JPS6124721A - Method and device of improving ground having soft and hard layer mixed together - Google Patents

Abstract

PURPOSE:To enable a single pouring pipe to be penetrated in succession in a ground down to a given depth, by a method wherein the pouring pipe is rotated or vertically moved in a soft ground and fluid is injected in a hard ground to penerate the pouring pipe into a ground. CONSTITUTION:An excavating and chemical pouring pipe comprises an upper inner pipe 2 and a lower inner pipe 3, which are axially movable, and an outer pipe 1 which has a gap between the inner pipes 2 and 3 and the outer pipe and is located in a manner to surrounded the inner pipes. In the soft layer of a ground, the pouring pipe is penetrated into a ground only through rotation and vertical movement of the pouring pipe, and in a hard layer, fluid is pressed in a gap 6 between the inner and the outer pipe, and the fluid is injected below the pouring pipe through a passage 21 to penetrate the pouring pipe. Thereafter, chemical is fed with pressure in the upper inner pipe hole 4 and a gap 6, and after the chemical is mixed in a recess mixing chamber 13, the chemical is injected as an annular elastic body 14 is forcibly spread outwardly.

Description

[Detailed Description of the Invention] The invention relates to a double pipe for excavating and injecting chemical liquids, and more specifically, it is a double pipe for drilling and chemical injection, and more specifically, it is a double pipe for drilling and chemical injection into the ground using only its own weight or the rotational or vertical motion force applied to it, without using any fluid. Excavation is carried out to a predetermined depth by alternately repeating the steps of introducing the pipe into the ground and ejecting fluid such as air or water from the lower end of the pipe from the passage provided in the pipe.
In this state, a soil improvement chemical solution (hereinafter simply referred to as the chemical solution) is then pumped into the two inner and outer passages provided in the pipe, and the liquid pressure closes the passage provided at the lower end of the pipe. The present invention relates to a construction method for improving soft ground by injecting a chemical solution into the ground through an injection hole drilled in a peripheral wall of a pipe, and an apparatus for carrying out the method.

(Prior art) Various conventional methods and equipment for improving soft ground have been proposed, but the conventional methods and equipment are: - First, use an excavator to make a hole in the ground, and then insert a chemical injection pipe into the hole. Method and device for injecting chemical solution using a double-pipe method and device for excavating with water using a drilling and chemical injection pipe, and then injecting chemical solution. ■For areas with soft ground throughout the layer, methods have been developed in which only a chemical layer injection pipe is used to enter the underground, followed by injecting chemical liquid.

However, the method and device described in (■) required two devices: an excavator and a chemical injection pipe, and the process was complicated and costly as the excavation pipe and chemical injection pipe had to be taken in and out. . In addition, in method (2), since water is used throughout the excavation, the diameter of the hole is much larger than the diameter of the pipe, and a considerable gap is created between the inner wall of the hole and the outer wall of the injection pipe, and the injected chemical solution is absorbed into the hole. The chemical solution escaped in the vertical direction of the gap between the wall and the pipe wall, requiring a large amount of chemical solution and making it impossible to work efficiently. For this reason, various methods have been developed to prevent the chemical from escaping, but the devices tend to be complicated, and at present they are not sufficiently effective. Furthermore, method (■) is effective only when there is no hard layer in the ground at all, but if there is even a slight hard layer in the ground, the pipe will not be able to enter the ground, so this method is not suitable. Because of this, it could only be used in a very limited number of construction projects.

(Objective of the present invention) The present invention has discovered a construction method that can efficiently and quickly improve the geology of any geological ground with a small amount of chemical solution, which could not be achieved with the conventional construction method equipment described above. We have developed the equipment necessary to implement this construction method, and no matter what the geology of the ground, a single pipe can be used to
It is possible to excavate and inject chemicals, there is no need to take the pipe in and out after excavation, and the injected chemicals can be efficiently injected into the target stratum without escaping up or down through the gap between the ground and the pipe wall. The object of the present invention is to provide a method and a device necessary therefor.

(Structure of the present invention) In order to achieve the above object, the structure of the present invention includes an inner tube in which the whole or a portion thereof can be moved in the axial direction, and a gap in the inner tube. Then, using a double excavation and chemical injection pipe consisting of an outer pipe installed to surround it, in the soft layer of the ground to be improved, the dead weight of the pipe and rotation or vertical movement are applied to it. When the inner pipe penetrates into the ground and hits a hard stratum, and it becomes impossible to penetrate with these forces alone (this can be easily seen because the pipe does not descend), the inner pipe hole or the lower end of the pipe that communicates with the above-mentioned gap should be The pipe body is inserted into the ground while repeatedly ejecting fluid such as air or water through the passage and drilling the hole.
The tube enters the tube to a predetermined depth, and immediately the chemical solution is pumped into the inner tube hole and the gap between the inner and outer tubes simultaneously or with a time lag, and this liquid pressure causes the whole or part of the inner tube to fall, and the tube is removed. The passage leading to the lower end is blocked to prevent the medicinal solution from flowing out from the lower end of the tube, and the injection hole provided in the inner tube is communicated with the injection hole for the inner tube provided in the outer tube. By communicating the gap with the injection hole for the outer pipe provided in the outer pipe, each chemical liquid is ejected from each injection hole, and two types of chemical liquids can be mixed or injected into the ground separately. A ground improvement method and equipment used to carry out the method, comprising an upper inner pipe, an axially movable lower inner pipe, and an outer pipe arranged with a gap surrounding them. A clay pipe communication hole is bored in the peripheral wall of the upper inner tube, which leads to the gap between the inner and outer tubes, and a portion of the lower inner tube is housed in the upper inner tube, with the limb tubes located above. (when entering underground): - a lower inner pipe communication hole that communicates with the gap and the earthen pipe communication hole; and an injection hole that communicates with the inner pipe injection hole when the limb pipe falls; A blocking plug for closing the lower inner tube hole is provided between the lower inner tube communication hole and the injection through hole, and the outer tube further surrounds the upper inner tube and the lower inner tube. They are provided with a gap between them, and an injection hole for the inner tube and an injection hole for the outer tube are bored in the peripheral wall of the outer tube, either close to each other or with an appropriate distance between them.

Both the injection hole for the inner tube and the injection hole for the outer tube are connected to the excavated chemical liquid injection hole so that when the lower inner tube falls, the former communicates with the injection hole, and the latter communicates with the gap between the inner and outer tubes. It consists of heavy pipes.

(Example) Embodiments of the invention will be described with reference to the drawings.

Figure 1 shows the condition of the pipe when it enters the underground.
The lower inner tube (8) is in the upper position, and FIG. 2 shows the state of the tube body when liquid medicine is injected, and the lower inner tube (8) is in the lowered position.

In Figure 1, (1) is the outer tube, (2) is the upper inner tube,
(8) is the lower inner tube, and the outer tube (1) is the upper inner tube (2).
) and the lower inner tube (3), extending over the entire length of the tube body (5), forming a gap (6) between the upper inner tube and the lower inner tube at the upper part, but forming a gap (6) between the lower inner tube and the lower inner tube. It is slidably attached to the inner tube. And the lower inner tube (3
), an injection hole for the outer tube (11) and an injection hole for the inner tube (12) are formed adjacent to each other, and a concave mixing chamber (13) is provided in series with them. , an annular elastic body (14) is fitted into the chamber with a gap.◇The upper inner tube (2) is fixed to the outer tube (1) by the threaded portion (16), and the upper inner tube (2) is fixed to the outer tube (1) over the entire length. A gap (6) is provided between the outer cotton tube (1) and the outer tube (1). In addition, the limb canal has an upper canal hole (4
) is formed through it, and a large diameter part (17) with a larger pipe hole is formed at the bottom, and an upper inner pipe communication hole communicating with the gap (6) is below it. (8) is pierced. The lower inner pipe (8) is penetrated by the lower inner pipe hole (5), and as is clear from Figure 1, when it is in the upper position (when entering underground), its upper part is connected to the upper inner pipe. The upper and lower inner pipe gaps (18) are formed in the fitted portions (to be described in detail later) in a liquid-tight manner. An injection hole (10) is drilled below it, and when the lower inner pipe is in the upper position (when entering underground), the gap between the inner and outer pipes (
6) and a lower inner pipe communication hole (9) that communicates with the upper inner pipe communication hole (8) that communicates with the upper inner pipe, and the outer wall of the lower inner pipe below it is used for injection into the outer pipe. Hole (11
) and an outer tube (1) in which an injection hole (12) for the inner tube is formed.
) is slidably in close contact with the inner wall of the

Further, there is a lower inner tube hole (toward) below the injection through hole and above the lower inner tube communication hole (9), that is, between these two holes.
A plug (7) is screwed to close the hole (6). This lower inner pipe (8) is placed in the upper position as shown in Figure 1 when no chemical solution is injected, that is, when entering underground.
A fall prevention pin (19) attached via a fall prevention member (2o) prevents the body from falling downward. However, this drop prevention pin has upper and lower inner tube holes (4),
When the chemical solution is pressurized into (5), it is cut off by the liquid pressure (because the lower inner tube hole (5) is blocked by the plug (7)), and the lower inner tube is cut off as shown in Figure 9. It falls to a downward position. Note that the fall prevention pin is not necessarily necessary, and the fall may be prevented by the frictional force between the lower inner pipe, the outer pipe, and the soil inner pipe. Furthermore, (15) is a lower end member, which includes a gap (6), two-way through holes (8), (9), and a lower inner pipe hole (5).
A passage (21) is formed through which air and water fluids sent through the tube and outer pipe hole (23) pass, and fluid from above passes through this passage, but earth, sand, water, etc. from below do not pass through this passage. A non-return valve (22) is installed. Note that the lower end member (15) may be integrally formed as a part of the outer tube (1), and it goes without saying that the object of the present invention can be achieved even without a check valve.

Next, we will explain the construction method using this device's sound and its working condition.0 First, the pipe body (5) is made vertical and begins to enter the ground.At this time, the lower inner pipe (3) is shown in Figure 1. As shown in FIG. If the ground blocked by is soft, the tube body (5) will enter the ground due to its own weight or the rotation or vertical motion given to the tube body.And when it hits a hard stratum ( Immediately press fluid such as air or water into the gap (6) between the inner and outer tubes. The pressurized fluid passes through the gap (6) to the upper inner pipe communication hole (8), the lower inner pipe communication hole, and the plug (7).
Passing through the lower inner tube hole (5) below the outer tube hole (23)
- furthermore, a passageway (2) formed in the lower end member (15).
After 1), the pipe is ejected downward, and the pipe enters the pipe while drilling a hole.When the pipe enters the pipe at a faster speed, that is, it has entered a soft stratum.
Immediately stop the pressure injection of the fluid, try to enter the tube again only by its own weight, rotation, or vertical movement, repeat this process until the tube (5) reaches a predetermined depth, and then The medicinal liquid is immediately pumped into the upper inner tube hole (4) and the gap (6) at the same time or with a time difference. Upper inner tube hole (4)
The chemical liquid pumped into the lower inner tube hole (5) enters the lower inner tube hole (5), and the liquid pressure of the chemical liquid acts on the blocking plug (7), and the lower inner tube (3) connects with the upper inner tube (2) and outer tube (1). Due to the frictional force of , it overcomes the fall prevention bottle and falls to the position shown in Figure 2. In this state, the chemical solution forced into the gap (6) passes through the upper inner tube communication hole (8), the upper and lower inner tube gaps (18), and enters the outer tube injection hole (11) formed in the outer tube. and is ejected into a concave mixing chamber (13) connected thereto. - The chemical liquid pumped through the inner tube hole (4) of the brave section reaches the large diameter section and the lower inner tube hole (5). However, the blockage plug (A) prevents it from flowing downward, and the drop causes the injection hole (10) to flow downward.
Since it communicates with the injection hole (12) for the inner tube provided in the outer tube, it is injected into the concave mixing chamber through these. These two types of chemical solutions come into contact with the annular elastic body (14), are prevented from moving forward, and are thoroughly mixed in the concave mixing chamber, after which they are ejected out of the tube while pushing the annular elastic body (14) outward. , injected into the ground. At this time, some of the outer wall of the outer pipe and the earth and sand in the ground were drilled using fluids such as air and water to allow the pipe to enter, but the rest was made by its own weight, rotation, or vertical movement without using fluids. Because the chemical solution was injected into the ground, there are many parts that are in close contact with each other, and when injecting the chemical solution, the chemical solution that comes out of the pipe is injected radially into the ground instead of flowing in the direction of the pipe, so it can be effectively grounded very quickly and without waste. Improvements can be made.

(Effects of the present invention) With the above-described configuration, the present invention can expect the following effects. That is, according to the present invention, there are two steps: a step in which the tube enters the ground only by its own weight, rotation, or vertical movement, and a step in which the tube enters the ground while excavating using a fluid such as water or air. This process can be repeated as needed to reach the specified depth, so even in areas where soft ground layers, hard ground layers, and boats coexist, one tube can be used continuously. The tube body can be advanced to a predetermined depth,
Subsequently, the chemical solution is immediately injected into the ground through the tube, so a simple device is sufficient. Moreover, according to the construction method and apparatus of the present invention, since excavation with fluid is performed only in hard ground layers, the outer wall of the pipe body and the ground are in close contact with each other. Since there is no upward or downward escape, the chemical solution can be injected quickly, reliably, and without waste.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing the state of the pipe when it enters underground. Figures 2.3.4.5.6.7.8 are r-r, n~■, lf[-Ill, IV-IV in Figure 1, respectively.
, VV, VT-Vl, and VU-■ planes. FIG. 9 is a longitudinal cross-sectional view showing the state of the tube during injection of the drug solution. Figures 10111.12, 13, and 14 are shown in Figure 2, respectively.
XI, X[I-, is a vertical cross-sectional view in the 4th plane. A. Pipe body, 1. Outer pipe, 2. Upper inner pipe 3. Lower circular pipe, 4.. Soil inner pipe hole 5. Lower inner pipe hole, 6.. Gap, 7.. Blocking plug. 8. Upper inner pipe. communication hole

Claims (2)

[Claims] (1) A double excavation and chemical injection pipe consisting of an inner pipe at least partially movable in the axial direction and an outer pipe surrounding the inner pipe with a gap between the inner pipe and the outer pipe surrounds the inner pipe with a gap between the inner pipe and the outer pipe. In this method, the excavation and chemical injection pipe is inserted underground by only the weight of the pipe or rotation or vertical movement of the pipe. A fluid such as air or water is ejected through a passageway and penetrated into the ground while drilling, as appropriate, to excavate to a predetermined depth, and then a chemical solution is subsequently pressurized into the pipe hole and the gap at the same time or at a staggered time. The liquid pressure lowers part or all of the inner tube, closing the passage leading to the lower end of the tube body, and connecting the liquid injection holes provided in the inner and outer tubes, thereby allowing the liquid to flow inside and out. A method for improving ground with mixed hard and soft layers by injecting into the stratum through an injection hole provided in the peripheral wall of the pipe (2) An upper inner tube (2) that does not move and has an upper communication hole in the lower part, and a part of the tube is housed in the upper inner tube,
A lower communication hole (8) that communicates with the upper pipe communication hole when lowered
) and an injection through hole (9), and a lower inner tube provided with a plug (7) for closing the lower inner tube hole (5) in the middle of each of these holes, and surrounding these tubes, These and gaps (6)
It consists of an outer tube (1) arranged with a
The lower inner tube is normally prevented from falling due to the frictional force between the upper inner tube and the outer tube or by a fall prevention pin (14), but due to the chemical pressure, it falls downward and the injection through hole (1
0) and the inner tube injection hole (12) are positioned so that they communicate with each other, and as the lower inner tube falls, the gap (6)
A double excavation and chemical liquid injection pipe in which the outer pipe injection hole (11) and the outer pipe injection hole (11) communicate with each other.