JPH0552367B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a composite injection method in which a plurality of injection materials having different consolidation times are injected into the ground to solidify the ground, and in particular, The present invention relates to a ground injection method for consolidating the ground extremely quickly and easily by simultaneously injecting a plurality of different injection materials.

[Conventional technology]

As a technique for improving complex ground, a so-called composite injection method is generally used, in which grout with a short setting time and grout with a long setting time are injected into the ground.

Conventionally, this type of composite injection method uses double pipes to first inject grout with a short setting time into the ground to fill rough areas, weak areas, or voids around the injection pipe, and then takes a long time to set. A known method is to inject long grout between soil particles and allow it to penetrate into the ground.

Furthermore, using a triple pipe, the combined liquid (injected liquid with a short solidification time) of two liquids sent separately from two pipes is injected from the upper discharge port, and at the same time, the combined liquid (injected liquid with a long solidification time) is injected from the lower discharge port. A composite injection method in which grout is injected is known.

[Problem that the invention seeks to solve]

However, in the former method, which uses double pipes, grouts with different setting times are injected separately, so it is necessary to switch between these grouts at the time of injection. is not possible. Furthermore, this construction method does not allow for a large amount of liquid to be fed, resulting in a decrease in construction efficiency.

In addition, the latter method using triple pipes allows simultaneous injection of grouts with different solidification times, but the use of triple pipes increases the diameter of the injection pipe hole, resulting in high drilling costs and poor construction efficiency.

Therefore, an object of the present invention is to enable simultaneous injection of a plurality of injection materials having different consolidation times into the ground by using an injection pipe with a small hole diameter having two pipes such as a double pipe. Therefore, it is an object of the present invention to provide a ground injection method that quickly and easily consolidates the ground and improves the above-mentioned drawbacks of the prior art.

[Means for solving problems]

In order to achieve the aforementioned object, according to the present invention:
An injection pipe having two pipe lines and a plurality of discharge ports at different positions in the axial direction, the discharge ports having an injection port communicating with one pipe line and a injection port communicating with the other pipe line. one of the two pipelines, using injection pipes that are respectively opened and in which at least two of the plurality of discharge ports are formed such that the aperture ratios of the injection ports opened therein are different; A plurality of injection materials having different solidification times are simultaneously injected from the plurality of discharge ports by sending the main material from the pipe and the reactant from the other pipe.

Hereinafter, the present invention will be explained using the accompanying drawings. FIG. 1 and FIG. 2 are a sectional view of a specific example of an injection pipe used in the construction method of the present invention and an explanatory diagram of the construction method of the present invention, respectively. In FIG. 2, reference numeral 1 indicates an injection pipe having two pipelines, which is used in the construction method of the present invention, and shows an example of a double pipe. In addition to a double pipe, the injection pipe 1 may be a pipe in which two pipes are provided in parallel. (Not shown) The injection pipe 1 has an outer pipe line 2 and an inner pipe line 3, and the injection pipe 1 has an outer pipe line 2 and an inner pipe line 3 at different positions in the axial direction, that is, at different positions in the length direction of the injection pipe 1. a plurality of discharge ports 5 leading to
Further, the discharge ports 5, 5...5 have injection ports 4, 4...4 communicating with one pipe line, for example, the inner pipe line 3, and the other pipe line, for example, the outer pipe line 2.
The injection ports 6, 6...6 are opened, respectively.

Furthermore, at least two of the above-mentioned discharge ports 5, 5...5 have injection ports 4 and 6 opened therein.
For example, as shown in FIG. 5, injection ports 4 (diameter Φ1.3 mm) and injection ports 6 (diameter Φ1.0 mm) in one discharge port 5 are formed with different aperture ratios.
As shown in Fig. 6, the diameter ratio of the injection ports 4 (diameter Φ1.3 mm) and 6 (diameter Φ1.5 mm) in the other discharge port 5 is 1.3:1. : formed to be 1.5.

Using the injection pipe 1 constructed in this way, one pipe line, for example, the inner pipe line 3, is connected as shown in FIG.
When the injection material as the main material is sent through the main material and the reactant is sent through the other pipe, for example, the outer pipe pipe 2, the main material is injected from the injection port 4 into the discharge port 5 and the reactant is injected from the injection port 6 into the discharge port 5, and both liquids meet within the discharge port 5 and are injected into the ground. At this time, since at least two of the discharge ports 5, 5, . At least two or more types of injection materials with different values are simultaneously injected into the ground.

In the construction method of the present invention described above, it is necessary that the injection material is injected from the injection ports 4 and 6. As a result, the injection material is injected into the ground from the discharge port 5, so even if the solidification time of the injection material from the discharge port 5 differs, the water permeability of the ground around the discharge port 5 may vary, as will be described later. Even if the resistance pressure (or ground pressure) changes during injection,
A substantially constant discharge amount can be obtained from any of the discharge ports 5, 5...5, and the ground can be solidified reliably.

[Effect]

In the construction method of the present invention described above, first, as shown in FIG. Excavation water is sent through the outer pipe conduit 2 and is injected from the lower discharge port 8 in the direction of the arrow to drill holes. At this time, the discharge port 5 is connected to the cork stopper 7.
It is closed by.

Next, as shown in FIG.
When the injection material as the main material, for example, a mixture of a water glass aqueous solution and a reactant, is sent through the liquid pressure, the valve 9 falls down and closes the lower discharge port 8, and the cork stopper 6 is ejected to close the discharge port. 5, 5...5
is opened, and the injection material is injected through the injection ports 4, 4...4 to the discharge ports 5, 5...5.

Further, at the same time, when a reactant is sent through the outer tube conduit 2, this liquid is jetted and merged with the jetted liquid in the discharge port 5 from the jetting port 6. At this time, the discharge ports 5, 5...
Since at least two of the injection ports 4 and 6 have different diameter ratios, the confluence ratio of the main material and the reactant is different, so at least two types of injection materials with different solidification times are simultaneously poured into the outside A of the injection pipe 1. Injected.

That is, in the construction method of the present invention, the injection material with a short consolidation time is injected from one discharge port 5, and the injection material with a long consolidation time is injected from the other discharge port 5 at the same time.

Figure 3 shows the resistance pressure (ground pressure) (Kg/cm ² ) at each injection pressure from the injection port 4 (expressed as pump pressure when sending the injection material) and the injection port (nozzle).
FIG. 4 is a graph showing the same relationship as FIG. 3 when the nozzle aperture (injection aperture) is changed. As is clear from Figures 3 and 4, for example, if the pump pressure is 80Kg/ ^cm2 , even if the resistance pressure (Kg/ ^cm2 ) in the ground changes, the resistance pressure will be 50Kg/ ^cm2. Until then, the flow rate from the nozzle is constant.

Therefore, in the construction method of the present invention, if the pump pressure is increased to about 1.2 to 1.3 times or more than the resistance pressure,
Regardless of changes in resistance pressure, and even though injection materials with different consolidation times are discharged from each outlet, a constant discharge amount can be obtained even if the permeability of the ground is different, and the Can be solidified reliably.

In other words, the injection material with a short consolidation time will harden faster than the injection material with a longer consolidation time, so the injection resistance of the surrounding ground will be greater, but despite this, a constant flow rate corresponding to the nozzle diameter is ensured, In addition, the permeability of the upper and lower layers of the ground is different, and therefore the injection resistance is different, but despite this, a constant flow rate is always ensured, and the ground pressure (resistance pressure) changes due to various reasons. However, in spite of this, a constant flow rate is always ensured, and therefore, according to the construction method of the present invention, by selecting the pump pressure to a desired value, a constant discharge flow rate is ensured, and the ground is reliably solidified. tied.

〔Effect of the invention〕

As described above, according to the method of the present invention, when injecting multiple injection materials with different consolidation times into the ground, simultaneous injection is possible using an injection pipe with a small hole diameter having two pipes such as a double pipe. This allows quick and easy soil consolidation, and
Regardless of differences or fluctuations in the injection resistance pressure, by selecting the pump pressure to a desired value, the injection is maintained at a constant discharge rate, thereby making it possible to solidify the ground reliably.

[Brief explanation of drawings]

Figures 1 and 2 are a sectional view of a specific example of an injection pipe used in the construction method of the present invention and an explanatory diagram of the construction method of the present invention, respectively, and Figures 3 and 4 respectively show the flow rate from the nozzle with respect to the resistance pressure. FIGS. 5 and 6 are enlarged partial sectional views showing the discharge port portion of FIG. 2. FIG. 1...Injection pipe, 2...Outer pipe line, 2a...Outer pipe, 3...Inner pipe line, 3a...Inner pipe, 4, 6...
Spout port, 5...Discharge port, 8...Lower discharge port, 9...
…valve.

Claims (1)

[Claims] 1. An injection pipe that has two pipe lines and a plurality of discharge ports at different positions in the axial direction, and the discharge ports include an injection port that communicates with one pipe line and an injection port that communicates with the other pipe line. are respectively opened, and at least two of the plurality of discharge ports are formed so that the diameter ratios of the injection ports opened therein are different, and one of the two pipes is A ground injection method characterized in that a plurality of injection materials having different consolidation times are simultaneously injected from the plurality of discharge ports by sending a main material from a pipe and a reactant from the other pipe.