chemical liquid is uniformly sprayed onto the foamy fluid, and the two are smoothly mixed.

(4) Cavity Filling Step After mixing the liquids A and B, the resulting foamy fluid is quickly filled in the cavities. The cavity may be filled in the same manner as the known backfill injection method (FIG. 2). For example, make a hole 5 on the lining surface and have a diameter of 2.5 to 6 cm up to a depth of about 2 to 200 cm.
The pipe 7 of a certain degree is inserted, and the foamy fluid 8 is injected using the above-mentioned foam mixing device 10. Although the filling time depends on the size of the cavity, it is usually about 1 to 180 minutes. When the cavities are large, the holes are injected into the lining surface in order to fill the holes evenly. In addition, a plurality of holes are formed in the lining surface according to the expansion of the cavity, and the lateral (horizontal) filling is confirmed by the outflow of the foamy fluid from the holes other than the injection hole. Further, in some cases, the monitoring pipe 9 is pushed out from the lining surface according to the depth of the cavity, and the foamy fluid flows out through the pipe to confirm the filling in the depth direction, particularly the vertical direction. The confirmation of filling may be performed by visual confirmation with a fiberscope, monitoring of the filling pump pressure, optical / electrical or acoustic sensor means, or the like. Even after the completion of filling, some foaming continues due to the reaction between the liquid A and the liquid B, but no excessive pressure is brought about. Further, as a result, the entire cavity is completely filled with the filler 8 (FIG. 3).

[0026]

EXAMPLES The present invention will be described more specifically below with reference to examples and comparative examples. The foaming half-life, foaming rate, defoaming property, uniaxial compressive strength and specific gravity in these examples were measured by the following methods. "Parts" represent parts by weight. (1) Foaming half-life, foaming rate, and antifoaming solution A was prepared according to predetermined conditions, and this was foamed to form a foamy fluid, and its volume (V ₁ ) was measured with a graduated cylinder. The change of the foam surface due to defoaming was measured in the graduated cylinder, and the time required for the volume of the foamy fluid to reach 1/2 of V ₁ was defined as the foaming half-life. Further, V ₁ was divided by the total amount (V ₀ ) of the chemical liquid before mixing to obtain the foaming rate. Furthermore, the change of the foam state due to the addition of the liquid B was observed to evaluate the defoaming property, and when the defoaming was remarkable, it was represented by x, and when the defoaming was hardly observed, it was represented by ◯. (2) Uniaxial compressive strength It was measured by the compressive strength test method for concrete (JIS-A1108). (3) Specific gravity Determined by dividing the weight of the cured product by the volume.

Example 1 Polyol (Polypropylene glycol (OH number 50
0)) 20 parts, foaming agent (bifunctional polyethylene glycol-based nonionic surfactant) 25 parts, curing catalyst (amine-based) 3
Parts, 7 parts of a foam-holding agent and 45 parts of water were mixed to prepare a solution A, and compressed air was blown into the solution to make it foam up to 10 times the volume of the stock solution. Liquid B containing isocyanate (MDI polyalkylene glycol prepolymer) was added and mixed so that the weight ratio of liquid A: liquid B was 1: 2. Almost no defoaming was observed, and the time required for curing (curing time) was 5 minutes. The volume of the cured polyurethane body has increased to 120% before curing, and the uniaxial compressive strength is 5.2k.
The gf / cm ² and the specific gravity were 0.05.

Example 2 Foaming and curing were carried out in the same manner as in Example 1 except that the composition of the liquid A was changed as shown in Table 1. The results are also shown in Table 1.

[0029]

[Table 1]

Comparative Example 1 The same procedure as in Example 1 was repeated except that the foaming agent was not used, and the chemical solutions were mixed in the proportions shown in Table 1 to prepare and cure a foamy fluid. As shown in Table 1, the compressive strength is good, but the foaming ratio is low and the specific gravity is large. Comparative Example 2 A foamy fluid was cured in the same manner as in Example 2 except that crude MDI was used as the solution B. The addition of solution B caused defoaming, and the volume of the foamy fluid was once greatly reduced. After that, due to the reaction of both liquids, foaming occurred and the volume increased again and the resin cured. Example 3 A foamy fluid was prepared and cured in the same manner as in Example 2 except that alkylbenzene sulfonic acid (anionic foaming agent) was used as the foaming agent. The foam retention was good, but the strength after curing was a little poor at 2.0 kgf / cm ² .

[0031]

EFFECT OF THE INVENTION The foaming liquid chemical composition of the present invention (1) can be used without problems even in places with running water or spring water, because it cures quickly and provides sufficient early strength; (2) low specific gravity Therefore, there is no problem due to the load of the filler, which is a unique feature of the urethane filler. Then, the foam generated by the foaming operation is maintained almost without disappearing until it is cured. Further, by performing the foaming process by blowing gas, it is possible to greatly reduce the pressure applied to the area around the filling due to the urethane foaming pressure, which has been a serious problem in the conventional urethane-based filler. Therefore, the lining surface is not damaged or destroyed after filling. Furthermore, since a large amount of air is contained during construction, the amount of chemical liquid used can be minimized. Furthermore, since the filler expands to some extent due to foaming due to the reaction, it is possible to substantially completely fill the cavity, and as a result, the back surface of the lining and the ground are integrated,
The collapse of the ground into the cavity is prevented.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view explaining a cavity generation mechanism in a conventional tunnel.

FIG. 2 is a schematic view showing an example of a foam filling method using the chemical composition of the present invention.

FIG. 3 is a schematic cross-sectional view of a tunnel reformed by a foam filling method using the chemical composition of the present invention.

FIG. 4 is a schematic cross-sectional view of an apparatus useful for foaming and mixing the liquid chemical composition of the present invention.

FIG. 5 is a schematic cross-sectional view of an apparatus useful for foaming and mixing the liquid chemical composition of the present invention.

[Explanation of symbols]

1 tunnel 2 natural ground 3 steel support 4 lining concrete 5 Cavity filling chemical solution injection hole 6 cavities 7 Filler injection pipe 8 Filling material 9 Filling confirmation pipe 10 Foaming mixing device 11 First Room 12 Second room 13 Third Room 14 and 15 perforated partition wall 16,17 wire mesh 18 nozzles 19 Foaming filler 20 housing 21 First chemical liquid introduction hole 22 Compressed air introduction hole 23, 33 Second chemical liquid introduction hole 24, 34 tubes 25, 35 Second chemical solution injection nozzle

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuyuki Mitsuru 2-21 Torimi-cho, Nishi-ku, Nagoya, Aichi Sink Chemical Industry Co., Ltd. (72) Nobuo Nakajima 2-21 Torimi-cho, Nishi-ku, Nagoya, Aichi Sink (56) Reference JP-A-8-92555 (JP, A) JP-A-7-90273 (JP, A) JP-A-6-80967 (JP, A) JP-A-8-269452 ( JP, A) JP 7-26263 (JP, A) JP 10-212480 (JP, A) JP 54-112508 (JP, A) JP 55-114799 (JP, A) JP Sho 63-8477 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09K 17/00-17/50 E02D 3/12

Claims (7)

(57) [Claims] 1. A first chemical liquid (A liquid) containing a polyol, a foaming agent, a curing catalyst and water and a second chemical liquid (B liquid) containing an isocyanate for mixing air to form a foamy fluid. Cavity-filling foaming chemical composition. 2. A first chemical liquid (A) containing a polyol, a foaming agent, a curing catalyst, and water for mixing air to form a foamy fluid.
The composition according to claim 1, which comprises a liquid) and a second chemical liquid (B liquid) containing an isocyanate. 3. The composition according to claim 1, wherein the foaming agent is selected from amphoteric surfactants, nonionic surfactants, anionic surfactants and cationic surfactants. 4. The composition according to claim 1, wherein the liquid A is an aqueous solution containing 10 to 90% by weight of a polyol and 1 to 40% by weight of a foaming agent. 5. The composition according to claim 1, wherein the liquid B is a prepolymer containing a primary OH group. 6. The composition according to claim 1, wherein the foaming fluid obtained when air is mixed has a foaming half-life of 5 minutes or more. 7. The composition according to claim 1, wherein the liquid A and the liquid B are used in such a ratio that the uniaxial compressive strength of the cured polyurethane becomes ³ to 10 kgf / cm ² .