KR860001294B1 - Grouting method and grouting pipe - Google Patents

Abstract

The position of a grout-exit is different than the axis of a grouting pipe. The change of the grouting stage causes the grout to be poured in the ground through the movement of a double tube. Many compound liquidsf are sent throughout two tube passages of a double tube. The passages of a double tube have valves. The valves are opened or shut with the change of liquid pressure of a compound. Two compound liquids are mixed at the mixing part of electric double tube. The gelling time of a mixture is under 30 seconds.

Description

Injection method and injection tube used therein

1 (a), 1 (b), 1 (c) and 1 (d) are model views showing the injection mechanism according to the present invention, respectively.

2, 3, 4 and 7 are each a specific illustration of the injection tube according to the present invention,

2 (a) and 3 (a) are cross-sectional views showing the injection state of the purity grout, respectively.

Sections 2 (c) and 3 (c) are cross-sectional views taken along the line A-A of FIGS. 2 (a) and 3 (a), respectively.

2 (b) and 3 (b) are cross-sectional views showing injection states of the penetrating grout, respectively.

Sections 2 (d) and 3 (d) are cross-sectional views taken along line B-B in FIGS. 2 (b) and 3 (b), respectively.

4 (a) and 7 (a) are cross-sectional views each showing the injection state of the purity grout.

4 (b) and 7 (b) are cross-sectional views each showing the injection state of the permeable grout.

5 is a valve used in the inlet of FIG.

6 (a) and 6 (b) is a specific example of the inner tube used in the injection tube of Figure 4, respectively.

8 is a valve used for the injection pipe of FIG.

* Explanation of symbols for main parts of the drawings

1: Inner pipe 1a: Inner pipe

2: Appearance 2a: Appearance pipe

3: upper discharge port 4: lower discharge port

5: valve 6: spring

9: mixed snow 10: cover

12: ball valve 13: spring

14: closing rod 15: annular closing plate

The present invention relates to an injection method for improving the ground by discharging a grout from a plurality of discharge ports opened at different positions in the axial direction of a double pipe and an injection pipe used therefor.

The soft ground is usually a soft ground in which granulated soil layers and fine grain soil layers are alternately layered, but it is necessary to inject the grout into the ground and to solidify it.

In recent years, it is preferable in terms of pollution prevention that water glass grout injected in the construction work is reliably solidified at the point of injection without departing from the injection range.

In the present invention, particularly when injecting a plurality of grouts having different freezing time into the ground, the position of the discharge port through which the plurality of grouts are discharged is located in a shallow place at the upper side by using a double pipe located at a portion different from the axial direction of the injection tube. By injecting grout which has a high solidification time at the discharge port located, and injecting a grout which has a long solidification time at the discharge port located at the lower side, the above problem is solved, and homogeneous ground solidification is made possible.

That is, the object of the present invention is to inject the soft ground and the granulated soil layer and the fine-grained soil layer easily and uniformly uniformly in one step to form a homogeneous and fully indexed and high-strength solidified ground that is integrated as a whole. An object of the present invention is to provide an injection tube.

According to the present invention for achieving the above object, a plurality of heavy pipes are used in locations where the discharge port through which the gut is discharged is located at a different position in the axial direction of the injection pipe, and the double pipe is moved to change the injection stage. In the injection method of injecting a route into the ground, a plurality of compounding liquids are fed into two conduits formed in the double pipe, and a valve is attached to the conduit in the double pipe, and at least one of the compounding liquids. The valve is displaced by the change of the fluid pressure with or without the feed, and the injection of the grout can be changed at the discharge port different from the axial direction by changing the opening and closing of the flow path flowing to the plurality of discharge ports. Besides this, according to the present invention, two pipes are provided as injection pipes composed of double pipes used in the above-described injection method. A ground injection injection tube in which a plurality of compound liquids are fed into the ground through these two pipelines, and has a plurality of discharge ports opened at positions different from the axial direction, and the upper and lower pipes in the electrical double pipe. The valve is equipped with a displacement-dependent valve, and the valve is displaced up and down by the change of the fluid pressure depending on whether or not one of the plurality of compound liquids is supplied, thereby switching the opening and closing of the flow path to the plurality of discharge ports. In this way, the injection of the grout in the plurality of discharge ports described above is characterized.

Next, the present invention will be described in detail.

The gist of the present invention will be described with reference to the above-described conventional injection method as follows.

For the sake of easy understanding of the present invention, the grout having a solidification time of 30 seconds or less is referred to as chastity grout, and a grout having a longer solidification time is referred to as a permeable grout.

In order to prevent the injected grout from escaping around the injection tube, it is preferable to shorten the gelation time, but the continuity of the solidification cannot be obtained because the ground penetration is mainly the pulse.

On the other hand, the gelation time should be long for the penetration between the soil particles, but it is easy to deviate from the gap around the injection tube. In order to satisfy such conflicting constructional elements as one grout at the same time, it is easy to cause a bunch.

Therefore, the grout with short gelling time fills the gap around the injection tube to form a packer, while the long gelling time can penetrate through the soil particles and solidify the function so that injection can be performed without difficulty. Done.

The present invention enables such injection in one step. That is, according to the present invention, after injecting the permeable grout after forming the packer function as the purity grout using the double tube, the permeable grout is sealed around the infusion tube despite the long gelling time without any deviation. As it penetrates between the soil particles, it forms a solid body around the injection hole, and the target range can be solidified as planned.

In order to continuously carry out the above steps in one step, in the present invention, a double pipe having a position where discharge ports having different freezing times are discharged is located at different locations in the axial direction is used. Filling the gap around the injection tube, and filling the large gap by injecting the purity grout into the weak layer and the layer with the large gap, and consolidating the weak layer to constrain the injection area. Injecting a permeable grout, it is possible to infiltrate between the fine grains in a predetermined depth without the permeable grout is deviated out of the injection target range.

In general, when a long gelling time is injected into the ground, the injection liquid tends to deviate in the direction of the upper surface where the injection resistance is low. However, in the present invention, the purity of the upper layer is determined by the purity of the upper discharge port. There is a tendency for a solidified layer formed by the grout, so that the permeable grout can be penetrated and solidified to a predetermined depth without departing from the top.

The above is explained with reference to FIG.

When the injection tube A is installed in the ground and the pure grout is injected from the upper discharge port, the grout fills the gap around the injection tube and is press-fitted into a weak layer to make the injection target region restrained. The weak layer is mainly consolidated and strengthened. In the figure, D is a purity guru knot. (FIG. 1 (a)), (With this alone, watertightness cannot be obtained, and reinforcement of the entire ground is insufficient, and water or collapse is easily caused during excavation.)

Subsequent injection of the permeable grout at the lower outlet C, the permeable grout is prevented from deviating in the direction of the surface because the permeable grout is filled around the infusion tube, especially the top rough and weak layers. It is solidified. It also penetrates into the fine particle gap where purity purity grout has not penetrated, thus enabling ground enhancement.

In the figure, E is the permeable grout solidification. (Fig. 1 (b))

By raising the stage again, the above-described process can be repeated to completely improve the entire ground. (FIG. 1 (c) and FIG. 1 (d))

Illustrating the grout used in the present invention the following are used;

a. Suspended type grout with cement or clay as an active ingredient.

b. Watergrass-based grout resin-based grout.

Reaction agents of watergrass grout commonly used in the present invention include acids (inorganic acids, organic acids, etc.), salts (inorganic salts, organic salts, basic salts, neutral salts, acid salts, etc.), esters, aldehydes, amides, and alcohols. , Alkalis such as cement and lime can be used.

The molar ratio (SiO ₂ M ₂ O): 1.5 to 5.0 molar ratio of the liquid glass, anhydrous glass, water of the water, water crystallization and the like, the molar ratio of the alkali metal salt of silicic acid or silicic acid It is a mixture of alkali metal salts and silicic acids.

As the watergrass grout, any pH region such as an alkali region, a neutral region, and an acidic region is used.

In the present invention, the double pipe and the construction method are as follows.

In addition, in the purifying watergrass grout or the permeable watergrass grout which is commonly used in the present invention, the purifying reactant mixture and the infiltration blend are determined by changing the concentration of the reactant and the reactant itself. do.

For example, an inorganic salt or a reaction agent of an inorganic acid is suitable for the reaction mixture for purity grout, and esters and glyoxones are suitable for the formulation for permeability grout, but for example, the concentration of watergrass is low. At the same time, the concentration of the inorganic reactant may be used as a permeable watergrass grout, or the organic reactant may be used in combination with the pure watergrass grout.

In addition, the aqueous solution of acidic watergrass contains a mixture containing watergrass, alkaline acid salt, cement or other alkaline solution as a reactant, and when the concentration is high, it becomes a reagent mixture for purity grout. It is also possible to use a reactive mixture for penetrating grout. Therefore, in this invention, these shall also be included in a reactive agent.

The double pipe used in the present invention uses a plural double inlet pipe in which the position of the discharge port through which the grout is discharged is located in a different position in the axial direction of the injection pipe. Whether it can be replaced or not is a practical problem.

The present invention has solved such a problem, and the solidification time is different at the upper and lower discharge ports by displacing the position of the valve mounted in the double pipe only by the fluid pressure change caused by the presence or absence of the supply of a single compound liquid passing through the double pipe. Since it is possible to convert the discharge of the grout, the compound injection can be performed very simply.

One specific embodiment of the double tube according to the present invention will be described with reference to FIG.

In Figs. 2 (a), (c), 2 (b) and (d), 8a is an inner tube reverse valve, 8b is an external valve valve, 5 is a valve, 6 is a spring, and 7 is a metal crown. And 9 is a mixing room.

When the mixed solution forming the gut in the inner and outer tubes 1 and 2 is pressurized and transported through the pipe lines 1a and 2a, the reverse valves 8a and 8b are heated so that the valve portion is displaced downward by the fluid pressure of the inner tube liquid so that the lower discharge port 4 is opened. At the same time, two kinds of compound liquids coming out of the inner and outer tubes 1 and 2 are mixed in the mixing chamber 9 and discharged into the ground through the upper discharge port 3. 2 (c) is a cross-sectional view taken along the line A-A of FIG. 2 (a), and second (d) is a cross-sectional view taken along the line B-B of FIG. 2 (b).

Using this inlet tube, the purity reagent reactant was fed through the inner tube 1a and the molgra water solution was transferred through the outer tube 2a. The nutrient solution was mixed in the mixing chamber 9 to form a pure watergrass grout. It is discharged into the ground through the discharge port 3 (second (a) diagram, (c) figure.

Permeable water glass obtained by injecting a predetermined amount of purity grout, stopping the feeding of the purification agent mixture for once, and joining the infiltration reagent mixture into the aqueous solution of watergrass passing through the external pipe 2a at the upper end of the double pipe. When only the grout is injected, the valve 5 is displaced upward because there is no liquid in the inner pipe duct 1a, thereby closing the upper discharge port 3 and opening the lower discharge port 4 so that the permeable water glass grout is discharged from the discharge port below (second (b)). Fig. 2 (d) Fig. 2 When a predetermined amount of the penetrating watergrass grout is injected, the injection tube is moved to move the injection stage, and the above process is repeated.

The method of using the injection hole of FIG. 2 is to form a pure watergrass grout inside the tip of the injection tube and to discharge it into the ground, and FIG. 3 discharges the compound liquid constituting the grout at the upper discharge ports 3 and 3a and It is mixed outside the injection tube to form a pure watergrass grout and injected into the ground. According to this method, the gelling time is within a few seconds. It is possible to inject into the ground without causing the closing phenomenon due to gelation, and there is a characteristic that cannot be obtained in the method using the injection tube of FIG. In FIG. 3, 5 is a valve, 5a is a flow path in a valve, and 3, 3a is an external upper discharge port.

In the inner tube 1, the purified reagent mixture solution is fed and the external water 2 solution is transferred. In the external tube 2, the valve 5 is displaced downward by the liquid pressure of the purified reagent mixture, and the upper discharge ports 3, 3a are opened, The formed watergrass grout is formed and injected into the ground, and at the same time, the lower discharge port 4 is closed. (Fig. 3 (a) and 3 (c)), the feeding of the chastity reagent mixture solution is stopped, and the permeation reagent compound solution is joined to the aqueous solution of watergrass at the upper end of the appearance 2 to penetrate the watergrass grout. Is formed and fed through the exterior, the valve 5 is displaced upwards to close the upper discharge ports 3 and 3a, and the lower discharge ports 4 are opened to discharge the permeable water glass grout (FIG. 3 (b), 3rd). (d) degrees.

FIG. 3 (c) is a cross-sectional view taken along the line A-A of FIG. 3 (a), and FIG. 3 (d) is a cross-sectional view taken along the line B-B of the third (b).

4 is another specific embodiment of the injection tube according to the present invention, and is particularly suitable for injection of alternating purity grout and permeable grout.

In FIG. 4, (A) is sectional drawing which shows the injection state of a purity grout, (B) is sectional drawing which shows the injection state of a permeable grout. The injection pipe is composed of an inner pipe 1 and an outer pipe 2 and has an inner pipe pipe 1a and an outer pipe pipe 2a, respectively, and is a ground injection pipe for feeding a plurality of compound liquids into the ground through these two pipes, and at different positions in the axial direction. A plurality of opened discharge ports, i.e., an upper discharge port 3 and a lower discharge port 4, are provided, and a valve having displacements up and down is attached to the pipeline of the double pipe.

An annular closing plate 15 for opening and closing the upper discharge port 3 at the upper part and a closing rod 14 for opening and closing the lower discharge port 4 at the lower part thereof, which are integrally formed so that one of the above-mentioned compound liquids It is displaced up and down in accordance with the change of oil pressure by the presence or absence of the input and converts the opening and closing of the flow path to the electric upper outlet 3 and the lower outlet 4, thereby converting the injection of the grout in the ground at the upper outlet 3 or the lower outlet 4 It was made possible. Furthermore, the above-described injection tube is provided with a mixing unit 9 (or mixing chamber 9) to form a mixed liquid of two kinds of liquids fed through two pipes 1a and 2a and discharged from the upper discharge port 3, that is, the other discharge hole, In the lower discharge port 4, the compounding liquid supplied through one of the two previously mentioned pipelines 1a and 2a is discharged.

More specifically, when the above-mentioned inlet pipe is used to feed the purifying reagent through the inner pipe line 1a, and the aqueous watergrass solution or the permeable grout is fed through the outer pipe line 2a, the valve 5 is the inner pipe as shown in the fourth (a) diagram. It is lowered by the hydraulic pressure of the purifying reagent passing through the pipeline 1a. At this time, the annular closing plate is lowered 15 degrees downward to open the upper discharge 3 and at the same time the lowering rod 14 degrees is lowered to close the lower discharge port 4 and the inner pipe. The discharge port 3b is opened. For example, the inner tube 1 may be provided with a rubber cover 10 at the tip as shown in FIG. 6 (a). Mounting of the cover 10 is to fix the base 11 to the outer wall of the inner tube 1.

Therefore, the compound for chastity passing through the inner pipe line 1a is expanded by pushing the cover 10 through the inner pipe discharge port 3b and discharged to the mixing part (room) 9 and mixed with an aqueous solution of watergrass or permeable grout flowing from the outer pipe 2a. A formed grout is formed and injected into the ground at the upper discharge port 3. At this time, as described above, the cover 10 is mounted at the tip of the inner tube 1, and the mixture for purity of the inner tube canal 1a is discharged toward the bottom of the mixing chamber 9 through the inner tube discharge port 3b and flows in the upper discharge port 3 direction, so The purity grout flows upward from the inside of the mixing chamber 9 so that no gel remains at the bottom of the mixing chamber 9. As shown in Fig. 6 (b), the inner tube 1 is not required to be fitted with the cover 10, and 8 is a ridge rubber reverse zone so that the 9 purity grout inside the mixing chamber is connected to the outer tube 2a. To prevent backflow in the direction. The mounting of the reverse valve 8 can be known arbitrarily, 12 is a ball valve and 13 is a spring for supporting it, which prevents the purity gut injected into the ground from the upper discharge port 3 from flowing back into the injection pipe at the lower discharge port 4. It is to work.

Subsequently, the feeding of the purifying reagent mixture is stopped in the inner tube duct 1a, and the permeable gurut obtained by joining the reactant to the aqueous solution of watergrass in the upper duct of the outer duct 2a in the outer tube 2a.

4 (b) is a cross-sectional view of the state diagram when the supply of the purifying reagent mixture liquid is stopped in the inner tube duct 1 and the electric permeable grout is fed in the outer duct line 2a.

When the liquid is stopped in the inner pipe line 1a, there is no fluid pressure and the valve 5 is raised by the action of the spring 6. Then, the upper discharge port 3 is closed by the annular closing plate 15, and at the same time, the inner tube discharge port 3b is also closed by the closing rod 14, and the lower discharge port 4 is opened.

In this state, when the permeable grout is fed from the outer duct 2a, the permeable grout is injected into the ground by pressing the ball bilge 12 through the lower discharge port 4.

At this time, the permeable grout must pass through the mixing chamber 9 and is discharged out of the tube from the lower discharge port 4, so that the chastity grout remaining in the mixing chamber 9 is discharged out of the tube by the permeable grout. Therefore, there is no fear of gelation in the mixing chamber 9 remaining in the mixing chamber 9, and when the above operation is reversed, the conversion of the purity grout is smoothly performed.

In general, the industry of sufficiently mixing and forming the pure grout in the mixing chamber in the injection pipe and injecting it into the ground has better mixing property than the method of joining and forming outside the injection pipe. In the case of injecting permeable grout after injecting permeable grout, the purity of the grout remaining in the mixing chamber becomes gelated between converting the purity grout into the permeable grout and injecting into the soil. It is either impossible or clogged and requires very high pressure.

In the present invention, since the permeable grout is injected through the mixing chamber 9 after the purity of the grout is injected into the ground, the mixing chamber 9 is cleaned by the permeable grout so that the purity of the grout remaining in the mixing chamber 9 remains. Is extruded out of the injection tube to prevent the obstacles due to gelation of the residual purity grout as described above.

7 is a cross-sectional view showing the injection state of the seventh (a) or the purity grout as another separate embodiment of the injection tube according to the present invention, Figure 7 (b) is a view showing the injection state of the permeable grout One cross section. The structure of this injection tube is the same as that of the injection tube shown in FIG. 4 except for the valve 5. That is, in the injection pipe of FIG. 7 type, the valve 5 has the structure shown in FIG. This valve 5 has an annular closing plate 15 and a closing rod 14 arranged on the central axis of the annular closing plate 15 as evident from FIGS. 7 and 8, and the annular closing plate 15 has any number of through holes 3C. It is made of snow. The position of the through hole 3C is a position that coincides with the upper discharge port when the valve 5 descends to the lower side and the closing rod 14 is engaged with the lower discharge port 4 and the displacement is stopped, as shown in FIG. 7 (a).

A valve 5 having such a structure is installed in the injection pipe as shown in FIG. 7, and the purifying reagent is supplied through the inner pipe line 1a as in the injection pipe of FIG. 4, and the aqueous watergrass solution or the permeable grout is introduced through the outer pipe line 2a. The lower valve 5 is lowered by the hydraulic pressure of the purifying reagent passing through the inner tube duct 1a as shown in FIG. 7 (a).

At this time, the annular closing plate 15 is lowered downward, and the through hole 3C coincides with the upper discharge port 3 to open the upper discharge port 3, and simultaneously closes the lower discharge port 4 by lowering the closing rod 14 degree downward. For this reason, the pure water compounding agent flowing in the inner pipe line 1 and the aqueous watergrass solution or permeable grout flowing in the outer pipe line 2a are mixed in the mixing chamber 9 to form a pure grout. It is injected into the ground via the upper discharge port 3.

Subsequently, the feeding of the purifying reagent mixture of the inner tube duct 1a was stopped, and the permeable gurut obtained by joining the anti-solvent to the aqueous solution of watergrass in the upper duct of the outer duct 2a or the watergrass solution was transferred to the 7th (b). As shown in the figure, since there is no hydraulic pressure from the inner pipe line 1a, the valve 5 is pushed upward by the action of the spring 6 so that the through hole 3C is inconsistent with the upper discharge port 3, and the upper discharge port 3 is closed by the annular closing plate 15. At the same time, the lower discharge port 4 is opened. Therefore, the permeable gut of the outer duct 2a is injected into the ground by pressing the ball valve 12 through the lower discharge port 4.

At this time, the permeable grout is pushed out of the tube by purifying the pure grout remaining in the mixing chamber 9 as in the case of the above-mentioned fourth degree injection tube.

The purity guarut of the present invention is as described above. It may be formed by mixing an aqueous solution of watergrass and an aqueous solution of a purity reagent, or a mixture of watergrass and a reactant may gel itself, and a penetrating watergrass grout with a long enough time to gelate. It can also form by joining aqueous solution of a formation reagent. In this case, when the permeable grout is fed through the exterior and the inner tube is fed with the purity reagent mixture solution to discharge the purity water glass grout, the purity reagent mixture is joined to the permeable water glass grout and the permeable water glass sphere When discharging the route, a method of stopping the inflow of the purifying reagent compounding agent may be used. Compared with the latter, the former can increase the watergrass concentration of the pure watergrass grout, so that the concentration of the pure grout can be high and the gelation time can be shortened, so the excellent filling effect by the pure grout can be expected. The latter is characterized in that the conversion operation of the permeable and pure purity grout is easier than the former.

Furthermore, the injection method according to the present invention is a method of injecting the other grout without the movement of the injection tube after injecting one grout at a predetermined injection depth, or moving the infusion tube to inject one of the grouts. It is to include both of the method of injecting the other grout. In the present invention, the injection amount of the purity grout is preferably 5 l or more per 1 m of the injection depth in the region to be injected, and the interval in the depth direction of the position where the purity grout is discharged is within 1 m, usually within 0.5 m. Is good. The solidification time of the chastity grout is within 30 seconds, preferably within 15 seconds.

Thereby, the filling effect around the injection pipe by the purity grout appears, and the effect which makes the ground restrained is also shown.

Furthermore, the solidification time of the permeable grout is preferably 30 seconds or more, usually 1 minute or more.

Next, the present invention will be described in more detail with reference to Examples.

Example 1

The double gut of FIG. 4 was used to inject the following grout into the strata where the fine sand and the gravel ground alternated in Tokyo.

When the first liquid and the second liquid are conjoined in the same amount, the gelation time is 5 minutes. When the first liquid and the third liquid are conjoined in the same amount, the gelation time is 2 seconds.

The double pipe is installed to a predetermined depth, and externally, the first liquid is discharged in the same amount to the inner tube, and the purity of the grout is injected. The same amount of the third liquid was combined to infiltrate the permeable grout, and after the prescribed amount was finished, the stage was raised, and the above injection was repeated.

After excavation and irradiation after injection, purity guarut penetrates between the injection tube and the ground, and the rough layer, and permeable guarut penetrates into the part and fine layer where the above-mentioned purity guarut does not penetrate. It has been found that the ground is homogeneously elevated.

Example 2

Using the double pipe of FIG. 7, the present invention was used for the test work in the bottom-floor dead sand layer having groundwater.

I solution: Sodium phosphate 5%

Solution II: Watergrass was added to the lactic acid, pH was adjusted to 3 with 7 mol of [SiO ₂ ], and the mixture was blended so that the gelation time was 1 hour.

When the same amount of the first liquid and the second liquid are combined, the gel is formed in 15 seconds.

In the same manner as in Example 1, the first liquid was injected into the inner tube and the second liquid was uniformly introduced in the outer tube, and then a predetermined amount was injected. Only the second liquid was injected to raise the stage, and the injection was continued.

As a result of excavation after injection, the pure grout was mainly found in the granulation layer around the injection tube and the ground, and the permeable grout was mainly infiltrated in the granulated soil layer.

There was no deviation of the permeable grout.

Example 3

This invention was implemented in the ground of the history of the history of history and the fine sand of the silk thread of Tokyo.

The double pipe shown in FIG. 4 was installed and tested at a predetermined depth.

[combination]

Solution I: No. 3 watergrass mixed in aqueous solution of lactic acid

[SiO ₂ ]: 7 molarity

pH: 1.0, the mixture liquid of gelation time 15 hours was adjusted.

II liquid: 10% sodium bicarbonate solution

III solution: No. 3 watergrass solution 20% solution

First, the third liquid is introduced from the inner tube, and the first liquid is introduced from the outer tube. Then, the confluence of the solution, which is pH 7.5 and the gelation time of 2 seconds, is injected. Then, the second liquid was condensed with the first liquid, the confluence of the pH of 5.5 and the gelation time was 10 minutes, the stage was raised, and the above operation was repeated.

After excavation and investigation, it was found that the purity of the grout was filled around the injection tube and the interface of the arc layer, and the infiltrating grout penetrated between the soil particles and was homogeneously solidified.

Example 4

The same test as in Example 3 was conducted using the same ground as in Example 3 and using the injection tube shown in FIG.

[combination]

I liquid: same as I liquid of Example 3

II liquid: same as II liquid of Example 3

First, the first liquid is introduced from the exterior and the third liquid is introduced from the inner tube, and the confluence of the liquid is injected into the confluence with a gelation time of 5 seconds. The first liquid was injected with a confluence solution having a confluence pH of 5.5 and a gelation time of 10 minutes to raise the stage, and the above injection was repeated.

Excavation investigation revealed that the suspension was filled with a short gelling time at the interface between the injection and the surroundings and the arc layer, and the grout, which had long gelling time, was infiltrated homogeneously between soil particles.

Example 5

Injection experiments were performed in the same ground as in Example 3 using the double tube of FIG.

[combination]

This compound is gelled at 20 minutes / 20 ° C.

The same amount of the first liquid and the second liquid are gelled in 20 seconds.

After the double tube is installed with a predetermined depth, the external liquid is injected in the same amount as the first liquid and the second liquid is injected into the inner tube to purify the grout, and then the injection of the second liquid is stopped. After the injection of the predetermined amount was completed, the stage was raised and the above injection was repeated.

Excavation and excavation after injection showed that purity guarut penetrates into the white state between the injection tube and the ground, and the granules are infiltrated homogeneously by penetrating into the part and the three layers where the purity guarut is not penetrated. It turned out.

Claims (7)

In the injection method of injecting the grout into the ground by using a double pipe in which a plurality of double pipes are provided in a position where the discharge port through which the grout is discharged is different in the axial direction of the injection pipe, and the injection pipe is changed to change the injection stage. And a plurality of compounding liquids are supplied to two pipes formed in the double pipe, and a valve is attached to the pipes in the double pipe, and the fluid pressure accompanying the presence or absence of supplying at least one of the compound liquids in the above-mentioned plurality of compound liquids. And the valve is displaced by the change to change the opening and closing of the flow paths of the plurality of discharge ports, thereby making it possible to change the injection of the grout at the discharge ports different from the axial direction. The method of claim 1, wherein a mixed liquid of two compound liquids fed into the above two pipes is discharged from one of the discharge ports, and the other discharge port is supplied into one of the two pipes. Characterized in that only the liquid mixture is discharged, wherein the two mixture liquid mixture is formed by mixing in the mixing portion in the electric double tube, the compound liquid fed into the one pipe is discharged from the discharge port through the mixing portion Injection method. The method of claim 2, wherein the mixture solution of the two preceding formulations is a grout having a gelation time of 30 seconds or less, is discharged from the upper discharge port, and the formulation solution fed to the single passageway has a gelation time of 30 seconds or more. It is a grout and the injection method discharged from a lower discharge port. A ground injection double injection pipe having two pipelines, wherein a plurality of compounding liquids are fed into the ground through the two pipelines, comprising a plurality of discharge ports opened at different positions in the axial direction, and The pipeline is equipped with valves with displacements up and down, and the valves are displaced up and down due to the change of fluid pressure due to the presence or absence of one of the plurality of compound liquids. And converting the grout injection of the plurality of discharge ports. The injection tube according to claim 4, wherein there is a mixing portion in the injection tube, whereby a mixed liquid of two compound liquids fed into the two lines from the mixing portion is formed. The method according to claim 4 or 5, wherein a mixed liquid of two compound liquids fed into two pipes is discharged from one of the discharge ports described above, and one of the two pipes is discharged from the other discharge port. The compounding liquid fed into the pipe line is discharged, and the compounding liquid to be fed into the first one pipe is discharged through the electric mixing unit. The compound mixture according to claim 5 or 6 has a gelation time of 30 seconds or less, and is discharged from the upper discharge port. Injection pipe which is discharged from the lower discharge port and is a grout of 30 seconds or more.

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