JPH0830332B2 - Ground injection method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite injection method for injecting a plurality of injection liquids having different setting times into the ground to consolidate the ground, and particularly to a plurality of injection solutions having different setting times. The present invention relates to a ground injection method capable of solidifying the ground extremely quickly and easily by simultaneously injecting the water from the injection port.

[0002]

2. Description of the Related Art Generally, a so-called composite pouring method is used as a technique for improving a complicated ground, in which a grout having a short setting time and a grout having a long setting time are poured into the ground.
Conventionally, this type of composite pouring method uses a double pipe to inject grout with a short setting time into the ground to fill the rough parts, weak parts or voids around the injection pipe, and then set the setting time. It is known that a long grout is injected between soil particles to penetrate into the ground.

In the above-mentioned composite injection method, an injection method in which grout having a short setting time is injected from the upper discharge port of the double pipe and grout having a long setting time is injected from the lower discharge port of the double pipe at the same time. Is also known.

Furthermore, a confluent liquid of two liquids separately fed from two pipe lines using a triple pipe (injection liquid having a short setting time)
There is known a composite injection method in which grouting is injected from the upper discharge port and simultaneously grout having a long setting time is injected from the lower discharge port.

[0005]

However, in the former construction method using a double pipe, grouts having different setting times are separately injected, and therefore it is necessary to switch these grouts during injection. The operation is complicated and quick and easy injection is not possible. Furthermore, this method cannot increase the amount of liquid to be sent, resulting in low construction efficiency.

In the latter method using a triple pipe, it is possible to inject grout with different setting times at the same time, but since it is a triple pipe, the diameter of the injection pipe hole is large, the drilling cost is high, and the construction efficiency is high. Becomes worse. Furthermore, this method requires complex adjustments of the main material, the reaction mixture composition for flash setting, and the reaction composition preparation for slow setting, which is complicated.

Further, in the above description, even if grouts having different gelling times are injected from different outlets, whether they are double tubes or triple tubes, the grouts having different gelling times are injected. Communicate with each other through the voids around the injection tube and are mixed into grout with the same gelling time, so that composite injection cannot be achieved.

Usually, the ground to which the pouring method is applied is soft ground, but in this ground, it is customary that layers having different water permeability are piled up in the horizontal direction during the ground formation process. The hydraulic conductivity is larger in the horizontal direction than in the vertical direction, so that the injected injection liquid (grout) deviates through the injection pipe into a layer having a high hydraulic conductivity.

Therefore, the object of the present invention is not only to extremely rapidly and easily consolidate the ground by simultaneously injecting a plurality of injecting liquids having different consolidating times from a plurality of injecting ports, but also to raise and lower the ground around the injecting pipe. It is an object of the present invention to provide a ground injection method in which the drawbacks of the above-mentioned known art are improved by allowing the injection liquids injected from the positions not to be mixed with each other and to be ejected and injected into the ground independently.

[0010]

In order to achieve the above object, according to the invention, there is at least two conduits,
A ground injection method for injecting an injection liquid into the ground by using an injection pipe having a plurality of injection ports at different axial positions, wherein each injection port is provided with a discharge port communicating with one pipeline A. And at least one of the injection ports is provided with a discharge port that communicates with the other pipe line B, and at least two of the plurality of injection ports are discharged from one pipe line A and the other pipe line. Using an injection pipe formed so that the flow rate ratio of the discharge amount from the passage B is different, the main material mixture liquid of the injection liquid is sent from one of the passages A, and the reaction of the injection liquid from the other passage B is performed. It is characterized in that the agent mixture liquid is sent, and a plurality of injection liquids having different setting times are simultaneously injected from the plurality of injection ports, respectively.
When the above-mentioned injecting solution is obtained by merging the mixed liquids to be fed to the conduit A and the conduit B of the injecting pipe at the flow rate ratio, the setting time is within 15 minutes, and the shorter setting time is 30 minutes. It is characterized by being within seconds.

[0011]

DETAILED DESCRIPTION OF THE INVENTION The present invention will now be described in more detail with reference to the accompanying drawings. FIG. 1 is a side view of a specific example of the double pipe X used in the present invention, which is basically composed of an outer pipe 1 and an inner pipe 2 arranged therein. The double pipe X includes a flash injection pipe a and a slow injection pipe b,
The instantaneous setting injection pipe a has an injection port 3 for injecting an injection liquid having a short gelation time, and the loosening injection pipe b has injection ports 3, 3, ... 3 for injecting an injection liquid having a long gelation time. . In these injection tubes a and b, the instantaneous injection tube a is arranged in the upper part of the double tube X and the loose injection tube b is arranged in the lower part in FIG. 1, but this arrangement is arbitrary. Engagement is installed at a point. c is the end of the double tube X, and 4 is a metal crown.

FIG. 2 is an enlarged cross-sectional view of the instant injection pipe body a in FIG. 1, FIG. 2 (a) shows a state during perforation, FIG. 2 (b) shows a state during injection, and FIG. ) Shows a sectional view of the injection port 3 of the instantaneous injection pipe a.

FIG. 3 is an enlarged sectional view of the loose injection tube body b in FIG. 1. FIG. 3 (a) shows a state during perforation, FIG. 3 (b) shows a state during injection, and FIG. 3) shows a cross-sectional view of the injection ports 3, 3 ... 3 of the loose injection tube b.

FIG. 4 is an enlarged sectional view of the end portion c of the double pipe X in FIG. 1, and FIG.
(B) shows the state during injection.

First, as shown in FIG. 2A, perforated water is fed in the direction of the arrow through the conduit 6 of the outer tube 1. As shown in FIG. 4 (a), this drilling water is sent to the end portion c, the spring 8 of the valve 7 is pushed down to open the pipe 6 a, and the pipe 6 a is opened to the ground. And the double pipe X is set to a predetermined depth. At this time, since the inlet 3 shown in FIGS. 2A and 3A is closed by the opening / closing tip 5 made of metal or synthetic resin, the perforated water does not leak from here.

Next, as shown in FIG. 2 (b), when the main material mixture liquid A is fed from the outer pipe line 6 and the reactant mixture liquid B is fed from the inner pipe line 9 in the directions of the arrows, first, As shown in FIG. 4 (b), the reactant mixture liquid B is dropped at the terminal end c to close the outer pipe line 6 a. As a result, the reagent mixture liquid B in the inner pipe line 9 Is under pressure,
The closed bundle tip 5 shown in FIGS.
It is blown off to the outside by the pressure of, and the injection port 3 is opened.

The inlet 3 is shown in FIGS. 2 (b), (c) and FIG.
As shown in (b) and (c), discharge ports 11, 11 ... 11 communicating with one pipeline A, for example, the outer pipeline 6, are provided, and at least one of the injection ports 3 is provided. A discharge port 12 communicating with the other pipeline B, for example, the inner pipeline 9 is provided.

Further, at least two of the plurality of inlets 3, 3, ... 3 are discharged from one conduit A (outer conduit 6) and the other B (inner conduit 9). 2) are formed so that the flow rate ratios of the discharge amounts from) are different. Specifically, for example, one injection port 3 is shown in FIGS. 2 (a), (b), (c),
In particular, as clearly shown in FIG. 2C, one discharge port 11 (diameter Φ1.0 mm) communicating with the outer pipe conduit 6 is provided, and a discharge port 12 (respectively diameter Φ1.mm) communicating with the inner pipe conduit 9 is provided. 2 (0 mm), and the other one injection port 3 is shown in FIG.
(B), (c), especially as clearly shown in FIG. 3 (c),
Discharge ports 11 (diameter Φ1.0 mm) communicating with the outer pipe line 6 and discharge ports 12 (diameter Φ1.0 mm) communicating with the inner pipe line 9 are provided one by one. As a result, the discharge port 11 leading to the one pipeline A
And at least two inlets 3 having different ratios of the number of outlets 12 communicating with the other conduit B are formed,
These at least two inlets 3 are formed so that the flow rate ratio of the discharge amount from one conduit A and the discharge amount from the other conduit B is different.

When the closed bundle tip 5 shown in FIGS. 2 (a) and 3 (a) is removed and the injection port 3 is opened, as shown in FIG. 2 (b),
As shown in (c) and FIGS. 3 (b) and 3 (c), the main material mixture liquid A and the reactant mixture liquid B are discharged from the discharge port 11 and the discharge port 12 into the spout 3, respectively, and mixed. As a result, a plurality of infusates having different setting times are formed.

The plurality of injection liquids are simultaneously injected into the ground through the plurality of injection ports 3, 3 ... 3 described above.
These injection liquids are supplied from the conduits A and B to the respective injection ports 3, 3, ... 3
The setting time is adjusted within 15 minutes and the shorter setting time is adjusted within 30 seconds according to the flow rate of the compounded liquid discharged into the inside. In addition, in the present invention, it is also possible to use an infusion solution longer than the setting time of these infusion solutions together.

In the above-mentioned present invention, the main material mixture liquid (A
Liquid) is a water-glass compounded liquid, or a grout capable of gelling itself (for example, a liquid mixture of water glass and a reactant),
Further, the reactant mixture liquid (liquid B) is a mixture liquid containing various hardening agents or cement suspensions compatible with the main material mixture liquid.

The flow rate ratio of these liquids A and B to the inlet may be 1: 1 and can be selected to any other flow ratio. Further, this ratio may be changed during the injection.

FIGS. 5, 6 and 7 (a) and 7 (b) are sectional views showing the method of the present invention using another type of injection pipe, and FIG. 6 shows the injection state, and FIGS. 7 (a) and 7 (b) show examples of the injection port.

The above-mentioned injection pipe is a double pipe X composed of an outer pipe 1 and an inner pipe 2 as in FIG. 1, but a closed bundle 14 is slidably fitted to the end of the inner pipe 2. 1, and three injection ports 3 are provided at different axial positions, that is, different vertical positions, which is different from FIG. Moreover, these inlets 3
Are different in the ratio of the numbers of the discharge ports 11 communicating with the outer pipe conduit 6 and the discharge ports 12 communicating with the inner pipe conduit 9, respectively.
Therefore, as will be described later, the gel times of the AB confluent liquids discharged and mixed at the respective inlets 3 are all different.

First, as shown in FIG. 5, each inlet 3
With the closed bundle tip 5 fitted thereinto, the double pipe X is set at a predetermined depth in the ground by excavating the metal crown 4 while feeding the drilling water through the outer pipe line 6. Since the closed bundle tip 5 is fitted in each of the inlets 3, the drilling water is discharged into the ground through the outer pipe lines 6 and 6a without leaking.

After excavation, as shown in FIG. 6, when the main material mixture liquid A is fed through the outer pipe line 6 and the reactant mixture liquid B is fed through the inner pipe line 9, respectively, first, The reactant mixture liquid B pushes down the closing bundle 14 fitted to the end of the inner pipe 6 to close the outer pipe line 6a. As a result, the outer pipe line 6 is closed, and the reagent mixture liquid B in the inner pipe line 9 is also in a pressurized state, and the closed bundle tip 5 in FIG. 6 is blown out and the injection port 3 is opened.

Thereafter, the liquid A in the outer pipe line 6 and the liquid B in the inner pipe line 9 are respectively discharged into the discharge port 1 through the opened injection port 3.
It is discharged through 1 and 12 and mixed.

The injection port 3 is, for example, as shown in FIG. 7A, two discharge ports 11, 11 communicating with the outer pipe line 6.
(Each caliber Φ1.0 mm) and one discharge port 12 (caliber Φ1.0 mm) communicating with the inner pipe line 9 and the ratio of the numbers of these discharge ports 11 and 12 is 2: 1. As shown in FIG. 7 (b), one discharge port 11 (diameter Φ1.0 m that communicates with the outer pipe line 6
m) and the two outlets 12 and 12 (each having a diameter of Φ1.0 mm) communicating with the inner pipe line 9, and the ratio of the number of these outlets 11 and 12 is 1: 2. As shown in
Each of the outlets 11 and 12 communicating with the outer pipe line 6 and the inner pipe line 9 has one outlet, and the ratio of the number of these outlets 11 and 12 is 1: 1. Therefore, the flow rates of the AB confluents at the respective injection ports 3 are all different, and the injection liquids having different gel times are injected from the respective injection ports 3 into the ground.

Generally, in the above-ground portion, when the fluid in the injection pipe is discharged into the air from the discharge port, the pressure in the injection pipe depends on the size and flow rate of the discharge port, and the smaller the discharge port diameter with respect to the flow rate, The larger the flow rate with respect to the discharge port diameter, the higher the pressure in the injection pipe, that is, the discharge pressure. Further, when the discharge port diameter is large with respect to the flow rate, or when the flow rate is small with respect to the discharge port diameter, the injection pipe internal pressure, that is, the discharge pressure becomes small. Also, the fluid pumped through the injection pipe line is injected from the injection port in a predetermined amount corresponding to the size of the discharge port diameter. The higher the pressure inside the tube, the more difficult it is for the amount of injection to change even if the resistance pressure outside the injection port changes.

The diameter of the discharge port is determined so that the injection material from the discharge port produces a pressure with respect to the flow rate in the injection pipe in the above-ground portion, and this discharge pressure is preferably 10 kgf / cm ² , more preferably 15 kgf / cm ^2. That is all.

In the present invention, the compounded liquid is pressurized at a high pressure (10 kgf / cm above the ground) from a plurality of outlets communicating with one of the channels of the injection pipe.
² , preferably 15 kgf / cm ² ), and the compounded liquid may be discharged at high pressure from the discharge port leading to the other pipe line,
In some cases, the discharge may be performed so that the pressure in the pipe is hardly applied. The hole diameter of the discharge port is preferably about 0.2 to 2.0 mm. Further, in the present invention, the internal pressure of the tube may be several hundred kgf / cm ² . Further, a gas or a fluid other than the injecting liquid may be pressed into the injection pipe together with the injecting liquid or in advance of the injecting liquid, so that the injecting liquid can be easily permeated or mixed into the ground.

Further, according to the present invention, different gelling times can be set accurately, and the amount of the injecting liquid discharged to the discharge port does not easily change even when the resistance pressure changes during injection. Can hold exactly. In the present invention, in order to change the merging ratio of the liquid A and the liquid B, the ratio of the diameters of the discharge ports is changed or the ratio of the number of discharge ports is changed.

Further, according to the present invention, it is possible to prevent the injection liquids having different gelling times from being mixed in the space of the outer wall of the injection pipe, and to inject the injection liquids having different gelling times into the ground independently.

In general, when a liquid is pumped at a high pressure into a pipe provided with n discharge ports each having a fine hole of the same diameter, the liquid is sprayed from each discharge port in a uniformly divided amount of 1 / n. As the flow rate increases, the pipe pressure increases, and when the pressure is much higher than the resistance outside the discharge port (ground injection pressure), the discharge is performed in a uniform amount without being affected by the external resistance. If the pipe pressure is the same, the discharge amount increases as the discharge port diameter increases. The injection pipe used in the present invention is configured so that the liquid A and the liquid B thus discharged are combined and mixed in the mixing chamber of the injection port and injected into the ground.

[0035]

The present invention described above is a double injection pipe having a plurality of injection ports at different axial positions, each of the injection ports being provided with a discharge port communicating with one of the conduits A, and At least one of the inlets is provided with a discharge port that communicates with the other conduit B, and at least two of the plurality of inlets are discharged from one conduit A and discharged from the other conduit B. Since the injection pipes are formed so that the flow rate ratios of the amounts are different, it is possible to simultaneously inject a plurality of injecting liquids having different consolidating times from a plurality of injecting ports, which can consolidate the ground extremely quickly and easily. It is a thing.

Further, according to the present invention, the gelling time of the combined liquid mixture of the main material mixture liquid (A liquid) and the reactant mixture liquid (B liquid) is 15
Formulated to be within 5 minutes, preferably within 5 minutes, more preferably within 1 minute, and the shorter gelling time is within 30 seconds, preferably within 15 seconds. Therefore, the injection liquids injected from the upper and lower positions around the injection pipe can be ejected and injected independently into the ground without being mixed with each other.

That is, a portion of the instantaneous injection liquid having a short gel time injected from one injection port 3 and the injection liquid having a longer gelation time injected from the other injection port 3 are partially. The mixture is mixed and unevenly injected into the space around the injection pipe and filled, but of these, the instantaneous injection liquid has poor permeability, so as shown in FIG. The space around the inlets 3 and 3 is first filled, and the closing layer 13
On the other hand, on the other hand, the injection solution having a longer gelation time is shown in FIG.
As shown in (b), it penetrates in the arrow direction between the surrounding soil particles.

That is, as shown in FIG.
A strong cylindrical closed layer 13 is formed around the space between the upper and lower inlets 3, 3 around the inlet pipe X, including the surrounding soil. Since the closed layer 13 is destroyed and penetrated in the direction of the arrow between the soil particles,
The top and bottom injections do not mix.

In contrast to the present invention, when the soil layer is rough, one injection solution is within 10 minutes, preferably one minute, and the other injection solution with a shorter gel time is within 15 seconds. Good. In this case, the entire injection target area is solidified with the injection liquid. However, when the soil layer is a thin layer, only the area around the injection pipe is solidified with the A / B confluent for primary injection, and the A / B confluent with a longer gelation time is secondary injected to solidify the entire ground. It is desirable to tie. Further, the primary injection may be carried out for each stage, only in the lowermost part, or in the middle.

The injection function by injection in the present invention will be described below. When pumping water to a pipe with an inner diameter of 4 cm, almost no pump pressure is generated. 9 and 10 show the results of measuring the injection pressure (pump pressure) and the discharge amount by mounting the tip portion having the injection port at the end of this pipe. For comparison, a tip having three discharge ports each having a diameter of 1 cm was attached to the end of the pipe to feed water of 1 to 20 l / m, but almost no discharge pressure was observed. .

FIG. 9 shows a nozzle having a nozzle diameter of 1.0 mm, and FIG. 10 has a tip portion having a discharge port of 1.5 mm, which is attached to a pipe, the pump pressure is changed variously, and water is fed so that the pump pressure maintains a predetermined pressure. Moreover, the downstream side of the injection port is also connected by a pipeline, and a resistance pressure is applied by a valve in the pipeline to generate a pressure corresponding to the resistance pressure of the ground, and the flow rate (l / Min) and resistance pressure (kgf / cm ² ) were measured, and the results are shown in the graph. As can be seen from FIGS. 9 and 10, for example, using a pump pressure of 80 kg / cm ² , the resistance pressure (kg / cm ² ) changes even if the resistance pressure in the ground changes.
The flow rate from the nozzle is constant up to about 50 kg / cm ² . That is, it can be seen from FIGS. 9 and 10 that there is a region where a constant discharge amount can be obtained despite the change in the ground resistance pressure.

[0042]

Examples of the invention

Example 1 (1) An experiment was conducted using the injection tube (double tube) shown in FIG. In the injection pipe of FIG. 1, the liquid A (outer pipe side) was provided with six discharge ports, and the liquid B (inner pipe side) was provided with five discharge ports. Therefore, the A liquid is discharged equally divided into 1/6 and the B liquid into 1/5.

Therefore, two A-side and one B-side outlets are arranged in the upper injection port, and one A- and B-liquid outlet is arranged in the lower injection port. A liquid 2/6, B liquid 1
/ 5 mixed solution is A solution 1/6, B solution 1 from the lower injection port
/ 5 mixed solution is injected respectively.

Further, one inlet is arranged in the upper stage, and four inlets are radially arranged in the lower stage.
2/6 of the liquid flow rate and 1/5 of the B liquid flow rate are (1/6) × 4 of the A liquid flow rate and (1/5) × of the B liquid flow rate for the entire lower stage.
4 are each infused.

(2) Injecting conditions Using the above-mentioned injecting pipe, when injecting the injecting liquids of the liquid A and the liquid B into the pipes at 10 l / min, the injecting liquids are distributed to the respective inlets in the same amount. To discharge. Therefore, when 6 discharge ports are provided in the A liquid side conduit and 5 discharge ports are provided in the B liquid side conduit, the discharge amounts are 2 l / min and 1.67 l / min, respectively. Also, when the pressure inside the pipe is measured on the ground, A liquid is 15 kgf / cm.
² , the solution B was 20 kgf / cm ² .

The discharge ratio of the liquid A and the liquid B at the injection port of the instantaneous grouting was 1.67 × 2: 2 = 1.67: 1, and the injection amount of the instantaneous grouting was 5.3 l / min. The discharge ratio of the liquid A and the liquid B at the injection port of the slow-flowing grout was 1.67: 2 = 0.84: 1, and the injection amount of the slow-flowing grout was 14.7 liters.

(3) Injection Solution Used and Gelation Time The following formulation was used to form three kinds of injection solutions. Sodium silicate formulation A liquid 50cc per molar ratio 3.7 of the infusate _{-1 (SiO 2: 25.6%)} 25cc water 25 cc B liquid 75% phosphoric acid 2.0 cc 40% per 50cc commercial glyoxal 3.0cc water rest

Mixture of injection liquid-2 Liquid A Same as injection liquid-1 Liquid B 75% per 50 cc 75% phosphoric acid 1.8 cc 40% commercial glyoxal 5.0 cc Water remaining

Mixture of injection liquid-3 Solution A Same as injection solution-1 Solution B 50 cc 75% phosphoric acid 3.0 cc 40% commercial glyoxal 0.5 cc Water remaining

The gelation time is shown in Table 1.

[Table 1]

(4) Injection The test injection of the present invention was carried out for foundation excavation work. At this site, during excavation work, chemical injection was considered in order to prevent the impact on neighboring buildings due to loosening of the ground. The ground conditions are high groundwater level, gravel-mixed sand that easily collapses, and the improvement depth is as shallow as -0.5 to 4.5 m, the injection liquid is easy to escape to the ground surface, and the double pipe instantaneous connection method may be the ground. It is a ground that causes uplift.

Using the method of the present invention, an injection hole pitch of 80 cm was used to inject 400 liters per 1 m of injection depth. The injection stage moved from the bottom to the top every 1 m. When injection was performed using only injection liquid-3, liquid A and liquid B were injected from around the injection pipe.
The liquid mixture deviated without gelling.

When the injection liquids 1 and 2 were similarly injected from different injection holes, there was no deviation to the ground surface. In addition, the ground uplift did not occur. Further, when 80 l of the injection liquid-1 was first injected at the bottom of the injection stage and then 380 l of the ground injection liquid-3 was injected per 1 m, there was no deviation to the ground surface. Furthermore, the ground uplift did not occur. For comparison, a double tube was used to
When 1, 2, and 3 were combined and injected at a flow rate ratio of liquid A and liquid B of 1: 1, they were deviated to the ground surface. Similarly, when the injection liquids-1, 2 and 3 were jointly injected at a flow rate ratio of liquid A / liquid B of 1: 1.67, remarkable ground uplift was caused.

After the injection, a drilling survey was conducted to examine the distribution of the solidification. As a result, in the injection liquid-3, the solidification varied from 0.3 to 1.5 m. The injection liquid-1 was 0.9 to 1.2 m, and the injection liquid-2 was 0.7 to 1.2 m, which was a good result. Injection-1
When the injection liquid-3 is injected after first injecting, a solid solidified body is formed in a cylindrical shape (diameter 10 to 20 cm) around the injection pipe, and the solidified body is 1.0 to 1.0 cm in diameter with the solidified body as the center. A homogeneous consolidation area of 1.1 m was formed.

For comparison, using a Φ70 mm casing, after drilling up to 4.5 m, this injection pipe was inserted, and between the casing and the injection liquid -3 blended AB mixture liquid (1: 1.67). )
While pouring in, pull up the casing to form a gelled product with only one type of instantaneous grout around the injection tube,
Then, the injection liquid-3 was injected through the main injection tube in the same manner as above.
The excavation survey revealed variations of 0.4 to 1.5 m.

From the above, when injecting liquids having different gelling times are combined to form a solidified body around the injecting pipes with an injecting liquid having a short gelling time, an injecting liquid having a longer gelling time is further injected. It can be seen that the effect of the present invention can be obtained.

[0057]

Example 2 Using the injection tube of Example 1, an experiment was further conducted under the following conditions. (1) Injection Solution Used First, the following solutions A and B are prepared. Solution A: Acidic silicic acid aqueous solution. A water glass with a molar ratio of 2.7, a SiO ₂ content of 26% by weight, and a specific gravity of 1.32 / 20 ° C. was mixed with sulfuric acid to obtain PH.
Prepare 2.0 acidic silicic acid aqueous solution. The content of water glass in this acidic silicic acid aqueous solution is 25% by volume. Solution B: 25% by volume solution of the above water glass.

Mixing of injection liquid-1 and gelation time If the confluence ratio of liquid A and liquid B is 1: 1.5 (flow ratio), the gelation time of the confluence liquid A / B (injection liquid) is 15 seconds. Therefore, assuming that the mixing ratio A: B in the upper inlet is 1: 2.5, the gelation time is 40 seconds, and the mixing ratio A in the lower inlet A:
When B = 1: 1.25, the gelation time is 3 seconds.

Mixing of injection liquid-2 and gelation time If the confluence ratio of liquid A and liquid B is set to 1: 1 (flow ratio), the gelation time of the confluence liquid A / B (injection liquid) is 20 minutes. Thus, assuming that the mixing ratio A: B = 1: 1.67 at the upper inlet, the gelation time is 5 as shown in the graph of FIG.
When the mixing ratio A: B = 1: 0.83 at the lower injection port, the gelation time is 4 hours, and the gelation time of the sand gel mixed with the soil of the injection ground is 20 minutes.

(2) Injection conditions Using the formulation of injection liquid-2, while injecting liquid A and liquid B at 10 l / min each, liquid B was added at a flow rate of 5 l / min by another pump at the first injection stage. And the flow rate of the solution B was set to 15 l / min, and the injection solution having the composition of the injection solution-1 was injected. For the subsequent stage, an injection liquid having a composition of injection liquid-2 was used, and injection was performed in the same manner as in Example 1.

(3) Injection The test of the method of the present invention was conducted at the starting portion of the propulsion method. The site is an alluvial ground with complex alternating layers of relatively soft cohesive soil and sandy soil with high groundwater.

GL-3.0-5.0 with 1m injection hole pitch.
In the section of m, 400 l was injected per 1 m of injection depth. The injection stage moved upward every 1 m from the bottom. As the injection liquid, 10% of the injection liquid-1 and 90% of the injection liquid-2 were used. At the bottom injection stage, after injecting the entire amount of the injection liquid-1 per injection, inject the injection liquid-2 at an injection depth of 1 m.
Each injection was carried out in 360 l and the injection stage was moved.

After injection, the face of the starting portion was observed,
A strong solidified body with a diameter of 15 to 20 cm is formed around the injection tube, a homogeneous solidified body is formed around it, and the solidified bodies of the adjacent injection tubes are completely continuous and solidified. It was In addition, neither uplift of the ground nor deviation of the injected liquid to the ground surface was observed.

FIG. 12 is a schematic view showing an injection state when the injection port of the injection pipe of the present invention is continuously installed up to the upper side.
In this case, it is possible to inject all the stages at once with one injection tube without pulling the injection stage upward. What is required is that even if the number of discharge ports is increased, the gelation time of each discharge port is different, and the injection resistance of the surrounding ground is different, the prescribed injection can be secured and the injection with a short gelation time is possible. When the injection port 3a for the liquid and the injection port 3b for the long gelation time are simultaneously injected, the injection liquid for the short gelation time is mainly composed of veins, and the injection liquid for the long gelation time is the soil particles. Since the penetration mainly takes place, the former will fill the rough and weak areas around the area earlier, and the latter will gradually penetrate into the smaller areas.
This is because reliable composite injection is possible. Note that, in FIG. 12, the injection port for the injection liquid having a short gel time and the injection port for the long injection liquid may be alternately provided in the vertical direction.

FIG. 13 is an explanatory view of another embodiment according to the present invention, in which a plurality of injection pipes X are installed on a predetermined ground Y to be injected, and liquids A and B are simultaneously supplied to these injection pipes X. Pump P
This is an example in which the liquid is sent via 1 and P2 to inject and solidify the ground Y. In this case, the construction efficiency is immeasurably improved.

[0066]

As described above, according to the present invention, it is of course possible to consolidate the ground extremely quickly and easily by simultaneously injecting a plurality of injecting liquids having different consolidating times from a plurality of inlets. Do not mix the injection liquids injected from the upper and lower positions around the injection pipe, inject them independently into the ground and inject them into the ground. It is injected while maintaining the discharge amount and the predetermined gelling time, which makes it possible to firmly solidify the ground.

[Brief description of drawings]

FIG. 1 is a side view of a specific example of an injection tube used in the present invention.

2A and 2B are enlarged cross-sectional views of the instant injection pipe body in FIG. 1, in which FIG. 2A shows a state during perforation, FIG. 2B shows a state during injection, and FIG. 2C is a sectional view of an injection port. .

3 is an enlarged cross-sectional view of the loose injection tube body in FIG. 1, (a) showing a state during perforation, (b) showing a state during injection, and (c) a cross-sectional view of an injection port. .

4A and 4B are enlarged cross-sectional views of the distal end portion of the injection pipe in FIG. 1, where FIG. 4A shows a state during perforation and FIG. 4B shows a state during injection.

FIG. 5 is a cross-sectional view of another type of injection pipe according to the present invention, showing a state in which drilling water is being sent.

6 is a cross-sectional view of an injection tube of the type shown in FIG. 5, showing the injection state.

FIG. 7 is a cross-sectional view of a specific example of the injection port according to the present invention, in which (a) is an example in which two discharge ports communicate with the outer pipe line and one discharge port communicates with the inner pipe line. , (B) is an example in which one discharge port communicates with the outer pipe line and one discharge port communicates with the inner pipe line.

FIG. 8 is a cross-sectional view showing an injection state of an instantaneous infusion liquid and a permeable infusion liquid according to the present invention, in which (a) is a shield formed in a space around an injection port by the instantaneous injection liquid. A closed layer is shown, and (b) shows the permeation state between the soil particles of the permeable injectable solution.

FIG. 9 is a graph showing a relationship between a resistance pressure and a flow rate from a nozzle due to a change in pump pressure for a nozzle diameter Φ1.0 mm.

FIG. 10 is a graph showing a relationship between a resistance pressure and a flow rate from a nozzle due to a change in pump pressure for a nozzle diameter Φ1.5 mm.

FIG. 11 is a graph showing the relationship between the ratio of solution B / solution A and the gelation time.

FIG. 12 is a schematic view showing an injection state of a modified example of the injection pipe of the present invention.

FIG. 13 is an explanatory diagram of another specific example according to the present invention using a plurality of injection tubes.

[Explanation of symbols]

 1 Outer pipe 2 Inner pipe 3 Injection port 6 Outer pipe line 6a Outer pipe line 9 Inner pipe line 11 Discharge port 12 Discharge port 13 Closed layer 14 Closed bundle a Instantaneous injection pipe b Loose injection pipe X double tube

Claims (2)

[Claims] 1. A ground injection method for injecting an injection liquid into the ground by using an injection pipe having at least two pipe lines and having a plurality of injection ports at different positions in the axial direction, wherein The inlet is provided with a discharge port that communicates with one pipeline A,
Further, at least one of the injection ports is provided with a discharge port communicating with the other pipe line B, and at least two of the plurality of injection ports are discharged from one pipe line A and the other pipe line B.
Using the injection pipes formed so that the flow rate ratios of the discharge amounts thereof are different, the main material mixture liquid of the injection liquid is sent from one pipe line A, and the reactant mixture liquid of the injection liquid from the other pipe line B. And a plurality of infusion solutions having different consolidation times are simultaneously infused from the plurality of infusion ports, respectively, and the infusion solution is delivered to each of the conduit A and the conduit B of the injection pipe. When the mixed liquids are mixed at the flow rate ratio, the setting time is 15
Ground injection method characterized in that the solidification time of the shorter one is less than 30 seconds within minutes. 2. The ground injection method according to claim 1, wherein an injection liquid having a longer setting time than that of the injection liquid according to claim 1 is used together.