JP2006118230A - Chemical injection apparatus for soil improvement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chemical injection apparatus for soil improvement, which is for use in injecting a chemical into the ground containing a huge amount of groundwater, and can prevent backflow of the groundwater via the interior of the injection apparatus. <P>SOLUTION: The chemical injection apparatus for soil improvement is formed of a chemical discharging section (2); a packer section (3) connected to a proximal end of the chemical discharging section (2), and having an inflatable section (301) inflatable by air; and a connection section (4) connected to a distal end of the packer section (3) and having a double-pipe rod connected thereto. Then the connection section (4) has arranged therein a chemical passage (5) extending in a longitudinal direction and having both ends thereof opened; and an air passage (6) having a proximal end thereof opened and a distal end thereof extended to a rear side of the inflatable section (301). Herein the chemical discharging section (2) is provided with a valve body (7) and an elastic means (8). The valve body (7) can open/close a distal end of the chemical passage (5). The elastic means (8) energizes the valve body (7) in a direction that closes the distal end of the chemical passage (5). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a ground solution improvement chemical injection device used for infiltrating a chemical solution such as cement milk into the ground for ground improvement, and more specifically, a check valve is provided at the tip of the ground solution injection device. The present invention relates to a ground solution improving chemical liquid injection device capable of preventing backflow.

  In general, when improving the ground, a chemical solution injection device for ground improvement is inserted into the borehole formed in the ground, and then chemical solution such as cement milk penetrates into the ground through this chemical solution injection device for ground improvement. Is done.

  Here, a conventional ground improvement chemical solution injection device will be described. FIG. 4 illustrates the structure of a conventional ground improvement chemical solution injection device (hereinafter simply referred to as “injection device”) 41. FIG. 2 is a partial cross-sectional view along the longitudinal direction, and a conventional chemical solution injection device 41 has a substantially cylindrical shape, and is located on the distal end side and discharges a chemical solution into the ground. And a packer portion 43 connected to the base end side of the chemical solution discharge portion 42, and a connection portion 44 connected to the base end side of the packer portion 43 and connected to a rod or the like in use. The outer periphery of the packer portion 43 expands in the outer peripheral direction by supplying air to the back surface side, and can be contracted by removing the supplied air in this expanded state. Expansion part 4301 made of rubber is circumferentially provided.

  And inside the chemical | medical solution injection apparatus 41, the chemical | medical solution conveyance path 45 is formed along the longitudinal direction of the chemical | medical solution injection apparatus 41, and this chemical | medical solution conveyance path 45 has the base end side of the base end of the said connection part 44. The tip is opened at the tip, and the tip is opened at the tip of the drug solution release portion 42. As a result, the chemical liquid supplied from the base end side of the chemical liquid transport path 45 is discharged into the ground from the distal end side of the chemical liquid discharge section 42 while being transported in the chemical liquid transport path 45, thereby causing the chemical liquid to enter the ground. Can penetrate.

  In addition, an air conveyance path 46 is formed inside the chemical solution injection device 41, and the proximal end side of the air conveyance path 46 communicates with the outside of the injection device 41 via the joint 47 at the connecting portion 44. In use, an air pipe or the like (not shown) can be connected to the joint 47.

  On the other hand, the front end side of the air conveyance path 46 communicates with the inside of the inflating portion 4301, so that when air is injected into the air conveyance path 46 through the joint 47, this air passes through the air conveyance pipe 46. If it is guided to the inside of the expansion part 4301 while being conveyed and further injects air, the expansion part 4301 expands to the outer peripheral side by the air pressure, and the expansion part 4301 contracts by removing the air in the expanded state. To go.

  And when inject | pouring a chemical | medical solution in the ground using the injection | pouring apparatus 41 comprised in this way, while connecting an air pipe | tube to the joint 47, the connecting part 44 has a rod provided with a chemical | medical solution conveyance path, etc. In a state where the chemical solution transport paths are connected to each other, the chemical solution injection device 41 is inserted into the borehole formed in the ground. First, air is supplied into the air conveyance path 46 to inflate the expansion portion 4301, thereby forming a closed space on the distal end side of the expansion portion 4301. In this state, chemical liquid such as cement milk is supplied into the chemical liquid conveyance path 45.

  Then, the chemical liquid supplied into the chemical liquid conveyance path 45 is discharged from the distal end side opening of the chemical liquid discharge part 42 to the outside of the injection device 1, and further discharged from the chemical liquid discharge part 42 when the chemical liquid is supplied at a high pressure. The chemical solution penetrates into the ground, making it possible to improve the ground.

  In this way, it is possible to improve the soft ground and the like by using an injection device, but at this time, if the ground contains a large amount of groundwater, the groundwater in the ground may flow backwards. There is.

  In this regard, in the past, a “water stop device at the drilling rod insertion port” (Japanese Patent Laid-Open No. 2001-20700) has been proposed in order to prevent groundwater from being ejected from around the excavation rod when drilling the underground. By using this, it is possible to prevent the ejection of groundwater from around the injection device even when the chemical solution is injected, but even if such a device is used, the groundwater that passes through the inside of the injection device can be prevented. It is impossible to prevent eruption.

That is, in the case of the injection device, as described above, the chemical solution transport path for discharging the chemical solution is formed inside the device, and the tip portion is injected for the purpose of discharging the chemical solution. It communicates with the outside of the device. Therefore, when this injection device is inserted into the borehole, if there is a large amount of groundwater, there is a problem that the groundwater will be ejected through this chemical solution transport path, so that the chemical solution is injected. In this case, there is a problem that the chemical solution must be supplied at a pressure exceeding the water pressure of the groundwater.
JP 2001-20700 A

  Then, this invention makes it a subject to provide the chemical | medical solution injection | pouring apparatus for ground improvement which can prevent the backflow of groundwater through the inside of an injection | pouring apparatus, when inject | pouring a chemical | medical solution in the ground which contains a lot of groundwater. .

  A ground solution improving chemical injection device according to the present invention includes a chemical solution discharge portion, a packer portion connected to a proximal end side of the chemical solution discharge portion and inflated by injecting air, and a base of the packer. A connecting portion to which the double tube rod is connected, which is connected to the end side, and a chemical solution conveyance path having both ends along the longitudinal direction opened therein and a base end portion being opened In addition, in the chemical solution injection device for ground improvement provided with an air conveyance path extending to the back side of the inflating portion, the distal end portion of the chemical solution discharge section is arranged to be able to open and close the distal end side of the chemical solution conveyance path. In addition, the valve body is urged by an elastic means in a direction to close the distal end side in the chemical solution conveyance path.

  In the chemical improving device for ground improvement according to the present invention, the valve body is disposed in such a manner that the opening of the chemical solution conveying path for releasing the chemical solution can be opened and closed, and the valve body is closed by the elastic means. Energized in the direction. Therefore, in a normal state where no chemical solution is released, the opening on the front end side of the chemical solution conveyance path is closed, thereby preventing backflow of groundwater. On the other hand, when a chemical solution is supplied into the chemical solution conveyance path, the valve body moves in a direction to open the distal end side opening of the chemical solution conveyance route by the pressure of the chemical solution, and thereby the chemical solution can be discharged.

  In the chemical improvement device for ground improvement of the present invention, the packer in which the chemical solution discharge portion located on the distal end side and the expansion portion connected to the proximal end side of the chemical solution discharge portion and inflated by injecting air are provided around And a connecting portion connected to the base end side of the packer to which the double tube rod is connected in use, and inside thereof, a chemical solution having both ends along the longitudinal direction opened. The conveyance path and the base end portion communicate with the outside through a joint, and the distal end portion includes an air conveyance path extended to the back side of the expansion portion.

  In the chemical solution discharge section, a valve body is disposed so as to be openable and closable at the distal end side of the chemical solution conveyance path, and the valve body is closed by the elastic means in the direction of closing the distal end side of the chemical solution conveyance path. Is being energized.

  Here, the tip side of the chemical solution transport path is arranged to be openable and closable, a spherical valve element is inserted inside the chemical solution discharge portion, and a ring member is locked to the inner periphery of the tip side of the chemical solution discharge portion. A spring receiver may be brought into contact with the back surface of the locking member, and an elastic body such as a spring may be interposed between the valve body and the spring receiver. Thereby, it becomes possible to infiltrate a chemical | medical solution in the ground, preventing the backflow of groundwater effectively.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a chemical improvement device for ground improvement (hereinafter simply referred to as “chemical injection device”) according to the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing the structure of the chemical injection device of this embodiment. In the figure, reference numeral 1 denotes the chemical liquid injector of this embodiment.

  And the chemical | medical solution injection device 1 of a present Example is made into the substantially cylindrical shape, the chemical | medical solution discharge | release part 2 arrange | positioned at the front end side, the packer part 3 connected with the base end side of this chemical | medical solution discharge | release part 2, and this packer It is connected to the base end side of the part 3 and has a connecting part 4 connected to the double tube rod in use.

  Further, on the outer peripheral side of the packer part 3, an inflatable part 301 made of rubber having both end portions fixed by a fixing member 302 is provided around, and the inflating part 301 receives air on its back side, It expands to the outer peripheral side and can be contracted to its original shape by removing air in the expanded state. In FIG. 1, reference numeral 13 denotes an O-ring for sealing between the components.

  Next, in the chemical injection device 1 in the present embodiment, a chemical conveyance path 5 is formed in the inside along the longitudinal direction. And the front-end | tip part of this chemical | medical solution conveyance path 5 is opened at the front-end | tip part of the said chemical | medical solution discharge | release part 2, Moreover, the base end part of the chemical | medical solution conveyance path 5 is opened at the base end side of the said connection part 5, Thus, when the chemical solution is supplied from the proximal end side opening, the supplied chemical solution can be discharged to the outside from the distal end opening of the chemical solution discharge portion 2 while being conveyed in the chemical solution conveyance path 5.

  Moreover, in the chemical injection device 1 of the present embodiment, an air conveyance path 6 is formed inside the chemical liquid conveyance path, and the base end portion of the air conveyance path 6 is the connection part 4. An opening is formed on the proximal end side, and the distal end portion communicates with the inside of the inflatable portion 301. As a result, when air is injected into the air conveyance path 6, the supplied air is guided to the inside of the inflating portion 301 while being conveyed through the air conveyance pipe 6, and when the air is further injected. The inflatable portion 301 can be expanded to the outer peripheral side by air pressure.

  Therefore, in the chemical injection device 1 of the present embodiment, a double pipe structure having the chemical solution conveyance path 5 and the air conveyance path 6 therein is provided. For this purpose, an air tube, a chemical solution supply pipe, and the like are provided in the connecting portion 4. Only by connecting, a chemical solution can be released into the closed space while forming a closed space in the borehole or the like.

  In the present embodiment, the opening of the chemical transport path 5 is positioned around the opening of the air transport path 6 on the base end side of the connecting section 4. In the packer unit 3, the chemical transport path 5 However, the positional relationship is not particularly limited as long as the chemical solution transport path 5 and the air transport path 6 are formed inside.

  Next, FIG. 2 is a cross-sectional view showing the structure of the tip portion of the drug solution injector 1 of the present embodiment. In this embodiment, the drug solution discharge portion 2 has an outer diameter tapered toward the tip portion. The shape is made smaller, and a chemical solution transport path 5 is formed in the inside, and the tip of the chemical solution transport path 5 is opened at the tip of the chemical solution discharge section 2. A spherical valve element 7 is movably disposed in the chemical solution conveyance path 5 so as to be able to close the chemical solution conveyance path 5, thereby opening and closing the opening of the chemical solution conveyance path 5. .

  That is, in the present embodiment, the chemical solution transport path 5 formed in the chemical solution discharge section 2 has a reduced diameter at an arbitrary location, thereby forming the valve seat portion 9 on the tip side, and the chemical solution transport path 5 The valve body moving space 10 is defined between the valve seat portion 9 and the tip side opening. A spherical valve body 7 having a diameter capable of closing the valve seat 9 and forming a space with the inner wall of the moving space 10 is inserted into the moving space 10.

  On the other hand, a snap ring 11 is locked in the vicinity of the distal end portion of the chemical solution delivery path 5 in the chemical solution discharge portion 2, and a spring receiver 12 is brought into contact with the valve body 7 side of the snap ring 11 so that the spring ring receives the spring ring 12. 12, and a spring 8 as an elastic body is interposed between the spring receiver 12 and the valve body 7 so as to be supported by the spring receiver 12. With such a configuration, the valve body 7 is urged by the spring 8 in a direction to close the chemical liquid conveyance path 5, and the chemical liquid conveyance path 5 can be freely opened and closed.

  To further explain this relationship, in FIG. 2, the valve body 7 is urged by a spring 8 in a direction to close the chemical liquid conveyance path 5, that is, the opening of the chemical liquid conveyance path 5 is The valve body 7 is closed inside. In the present embodiment, the spring receiver 12 is configured such that the back surface thereof is supported by the snap ring 11, and the spring 8 is configured to be supported by the spring receiver 12. Therefore, the spring receiver 12 and the spring 8 jump out. There is no.

  Next, in this state, when the chemical liquid is supplied into the chemical liquid conveying path 5 at a pressure that can counteract the urging force of the spring 8, and the supply of the chemical liquid is continued, the valve body 7 is as shown in FIG. Due to the pressure of the chemical liquid, the inside of the moving space 10 moves toward the distal end side of the chemical liquid discharge section 2 against the urging force of the spring 8.

  Then, the closing of the chemical solution transport path 5 is released, and the valve body 7 has a diameter capable of forming a space with the inner wall of the moving space 10, so that the chemical solution supplied to the chemical solution transport path 5 is While passing between the inner wall of the moving space 10 and the valve body 7, it is discharged to the outside from the tip of the chemical solution discharge portion 2, thereby enabling injection of the chemical solution into the ground.

  When the supply of the chemical solution is stopped after the injection of the chemical solution is completed, the valve body 7 returns to the original position as shown in FIG. 2 again by the urging force of the spring 8, and the chemical solution conveyance path 5 is closed by the valve body 7. Thus, it is possible to prevent the underground groundwater from flowing backward.

  Thus, in the chemical injection device 1 of the present embodiment, since the valve body 7 serving as a check valve is provided inside the chemical discharge unit 2 that discharges the chemical, the injection of the chemical is not hindered. It is possible to effectively prevent the reverse flow of groundwater into the apparatus.

  In the present embodiment, a rubber spherical body is used as the valve body. However, the valve body is not necessarily made of rubber and may be made of metal or resin. The valve body does not necessarily need to be spherical, and may have any shape as long as the valve seat can be closed and an outer diameter can be formed between the inner wall of the moving space 10.

  Next, a description will be given of a method of using the chemical injection device 1 of the present embodiment configured as described above. When the ground improvement is performed using the chemical injection device 1 of the present embodiment, the chemical injection of the present embodiment is performed. The connecting part 4 in the apparatus 1 is connected to a double tube rod 14 in which a chemical liquid conveying path and an air conveying path are formed, a chemical liquid conveying path 5 of the connecting part 4 and a chemical liquid conveying path of the double pipe rod, and a connecting part. 4 is connected so that the air conveyance path of the double tube rod communicates with the air conveyance path of the double tube rod. Further, the chemical solution supply means and the air supply are respectively connected to the chemical solution conveyance path 5 and the air conveyance path 6 of the double tube rod 14. In this state, the chemical injection device 1 of this embodiment is inserted into the boring hole or the like.

  And after inserting the chemical | medical solution injection apparatus 1 of a present Example to the predetermined depth, air is supplied in the flow path 6 for air, the expansion part 301 is expanded, and the inner wall of a boring hole is pressed on the outer periphery of the expansion part 301 Thus, a closed space is formed on the tip side of the expanding portion 301 in the boring hole.

  Further, in this state, a chemical solution is supplied into the chemical solution conveyance path 5 at a high pressure. Then, as described above, the valve body 7 is moved by the pressure of the chemical liquid, and the closing of the chemical liquid conveyance path by the valve body 7 is released, and the chemical liquid is discharged from the distal end side of the chemical liquid discharge section 2, thereby It is possible to improve the ground by penetrating the chemical solution.

  On the other hand, after the injection of the chemical solution is completed, the supply of the chemical solution is stopped, whereby the chemical solution conveyance path 5 is closed by the above-described action, thereby preventing the reverse flow of the groundwater.

  Thus, in the chemical injection device 1 of the present embodiment, since the chemical solution transport path can be closed by the valve body when no chemical solution is supplied, groundwater is prevented from flowing back through the inside of the device. In addition, the chemical solution transport path 5 can be closed only by stopping the supply of the chemical solution, and a special operation for preventing the backflow of groundwater is unnecessary.

  In the above description, the embodiment in which the valve body is inserted into the chemical liquid discharge portion 2 has been described. However, in the chemical liquid injection apparatus of the present invention, the valve body is arranged so that the opening on the front end side of the chemical liquid transport path 5 can be opened and closed. The valve body may be urged by an elastic means in a direction to close the distal end side opening in the chemical solution transport path, and is not necessarily limited to the above-described structure.

  In this invention, since it is set as the structure which prevents a reverse flow of groundwater using a valve body, it is applicable not only to ground improvement but all the chemical | medical solution injection | pouring operations which can consider the possibility that groundwater may eject by excavation.

It is sectional drawing which shows the structure of the Example of the chemical injection device of this invention. It is sectional drawing for demonstrating the insertion structure of the valve body in the Example of the chemical | medical solution injection device of this invention. It is sectional drawing for demonstrating the effect | action of the valve body in the Example of the chemical | medical solution injection device of this invention. It is a partial cross section figure for demonstrating the conventional chemical | medical solution injection | pouring apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Chemical liquid injection device 2 Chemical liquid discharge | release part 3 Packer part 301 Expansion part 302 Fixing cover 4 to fix an expansion part 4 Connection part 5 Chemical liquid conveyance path 6 Air conveyance path 7 Valve body 8 Spring 9 Valve seat part 10 Movement of valve body Space 11 Snap ring 12 Spring receiver 13 O-ring

Claims (4)

A chemical solution discharge portion (2), a packer portion (3) connected to the base end side of the chemical solution discharge portion (2) and having an expansion portion (301) that expands by air, and the packer portion (3) A connecting portion (4) to which the double tube rod is connected, which is connected to the base end side, and a chemical solution conveyance path (5) in which both end portions along the longitudinal direction are opened, and a base In the chemical injection device for ground improvement provided with an air conveyance path (6) in which the end portion is opened and the tip portion is extended to the back side of the expansion portion (301),
A valve body (7) is disposed in the chemical liquid discharge section (2) so that the front end side of the chemical liquid conveyance path (5) can be opened and closed, and the valve body (7) is mounted by an elastic means (8). The ground solution improving chemical liquid injection device, wherein the chemical liquid conveying path (5) is urged in a direction to close the front end side.   A valve body (7) is inserted into the chemical solution delivery path (5) inside the chemical solution discharge section (2) in such a manner that the front end side of the chemical solution transfer path (5) can be opened and closed, and the chemical solution discharge section (2). A ring member (11) is locked to the inner periphery on the tip side of the ring member, a spring receiver (12) is brought into contact with the back surface of the ring member (11), and elastic means is provided between the valve body (7) and the spring receiver (12). The ground solution improving chemical liquid injector according to claim 1, wherein (8) is interposed.   The ground solution improvement chemical liquid injection device according to claim 1 or 2, wherein the valve body (7) is a sphere.   The ground solution improvement chemical injection device according to any one of claims 1 to 3, wherein the elastic means (8) is a spring.

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