JPH0791824B2 - 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 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 of consolidating the ground extremely quickly and easily by pouring in the lateral 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 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.

[0004]

However, in the former double pipe, since grouts having different setting times are separately injected, it is necessary to switch these grouts during injection, which complicates the operation. It has been impossible to inject quickly and easily. Furthermore, this injection pipe cannot increase the amount of liquid to be sent, resulting in low construction efficiency.

Further, the latter triple pipe allows simultaneous injection of grout having different setting times, but since it is a triple pipe, the diameter of the injection pipe becomes large, the drilling cost becomes high, and the construction efficiency becomes poor. Furthermore, this triple pipe is complicated because it requires adjustment of the composition of the main material, the reaction mixture composition for instant setting and the reaction composition formulation for slow setting. Further, in this triple pipe, the injection liquid from the upper discharge port is injected horizontally, while the injection liquid from the lower discharge port is injected vertically downward.

[0006] Normally, 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 in the process of ground formation. Therefore, the hydraulic conductivity in the horizontal direction is larger than in the vertical direction,
The discharge port of the injection pipe is more naturally injected in the horizontal direction on the side wall of the injection pipe than in the downward vertical direction at the end of the injection pipe.

The applicant has applied for an injection tube based on this idea as Japanese Patent Application No. Sho 62-240656. The injection pipe according to this prior application has two pipe lines and also has a plurality of discharge ports oriented in the horizontal direction at different axial positions, and the discharge port communicates with one pipe line and the other pipe. Each of the ejection ports communicating with the passage is opened, and at least two of the plurality of ejection ports are formed such that the diameter ratios of the ejection ports opened therein are different from each other.

The feature of the invention of this prior application is that the liquid A and the liquid B are continuously injected simultaneously from the inner pipe and the outer pipe, respectively, and the instantaneous setting gel is caused by the difference in the ratio of the injection amount from the injection ports opening at the upper and lower discharge ports. And to form a loose gel. For this reason, even if a slight amount of spray is generated from the spray port, a problem that a predetermined gel is not formed occurs.

That is, in the prior invention in which the injection amount is adjusted by the ratio of the diameters of the injection ports, even a slight difference in the diameters causes a large change in the area of the injection port and a large change in the ratio of the injection amounts. Therefore, the error in the formation of the injection port greatly affects the gelation time.

Therefore, an object of the present invention is to simultaneously inject a plurality of injection materials having different consolidation times into the ground in a 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 solidifies the ground quickly and easily, and further improves and develops the above-mentioned prior invention.

[0011]

In order to achieve the above-mentioned object, according to the present invention, there is provided an injection pipe having two pipe lines and a plurality of discharge ports at different axial positions. ,
One or a plurality of injection ports that communicate with one of the conduits and one or a plurality of injection ports that communicate with the other of the conduits are opened in the discharge port, and at least two of the plurality of discharge ports are in the discharge port. Using the injection pipes formed so that the ratio of the number of the injection ports of one pipeline and the number of the injection ports of the other pipeline are different from one of the two pipelines By feeding the main material and the reactant from the other pipe, a plurality of injection materials having different setting times are injected laterally and simultaneously from the plurality of discharge ports.

The present invention will be described below with reference to the accompanying drawings. 1 and 2 are a cross-sectional view of one 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. FIG. 1 shows the state of sending the drilling water, and FIG. 2 shows the state of injection. 1 and 2, reference numeral 1 denotes an injection pipe having two pipe lines according to the method of the present invention, showing an example of a double pipe. The injection pipe 1 has an outer pipe line 2 and an inner pipe line 3 and is oriented in different positions in the axial direction, that is, in different positions in the longitudinal direction of the injection pipe 1 in the lateral direction leading to the outside A of the injection pipe 1. Has a plurality of discharge ports 5, 5 ... 5 and further has one or a plurality of injection ports 4, 4 communicating with one of the discharge ports 5, 5 ,. .. 4 (or 4 ', 4' .. 4 ') and the other conduit, for example the injection port 6, 6 ... 6 (or 6', 6 '.
・ 6 ') are opened respectively.

Further, among the above-mentioned discharge ports 5, 5, ... 5,
At least two of them are formed so that the ratio of the number of the ejection openings of one of the conduits opened therein and the number of the ejection openings of the other conduit are different from each other. For example, as shown in FIG. 5, the injection ports 4 (diameter Φ 1.0 mm) and 6 are provided in one discharge port 5.
(Diameter Φ 1.0 mm) and 6 '(diameter 1.0 mm) are open, and the ratio of the number of the injection port of the inner pipe line to the injection port of the outer pipe line is 1: 2, as shown in FIG. As described above, the other one discharge port 5 has an injection port 4 (diameter Φ 1.0 mm) and an injection port 4 ′ (diameter Φ Φ).
1.0 mm) and 6 (diameter Φ 1.0 mm) are opened, and the ratio of the number of the injection port of the inner pipe line to the injection port of the outer pipe line is 2: 1.

As shown in FIG. 2, the injection pipe 1 constructed as described above is used to feed an injection material as a main material through one pipe line, for example, an inner pipe line 3, and the other pipe line. For example, when the reaction agent is fed through the outer pipe line 2, the main material is injected from the injection port 4 into the ejection port 5 and the reaction agent is injected from the ejection ports 6 and 6 ′ into the ejection port 5, The liquids merge in the discharge port 5 and are horizontally injected into the ground. At this time, at least two of the discharge ports 5, 5 ... 5 have different numbers of injection ports from one pipe line opened therein and the number of injection ports from the other pipe line are different from each other. At least two kinds of injection materials having different confluence ratios of the material and the reaction agent and having different setting times are simultaneously injected into the ground.

In the present invention described above, the injection ports 4, 4'and 6, 6'are all formed with a reduced diameter as shown in FIGS. The squeezing of the diameter is performed in the above-ground portion to such an extent that the injection material from the injection ports 4, 4'and 6, 6'produces a pressure with respect to the flow rate in the injection pipe, that is, the injection is performed at a certain speed. The injection pressure is 1 kgf / cm ² or more, preferably 10 kgf / cm ^2, more preferably 15~20kgf / 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 becomes small. The higher the pressure inside the pipe, the more difficult it is for the discharge amount to change, even if the resistance pressure outside the discharge port changes.

Further, according to the present invention, different gelling times can be set accurately, and the injection amount of the injecting liquid to the ejection port does not easily change even when the resistance pressure changes during injection. Can hold exactly. That is, when the present inventor obtains a predetermined injection amount, it is possible to perform the operation accurately by adjusting the number of the injection ports as compared with the invention of the prior application that adjusts the diameter of the injection ports. Focusing attention, the present invention has been completed. This is because the injection amount is almost proportional to the injection area when the pressure is constant. In order to double the injection amount, there are a method of increasing the diameter of the injection port and a method of increasing the injection port, but the effect of the error when increasing the diameter on the area is the error caused by increasing the number of the diameters. Will be greater than the effect of. Therefore, it is easier to determine the confluence ratio of the A and B confluents by the ratio of the number of ejection ports than by the aperture ratio of the ejection ports, and the gelling time of the confluent can be accurately determined.

Furthermore, the present inventor has noticed that when the fluid is ejected from the ejection port by increasing the internal pressure, the smaller the ejection port diameter with respect to the resistance pressure from the outside, the smaller the variation of the ejection amount. It was found that increasing the number of injection ports to increase the number of injections makes it possible to obtain an injection amount that is less affected by fluctuations in resistance pressure from the outside, and thus it is easier to obtain a predetermined gelation time. It was

According to the present invention, as will be described later, even if the solidification time of the injection material from the discharge port 5 is different, or the water permeability of the ground around the discharge port 5 is different, further injection is performed. Even when the permeation resistance of the ground changes due to the progress of gelation of the injected liquid, a substantially constant discharge amount can be obtained from the discharge ports 5, 5 ... 5 and the ground is firmly solidified.

The main material used in the present invention is water glass or an injectable material which can be solidified by itself, and examples thereof include a mixed solution of water glass and a reactant, non-alkaline water glass grout, cement grout, and the like. , The reaction agent is various caking agents or caking accelerators, salt, alkali such as lime, non-alkaline water glass compounded solution, carbon dioxide gas, carbonated water, etc. for a mixed solution of water glass and a reaction agent, Examples of the non-alkaline water glass grout include water glass, cement, various alkali salts, water glass grout, and the like, and for cement grout, water glass, various salts, non-alkaline water glass compounding liquid, and the like. Although not shown in the figure instead of the above-mentioned discharge port 5, a groove may be formed in the circumferential direction of the injection pipe. In this case, a rubber ring is fitted in the groove instead of the plug 7 of FIG.

[0022]

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 lower 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 discharged from the end discharge port 8 in the direction of the arrow for drilling. At this time, the discharge port 5 is closed by a stopper 7, for example, a rubber stopper, a rubber ring, a steel stopper or the like.

Then, as shown in FIG. 2, when an injection material as a main material, for example, a mixed solution of a water glass aqueous solution and a reactant is sent through the inner pipe line 3, the closing bundle metal fitting 9 is caused by this liquid pressure. It drops and closes the end discharge port 8 and releases the stopper 7 to open the discharge ports 5, 5, ... 5, The injection agent is discharged through the injection ports 4, 4 ,. Is injected into. Further, at the same time, when the reactant is fed through the outer pipe line 2, this liquid is jet-merged from the jet port 6 to the jet liquid in the discharge port 5. At this time, since at least two of the discharge ports 5, 5, ... 5 have different ratios of the number of injection ports from the inner and outer pipe lines, the merging ratios of the main material and the reactant are different, and at least two kinds having different consolidation times The above injection materials are the injection pipes 1
Is injected laterally to the outside A of the. That is, in the method of the present invention, the injection material having a short setting time is injected from one discharge port 5 and the injection material having a long setting time is injected simultaneously and laterally from the other discharge port 5.

FIG. 3 shows the injection function by injection in the present invention.
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 (honp 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 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. 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 is clear 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
The flow rate from the nozzle is constant up to about 50 kg / cm ² .

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. Furthermore, the present inventor has completed the present invention by focusing on the following points, except for the drawbacks of the prior invention. That is, according to the experiment, for example, the pump pressure is 30 kg / c
If injecting m ^2, and the injection quantity on the ground (when the resistance pressure of the ground is zero) is approximately 3l / min in the nozzle diameter ø1.0 mm, becomes substantially 6l / min at a nozzle diameter Φ1.5 mm. This means that when adjusting the number of injection ports to double the injection amount, the nozzle diameter Φ1.0 mm should be increased to two, whereas in order to adjust by the size of the nozzle diameter, Nozzle diameter Φ1.0 mm
Means increasing by 0.5 mm.

Further, the former can be surely and accurately performed by adjusting the number of injection ports by increasing or decreasing the number of injection ports, while the latter must be adjusted by a fine size. This means that the amount of discharge changes drastically due to slight differences in diameter, which means that machining is extremely difficult.

Further, comparing FIG. 3 with FIG. 4, when the nozzle diameter is large, the flow rate from the nozzle is larger than when it is small, and when the ground resistance pressure is the same, the discharge amount is large, so the resistance pressure The change in the discharge amount with respect to the change in Eq. Therefore, for changes in the ground resistance due to changes in the ground or changes in the permeability of the ground during injection,
The larger the nozzle diameter, the larger the change in the injection amount. In particular, the higher the resistance pressure, the greater the degree of decrease in the injection amount from the nozzle. This means that rather than changing the nozzle diameter to change the injection amount, changing the injection amount by increasing or decreasing the number of nozzles with a small diameter ensures a constant injection amount even when the resistance pressure changes. This means that it is possible to always maintain a constant gelation time.

Therefore, even though 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 solid is surely solidified on the ground. You can That is, since the injection material with a short setting time is more quickly solidified than the injection material with a long setting time, the injection resistance of the surrounding ground is large, but nevertheless, a constant flow rate corresponding to the nozzle diameter is secured, In addition, although the soil has different permeability in the upper and lower layers, and therefore the injection resistance is different, nevertheless, a constant flow rate is always secured, and the soil pressure (resistive pressure) changes due to various causes. Nevertheless, a constant flow rate is always ensured. Therefore, according to the method of the present invention, a constant discharge flow is ensured by selecting the pump pressure to a desired value, and the ground is reliably solidified.

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, if the main agent is fed from the inner tube and the reactant is fed from the outer tube, the grout having a short setting time fills the rough portion or the fine portion of the upper layer from the upper discharge port and at the same time from the middle discharge port. The grout having a long gelation time is discharged, and the grout having a long solidification time is superposed and injected from the discharge port at the lowermost end.

FIG. 7 shows an example in which the structure of FIG. 2 is continued up to the upper part of 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. 7, the outlets for grout having a short gelation time and the outlets for a long grout may be provided alternately in the vertical direction.

FIG. 8 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.

[0033]

[Compound]

Solution A: 35 liters of water glass, 7 liters of 75% sulfuric acid, and remaining water per 100 liters. (PH about 1.7) Solution B: 3 liters of water glass per 100 liters, remaining water. When liquids A and B are combined at a ratio of 0.5: 1.0 (volume ratio), gelation occurs in 8 seconds, when they are combined at 1.0: 1.0 (volume ratio), gelation occurs in 20 minutes, and when combined at 1.0: 0.5 gelation occurs in 60 minutes. To do. Liquid A was ejected from the inner pipe, and liquid B was ejected from the outer pipe. When excavated, the injection liquid from each discharge port was infiltrated and solidified, and a column-shaped homogeneously solidified body with a cross-sectional area of approximately 1.2 m ² and a length of approximately 1.5 m was formed. It was confirmed.

For comparison, the same double pipe as described above is provided with one injection port having a diameter of 1.5 mm instead of the injection ports 6 and 6'in the uppermost ejection port, and the ejection port 4 in the lowermost ejection port. When excavation was carried out using an injection pipe with a 1.5 mm diameter injection port instead of 4 ', the diameter of the consolidation cross-section varied from 1.5 to 0.8.

[0035]

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 can be performed by using this, which enables quick and easy ground consolidation, and a predetermined discharge amount and a predetermined gelling time at each discharge port, regardless of the difference or fluctuation of the injection resistance pressure. Is held and injected, which makes it 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 and an explanatory view of the method of the present invention.

FIG. 2 is 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.

FIG. 3 is a graph showing the relationship between the resistance pressure and the flow rate from a nozzle (diameter Φ1.0 mm).

FIG. 4 is a graph showing the relationship between the resistance pressure and the flow rate from a nozzle (diameter Φ1.5 mm).

5 is an enlarged partial cross-sectional view showing a part of the discharge port portion of FIG.

FIG. 6 is an enlarged partial cross-sectional view showing another part of the discharge port portion of FIG.

FIG. 7 is another specific example of the method of the present invention.

FIG. 8 is still another specific example 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 4'jet port 5 discharge port 6 jet port 6 'jet port

Claims (1)

[Claims] 1. An injection pipe having two pipe lines and a plurality of discharge ports at different axial positions, wherein the discharge port has one or a plurality of injection ports communicating with one pipe line. And one or a plurality of injection ports that communicate with the other pipe line, respectively, and at least two of the plurality of discharge ports are opened therein. The number of injection ports of the one pipe line and the other pipe line. By using the injection pipe formed so that the ratio of the number of the injection port of each different, by sending the main material from one of the two pipelines, by sending the reactant from the other pipeline,
A ground pouring construction method characterized in that a plurality of pouring materials having different setting times are injected laterally and simultaneously from the plurality of ejection ports.