JPH07252822A - Ground grouting method - Google Patents

Abstract

PURPOSE:To consolidate the ground very quickly and simply by grouting multiple impregnants having different consolidation periods concurrently in the horizontal direction. CONSTITUTION:A grouting pipe 1 has two lines 2, 3, and one line is provided with multiple injection ports 4 facing in the horizontal direction to the outside of the grouting pipe 1 through discharge ports 5 provided across the other line at different positions in the axial direction. The injection ports 4 are provided at part of the discharge ports 5, and multiple grouting pipes 1 are installed in the ground. At least two of multiple grouting pipes 1 are used, an impregnant consolidatable by itself is fed through one line, and it is injected and grouted into the ground from the discharge ports 5 through multiple injection ports 4. A consolidation accelerator is fed through the other line, and it is injected and mixed into the discharge ports 5 from the injection ports 4, and it is grouted into the ground. Multiple impregnants having different consolidation periods can be concurrently grouted into the ground from multiple grouting pipes 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite pouring method for pouring a plurality of injection materials having different setting times into the ground to consolidate the ground, and particularly to simultaneously applying a plurality of injection materials having different setting times at the same time. In addition, the present invention relates to a ground pouring method for consolidating the ground extremely quickly and easily by pouring in the horizontal direction.

[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.

Further, 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 pouring method in which the grout is injected in the horizontal direction from the upper discharge port, and at the same time, the grout having a long consolidation time is injected in the lower vertical direction from the lower discharge port.

[0004]

However, in the former method using a double pipe, grouts having different setting times are separately injected, and therefore it is necessary to switch these grouts at the time of injection. However, the injection is complicated and quick and easy injection is impossible. 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 simultaneously inject grout with different setting times, but since the triple pipe is used, the diameter of the injection pipe hole is large, the drilling cost is high, and the construction efficiency is high. become worse.

[0006] Furthermore, this method requires adjustment of the composition of the main material, the reaction mixture composition for instant setting and the reaction composition formulation for slow setting,
It gets complicated. Further, in this method, the injection liquid from the upper discharge port is injected horizontally, but the injection liquid from the lower discharge port is injected vertically downward. Usually, the ground targeted by the pouring method is soft ground, but in this ground, it is customary that layers with different water permeability are accumulated horizontally in the process of ground formation. Therefore, the hydraulic conductivity is larger in the horizontal direction than in the vertical direction, and it is not possible to place the discharge port of the injection pipe in the horizontal direction on the side wall of the injection pipe rather than in the downward vertical direction at the end of the injection pipe. Injected without.

Therefore, an object of the present invention is to simultaneously inject a plurality of injection materials having different consolidation times into the ground in the horizontal direction by using an injection pipe having a small hole diameter having two pipe paths such as a double pipe. It is an object of the present invention to provide a ground injection method that enables injection, and therefore fastens and easily solidifies the ground and improves the above-mentioned drawbacks existing in the prior art.

[0008]

In order to achieve the above-mentioned object, according to the present invention, there is provided an injection pipe having two conduits, one of which is crossed over the other. An injection configured such that a plurality of horizontally oriented injection ports communicating with the outside of the injection pipe through the provided discharge ports are provided at different axial positions, and the injection ports are provided at a part of the discharge ports. A plurality of pipes are installed in the ground, at least two of the plurality of injection pipes are used to deliver the injectable material which can be solidified by itself through the one pipe line, and is discharged through the plurality of injection ports. It is injected and injected into the ground from the outlet, and further, the solidification accelerator is fed through the other pipe line, injected and mixed from the injection port into the discharge port, and injected into the ground. The injection material can be injected into the ground simultaneously from multiple injection pipes. The features.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described below with reference to the accompanying drawings.

1 and 2 are a cross-sectional view of a specific example of an injection pipe used in the method of the present invention and an explanatory view of the method of the present invention.

In FIG. 2, reference numeral 1 denotes an injection pipe having two pipe lines used in the method of the present invention, showing an example of a double pipe. The injection pipe 1 may be a double pipe or two pipe lines provided in parallel. The injection pipe 1 has an outer pipe line 2 and an inner pipe line 3, and one of these pipe lines, for example, the inner pipe line 3 has a horizontal direction that leads to the outside A of the injection pipe 1. A desired plurality of injection ports 4, 4, ... 4 facing each other are provided at different positions in the axial direction, that is, at different positions in the length direction of the injection pipe 1. The injection ports 4, 4 ... 4 communicate with the outside A of the injection pipe 1 through discharge ports 5, 5 ... 5 that cross the outer pipe line 2.

Further, a part of the discharge port 5, for example, FIG.
An ejection port 6 is provided at the uppermost ejection port 5 in the above.
When the injecting material which can be solidified by itself is sent through the inner pipe line 3 as shown in FIG. 2 using the injecting tube 1 configured as described above, the injecting material is injected into the injection ports 4, 4, ... It is injected and injected into the ground through the discharge port 5, 5 ,.

Further, when the caking accelerator is sent through the outer pipe line 2, the caking accelerator is discharged from the injection port 6 to the discharge port 5.
Is injected and mixed into the injection liquid of the injectable material which can be solidified by itself and is injected into the ground as an injectable material having a short setting time. The caking accelerator may be continuously injected or intermittently injected.

In the present invention described above, the injection ports 4 and 6 are provided.
Both are formed with a reduced diameter as shown in FIGS. 1 and 2. The squeezing of this diameter is caused by
The material is injected to such a degree that pressure is generated with respect to the flow rate in the injection pipe, that is, injection is performed at a certain speed. This injection pressure is preferably 1 kgf / cm ² or more.

Generally, in the above-ground portion, when the fluid in the injection pipe is discharged into the air from the injection port, the pressure in the injection pipe depends on the size and the flow rate of the injection port, and the smaller the injection port diameter with respect to the flow rate, The larger the flow rate with respect to the injection port diameter, the higher the injection pipe internal pressure, that is, the injection pressure. Further, when the injection port diameter is large with respect to the flow rate or when the flow rate is small with respect to the injection port diameter, the injection pipe internal pressure, that is, the injection pressure hardly occurs.

In the present invention, since the injection liquid is in the injection state in this way, as will be described later, even if the solidification time of the injection material from the discharge port 5 is different, the water permeation of the ground around the discharge port 5 is also caused. Even if the sex is different, and even if the permeation resistance of the ground changes due to the progress of gelation of the injected liquid, an almost constant discharge amount can be obtained from any of the discharge ports 5, 5, ...
Firmly solidify the ground.

Examples of the injectable material which can be solidified by itself in the present invention include a mixed solution of water glass and a reaction agent, non-alkaline water glass grout, cement grout and the like. For the mixed solution of the and the reactant, salt, alkali such as lime, non-alkaline water glass compounding solution, carbon dioxide, carbonated water, etc.For non-alkaline water glass grout, water glass, cement, alkali, various salts, For cement grout such as water glass grout, water glass, various salts, non-alkaline water glass compounding liquid and the like can be mentioned.

Although not shown, the groove may be formed in the circumferential direction of the injection pipe instead of the discharge port 5 described above. In this case, a rubber ring is fitted in the groove instead of the plug 7 of FIG.

[0019]

In the method of the present invention described above, first, as shown in FIG. 1, the closing bundling member 9 of the inner pipe 3a is arranged away from the end discharge port 8 of the outer pipe 2a and the end discharge port 8 is opened. In this state, the drilling water is sent through the outer pipe line 2 and jetted from the end discharge port 8 in the direction of the arrow to drill a hole. At this time, the discharge port 5 is closed by a stopper 7 (rubber stopper, rubber ring, steel stopper, etc.).

Next, as shown in FIG. 2, an injection material which can be solidified by itself through the inner pipe line 3, for example, a mixed solution of a water glass aqueous solution and a reaction agent, which has a long hardening time, is used. When the liquid is sent, the closing bundle 9 is dropped by this hydraulic pressure to close the end discharge port 8 and discharge the cork stopper 6 to open the discharge ports 5, 5, ... 5, The injection material is the injection port 4 ,
It is injected in the horizontal direction from the discharge ports 5, 5 ... 5 into the ground through 4 ...

Further, at the same time, when the solidification accelerator is fed through the outer pipe line 2, this liquid is jetted and mixed from the injection port 6 into the injection liquid in the discharge port 5, and the injection pipe 1 is used as an injection material having a long consolidation time. Is injected horizontally on the outer side A of the.

That is, in the method of the present invention, one discharge port 5
From the other ejection port, and from the other ejection port 5, the infusion material having a long consolidation time is simultaneously injected in the horizontal direction.

The injection function by injection in the present invention is shown in FIG.
And it demonstrates in FIG. When pumping water to a pipe with an inner diameter of 4 cm, almost no pump pressure is generated. An example of the result of measuring the injection pressure (pump pressure) and the discharge amount by mounting the tip end portion having the injection port at the end of this pipe is shown in FIGS. 3 and 4.

For comparison, a tip portion having three discharge ports each having a diameter of 1 cm is attached to the end portion of the pipe as described above.
Although water was delivered up to 20 l / m, almost no discharge pressure was observed.

FIG. 3 shows a nozzle having a nozzle diameter of 1.0 mm, and FIG. 4 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 sent 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. 3 and 4, for example, using a pump pressure of 80 kg / cm ² , even if the resistance pressure (kg / cm ² ) in the ground changes, the resistance pressure of 50 kg / cm ²
The flow rate from the nozzle is constant up to the maximum.

That is, there is a region where a constant discharge amount can be obtained despite the change in the ground resistance pressure.
And it can be seen from FIG. Therefore, even if the injection materials having different setting times are discharged from the respective discharge ports, a constant discharge amount can be obtained even if the water permeability of the ground is different, and the ground can be reliably solidified.

That is, since the injection material having a short setting time is harder than the injection material having a long setting time, the injection resistance of the surrounding ground becomes large, but nevertheless, a constant flow rate corresponding to the nozzle diameter is obtained. In addition, the soil has different permeability in the upper and lower layers, and therefore the injection resistance is different.However, a constant flow rate is always secured, and the ground pressure (resistive pressure) is kept due to various causes. Although it changes, nevertheless a constant flow rate is always secured. Therefore, according to the method of the present invention, a constant discharge flow rate is secured by selecting the pump pressure to a desired value, and the ground is reliably consolidated. To be done.

Further, according to the method of the present invention, grouts having different setting times can be surely injected at the same time by using the double injection pipe, and it is not necessary to change the injection liquid as in the conventional injection method. Is high. For example, in the state of FIG. 2, the injection can be performed while pulling up the injection pipe from the lowest stage to the upper stage of the injection range. In this case, the grout having a short solidification time fills the rough or fine portion of the upper layer from the upper discharge port, and at the same time, the grout having a long solidification time is superposed and injected into this region from the lower discharge port.

FIG. 5 shows an example in which the structure of FIG. 2 is continued up to above the injection pipe. In this case, all stages can be injected at one time with one injection tube without pulling the injection stage upward. What is necessary is that even if the number of ejection ports is increased, the gelation time of each ejection port is different, and the injection resistance of the surrounding ground is different, a predetermined injection can be ensured, and the ejection port A and the ejection port B can be secured. When the injection from the same time is performed at the same time, the infusion solution with a short gel time mainly consists of veins, and the infusion solution with a long gel time mainly consists of penetration between soil particles. This is because a weak compound is filled, and the latter gradually penetrates into a fine part, so that reliable composite injection is possible.

It should be noted that, in FIG. 5, the grout discharge port having a short gel time and the grout discharge port having a long gel time may be alternately provided in the vertical direction.

FIG. 6 shows an example in which a predetermined injection target ground is simultaneously injected from a plurality of injection pipes based on the same principle. In this case, the improvement of construction efficiency is immeasurable. In FIG. 6, P ₁ and P ₂ are liquid delivery parts, and pipes that communicate with the injection pipe 1 from the liquid delivery parts are branch pipes.

[0033]

[Example] Using the injection pipe of FIG. 1, a test construction was performed on the injection ground in Tokyo. In this case, the inner diameter of the outer tube is 4 cm, the inner diameter of the inner tube is 2 cm, and the inner wall thickness of the inner tube is 1 mm. The distance between the discharge ports is 50 cm, and the nozzle diameter of the uppermost injection ports 4 and 6 is 1 mm.
And the nozzle diameters of the middle and bottom injection ports 4 are 1.5 mm
And

[Formulation] 35 liters of water glass per 100 liters of solution A,
When 3 g of a commercial glyoxal solution, 1.2 l of 75% phosphoric acid and the remaining water are used, gelation occurs in 30 minutes. Also, for each 100 liters of solution B, 35 liters of water glass, 7 liters of 75% sulfuric acid, and the remaining water were prepared.
When the liquids are combined at a ratio of 1: 1, gelation occurs in 5 seconds.

After excavation, the permeation and solidification of the injection liquid from each discharge port was confirmed, and the cross-sectional area was about 1 m ² and the length was about
It was confirmed that a 1.5 m columnar, homogeneously permeated solid body was formed.

For comparison, an injection test was carried out by equipping the same double tube as described above with a tip portion provided with three discharge ports at axial intervals of 50 cm. The diameter of one discharge port was 1 cm. At the above-ground part, the liquid A was fed from the outer pipe at 9 l / min and the liquid B was fed from the inner pipe at 9 l / min, but the pump pressure was almost zero. When the injection pipe was injected into the ground and the above liquid A and liquid B were injected from the inner and outer pipes at a rate of 9 l / min in a total of 600 l to excavate, the bottom discharge port and the bottom discharge port were closed. It was confirmed that the injection liquid was being discharged only from the middle discharge port, and the injection liquid spreads in a pulse pattern centering on the middle discharge port, and was unevenly pulsed in the range of 1 to 6 m from the injection hole. It was found to have solidified into a shape.

[0037]

As described above, according to the method of the present invention, when injecting a plurality of injection materials having different consolidation times into the ground, an injection pipe having two small pipe diameters such as a double pipe is provided. Simultaneous injection is possible by using this, which enables quick and easy ground consolidation, and injection is performed while maintaining a predetermined discharge amount at each discharge port, regardless of the difference or fluctuation of injection resistance pressure. As a result, it becomes possible to firmly solidify the ground.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a specific example of an injection pipe used in the method of the present invention.

FIG. 2 is an explanatory view of an injection pipe used in the method of the present invention.

FIG. 3 is a graph showing a relationship between a resistance pressure and a flow rate from a nozzle.

FIG. 4 is a graph showing a relationship between a resistance pressure and a flow rate from a nozzle.

FIG. 5 is an explanatory view of another embodiment of the method of the present invention.

FIG. 6 is an explanatory view of another embodiment of the method of the present invention.

[Explanation of symbols]

 1 injection pipe 2 outer pipe line 2a outer pipe 3 inner pipe line 3a inner pipe 4 jet port 5 discharge port 6 jet port 8 end discharge port 9 closed bundle metal fitting

Claims (1)

[Claims] 1. An injection pipe having two pipe lines, wherein one pipe line has a horizontally oriented injection port communicating with the outside of the injection pipe through a discharge port provided across the other pipe line. A plurality of injection pipes, which are provided at different positions in the axial direction and further provided with an injection port at a part of the discharge port, are installed in the ground, and at least two of the injection pipes are provided. A book is used to deliver an injectable material that can be solidified by itself through one of the conduits, and is injected into the ground from the discharge opening through the plurality of injection openings, and a solidification accelerator through the other conduit. Is injected, mixed and injected into the discharge port from the injection port, and injected into the ground, whereby a plurality of injection materials having different consolidation times are simultaneously injected into the ground from a plurality of injection pipes. Ground injection method.