JPH0578666A - Fluid agent for concretion of rock bed - Google Patents

Abstract

PURPOSE:To provide the subject fluid agent composed of a two pot-type expandable urethane resin prepared by combination of a solution mainly composed of water and a urea with another solution mainly composed of an isocyanate prepolymer, showing a low viscosity when both the solutions are mixed, and excellent in penetration properties. CONSTITUTION:The objective fluid agent composed of a two pot-type expandable urethane resin obtained by combination of (A) a solution prepared by using water and a urea as the main components and blending a catalyst such as ethylenediamine therewith with (B) another solution mainly composed of an isocyanate prepolymer synthesized preferably by polymerizing diphenylmethane 4,4'-diisocyanate and tolylene diisocyanate with polyethylene glycol and polypropylene glycol in the presence of a catalyst and capable of providing a flame-retardant expanded cured material. In addition, the contents of water and the urea in the above-mentioned component (A) are preferably 48-64wt.% and 20-40wt.%, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bedrock-consolidating chemical solution used for a bedrock consolidation method for improving a soft bedrock into a solid bedrock.

[0002]

2. Description of the Related Art Conventionally, when drilling holes in soft rock (including the ground) to perform tunnel construction, in order to prevent the fall of the tunnel face, the top of the tunnel face must be
A hole can be drilled along the arch of the roof, and a two-part curing type chemical solution with a curing time of 1 to 5 minutes can be injected into this hole to penetrate into the rock and harden to strengthen it. It is being appreciated. However, in the bedrock consolidation method, since it takes a long time to cure the resin, the resin penetration area becomes large, the amount of the resin used increases, and the resin press-in time also becomes long. .. Therefore, the present applicant has positioned a rock bolt having a chemical solution discharge hole at the tip end side in a hole formed in a rock bed to the root, and set a hardening time after mixing the two liquids to 5 in the rock bolt.
In a state where a rock-solidifying chemical consisting of a two-pack type urethane foam resin for 30 seconds is press-fitted, the rock-solidifying chemical is filled in the hole and then penetrated into the rock, and a rock bolt is left in the hole. A method has been developed for hardening the bedrock by hardening the chemical liquid that fills the holes and penetrates the bedrock, and has already filed an application (Japanese Patent Application No. 61-130531, so-called “P”).
U-IF method ").

[0003]

However, the chemicals used in these methods are all combinations of a solution A containing a polyol as a main component and a solution B containing a polyisocyanate as a main component, and the -OH and the poly of the polyol are combined. The urethane foam resin is configured to react with -NCO of isocyanate to generate a urethane foam resin. Since this urethane foam resin easily burns, a flame retardant resin is desired from the viewpoint of ensuring the safety of the working environment. There is. Therefore, a method of imparting flame retardancy to a cured product by using a water glass aqueous solution and a curing polyol as the liquid A and a polyisocyanate as the liquid B to disperse and contain non-combustible water glass in the cured product. It has been proposed (JP-A-55-160079). However, the chemical liquid of this method has a significantly higher viscosity when mixed with two liquids and is slightly inferior in foamability to the conventional chemical liquid containing no water glass. For this reason, the resistance when penetrating into the bedrock becomes extremely large, and although it penetrates into the part with many gaps, it does not penetrate into the dense part with few gaps,
It is a problem that the penetration area is biased. Further, there is also a problem that it takes a very long time to penetrate. Therefore, when injecting the chemical solution into the rock containing a dense part, the chemical solution discharge pressure may be set higher, but this may disturb the ground to be improved and cause collapse, Not preferable.

The present invention has been made in view of the above circumstances, and the resulting foamed and cured product is flame-retardant and has a low viscosity when mixed with two liquids and has an excellent penetrability. The purpose is to provide.

[0005]

In order to achieve the above object, a bedrock consolidating chemical solution of the present invention comprises a solution A containing water and urea as main components and a solution B containing isocyanate prepolymers as main components. It is composed of a two-component foamed urethane resin in combination with.

[0006] In the present invention, the phrase "having as a main component" is intended to include a case where the whole is made up of only the main component.

[0007]

That is, the present inventors have carried out a series of studies on a chemical liquid in which the obtained foamed and cured product is flame-retardant and the chemical liquid when mixed with two liquids has a low viscosity. As a result, as the main component of the liquid B, not just polyisocyanate,
When an isocyanate prepolymer is used, A
Even if a polyol such as ethylene glycol is not used as the liquid, only the water and the catalyst are used to form the -NCO of the prepolymer.
Was found to cure by reacting with -OH of water. Therefore, when water and urea, which is a flame retardant, are used as the main components of liquid A, the viscosity is very low when mixed with liquid B and it has excellent permeability, and it is flame-retardant and safe during work. The present invention has been achieved by finding out that it becomes a chemical solution that can secure

Next, the present invention will be described in detail.

The bedrock consolidation liquid of the present invention is a combination of liquid A containing water and urea as main components and liquid B containing isocyanate prepolymer as a main component.

Examples of the urea used in the above-mentioned solution A include urea and various urea derivatives and urea modified products. Since these ureas are nonflammable, they are dispersed and contained in the foamed cured product after the two liquids are mixed to impart flame retardancy to the foamed cured product. It also has an increasing effect on the foamed cured product. Moreover, the foamability is not impaired.

In addition, the solution A usually contains a catalyst together with water and ureas. Examples of such a catalyst include ethylenediamine, triethylenediamine, triethylamine, ethanolamine, diethanolamine,
Aliphatic amines such as dimethylethanolamine, 2,
4,6-Tris (dimethylaminomethyl) phenol-
N, N, N ', N'-tetramethylmethanediamine,
Aromatic amines such as 4,4'-diaminodiphenylamine, or the combined use of these with an organometallic catalyst such as dibutyltin bilaurate, tin octylate, stannic chloride, lead octenoate, or lead naphthenate. .. Among them, 2,4,6-tris (dimethylaminomethyl) phenol-N, N, N ', N'-tetramethylmethanediamine is preferable.

Incidentally, it is preferable that water is contained in an amount of 48 to 64% by weight (hereinafter abbreviated as "%") and urea is contained in an amount of 20 to 40% with respect to the whole liquid A. This is because if the amount of water is less than 48%, the urea is not dissolved and the liquid is separated, and conversely, if the amount of water exceeds 64%, the proportion of urea decreases and it is difficult to obtain the flame retardant effect.

On the other hand, the isocyanate prepolymer, which is the main component of the liquid B, is generally obtained by partially polymerizing a polyisocyanate component and a polyol component, and any substance may be used. , Above all,
Diphenylmethane-4 as a polyisocyanate component,
4'-diisocyanate (hereinafter abbreviated as "MDI") and tolylene diisocyanate (hereinafter abbreviated as "TDI")
And a prepolymer obtained by using polyethylene glycol (hereinafter abbreviated as “PEG”) and polypropylene glycol (hereinafter abbreviated as “PPG”) as a polyol component.

The above MDI has an action of hardening the obtained cured product, and it is preferable to add 70 to 80% to the whole liquid B. However, for the above MDI, the pure MD
I (MDI-P) and Polymeric MDI (MDI-P
There are two types of M), and it is preferable to use only MDI-P from the viewpoint of increasing the hardness of the cured product, but it is practical to use MDI-P and MDI-PM in combination from the viewpoint of cost. is there. The usage ratio of both is 1 for MDI-P
Then, it is preferable to set MDI-PM to a ratio of 1.5 to 2.

TD used together with the above MDI
I has the effect of increasing the foaming power during the curing reaction, and it is preferable to add 5 to 10% to the entire liquid B.

Further, the PEG is used for the MDIs,
Alternatively, MDI and TDI, or TDIs which are linked to each other, in particular -NCO of the obtained prepolymer
Has the effect of creating an environment that easily reacts with water. However,
If only PEG is used as the polyol component, the foaming property at the time of mixing the two liquids is poor. Therefore, PPG is used together with the PEG to supplement the foaming property at the time of mixing the two liquids.

The ratio of PEG and PPG used is
If PEG (molecular weight 1000) is 1 mol, PPG
It is preferable to set (diol, molecular weight 400) to a ratio of 0.6 to 0.7 mol, and NCO% is 14 to 16
It is preferable to set to%.

Further, it is conceivable to add a foaming aid consisting of an inert solvent such as trichloromonofluoromethane, methylene chloride, pentane or the like to the liquid B, if necessary, but ensuring the safety of the worker. From the perspective of, its use should be kept to a minimum.

The liquid B thus obtained has a viscosity of 1
It is a solution of 100 to 200 cps (25 ° C.).

The bedrock consolidating chemical solution of the present invention is a combination of the solution A and the solution B, and both are mixed at the time of use. It is preferable to set the mixing ratio of both such that A: B is 1: 1 to 1: 3. Outside the above range,
Good rock consolidation effect cannot be obtained.

The above-mentioned bedrock consolidating chemicals are used for bedrock consolidation, for example, as follows. That is, first, as shown in FIG. 1, holes 22 are formed in the canopy portion 8 at the tip of the tunnel face at a predetermined interval along the canopy with a rock drilling machine 21 such as a jeanbo drill prior to the injection of the chemical liquid. (It is preferable to pierce upward from the horizontal surface at an angle of 10 to 20 °). Then, the hollow pipe-shaped rock bolt shown in FIG. 2 is inserted into the hole 22. This lock bolt is formed by connecting a packer part 1 made of a closed end type hollow pipe and a hollow lock bolt body 2 with a screw joint 3, and has an outer diameter of 27 mm, an inner diameter of 14 mm and a total length A of about 3 m.
Has a length B of 1 m, and the lock bolt body 2 has a length C of 2 m. Then, ten chemical solution discharge holes 4 having a diameter of 5 mm are formed on the outer periphery of the tip of the packer unit 1. A static mixer 5 is inserted in the packer unit 1 with its root side ring unit 6 fixed to the step 1a in the packer unit 1. Further, 7 is a joint with a check valve, which is normally removed and is fitted at the time of injecting the chemical liquid. Next, as shown in FIG. 3, a driving adapter 23 is attached to the rear end of the rock bolt main body 2 of the rock bolt inserted in the hole 22 and driven by a rock drill, a coal bit 24, etc. Figure 4 at the end
As shown in FIG. 4, a check valve-equipped joint 25 is attached, and a hose 11 with a connecting unit 10 is attached to the joint 25.
Is attached to the joint 25 with a check valve by one-touch. Then, the liquids A and B, which are the rock-solidifying chemicals of the present invention, are pressed into the rock bolts through the hose 11 at a pressure of ³ to 10 kg / cm ² . The liquid A and the liquid B thus press-fitted reach each other to the threaded joint 3 in a laminar flow state, and after reaching the packer unit 1, they are mixed by the static mixer 5 (see FIG. 2), and the state thereof is maintained. Is discharged from the chemical liquid discharge hole 4 at the tip of the lock bolt. In this case, the first ejected mixed liquid flows from the back side of the hole 22 toward the front opening, and then flows out from the opening. In order to prevent this, it is preferable to apply a foam-hardening type urethane-based chemical solution to the waste 40 or the like before press-fitting the bedrock-consolidating chemical solution, and push it near the opening to seal it as shown in FIG. .. When the discharged mixed liquid spreads to the surrounding ground and completely hardens, the pressure of the urethane press-fitting pump suddenly rises, so the press-fitting of the chemical liquid is stopped and the connection unit 10 is disconnected. In this way, the rock bolt is fixed in the hole 22 and the rock mass (ground) around the hole 22 is solidified with the hardened resin. This state is shown in FIG. In this way, bedrock consolidation is performed. 26 is the obtained consolidation area. As a result, as shown in FIG. 6, the entire canopy portion 8 is reinforced by the synergistic effect of the plurality of lock bolts and the consolidating regions 26 around them.

The bedrock consolidating chemical can be press-fitted using a self-drilling type rock bolt shown in FIGS. 7 and 8. This lock bolt is used for the packer unit 1.
The lock bolt main body 2 is connected by a screw joint, but the tip of the packer portion 1 is open, and a drill portion (see FIG. 8) 13 is fitted into this open portion. .. In this drill portion 13, four blades 14 are provided on the end face at the tip end at intervals of 90 ° in the circumferential direction, a center hole 15 is formed in the center of the end face, and between the blades and the blade. An outer peripheral hole 16 is formed in each case. The check valve-equipped joint is screwed to the rear end of the lock bolt body 2 when the chemical liquid is press-fitted. When the chemical solution is press-fitted using the rock bolt, the rock bolt is attached to the rock drill 28 as a drill as shown in FIG. 9, and water or the like is press-fitted into the rock bolt from the water (air) supply pipe 29 at the time of drilling a hole. Then, the soil, sand, etc. which the blade of the rock bolt cuts out,
The holes 22 are punched while being discharged to the outside of the holes 22. In this way, a hole is formed by using the lock bolt as a drill, the lock bolt is left in the hole, and then the check valve joint 25 is connected to the rear end of the lock bolt to connect the connecting unit 10 as shown in FIG. The attached hose 11 is connected by a one-touch, the liquids A and B of the rock consolidating chemicals are injected, and the central hole 15 and the outer peripheral hole 1 provided in the blade portion of the rock bolt tip are provided.
It is discharged from No. 6, and rock solidification (refer to FIG. 11) is performed in the same manner as the driving type. In this manner, the rock bolts are driven along the arch of the canopy portion 8 at predetermined intervals, and the solidified region 26 made of urethane resin is formed around the rock bolts to reinforce the canopy portion 8.

The consolidation region 26 thus obtained is
Even to the smallest detail, the solidification by the bedrock congealing liquid has prevailed, and even if the bedrock is dense or dense, it is uniformly consolidated. The foamed and hardened body in the consolidated region 26 is provided with flame retardancy due to the presence of ureas and has high strength.

Next, examples will be described together with comparative examples.

[0025]

Examples 1 to 4 and Comparative Examples 1 and 2 First, four kinds of solutions A were prepared with the compositions shown in Table 1 below.

[0026]

[Table 1] * 1: 2,4,6-Tris (dimethylaminomethyl) phenol-N, N, N ', N'-tetramethylmethanediamine and dibutyltin dilaurate were mixed in a ratio of 1: 6. * 2: The viscosity at 25 ° C. was measured with a B-type viscometer.

On the other hand, solution B-1 having the following composition was prepared. <Composition of liquid B-1> TDI-80 7.4 parts by weight MDI-P 14.8 〃 MDI-PM 160 〃 PEG 9.6 〃 PPG 8.2 〃 TMP 2 〃

A solution B-2 having the following composition was prepared. <Composition of liquid B-2> TDI-80 60 parts by weight MDI-P 40〃 MDI-PM 100〃

Then, the solutions B-1 and B-2 and the four kinds of solutions A were mixed at a ratio of 1: 1 in the combination shown in Table 2 below, and the permeability, curing time, The strength, foamability and flame retardancy of the cured product were evaluated. However, the permeability was measured according to the following simple test method. In addition, flame retardancy is J
It was measured according to the IS A 9514 method. The results are shown in Table 2 below.

<Measurement of Permeability> As shown in FIG. 13, the glass tube 51 was placed on a column whose bottom opening was closed with gauze 52.
160 g of silica sand 53 is packed, and the depth D of silica sand 53 is 22 cm
I chose Then, 50 g of the mixed liquid sample was injected from above, and the time for the liquid to penetrate downward and reach the gauze 52 at the bottom of the glass tube 51 was measured.

[0031]

[Table 2]

From the above results, it can be seen that all of the example products have excellent flame retardancy and cured product strength, and moreover have superior penetrability as compared with the comparative example product. Moreover, the foamability is also good.

[0033]

Industrial Applicability As described above, since the bedrock consolidating chemical solution of the present invention uses water and urea having a low molecular weight as the main components of the solution A, it reduces the viscosity of the whole chemical solution. You can Therefore, this bedrock-consolidating chemical has a lower viscosity and higher permeability than conventional ones, and the rock structure is so dense that it cannot penetrate sufficiently with conventional chemicals. It can permeate everywhere and form a uniform consolidated region. The solidified region becomes flame-retardant and strong due to the presence of the above-mentioned flame retardant urea. Also,
Since the chemical liquid of the present invention uses water, it has an advantage that it can be provided at a very low cost.

[Brief description of drawings]

FIG. 1 is an explanatory view of forming a hole in rock.

FIG. 2 is a vertical cross-sectional view of a driving type rock bolt used for press-fitting a rock consolidating chemical liquid of the present invention.

FIG. 3 is an explanatory diagram of a method for press-fitting a chemical liquid.

FIG. 4 is an explanatory diagram of a method for press-fitting a chemical liquid.

FIG. 5 is an explanatory diagram of a method for press-fitting a chemical liquid.

FIG. 6 is a state view of the canopy portion after construction by chemical solution press fitting.

FIG. 7 is a vertical cross-sectional view of a self-drilling type rock bolt.

FIG. 8 is an enlarged view of a main part of the lock bolt.

FIG. 9 is an explanatory diagram of a method for press-fitting a chemical liquid.

FIG. 10 is an explanatory diagram of a method for press-fitting a chemical liquid.

FIG. 11 is an explanatory diagram of a method for press-fitting a chemical liquid.

FIG. 12 is an explanatory diagram of a method for press-fitting a chemical liquid.

FIG. 13 is an explanatory diagram of a simple method for measuring permeability.

[Explanation of symbols]

 26 consolidation area

Claims (4)

[Claims] 1. A liquid containing water and urea as main components,
A rock-solidifying chemical liquid consisting of a two-component foamed urethane resin in which a liquid B containing an isocyanate prepolymer as a main component is combined. 2. The content of water in the entire liquid A is 48.
It is set to ~ 64% by weight and the content of ureas is also 20.
The bedrock consolidation chemical according to claim 1, which is set to -40% by weight. 3. The mixing ratio of the liquid A and the liquid B is the liquid A: B.
The liquid is set to 1: 1 to 1: 3.
The bedrock consolidation liquid described in. 4. The isocyanate prepolymer of the liquid B is obtained by reacting the following components (A) to (D) in the presence of a catalyst. Chemical liquid for bedrock consolidation. (A) Diphenylmethane-4,4'-diisocyanate. (B) Tolylene diisocyanate. (C) Polyethylene glycol. (D) Polypropylene glycol.