JP2023079942A - Injection apparatus used in high-pressure injection and agitation method, and high-pressure injection and agitation method - Google Patents

Abstract

To provide an injection apparatus which is free from restriction on increase in a nozzle size, enables easy structural design of a flow channel and has good fluid energy efficiency, and can improve construction efficiency of a high-pressure injection and agitation method.SOLUTION: An injection apparatus has a lower stage injection nozzle 21 of a curable material, and an upper stage injection nozzle 22 for compression air or high-pressure water are arranged at upper and lower parts of an apparatus side face. The lower stage injection nozzle 21 and the upper stage injection nozzle 22 are provided so that a vertical arrangement interval of the nozzles 21 and 22 is set at 34 mm and each of the nozzles has an angle of 2°, for example, so that jet flows are merged at a point of 500 mm from an apparatus center. For example, in construction in which general soil is regarded as an object ground, both fluids are integrated with each other by a negative pressure generated from a curable material jet which is jetted from the lower stage injection nozzle 21 and has large specific gravity, and destructive force and cutting force of the ground are increased.SELECTED DRAWING: Figure 2

Description

The present invention relates to an injection device (special monitor) used in a double-pipe two-way injection stirring method that enables high-speed, large-capacity, and ultra-high pressure injection ground improvement, and a high-pressure injection stirring method using the same. .

The high-pressure injection stirring method is known as one of the ground improvement methods. In the high-pressure injection stirring method, hardening material is injected at high pressure from an injection device (special monitor) attached to the tip of the rod, and the ground and hardening material are mixed and stirred while cutting the ground, and a cylindrical improved body is placed in the ground. It is a method to create Fig. 3 shows an outline of the normal construction of the high-pressure jet stirring method.

The injection device used in the conventional double-pipe high-pressure injection stirring method generally has an air nozzle around the concentric circle of the injection nozzle for ultrahigh-pressure hardening material, so the outer circumference of the cylindrical injection device Since the mounting area of the injection nozzle base placed in the part becomes large, there is a problem that the expansion of the nozzle size is restricted.

In addition, in the conventional injection device that adopts a concentric nozzle arrangement, each flow path in the double pipe is concentrated in one nozzle, so the structure design of the flow path is aimed at reducing fluid energy loss. There was also the problem of being restricted to

In addition, if it is difficult to cut the ground and discharge the sludge in the high-viscosity ground with the conventional high-pressure injection agitation method, ground cutting with high-pressure water, so-called pledget (see Fig. 4), is performed prior to the injection of the hardening material. Therefore, the number of ground cutting processes increased, which was inefficient.

Therefore, in view of the problems of the prior art described above, the object of the present invention is to provide a high-pressure injection stirring method that has no restrictions on increasing the nozzle size, has a simple structural design of the flow path, and has a good energy efficiency of the fluid. To provide a jetting device capable of improving the construction efficiency of the work and a high-pressure jetting stirring construction method using the same.

Such objects have a first injection nozzle for injecting hardening material and a second injection nozzle for injecting compressed air or high-pressure water, said first and second The injection nozzles are arranged above and below the side surface of the injection device, and the first and second injection nozzles are provided so that the two jets merge at a point horizontally separated from the side surface of the injection device by a predetermined distance. is achieved by an injector characterized by:

In the above injection device, the jet of compressed air or high-pressure water injected from the second injection nozzle arranged at the upper stage has a suction effect due to the negative pressure generated from the hardening material jet injected from the first injection nozzle arranged at the lower stage. The first and second injection nozzles are provided for receiving.

In addition, the above-mentioned purpose is to cut the highly viscous ground with high-pressure water injected from the second injection nozzle arranged at the upper stage, and at the same time, stir and mix the ground with the hardening material injected from the first injection nozzle arranged at the lower stage. This is achieved by a high-pressure injection stirring method that creates a cylindrical improved body.

According to the present invention, it is possible to arrange the flow paths of the double tubular portion of the injection device (the flow path of compressed air or high-pressure water and the flow path of the hardener) in parallel. Improves energy efficiency. In addition, high-speed construction of the high-pressure injection stirring method becomes possible by increasing the energy efficiency. In addition, by enabling high-speed construction, it is possible to reduce the amount of sludge discharged compared to the conventional method. In addition, the increased energy efficiency makes it possible to improve the diameter of the nozzle.

In addition, in high-viscosity ground, the hardening material is injected from the lower injection nozzle and high-pressure water is injected from the upper injection nozzle at the same time. . (See Fig. 5)

1 is a cross-sectional view showing an injection device according to the present invention; FIG. FIG. 2 is a cross-sectional view showing a state during injection (at the time of forming an improved body) by the injection device of FIG. 1 ; It is process drawing which shows an example of normal construction by a high-pressure injection stirring construction method. It is process drawing which shows an example of the high pressure injection stirring construction method which used a pledget together. It is process drawing which shows an example of the high pressure injection stirring construction method by this invention.

(Structure of injection device)
First, the configuration of an injection device according to the present invention will be described with reference to FIGS. 1 and 2. FIG.

The injection device 1 is a special monitor used for a double-pipe two-way injection stirring method.
The injection device 1 has a set of injection nozzles (injection nozzles 21 and 22) arranged in two upper and lower stages. Further, the injection device 1 is configured to be attachable to the tip of a double-tube rod, and has a double-tube flow path structure. The configuration of the injection device will be specifically described below.

The injection device 1, as shown in FIG.
a lower injection nozzle 21 (first injection nozzle) for injecting a hardening material;
- An upper injection nozzle 22 (second injection nozzle) that injects compressed air or high-pressure water,
a lower injection nozzle flow path 31 (first flow path) communicating with the inner flow path of the double tube rod;
- It has an upper injection nozzle flow path 32 (second flow path) that communicates with the outer flow path of the double tube rod.

The upper and lower injection nozzles 21 and 22 are separate and independent nozzles, and are arranged on the upper and lower sides of the injection device as shown in FIG. In addition, the upper and lower injection nozzles 21 and 22 are provided on independent (separate) nozzle bases 41 and 42 . The nozzle base 41 is a nozzle base dedicated to the lower injection nozzle 21 , and the nozzle base 42 is a nozzle base dedicated to the upper injection nozzle 22 .

The hardening material is pressure-fed through the inner channel of the double-tube rod (the inner tube of the double-tube rod), passes through the flow channel 31 of the injection device 1, and is jetted from the lower injection nozzle 21 .

Compressed air or high-pressure water is pumped through the outer channel of the double-tube rod (outer tube of the double-tube rod), passes through the flow channel 32 of the injection device 1, and is jetted from the upper injection nozzle 22 .

In the injection device used in the conventional double pipe construction method, the injection nozzles for compressed air are arranged concentrically around the injection nozzle for the hardening material, so that the high pressure air causes the hardening material jet to be concentric. However, the present invention is quite different.
That is, in the present invention, the nozzle 22 for injecting compressed air or high-pressure water is not provided concentrically with respect to the nozzle 21 for injecting the hardening material, and the compressed air is arranged so as to surround the hardening material jet. Nor does it jet high-pressure water. Therefore, in the present invention, it is not necessary to arrange the upper injection nozzle 22 close to the lower injection nozzle 21, and the upper and lower injection nozzles 21 and 22 can be arranged separately.
By separately arranging the upper and lower injection nozzles 21 and 22, each nozzle can be easily enlarged. Furthermore, since the concentric nozzle arrangement seen in the prior art is not adopted, it is possible to make the flow paths 31 and 32 communicating with the upper and lower injection nozzles 21 and 22 completely parallel. The effect of reducing fluid energy loss in the device is improved.

Further, as shown in FIG. 2, in the present invention, the upper and lower injection nozzles 21 and 22 are arranged so that the jet flows from each nozzle merge at a point (predetermined point) horizontally separated from the side surface of the injection device. is provided. In FIG. 2, the dashed-dotted line indicates the central axis of the jet flow from each nozzle. In the embodiment shown in FIG. 2, as an example, the nozzles 21 and 22 are arranged at a vertical interval of 34 mm so that the axes of the two jets converge at a point 500 mm from the center of the injection device, and each injection nozzle has an angle of 2°. are placed with

In the embodiment shown in FIG. 2, both of the injection nozzles 21 and 22 are inclined in the injection direction, but only one of them may be inclined and the other may be injected in the horizontal direction. Also, the values of dimensions, specifications, etc. shown in FIG. 2 are merely examples, and the features of the injection device of the present invention are not limited to these.

(Functional action of injection device in high-pressure injection stirring method)
Next, based on FIG. 2, the functional action of the injection device according to the present invention will be specifically described.

In the high-pressure injection stirring method using the injection device 1, first, the construction machine is installed at the center of the ground improvement body construction position, and the double pipe rod with the injection device attached to the tip is hung by a crane and erected on the construction machine. . Then, while the drilling water is discharged from the injection device at the tip of the double-pipe rod, the double-pipe rod is rotated by the construction machine and inserted to the planned depth in the ground.

Then, when the double-tube rod equipped with the injection device reaches the planned depth, the double-tube rod is pulled up while being rotated. Compressed air (or high-pressure water) is injected from the upper injection nozzle 22 and hardening material is injected from the lower injection nozzle 21 at the same time as the double tube rod is rotated and pulled up. In the present embodiment, two pairs of upper and lower injection nozzles 21 and 22 are provided for two-way injection.

The compressed air (or high-pressure water) injected from the upper injection nozzle 22 and the hardening material jet injected from the lower injection nozzle 21 are positioned at a predetermined distance in the horizontal direction from the side surface of the injection device, as shown in FIG. They merge at (predetermined points) to form a single integrated jet.

The fluid (compressed air or high-pressure water) injected from the upper injection nozzle 22 is determined, for example, according to the soil quality of the target ground. For example, when the soil quality of the target ground is general soil, compressed air is selected as the fluid to be injected from the upper injection nozzle 22, and when the target ground is highly cohesive soil, high-pressure water is selected.

For example, in the construction of general soil as the target ground, the compressed air from the upper injection nozzle 22 is sucked by the negative pressure (cavitation) caused by the hardening material jet with a large specific gravity injected from the lower injection nozzle 21, and interaction The formation of an integrated jet by , can increase the ground breaking force and cutting distance, and by making it a two-way jet, it enables large diameter improvement.

In addition, for example, in the construction of high-viscosity ground, the pledget effect is exhibited by injecting hardening material from the lower injection nozzle 21 and injecting high-pressure water from the upper injection nozzle 22 at the same time. That is, in the process of pulling up the double pipe rod while rotating, the high-viscosity ground is cut first by the pledget effect of the high-pressure water from the upper injection nozzle 22, and at the same time, the hardening material injected from the lower injection nozzle 21 is applied to the ground. By stirring and mixing, a cylindrical improved body is created. Therefore, even in highly viscous ground, it is possible to form the ground with only one process of pulling up the rod (see Fig. 5), and unlike the conventional technology shown in Fig. 4, there is no need to perform pledget in an additional process prior to injection of the hardening material. . As described above, according to the present invention, the pledget for cutting the ground and the injection of the hardening material can be carried out in parallel, so the construction efficiency is significantly improved compared to the conventional technology shown in FIG.

In this embodiment, as a specific example of the high-pressure injection stirring method using the injection device 1, soil improvement for general soil and highly viscous ground was mentioned, but the application of the present invention is not limited to this. For example, it can be used for strengthening the bearing capacity of soft ground, retaining and stabilizing excavated ground, preventing water leakage in the ground, and preventing liquefaction in the ground.

1 injection device (special monitor)
21 lower injection nozzle (first injection nozzle)
22 upper injection nozzle (second injection nozzle)
31 Flow path for lower injection nozzle (first flow path)
32 Flow path for upper injection nozzle (second flow path)
41 Nozzle base for lower injection nozzle 42 Nozzle base for upper injection nozzle

Claims (3)

a first injection nozzle for injecting hardening material;
a second injection nozzle for injecting compressed air or high-pressure water;
the first and second injection nozzles are arranged above and below the side of the injector;
An injection device used in a high-pressure injection stirring method, characterized in that the first and second injection nozzles are provided so that the jet flows merge at a point a predetermined distance away from a side surface of the injection device in the horizontal direction. The jet of compressed air or high-pressure water injected from the second injection nozzle arranged at the upper stage is sucked by the negative pressure generated from the hardening material jet injected from the first injection nozzle arranged at the lower stage. 2. The injection device used in the high-pressure injection stirring construction method according to claim 1, wherein the first and second injection nozzles are arranged. A high pressure injection stirring method using the injection device according to claim 1 or 2,
The high-viscosity ground is cut by the high-pressure water jetted from the second jet nozzle located in the upper stage, and at the same time, the ground is stirred and mixed with the hardening material jetted from the first jet nozzle located in the lower stage, thereby improving the columnar shape. A high-pressure injection stirring method characterized by creating a body.

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