JP2014221988A - Ground improvement method and outer pipe for chemical injection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ground improvement method capable of effectively utilizing an outer pipe for chemical injection, and the outer pipe for chemical injection.SOLUTION: An outer pipe for chemical injection 1 is configured so that a plurality of connection pipes 2 are connected together and a detachable connection part 4 is provided on the longitudinal midway thereof. An inner pipe 7 with discharge ports 7a formed on its peripheral wall is inserted into the outer pipe for chemical injection 1 extended to an upper surface of a subgrade S while the outer pipe for chemical injection 1 is left in an insertion hole h and installed in the subgrade S. A ground improvement chemical G supplied through the inner pipe 7 is injected from the discharge ports 7a into the subgrade S through injection ports 2a located in the subgrade S. Thereafter, a part upper than the detachable connection part 4 is pulled out to the upper surface of the subgrade S by disconnecting the outer pipe for chemical injection 1 installed on the subgrade S by the detachable connection part 4.

Description

  The present invention relates to a ground improvement method and a chemical solution injection outer tube, and more particularly to a ground improvement method and a chemical solution injection outer tube that can effectively use the chemical solution injection outer tube.

  In order to prevent liquefaction of the ground, various ground improvement methods have been proposed in which a ground improvement chemical solution is injected into the ground using a double pipe composed of an outer pipe and an inner pipe (see, for example, Patent Document 1). . In this ground improvement method, the ground is drilled using a casing rod to form an insertion hole, and then an outer tube is inserted into the insertion hole. Next, only the casing rod is pulled out on the ground, leaving the outer tube in the ground. Next, the inner tube is inserted into the outer tube installed in the ground, and the ground improvement chemical solution supplied through the inner tube is injected into the ground through the discharge port provided in the inner tube and the injection port provided in the outer tube. The target range is improved by the injected ground improvement chemical.

  After injecting the ground improvement chemical into the ground, the inner pipe is pulled up on the ground. On the other hand, the outer pipe is left embedded in the ground without being pulled out on the ground. That is, the inner tube is repeatedly used, but the outer tube is not used again once used.

JP 2011-32831 A

  The objective of this invention is providing the ground improvement method and outer tube | pipe for chemical | medical solution injection | pouring which can utilize a chemical | medical solution injection outer tube | pipe effectively.

  In order to achieve the above object, the ground improvement method of the present invention is such that after inserting an outer tube for injecting a chemical solution having an injection hole formed in a peripheral wall into a casing rod having an insertion hole formed in the ground, the casing rod is pulled out from the ground. Thus, the outer tube for injecting the chemical solution is left in the insertion hole and is installed in the ground, and is extended to the ground, and the inner tube having a discharge port formed on the peripheral wall is extended to the outer tube for injecting the chemical solution. In the ground improvement method in which the ground improvement chemical liquid inserted and supplied through the inner pipe is injected into the ground through the injection port located in the ground from the discharge port, the outer pipe for chemical injection is connected to a plurality of connection pipes. In addition, a structure in which a detachable connecting portion is provided in the middle of the longitudinal direction, and after the ground improvement chemical solution is injected into the ground, the outer pipe for injecting the chemical solution installed in the ground is connected by the detachable connecting portion. To release Ri, characterized in that to pull out the upper portion than the detachable coupling on the ground.

The outer tube for injecting a chemical solution of the present invention is inserted into a casing rod having an insertion hole cut in the ground, and then the casing rod is pulled out to be left in the insertion hole and installed in the ground. Then, after extending to the ground, an inner tube having a discharge port formed in the peripheral wall is inserted, and an injection port for injecting the ground improvement chemical solution supplied from the discharge port into the ground through the inner tube is formed in the peripheral wall. In the formed outer tube for chemical injection,
A plurality of connecting pipes and a detachable connecting part provided in the middle of the longitudinal direction when these connecting pipes are connected, and in a state where the plurality of connecting pipes are connected and installed in the ground, by the detachable connecting part, The upper and lower portions of the detachable connecting portion are configured to be disconnected.

  According to the present invention, the outer pipe for injecting the chemical liquid is connected to the plurality of connecting pipes, and the structure is provided with the detachable connecting portion in the middle in the longitudinal direction. The upper part and the lower part of the attaching / detaching connecting part of the outer tube for injecting a chemical solution installed in can be separated and released. Thereby, an upper part part can be pulled out on the ground rather than the attachment / detachment connection part of the outer tube | pipe for chemical | medical solution injection | pouring. Therefore, the upper portion of the outer tube can be used effectively by being repeatedly used.

It is explanatory drawing which illustrates the outer pipe | tube for ground improvement chemical | medical solution injection | pouring of this invention. It is explanatory drawing which illustrates the structure of the attachment / detachment connection part of FIG. It is explanatory drawing which illustrates the state which isolate | separated the attachment / detachment connection part of FIG. It is a perspective view which illustrates the attachment / detachment connection part of another structure. It is a front view which illustrates the engagement protrusion and engagement groove which comprise the attachment / detachment connection part of FIG. It is explanatory drawing which illustrates the state which connected the attachment or detachment connection part of FIG. 5 by front view. It is explanatory drawing which illustrates the process of drilling an insertion hole in the ground. It is explanatory drawing which illustrates the process of inserting an outer tube | pipe into a casing rod. It is explanatory drawing which illustrates the outer tube | pipe installed in the ground. It is explanatory drawing which illustrates the process which inserts an inner pipe | tube in an outer pipe | tube and is inject | pouring a ground improvement chemical | medical solution in the ground. FIG. 11 is a partially enlarged view of FIG. 10. It is explanatory drawing which illustrates the outer pipe | tube arrange | positioned in the ground after ground improvement. It is explanatory drawing which illustrates the state which pulled out the upper part rather than the attachment / detachment connection part of the outer tube | pipe of FIG. It is explanatory drawing which shows another example of the outer tube | pipe arrange | positioned in the ground after ground improvement. It is explanatory drawing which illustrates the state which pulled out the upper part rather than the attachment / detachment connection part of the outer tube | pipe of FIG. 14 on the ground.

  Hereinafter, the ground improvement method and the outer tube | pipe for chemical | medical solution injection | pouring of this invention are demonstrated based on embodiment.

  As illustrated in FIG. 1, the ground improvement chemical solution outer pipe 1 (hereinafter referred to as an outer pipe 1) of the present invention is configured by connecting a plurality of connecting pipes 2. The outer pipe 1 (that is, each connecting pipe 2) is formed of a resin such as vinyl chloride. A plurality of inlets 2 a are formed in the peripheral wall of the outer tube 1 so as to be separated from each other in the outer tube axial direction. Since the injection port 2a only needs to be arranged at a position where the ground improvement chemical solution G is injected into the ground S, the outer tube 1 is not formed with the connecting tube in which the injection port 2a is formed and the injection port 2a. It can also be configured by mixing a connecting pipe.

  The connecting pipes 2 adjacent to each other in the longitudinal direction are connected by a fixed connecting part 3 such as a bolt. The fixed connecting portion 3 cannot release the connection between the connected connecting pipes 2 without using a jig. That is, in the state where it is buried in the ground S, the connection of the connection pipes 2 by the fixed connection part 3 cannot be released and the connection pipes 2 cannot be separated.

  However, a detachable connecting portion 4 different from the fixed connecting portion 3 is provided in one place in the longitudinal direction when the plurality of connecting pipes 2 are connected. The detachable connecting part 4 can release the connection between the upper part and the lower part of the detachable connecting part 4 in a state where the plurality of connecting pipes 2 are connected and installed in the ground S.

  As illustrated in FIGS. 2 and 3, the detachable connecting portion 4 includes an engaging protrusion 5 a provided at the lower end portion of one connecting tube 2 and an engaging groove 5 b formed at the upper end portion of the other connecting tube 2. It consists of and. It is preferable that a plurality of sets of the engaging protrusions 5a and the engaging grooves 5b that are engaged with each other are arranged at intervals in the circumferential direction of the connecting pipe 2.

  The engaging groove 5b is formed in an L shape, and the engagement is not released unless the engaging protrusion 5a is moved in the circumferential direction of the connecting pipe 2 and then moved upward. That is, if one of the connecting pipes 2 is rotated by a predetermined angle around the center of the pipe axis and then the connecting pipe 2 is not moved upward, the connecting pipes 2 are not released from each other and cannot be separated from each other. ing. In addition, the structure by which the engagement groove | channel 5b was formed in the lower end part of one connection pipe 2, and the engagement protrusion 5a was provided in the upper end part of the other connection pipe 2 may be sufficient.

  In this embodiment, an engaging portion 5c extending in the tube axis direction is connected to the engaging groove 5b. When the engagement protrusion 5a is fitted to the locking portion 5c, inadvertent circumferential movement of the engagement protrusion 5a can be suppressed. That is, the connection between the connecting pipes 2 by the detachable connecting portion 4 is difficult to be inadvertently released without intention.

  Moreover, in this embodiment, the protective cover 6 which covers the attachment / detachment connection part 4 is further provided. The protective cover 6 is, for example, a rubber thin-film cylindrical body, and prevents the earth and sand in the ground S from entering the removable connecting portion 4 when the removable connecting portion 4 is placed and embedded in the ground S.

  The structure of the detachable connecting portion 4 is not limited to the structure illustrated in FIGS. 2 and 3, and various structures can be employed. Any structure that can release the connection between the connection pipes 2 by the detachable connection part 4 in the ground S by operating the connection pipe 2 located at the uppermost stage on the ground S (moving in the circumferential direction and moving up and down).

  For example, in the detachable connecting portion 4 illustrated in FIGS. 4 and 5, an outer peripheral surface having a stepped diameter is formed at the lower end portion of one of the connecting pipes 2, and an engaging protrusion 5 a is provided on the outer peripheral surface. Has been. An engagement groove 5 b is formed on the inner peripheral surface of the upper end portion of the other connecting pipe 2. The engaging groove 5b is continuously provided with a notch 5d opened at the end surface of the connecting pipe 2. Further, an O-ring 5 e is fitted on the inner peripheral surface of the other connecting pipe 2.

  In order to connect the connecting pipes 2 with the detachable connecting part 4, the engaging protrusions 5a are aligned with the notch parts 5d, and then the connecting pipes 2 are brought close to each other so that the engaging protrusions 5a are connected to the notch parts 5d. Pass through and push to the position of the engagement groove 5b. Next, as illustrated in FIG. 6, at least one of the connection pipes 2 is rotated with the pipe axis direction as the rotation axis direction, and the engagement protrusions 5 a are fitted into the engagement grooves 5 b. Thereby, the connecting pipes 2 are connected by the detachable connecting portion 4. Since the O-ring 5e is in contact with the outer peripheral surface with a stepped diameter of one of the connecting pipes 2 and reduced in diameter, the connecting pipes 2 can be connected in a watertight manner.

  In order to release the connection of the connection pipes 2 to each other, the reverse process of the connection is performed. That is, even if this detachable connecting portion 4 is used, the connecting tube 2 by the detachable connecting portion 4 in the ground S is operated by operating the connecting tube 2 positioned at the uppermost stage on the ground S (moving in the circumferential direction and moving up and down). You can unlink each other.

  In order to improve the ground S, first, the hole drilling device 10 is installed on the ground S as illustrated in FIG. Using this drilling device 10, the casing rod 9 is advanced into the ground S and drilled to form an insertion hole h.

  Next, as illustrated in FIG. 8, the outer tube 1 is inserted into the casing rod 9 in the ground S in which the insertion hole h is drilled. After the outer tube 1 is inserted into the casing rod 9, only the casing rod 9 is pulled out on the ground S. Accordingly, as illustrated in FIG. 9, the outer tube 1 is placed in the ground S while being inserted into the insertion hole h, and is extended to the ground S.

  Next, as illustrated in FIG. 10, the inner tube 7 is inserted into the outer tube 1 from the ground. The inner tube 7 is formed of, for example, rubber and has excellent flexibility, and a discharge port 7a is formed on the peripheral wall. Subsequently, the ground improvement chemical | medical solution G is supplied from the chemical | medical solution supply apparatus 11 through the inner tube | pipe 7 inserted in the outer tube | pipe 1. FIG. Examples of the ground improvement chemical solution G include water glass grout, cement grout and the like.

  The supplied ground improvement chemical | medical solution G is inject | poured into the ground S through the injection port 2a of the outer tube 1 in the ground S from the discharge port 7a of the inner tube 7 so that it may illustrate in FIG. An annular packer 8 is provided above and below the discharge port 7a on the outer peripheral surface of the inner tube 7, and the packer 8 is inflated to seal the gap between the inner tube 7 and the outer tube 1 to inject the ground improvement chemical solution G. Do. If necessary, annular packers are also provided above and below the inlet 2a on the outer peripheral surface of the outer tube 1 to seal the gap between the outer tube 1 and the insertion hole h.

  After injecting a predetermined amount of the ground improvement chemical solution G, the inner pipe 7 is moved upward so that the discharge port 7a is aligned with the other injection port 2a. Inject into the ground S. Sequentially, the inner tube 7 is moved upward in the same manner to perform the injection operation.

  After the operation of injecting the ground improvement chemical solution G using the outer pipe 1 is completed, the outer pipe 1 is newly installed in the ground S in another place and the same injecting work is performed. Complete the improvement.

  As illustrated in FIG. 12, after ground improvement of the target area of the ground G by injecting the ground improvement chemical solution G, the outer pipe 1 remains installed in the ground G. The symbol M in the figure indicates the upper end position of the ground improved range.

  Here, since the outer tube 1 of the present invention is provided with the detachable connecting portion 4 in the middle of the length, the connecting tube by the detachable connecting portion 4 in the ground S is operated by operating the uppermost connecting tube 2 on the ground S. Release the connection between the two. As a result, the connecting pipes 2 connected by the detachable connecting portion 4 are separated from each other, so that the upper portion of the detachable connecting portion 4 can be pulled out on the ground S as illustrated in FIG.

  That is, the lower part of the outer tube 1 that has finished the injection operation remains embedded in the ground S, but the upper part can be pulled out on the ground S. Therefore, the upper portion of the outer tube 1 can be repeatedly used with respect to the detachable connecting portion 4 and can be used effectively. Along with this, the length of the outer pipe 1 that remains buried in the ground S can be shortened, which is also preferable from the viewpoint of the ground environment.

  If the protective cover 6 is provided as in this embodiment, it is possible to prevent the earth and sand in the ground S from entering the detachable connecting portion 4, so that the engagement groove 5 b can be avoided from being clogged with earth and sand. Thereby, when releasing the connection between the connecting pipes 2 by the detachable connecting portion 4, it is advantageous to prevent a problem that it cannot be released or is difficult to release.

  As illustrated in FIG. 12, the arrangement position of the detachable connecting portion 4 in the ground S is preferably higher than the upper end or the upper end of the range where the ground is improved by the ground improving chemical S. Thereby, it becomes easy to avoid the malfunction which an upper part rather than the attachment / detachment connection part 4 and the attachment / detachment connection part 4 becomes difficult to move by the solidification effect | action of the ground improvement chemical | medical solution G.

  Alternatively, as illustrated in FIG. 14, the detachable connection portion 4 can be configured to be used for connection between the uppermost connection pipe 2 and the connection pipe 2 adjacent to the lower side of the uppermost connection pipe 2. . In this case, as illustrated in FIG. 15, since only the uppermost connecting pipe 2 is pulled out on the ground S, the uppermost connecting pipe 2 can be pulled out relatively easily.

DESCRIPTION OF SYMBOLS 1 Outer pipe | tube for chemical | medical solution injection | pouring 2 Connecting pipe 2a Inlet 3 Fixed connecting part 4 Detachable connecting part 5a Engaging protrusion 5b Engaging groove 5c Locking part 5d Notch part 5e O-ring 6 Protective cover 7 Inner pipe 7a Outlet 8 Packer 9 Casing rod 10 Drilling device 11 Chemical solution supply device G Ground improvement chemical solution h Insertion hole S Ground

Claims (7)

After inserting the outer tube for injecting the chemical solution with the injection hole formed in the peripheral wall into the casing rod with the insertion hole formed in the ground, the outer tube for injecting the chemical solution is inserted into the insertion hole by pulling out the casing rod from the ground. Leave it installed in the ground and extend it to the ground, insert the inner pipe with the discharge port formed in the peripheral wall into this chemical injection outer pipe, and supply the ground improvement chemical supplied through this inner pipe, In the ground improvement method of injecting into the ground through the injection port located in the ground from the discharge port,
The outer pipe for injecting the chemical liquid is connected to a plurality of connecting pipes, and is provided with a detachable connecting portion in the middle in the longitudinal direction, and the ground improvement chemical liquid is injected into the ground, and then installed in the ground. The ground improvement method characterized by pulling out an upper part above this attachment / detachment connection part on the ground by releasing the connection of the outer tube for chemical injection by the attachment / detachment connection part.   The ground improvement method according to claim 1, wherein the detachable connecting portion is disposed above an upper end portion or an upper end portion in a range where the ground is improved by the ground improvement chemical solution in the ground.   The ground improvement method according to claim 1 or 2, wherein the detachable connecting portion is used for connecting an uppermost connecting pipe and a connecting pipe adjacent to the lower side of the uppermost connecting pipe. After being inserted into a casing rod with an insertion hole drilled in the ground, this casing rod is pulled out, so that it is left in the insertion hole and installed in the ground, after being extended to the ground, In the outer tube for injecting a chemical solution in which an inner tube having a discharge port formed in the peripheral wall is inserted and an injection port for injecting the ground improvement chemical solution supplied from the discharge port into the ground through the inner tube is formed in the peripheral wall,
A plurality of connecting pipes and a detachable connecting part provided in the middle of the longitudinal direction when these connecting pipes are connected, and in a state where the plurality of connecting pipes are connected and installed in the ground, by the detachable connecting part, An outer tube for injecting a chemical solution, characterized in that the upper portion and the lower portion of the detachable connecting portion are disconnected.   The outer tube | pipe for chemical | medical solution injection | pouring of Claim 4 arrange | positioned above the upper part or upper end part of the range where the said attachment / detachment connection part is ground-improved by the said ground improvement chemical | medical solution in the ground.   The outer tube for medicinal solution injection according to claim 4 or 5, wherein the detachable connecting portion connects the uppermost connecting tube and a connecting tube adjacent to the lower side of the uppermost connecting tube.   The outer tube | pipe for chemical | medical solution injection | pouring in any one of Claims 4-6 in which the protective cover which prevents the invasion of the earth and sand in the ground to the said attachment / detachment connection part is provided.

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