JP2011144539A - Injection tube for soil improvement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an injection tube for soil improvement which is formed in a double simple structure with a small diameter, includes a monitor mechanism with high cutting and stirring performance in spite of the small diameter simple structure, and can be raised in rotational speed and lifting speed to shorten the construction period. <P>SOLUTION: This injection tube for soil improvement includes, at the bottom part, the monitor mechanism provided with an injection nozzle. The injection nozzle of the monitor mechanism is configured so that a solidification material liquid injection nozzle is positioned at the center, and an air injection nozzle is coaxially positioned on the outside thereof in the form of a double nozzle so that air can be injected around the solidification material liquid injected from the solidification material liquid injection nozzle simultaneously in the same direction. A set of a plurality of injection nozzles of the monitor mechanism of the injection tube are installed so that the center axes thereof in the injection directions are positioned parallel to each other. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention inserts an injection pipe having a monitor mechanism provided with a solidifying material liquid injection nozzle and an air injection nozzle in the lower part into the ground, and connects a swivel to the upper part of the injection pipe. Air is supplied at a high pressure, and the solidification material liquid is continuously ejected from the solidification material liquid injection nozzle of the monitor mechanism through the injection pipe to the outside of the pipe (for example, in the horizontal direction), and from the air injection nozzle to the solidification material liquid injection nozzle. The surrounding ground is cut mainly by the injection force of the solidified material liquid by injecting air continuously at a high pressure around the periphery and pulling up from the ground while rotating the injection tube, and the solidified material liquid is injected into the cutting area. The present invention relates to a ground improvement injection pipe which is stirred to build a ground improvement body.

  Conventionally, a soft ground improvement method for solidifying and improving a soft ground by high-pressure jet stirring of a solidifying material liquid is well known. In this soft ground improvement method, a swivel is connected to the upper part of the injection pipe having a monitoring mechanism at the lower part, this injection pipe is inserted from the ground to a predetermined depth in the ground, and then the swivel provided at the upper part of the injection pipe is solidified. Supply the solidified material liquid at high pressure from the material liquid supply port, continuously inject the solidified material liquid horizontally from the solidified material liquid injection nozzle of the monitor mechanism at the lower part of the injection tube, and pull it up while rotating the injection tube Thus, the ground around the ground is cut by the injection force (jet flow) of the solidified material liquid that is continuously sprayed, and the ground improved body is constructed by injecting and stirring the solidified material liquid into the cutting region.

In this ground improvement method, injection of a double pipe in which the inside of the inner pipe 32 as shown in FIG. 7 serves as a solidified material liquid supply passage 34 and the space between the inner pipe 32 and the outer pipe 33 serves as an air supply passage 35. The injection pipe 31 has a monitor mechanism 39 provided with a solidifying material liquid injection nozzle 41 and an air injection nozzle 42 for injecting air from the periphery of the solidifying material liquid injection nozzle 41 at the bottom. A swivel 36 provided with a solidified material liquid supply port 37 and an air supply port 38 is connected to the upper portion of the injection pipe 31, and the solidified material liquid supplied at a high pressure from the solidified material liquid supply port 37 of the swivel 36 is supplied with the solidified material liquid. At the same time, the air supplied from the air supply port 38 of the swivel 36 is injected through the air supply nozzle 35 through the air injection nozzle 42 through the air supply nozzle 42. And those ground improvement by injection around the nozzle 41,
The inside of the inner pipe 32 as shown in FIG. 8 is a solidification material liquid supply passage 34, the water supply passage 43 is between the inner pipe 32 and the intermediate pipe 40, and the air is supplied between the intermediate pipe 40 and the outer pipe 33. A triple pipe injection pipe 45 serving as a passage 35 is used. The injection pipe 45 includes a solidified material liquid injection nozzle 41 at a lower portion and an air injection nozzle 42 for injecting air from the periphery of the solidified material liquid injection nozzle 41. A monitor mechanism 39 provided with a water injection nozzle 44 provided at a 180-degree symmetrical position above the solidification material liquid injection nozzle 41, and a solidification material liquid supply port 37 and an upper portion of the injection pipe 45. A swivel 36 having an air supply port 38 and a water supply port 46 is connected, and a solidification material liquid supplied at a high pressure from a solidification material liquid supply port 37 of the swivel 36 is connected to a monitor mechanism 39 via a solidification material liquid supply passage 34. Solidification material liquid injection nozzle 41 At the same time, the air supplied at a high pressure from the air supply port 38 of the swivel 36 is injected around the solidified material liquid injection nozzle 41 from the air injection nozzle 42 via the air supply passage 35 and the water supply port of the swivel 36. There are some which improve the ground by jetting water supplied at a high pressure from 46 from a water jet nozzle 44 (see, for example, Patent Document 1).

  Further, when the injection pipes 31 and 45 having the swivel 36 at the upper part and the monitor mechanism 39 at the lower part are inserted into the ground, water is supplied from the solidification liquid supply port 37 of the swivel 36 at a high pressure to supply the solidification liquid supply path. There are a case where the ground is drilled and inserted while discharging downward from the opening 47 at the tip of the monitor mechanism 39 via 34, and a case where the ground is first drilled by a boring machine or the like and then inserted into this hole.

  And in the conventional monitoring mechanism of the injection pipe for ground improvement, there is one single-port solidified material liquid injection nozzle, and there are two single-port solidified material liquid injection nozzles arranged at 180 ° symmetrical positions. There are one and one single-portion solidifying liquid jet nozzle, and one water jet nozzle is provided on the opposite side of 180 degrees above the solidified liquid jet nozzle.

JP 04-48894

The conventional monitoring mechanism of the injection pipe for ground improvement has a high cutting agitation ability because the individual injection nozzles (injection ports) are dispersedly arranged and the injection nozzles do not have a synergistic effect with each other. However, since the diameter of the ground at the same depth cannot be increased by one rotation of the injection tube, the diameter is gradually increased to a predetermined diameter by several rotations. Accordingly, the rotation speed and the pulling speed of the ground improvement infusion pipe must be slowed down, which requires a long time, and therefore requires a long construction period and high construction costs.
Therefore, in order to improve cutting agitation efficiency, the injection pressure is increased or the injection dose by a large large-capacity pump is increased, but this requires a large-scale plant facility using high energy. Therefore, it will be difficult economically if it is not a large construction.
Moreover, since the thing using a triple pipe | tube as an injection pipe for ground improvement uses each supply apparatus and high-pressure pump of a solidification material liquid, air, and water, there exists a subject which requires much energy and enlarges an installation.

  The present invention has been proposed to solve such a problem. The purpose of the present invention is to provide a simple double-pipe small-diameter injection pipe and a monitoring mechanism with a small-diameter simple structure while cutting. The purpose of the present invention is to provide an injection pipe for ground improvement that has high agitation ability, can be installed at a higher rotation speed and a higher pulling speed, and can shorten the construction period.

In order to achieve the above object, a ground improvement injection pipe according to claim 1 of the present invention has a monitor mechanism provided with an injection nozzle at the lower part, and the injection nozzle of the monitor mechanism is a solidified material liquid injection nozzle. Is located in the center and the air injection nozzle is concentrically provided on the outer side in the form of a double nozzle, allowing air to be injected simultaneously in the same direction around the solidified liquid ejected from the solidified liquid spray nozzle. A ground improvement injection pipe, a swivel is connected to the top of the injection pipe, this injection pipe is inserted from the ground to a predetermined depth in the ground, and then a solidified material liquid and air are supplied from the swivel at a high pressure. The injection pipe is rotated and pulled up while injecting the solidified material liquid and air from the solidified material liquid injection nozzle and air injection nozzle of the lower monitor mechanism. Cutting to, a soil improvement for injection tube for construction of the soil improvement material by injecting hardening material liquid to the cutting area,
The injection nozzles of the monitoring mechanism of the injection tube are characterized in that a plurality of injection nozzles are provided in parallel and the central axes of the injection directions of the injection nozzles are arranged in parallel.

  With this configuration, jet fluid (solidified material liquid and air) can be jetted in parallel (parallel) from a pair of jet nozzles in parallel, minimizing the damping of the jet fluid in the ground cutting process, resulting from multiaxial fluid derivation The cutting and stirring function of the ground can be improved with a synergistic effect. Therefore, since the rotation speed and pulling speed of the ground improvement injection pipe can be increased, the construction speed can be increased as a result, and the construction period can be shortened by improving the improvement speed by shortening the improvement time. In addition, the efficiency of fluid (solidification material liquid and air) injection energy is improved. As a result, pumps for conventional construction methods can be used, so there is no need for expensive large-capacity pumps, and construction with standard consumables and piping equipment is possible. Cost can be reduced.

  In the ground improvement injection pipe according to claim 2 of the present invention, the ground improvement injection pipe is a double pipe of an inner pipe and an outer pipe, and the inside of the inner pipe serves as a solidified material liquid supply passage. An air supply passage is formed between the tube and the solidified material liquid supply passage. The solidified material liquid supply passage communicates with the solidified material liquid injection nozzle of the monitor mechanism, and the air supply passage communicates with the air injection nozzle.

  As a result, the double-tube simple structure small-diameter injection tube, the monitor mechanism can be a small-diameter simple structure, and standard equipment can be used. Moreover, it is a double pipe simple structure small diameter injection pipe, and its monitoring mechanism has a simple structure with a small diameter, but the cutting stirring ability of the ground is high.

Further, in the ground improvement injection pipe according to claim 3 of the present invention, the injection nozzles of the monitor mechanism are provided in a plurality of sets, and the injection nozzles of the set are provided at symmetrical positions in the horizontal circumferential direction. It is characterized by.
As a result, a set of spray nozzles capable of spraying the spray fluid (solidified material liquid and air) in parallel (in parallel) are provided at symmetrical positions, so that a multi-axis fluid derivative (for example, a pair of spray nozzles is a pair) In this case, the cutting and stirring function of the ground with a synergistic effect due to the biaxial fluid derivation is further improved.

The set of spray nozzles of the monitoring mechanism of the present invention is characterized in that the spray nozzles are set in parallel in the horizontal circumferential direction (Claim 4),
The set of spray nozzles of the monitor mechanism of the present invention is characterized in that the spray nozzles are set in parallel in the vertical direction (Claim 5).
Further, the set of spray nozzles of the monitoring mechanism of the present invention is a set of jet nozzles arranged in parallel in the vertical direction, and the jet nozzles of this set are provided at symmetrical positions in the horizontal circumferential direction, The pair of spray nozzles and the pair of spray nozzles at the symmetrical position on the other side are provided so that their positions are shifted from each other vertically (Claim 6).
Further, the set of spray nozzles of the monitoring mechanism of the present invention is characterized in that the spray nozzles are paired obliquely vertically.

Further, the spray nozzle of the monitoring mechanism of the present invention is a set in which the set of spray nozzles is provided at a symmetrical position in the horizontal circumferential direction, and one side is arranged in parallel in the horizontal circumferential direction, and the symmetrical position on the other side is up and down. (Claim 8),
In the spray nozzle of the monitor mechanism of the present invention, the pair of spray nozzles is provided at a symmetrical position in the horizontal circumferential direction, and one side is parallel to the horizontal circumferential direction, and the symmetrical position on the other side is oblique. It is a group that is vertically parallel (Claim 9),
In the spray nozzle of the monitor mechanism of the present invention, the pair of spray nozzles is provided at a symmetrical position in the horizontal circumferential direction, and one side is vertically aligned, and the other side is symmetrically aligned vertically. (Claim 10),

Further, the spray nozzle of the monitor mechanism of the present invention is provided at a symmetrical position in the horizontal circumferential direction, and at least one of the spray nozzles at the symmetrical position has a central axis in the mutual spray direction as a group. The injection nozzles are provided in parallel and the number of injection nozzles and the diameter of the injection nozzles are different at symmetrical positions, but the opposing injection reaction forces are set to be approximate values (claims). 11).
With this configuration, even if the number and the diameter of the injection nozzles are different at the symmetrical position, the opposing injection reaction force becomes an approximate value, so that the injection pipe can be prevented from bending.

In addition, the jet nozzles of the set of the monitor mechanism of the present invention are characterized in that the jet nozzles are arranged side by side with an interval between the jet central axes of the jet nozzles (claim 12).
Thereby, the synergistic effect by a multi-axis jet can be improved. If the interval between the spray nozzles in the set is less than 5 cm, the distance between the jet nozzles is too close, and jets ejected from each other come into contact with each other, resulting in attenuation of the jet fluid. Since the position where the ground reaches is also opened, the synergistic effect is reduced. Accordingly, the interval between the spray nozzles in the set is preferably in the range of 5 to 10 cm.

Furthermore, the spray nozzle of the monitor mechanism of the present invention is characterized in that the spray angle is inclined 5 degrees to 10 degrees obliquely downward from the horizontal direction (claim 13).
As a result, the jetting fluid is provided with a jetting angle that is inclined downward, so that the cut earth and sand are easily separated from the ground and moved downward, and the cutting function is improved.

The ground improvement injection pipe of the present invention has the following effects.
(1) Since the injection fluid (solidified material liquid and air) can be injected in parallel (parallel) from a plurality of injection nozzles, the attenuation of the injection fluid in the ground cutting process can be minimized, and The ground cutting and stirring function can be improved by a synergistic effect due to axial fluid derivation (for example, biaxial fluid derivation when the injection nozzle is a pair).
(2) Accordingly, since the rotation speed and the pulling speed of the ground improvement injection pipe can be increased during construction, the construction speed can be increased as a result, and the construction period can be greatly shortened.
(3) Since the construction speed is increased and the ground improvement speed is improved, the generation of excess liquid (waste mud) can be reduced accordingly.
(4) Since the efficiency of the injection energy of the injection fluid (solidified material liquid and air) is improved, the conventional standard pump can be used, so there is no need for an expensive large-capacity pump or large-scale plant equipment. Construction is possible with consumables and piping equipment, and costs are low.

(5) A small-diameter injection pipe with a simple structure of a double pipe, the monitor mechanism can be a simple structure with a small diameter, and standard equipment can be used. Moreover, it is a double pipe simple structure small diameter injection pipe, and its monitoring mechanism has a simple structure with a small diameter, but the cutting stirring ability of the ground is high.
(6) Since a set of injection nozzles capable of injecting parallel (parallel) injection fluids (solidified material liquid and air) are provided at symmetrical positions in the horizontal circumferential direction, a multiaxial fluid derivative (for example, an injection nozzle) When the pair is a pair, the cutting and stirring function of the ground due to the synergistic effect by the biaxial fluid derivation can be further improved, and the construction speed can be further increased.
(7) Even if the number and the diameter of the injection nozzles are different at symmetrical positions in the horizontal circumferential direction, the opposing injection reaction force becomes an approximate value, so that the bending of the injection tube can be prevented.

(8) Since each injection nozzle in the set has an interval between the injection central axes of the injection nozzles of 5 to 10 cm, a multi-axis jet (for example, a biaxial fluid derivative when the injection nozzle is a pair) The synergistic effect can be improved and the construction speed can be further increased.
(9) Since a spray angle inclined downward can be imparted to the jet fluid (solidified material liquid and air), the cut earth and sand are easily separated from the ground and moved downward, and the cutting stirring function is improved.

It is a center longitudinal cross-sectional view of the injection pipe for ground improvement which shows embodiment of this invention. It is a principal part front view of the monitor mechanism part of the injection pipe for ground improvement which shows embodiment of this invention. It is a principal part front view of the monitoring mechanism part of the injection pipe for ground improvement which shows other embodiment of this invention. It is a principal part front view of the monitoring mechanism part of the injection pipe for ground improvement which shows other embodiment of this invention. It is the principal part front view (a) of the monitoring mechanism part of the injection pipe for ground improvement which shows other embodiment of this invention, and its center longitudinal cross-sectional view (b). It is explanatory drawing which shows the ground improvement construction method using the injection pipe for ground improvement of this invention to construction process order (a) (b) (c) (d). It is sectional drawing which shows the conventional injection pipe for ground improvement. It is sectional drawing which shows the injection pipe for other conventional ground improvement.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a central longitudinal sectional view of a ground improvement injection pipe showing an embodiment of the present invention. FIG. 2 is a front view of a main part of a monitor mechanism portion of the ground improvement injection pipe showing an embodiment of the present invention. FIG. 3 is a front view of an essential part of a monitoring mechanism portion of a ground improvement injection pipe showing another embodiment of the present invention, and FIG. 4 is a ground improvement injection pipe showing still another embodiment of the present invention. FIG. 5 is a front view of the main part of the monitoring mechanism part of the injection pipe for ground improvement showing still another embodiment of the present invention, and FIG. ).

FIG. 1 shows a ground improvement injection pipe 1 (sometimes simply referred to as an injection pipe) having a swivel 6 connected to the upper part and a monitor mechanism 9 on the lower part. The ground improvement injection pipe 1 is formed by a double pipe of an inner pipe 2 and an outer pipe 3, the inside of the inner pipe 2 serves as a solidified material liquid supply passage 4, and the space between the inner pipe 2 and the outer pipe 3 is air. A supply passage 5 is provided.
The swivel 6 includes a solidification material liquid supply port 7 and an air supply port 8. The solidification material liquid supply port 7 communicates with the solidification material liquid supply passage 4 of the injection pipe 1 through a passage 7 a, The supply port 8 communicates with the air supply passage 5 of the injection tube 1 through the passage 8a.

  The monitor mechanism 9 is provided with an injection nozzle 10. The injection nozzle 10 of the monitor mechanism 9 has a solidified material liquid injection nozzle 11 located at the center, and an air injection nozzle 12 is provided concentrically in the form of a double nozzle on the outside of the injection nozzle 10. The air can be simultaneously jetted around the solidifying material liquid in the same direction. The solidified material liquid injection nozzle 11 communicates with the solidified material liquid supply passage 4 of the injection tube 1, and the air injection nozzle 12 communicates with the air supply passage 5 of the injection tube 1 through the solidified material liquid supply port 7 of the swivel 6. The solidified material liquid supplied at high pressure can be injected from the solidified material liquid injection nozzle 11 via the solidified material liquid supply passage 4 of the injection tube 1, and the air supplied at high pressure from the air supply port 8 of the swivel 6 is supplied to the injection tube 1. The air can be injected from the air injection nozzle 12 through the air supply passage 5.

  A plurality of injection nozzles 10 including the solidifying material liquid injection nozzles 11 and the air injection nozzles 12 are provided in parallel with the central axes of the respective injection directions. In this embodiment, the pair of injection nozzles 12 is shown as a pair, but is not limited to a pair. For example, the number of spray nozzles 10 may be three or four. The pair of injection nozzles 10 are provided at symmetrical positions in the horizontal circumferential direction of the monitor mechanism 9. Thereby, the solidification material liquid injected from each injection nozzle 10 and the injection reaction force of air are balanced, and the bending of the injection tube 1 can be prevented.

FIG. 2 shows a case where the injection nozzle 10 constituted by the solidifying material liquid injection nozzle 11 and the air injection nozzle 12 is provided as a pair in parallel in the horizontal circumferential direction of the monitor mechanism 9.
In this example, when the injection tube 1 is rotated, four injection nozzles 10 pass on the same circumferential line, and the injection nozzle 10 on the other side in a symmetrical position with the injection nozzle 10 on one side is Since it becomes a pair and is configured to enhance the ground cutting agitation function with a synergistic effect, the ground agitation ability of the ground is increased.

FIG. 3 shows a case where the injection nozzle 10 composed of the solidifying material liquid injection nozzle 11 and the air injection nozzle 12 is provided as a pair in parallel in the vertical direction of the monitor mechanism 9.
In this configuration, since the spray nozzles 10 are paired in parallel in the vertical direction, together with the synergistic effect of the cutting stirring function by the pair of spray nozzles 10, the ground of the fluid to be sprayed by the rotation of the injection pipe 1 (the hole wall surface). The cutting width is widened. Further, when the injection nozzles 10 are paired in parallel in the vertical direction, the injection tube 1 (monitor mechanism 9) can be used even with a small diameter.

In FIG. 4, the injection nozzles 10 constituted by the solidifying material liquid injection nozzle 11 and the air injection nozzle 12 are vertically displaced from each other in the horizontal circumferential direction, and are provided in pairs in parallel at oblique positions. Is the case.
In this configuration, since the injection nozzle 10 is paired in parallel with the upper and lower diagonal positions together with the synergistic effect of the cutting stirring function by the pair of injection nozzles 10, when the fluid is injected by rotating the injection tube 1, the injection Since the fluid stirs and stirs the hole wall surface of the ground with a time difference, the cutting stirrability is further improved. Further, since the injection nozzles 10 are paired in parallel in the upper and lower oblique positions, it is possible to cope with the injection pipe 1 (monitor mechanism 9) having a smaller diameter than the pair in parallel in the horizontal circumferential direction. .

FIGS. 5A and 5B show a case where the injection nozzle 10 constituted by the solidifying material liquid injection nozzle 11 and the air injection nozzle 12 is provided as a pair in parallel in the vertical direction of the monitor mechanism 9. This is a case where the one side and the other side of the symmetrical position are shifted up and down. In this example, for example, when viewed from the front side, when the injection nozzles 10, 10 on the other side of the symmetric position are vertically aligned in the vertical direction, the injection nozzles 10, 10 on the one side are the The injection nozzles 10 and 10 which are located at the upper and third positions and located at the other side of the symmetrical position are illustrated as being disposed at the second and fourth positions (the lowest position) from the top.
In this configuration, together with the synergistic effect of the ground cutting and stirring function by the pair of injection nozzles 10, for example, the injection nozzles 10 look like four vertically aligned in a vertical direction when viewed from the front side. The wall has a wide cutting width.

The configuration of the pair of injection nozzles 10 and 10 is not limited to that shown in FIGS. 2 to 5A and 5B. For example, a configuration in which the injection nozzles 10 as shown in FIG. 2 are provided in pairs in the horizontal circumferential direction, and the injection nozzles 10 as shown in FIG. 3 are paired in parallel in the vertical direction. 4 and a configuration in which the jet nozzles 10 as shown in FIG. 4 are paired in parallel in the upper and lower oblique positions may be combined on one side of the monitor mechanism 9 and the other side of the symmetrical position. .
In other words, the injection nozzle 10 composed of the solidifying material liquid injection nozzle 11 and the air injection nozzle 12 is paired in parallel in the horizontal circumferential direction on one side of the monitor mechanism 9, and vertically on the other side of the symmetrical position. In parallel, the spray nozzles 10 are paired in parallel in the horizontal circumferential direction on one side of the monitor mechanism 9, and in parallel in the upper and lower diagonal positions on the other side of the symmetrical position. When the nozzles 10 are paired, the jet nozzles 10 are paired in parallel in the vertical direction on one side of the monitor mechanism 9, and are paired in parallel in diagonally up and down positions on the other side of the symmetrical position. If yes.
By such a combination, a synergistic effect of the ground cutting agitation function can be expected with the characteristics of different pairs of injection nozzles.

  Although not shown, the spray nozzle 10 of the monitor mechanism 9 is provided at a symmetrical position in the horizontal circumferential direction, and at least one of the spray nozzles 10 at the symmetrical position is a plurality of pairs. The central axis of the injection direction may be provided in parallel, and the injection nozzle 10 may be provided at a symmetrical position with the number of injection nozzles 10 and the diameter of the injection nozzle 10 being different. In this case, the opposing injection reaction force between the injection nozzle 10 on one side and the injection nozzle 10 on the other side at the symmetrical position is set to be an approximate value. Accordingly, even if the number and the diameter of the injection nozzles 10 are different at the symmetrical position of the monitor mechanism 9, the opposing injection reaction force becomes an approximate value, so that the injection pipe 1 can be prevented from being bent.

Moreover, it is preferable that the pair of injection nozzles 10 and 10 of the monitor mechanism 9 are arranged in pairs with an interval h between the injection central axes of the injection nozzles 10 and 10 being 5 to 10 cm.
When the distance h between the pair of the injection nozzles 10 and 10 is less than 5 cm, the distance h is too close to each other, and the jets of fluid jetting each other come into contact (impact) and the injection force of the injection fluid is attenuated. Since the mutual interval h is too large and the position where the jet fluid reaches the ground hole wall surface is also opened, the synergistic effect is lowered. Therefore, the distance h between the pair of injection nozzles 10 and 10 is preferably in the range of 5 to 10 cm.

The spray angle of the spray nozzle 10 of the monitor mechanism 9 is preferably in the range of 10 degrees obliquely downward from the horizontal direction.
If the spray angle of the spray nozzle 10 is in the horizontal direction (the direction perpendicular to the injection pipe 1), the distance from the ground hole wall surface is the shortest. Is preferable. However, if the injection angle of the injection nozzle 10 is set obliquely downward from the horizontal direction, the distance between the injection nozzle 10 and the ground hole wall surface is increased. Therefore, the injection fluid is attenuated by that distance, but the injection angle is inclined downward with respect to the injection fluid. Therefore, the earth and sand cut by the ground are easily separated from the ground and moved downward, and the cutting function is improved. Therefore, an injection angle of 10 degrees obliquely downward from the horizontal direction is allowed. If the jet angle exceeds 10 degrees diagonally below the horizontal direction, the distance that the jet fluid reaches the ground hole wall surface becomes long, the fluid jet flow attenuates, and the fluid collision with the ground hole wall surface becomes diagonal. This is not preferable because the cutting ability is reduced.

Next, the construction procedure of the ground improvement method using the ground improvement injection pipe 1 according to the embodiment will be described with reference to FIG.
First, an example of the construction apparatus 20 used in this ground improvement method will be described. The construction apparatus 20 includes a reader 21, and a slide plate 22 is slidably (moved forward and backward) along the reader 21, and a drill head 23 is fixed to the slide plate 22. A feeding device (not shown) is connected to 22 so that it can move forward and backward along the reader 21. A ground improvement injection pipe 1 having a monitor mechanism 9 at the bottom is attached to a drill head 23, and the injection pipe 1 can be rotated by driving the drill head 23. Since the head 23 is fixed, the injection tube 1 can be advanced and retracted together with the drill head 23 by advancing and retracting the slide plate 22 along the leader 21 with a feeding device (not shown). Examples of the feeding device include a cylinder or a chain that is suspended and driven by sprockets provided at the upper end or the lower end of the leader 21.

Therefore, first, as shown in FIG. 6A, the injection pipe 1 is attached to the drill head 23 of the construction apparatus 20, and the construction apparatus 20 is set at a position where the ground is improved. A swivel 6 is connected to the upper portion of the injection tube 1 at this time.
Next, as shown in FIG. 6B, the injection tube 1 is inserted to a predetermined depth of the ground at a position where the ground is improved. The injection tube 1 is inserted into the ground by supplying high-pressure water from the solidifying material liquid supply port 7 of the swivel 6 and discharging it downward from the opening 13 at the tip of the monitor mechanism 9 through the solidifying material liquid supply passage 4. Drill the ground and insert it, or drill in advance with a boring machine and insert it into the hole. When the injection tube 1 is inserted by the former method, after reaching a predetermined depth, the ball 15 is introduced from the solidifying material liquid supply passage 4 to close the opening 13. Reference numeral 14 denotes a check valve.
Next, as shown in FIG. 6 (c), the solidified material liquid and air are supplied from the swivel 6 at a high pressure, and the solidified material liquid and air are supplied from the solidified material liquid injection nozzle 11 and the air injection nozzle 12 of the monitor mechanism 9 at the lower end of the injection pipe 1. While injecting air, the injection tube 1 is rotated and pulled up. Then, the injection force of the solidified material liquid and the air collides with the hole wall surface of the surrounding ground, the surrounding ground is cut, the cutting area is filled with the injected solidified material liquid, and the ground improvement body 16 is built. Accordingly, as shown in FIGS. 6C to 6D, the ground improvement body 16 is constructed from the lower side to the upper side as the injection pipe 1 is pulled up. FIG.6 (d) has shown a mode that the injection pipe 1 was pulled up on the ground and the ground improvement body 6 was built in the predetermined area of the ground.

  For supplying the solidified material liquid and air, the construction apparatus 20 includes pumps (not shown) for supplying the solidified material liquid and air, and each pump is connected to the solidified material liquid supply port 7 of the swivel 6 and the air by piping. The supply port 8 is connected. Accordingly, the solidified material liquid is supplied at a high pressure from the solidified material liquid supply port 7 of the swivel 6 and is supplied to the solidified material liquid injection nozzle 11 via the passage 7 a and the solidified material liquid supply passage 4, and the air is supplied to the swivel 6. High pressure is supplied from the port 8 and supplied to the air injection nozzle 12 through the passage 8 a and the air supply passage 5.

DESCRIPTION OF SYMBOLS 1 Ground improvement injection pipe 2 Inner pipe 3 Outer pipe 4 Solidification material liquid supply path 5 Air supply path 6 Swivel 7 Solidification material liquid supply port 8 Air supply port 9 Monitor mechanism 10 Injection nozzle 11 Solidification material liquid injection nozzle 12 Air injection nozzle

Claims (13)

There is a monitor mechanism provided with an injection nozzle at the bottom, the injection nozzle of the monitor mechanism is located at the center of the solidified material liquid injection nozzle, and the air injection nozzle is concentrically provided on the outside of it as a double nozzle An injection pipe for ground improvement in which air can be jetted simultaneously in the same direction around the solidification liquid ejected from the solidification liquid jet nozzle, and a swivel is connected to the upper part of the injection pipe. Is inserted from the ground to a predetermined depth in the ground, and then the solidified material liquid and air are supplied from the swivel at high pressure, and the solidified material liquid and air are ejected from the solidified material liquid injection nozzle and air injection nozzle of the monitor mechanism at the bottom of the injection pipe. While rotating the injection tube while pulling up, the surrounding ground is cut by the solidified material liquid and air injection force, and the ground improvement body is built by injecting the solidified material liquid into the cutting area A pipe,
An injection pipe for ground improvement, characterized in that a plurality of injection nozzles of the monitoring mechanism of the injection pipe are provided in parallel and the central axes of the injection directions are parallel to each other.   The injection pipe is a double pipe of an inner pipe and an outer pipe. The inner pipe serves as a solidified material liquid supply passage, and the space between the inner tube and the outer pipe serves as an air supply passage. The solidified material liquid supply passage is monitored. 2. The ground improvement injection pipe according to claim 1, wherein the solidification material liquid injection nozzle communicates with the mechanism, and the air supply passage communicates with the air injection nozzle.   3. The ground improvement injection pipe according to claim 1, wherein the spray nozzle of the monitoring mechanism has a pair of spray nozzles provided at symmetrical positions in the horizontal circumferential direction.   4. The ground improvement injection pipe according to claim 1, wherein a plurality of spray nozzles are arranged in parallel in a horizontal circumferential direction as a set of spray nozzles of the monitoring mechanism. 5. .   4. The ground improvement injection pipe according to claim 1, wherein a plurality of spray nozzles are arranged in parallel in the vertical direction as a set of spray nozzles of the monitoring mechanism. 5.   The set of spray nozzles of the monitoring mechanism is a set of a plurality of spray nozzles arranged in parallel in the vertical direction, and this set of spray nozzles is provided at a symmetrical position in the horizontal circumferential direction, and one set of spray nozzles The ground-improving jet nozzle according to any one of claims 1, 2, 3, and 5, wherein the jet nozzles having a symmetrical position on the other side are provided so as to be displaced from each other vertically. Injection tube.   4. The ground improvement injection pipe according to claim 1, wherein a plurality of the injection nozzles of the monitoring mechanism are arranged in a diagonally parallel manner. 5.   The injection nozzle of the monitoring mechanism is a set in which a set of injection nozzles are provided at symmetrical positions in the horizontal circumferential direction, a plurality of one side are arranged in parallel in the horizontal circumferential direction, and a plurality of symmetrical positions on the other side are arranged in parallel vertically. The ground improvement injection pipe according to any one of claims 1 to 3, wherein the injection pipe is a set.   The spray nozzle of the monitor mechanism is a set in which a set of spray nozzles are provided at symmetrical positions in the horizontal circumferential direction, and a plurality of one side are arranged in parallel in the horizontal circumferential direction, and a plurality of symmetrical positions on the other side are arranged in parallel diagonally up and down. The ground improvement injection pipe according to any one of claims 1 to 3, wherein the ground improvement pipe is a set.   The spray nozzle of the monitor mechanism is a set in which a set of spray nozzles is provided at a symmetrical position in the horizontal circumferential direction, and a plurality of one side are vertically aligned in parallel and a plurality of symmetrical positions on the other side are obliquely vertically aligned in parallel. The ground improvement injection pipe according to any one of claims 1 to 3, wherein the injection pipe is provided.   The injection nozzle of the monitor mechanism is provided at a symmetrical position in the horizontal circumferential direction, and at least one of the injection nozzles at the symmetrical position is provided in parallel with the central axis in the injection direction of each other as a set, The injection nozzles are different in the number of injection nozzles and the diameter of the injection nozzles at symmetrical positions, but the opposing injection reaction force is set to be an approximate value. The ground improvement injection pipe according to item 1.   The spray nozzles of the set of the monitor mechanisms are arranged in a line with a spacing between spray center axes of the spray nozzles of 5 to 10 cm. Injection pipe for ground improvement.   The injection nozzle for ground improvement according to any one of claims 1 to 12, wherein the injection nozzle of the monitor mechanism is inclined at an angle of 5 to 10 degrees obliquely downward from the horizontal direction.

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