JP4942025B2 - Hollow tube structure and method for forming columnar solidified pile - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a hollow tube structure used in a dry soft ground improvement method and a method for forming a columnar solidified pile.

  The soft ground improvement method includes a wet method using a liquid solidifying material and a dry method using a powdery solidifying material. The wet method requires a ground plant to make the cement-based solidified material liquid at the construction site, which causes problems such as construction costs and work burdens, and contamination of groundwater due to penetration of the solidified material into the basement. .

On the other hand, since the dry construction method is a method in which the solidified material is put into the ground as a powder by compressed air or the like, the problem of the wet construction method is solved. However, there is a problem that it is difficult to uniformly control the amount of powdered solidified material mixed with the ground. In order to solve such a problem, Japanese Patent Application Laid-Open No. 59-96325 discloses that a hollow body penetrated at a predetermined depth from the ground is sequentially filled with a bag body containing a predetermined amount of powdered solidified material. Then, a construction method is disclosed in which only the powdered solidified material stored in the bag body is left in the ground and the hollow tube is pulled up. The structure of the tip portion of this hollow tube receives force by a method in which the openable and closable protruding portions close to each other at the time of press-fitting. The structure is divided into two.
JP 59-96325 A (the third page, upper right column, FIGS. 1 to 6)

  However, the lid member at the tip of the hollow tube disclosed in Japanese Patent Application Laid-Open No. 59-96325 opens at the center of the pin with the weight of the solidifying material at the same time as pulling up. There is a problem in that the opening of the lid member is prevented by an obstacle such as glass or glass, and the bag body is not discharged from the hollow tube.

  Accordingly, an object of the present invention is to provide a hollow tube structure that can reliably open or close the lid member at the tip of the hollow tube only by rotating the hollow tube that has penetrated into the ground. It is providing the formation method of a column-shaped solidification pile.

  In this situation, the present invention has been intensively studied, and as a result, a lid member having a pair of half-disc-shaped lid body portions on the distal end surface of the hollow tube is attached so as to rotate along the opening surface of the distal end. A rotating body having a pair of wing members is attached to the tip of the hollow tube within a predetermined angle with respect to the hollow tube, and the pair of wing members and the lid member are linked by a specific means. Then, the lid member can reliably open and close the opening at the tip of the hollow tube in conjunction with the rotation of the rotating body, and the present invention has been completed.

That is, the present invention attaches a lid member having a pair of half-disc-shaped lid body portions to the distal end surface of the hollow tube so as to rotate along the opening surface of the distal end, and the distal end portion of the hollow tube And a rotating body having a pair of wing members attached to the peripheral surface portion within a predetermined angle with respect to the hollow tube, and a guide formed in the longitudinal direction of the pair of wing members. A guide rod member formed on the lid member is inserted into the elongated hole, and the pair of half-disc-shaped lid main body portions are rotated in conjunction with the rotation of the hollow tube, and the tip of the hollow tube is rotated. A hollow tube structure that opens and closes an opening is provided.

  The present invention also includes a step of penetrating the hollow tube of the hollow tube structure to a predetermined depth while rotating it forward into the ground, and a powdery solidified material from the opening on the ground side of the hollow tube into the hollow tube , A step of pulling up the hollow tube to the ground surface while rotating it in reverse, a step of leaving the solidified material in the ground from the opening of the tip of the hollow tube, and an underground stirring and mixing device penetrating into the ground The present invention provides a method for forming a columnar solidified pile including a step of stirring and mixing the solidified material and the local board.

  When the hollow tube structure of the present invention is used in a dry soft ground improvement method, the lid member rotates in the direction in which the pair of half-disc-shaped lid main body parts closes when penetrating into the ground while rotating forward. Thus, the opening at the tip of the hollow tube can be reliably closed. From this state, as long as the hollow tube is rotated forward, the ground reaction force acts on the lid member in the direction of closing the lid member, the opening is not opened, and the hollow tube is penetrated to a predetermined depth. Until then, the hollow interior can be emptied by a substantial volume. On the other hand, when the hollow tube charged with the powdered solidifying material is pulled upward, the hollow tube is rotated in the reverse direction. At this time, the lid member can be rotated in the direction in which the pair of half-disc-shaped lid main body portions are opened, so that the opening at the distal end of the hollow tube can be reliably opened. When the hollow tube is further rotated in the same direction from this state, the reaction force of the ground acts on the lid member in the direction of opening the lid member, and the opening is not closed. If the hollow tube is pulled up while maintaining this state, the powdered solidified material can be evenly placed in the depth direction in the ground.

  Next, a hollow tube structure according to an embodiment of the present invention will be described with reference to FIGS. 1 is a perspective view of the distal end portion of the hollow tube structure in a state where the lid member of the present example is closed, and FIG. 2 is a perspective view of the distal end portion of the hollow tube member constituting the hollow tube structure of FIG. 3 is a perspective view of the rotating body constituting the hollow tube structure of FIG. 1, FIG. 4 is a perspective view of the distal end portion of the hollow tube structure with the lid member of this example open, and FIG. FIG. 6 is a diagram of the hollow tube structure of FIG. 1 viewed from below, FIG. 7 is a diagram of the hollow tube structure of FIG. 1 viewed from the front, and FIG. 8 is a top view of the hollow tube structure of FIG. 4, FIG. 9 is a bottom view of the hollow tube structure of FIG. 4, and FIG. 10 is a front view of the hollow tube structure of FIG. Each figure is shown.

  The hollow tube structure 10 of FIG. 1 is obtained by assembling the rotating body 20 of FIG. 3 to the hollow tube member 10a of FIG. That is, the hollow tube member 10 a is attached with the lid member 3 having a pair of half-disc-shaped lid body portions 31 by the shaft 4 between the distal end flange 2 of the hollow tube 1 and the annular window portion 6. Is. The annular window portion 6 has a ring shape, and is fixed to the distal end flange 2 of the hollow tube 1 while having a space allowing the cover main body portion 31 to protrude and project. In the hollow tube structure 10, a rotating body 20 having a pair of wing members 22 is attached to the hollow tube member 10 a so as to be rotatable with respect to the peripheral surface portion of the arc-shaped split spacer 5 of the hollow tube 1. It is a thing. In the rotating body 20 of this example, the left half member 20a and the right half member 20b manufactured in advance are assembled to the hollow tube side member 10a, and both are brought into contact with each other (gap portion in FIG. 3). It is what was welded in. Therefore, the left half member 20a and the right half member 20b in the drawings excluding FIG. 3 (the drawings after assembly) are joined together. The rotating body 20 may be assembled from the beginning as an integral structure by being inserted from the upper end side of the hollow tube 1.

  In the hollow tube member 10a, a pair of a predetermined circumferential length and a radial length is provided directly above the distal end flange 2 of the hollow tube 1, that is, on the peripheral surface portion of the hollow tube 1 in which the annular member 20 is loosely fitted. The arc-shaped split spacer 5 is fixed to the hollow tube 1 so that the notch 8 is formed. After the assembly, a pair of protrusions 25 formed on the inner peripheral surface of the annular member 21 of the rotating body 20 so as to extend toward the center of the rotating body 20 are positioned in the notch 8. Thereby, the rotating body 20 can rotate within a predetermined angle with respect to the hollow tube 1. That is, the rotating body 20 can rotate around the hollow tube 1 by the length that the protrusion 25 on the rotating body 20 side moves in the circumferential direction in the notch 8. The circumferential length of the notch 8 is a length necessary for taking a shape in which the lid member opens the opening from the shape in which the lid member closes the opening of the hollow tube 1 in conjunction with the rotation of the hollow tube 1.

  The lid member 3 is installed at the tip of the hollow tube 1 so that the pair of halved members are point-symmetric with respect to the axial center of the hollow tube 1. That is, the half member of the lid member 3 includes a half disk-shaped lid main body portion 31, an arm member 33 extending outward from the radial end of the lid main body portion 31, and an upper surface of the arm member 33 upward. The guide rod member 33 is erected. The pivot support position 4 at which the lid member 3 is pivotally attached to the hollow tube 1 is the base end portion of the arm member 33 when the half members are in contact with each other at the straight portion to form a circular member. In addition, the lid body 31 and the tip flange 2 are opposed to each other. The angle formed between the longitudinal direction of the arm member 33 and the direction along the straight line portion of the lid main body 31 is substantially a right angle. When the lid member 3 having such a shape is rotated about the shaft 4 in the X direction in FIG. 2, the lid member 3 is closed, and when it is rotated in the Y direction, the lid member 3 is opened. It becomes a state.

  The rotating body 20 includes, in addition to the protrusion 25, an annular member 21 that is freely fitted around the hollow tube 1, a pair of left and right wing members 22 that extend outward from the annular member 21, and the longitudinal length of the wing member 22. A guide member 24 is provided on the side surface in the direction so as to form a guide slot 23 having a predetermined length between the blade member 22 and the wing member 22. The guide member 24 of this example is formed by bending a wire rod into a substantially L shape, and fixing one end to the annular member 21 and the other end to the wing member 22 by welding. The inner diameter of the annular member 21 is slightly larger than the outer diameter of the hollow tube 1 provided with the annular spacer 5. The protrusion length of the protrusions 25 is a dimension such that the inner diameter formed between the protrusions 25 is larger than the outer diameter of the hollow tube 1. Further, the width of the guide slot 23 is larger than the outer diameter of the guide bar member 33. The length of the guide slot 23 is such that the lid member closes the opening of the hollow tube 1 when the guide bar member 33 moves in the guide slot 23 in conjunction with the rotation of the rotating body 20. The guide rod member 33 has such a length that it can be positioned in the guide slot 23 within a range that can be opened.

  The wing member 22 is a member that forms the guide long hole 23, and functions as an underground resistor by the rotation of the hollow tube 1. Moreover, when the shape of the blade member 22 is a stirring blade shape, that is, a shape in which the upper surface is a downward inclined surface with respect to the normal rotation direction, the hollow member structure 10 penetrates into the ground. It is preferable in terms of improving efficiency.

  An example of a method for assembling the hollow tube member 10a and the rotating body 20 will be described. The guide rod member 33 of the hollow tube member 10a of FIG. 2 is inserted into the guide elongated hole 23 of the rotating body 20, and the protrusion 25 of the rotating body 20 is positioned in the notch 8 of the hollow tube member 10a. set. Next, the left half member 20a and the right half member 20b are integrated by welding. At this time, when the lid member 3 is rotated in the direction of the symbol X so as to close the lid, the position of the protrusion 25 of the rotating body 20 is brought into contact with one end of the notch 8 (FIG. 5). reference). When the hollow tube 1 further rotates in the Z direction (see FIG. 8) from this state, the hollow tube 1 and the rotating body 20 are united and rotate together in the rotation direction.

  In addition to the blade member 22 of the rotating body 20, a stirring blade (not shown) may be further attached to the hollow tube structure 10. As a result, the penetration into the ground becomes smoother, and the apparatus is suitable for use in the stirring and mixing step of the powdered solidified material placed in the ground and the ground.

  Next, a method for forming the columnar solidified pile of the present invention will be described with reference to FIG. FIG. 11 is a simplified diagram for explaining each step of the method for forming a columnar solidified pile of this example. In FIG. 11, the tip structure of the hollow tube structure is not shown for simplification of the drawing. The method for forming a column-shaped solidified pile according to the present invention includes a step of penetrating the hollow tube of the hollow tube structure to a predetermined depth while rotating the hollow tube forward in the ground (FIG. 11A), the ground of the hollow tube A step (FIG. 11 (B)) of pouring the powdery solidified material into the hollow tube from the opening on the side, pulling the hollow tube to the ground surface while rotating it in the reverse direction, and removing the solidified material from the tip opening of the hollow tube The process of leaving behind (FIGS. 11 (C) and 11 (D)) and the process of mixing the solidified material and the local board (FIG. 11 (E)) by penetrating the ground stirring and mixing device into the ground. .

  When the hollow tube 1 penetrates into the ground or immediately after the penetration, the tip of the hollow tube structure 10 adopts the structure shown in FIGS. That is, in the hollow tube structure 10 of FIG. 1, when the hollow tube 1 is rotated in the Z direction (clockwise direction in the figure), the pivot support position 4 of the lid member 3 is similarly moved (FIG. 2). FIG. 5 and FIG. 6). Then, since the distance between the shaft support position 4 and the guide rod member 33 is constant, the guide rod member 33 is guided by the guide member 24 in conjunction with the movement, and the inside of the guide long hole 23 passes through the hollow tube 1 side (inside Move to). Thereby, a pair of half disk-shaped lid main-body parts 31 mutually close, and the opening of the hollow tube 1 closes (FIGS. 5-7). When the hollow tube 1 is further rotated forward from this state, the reaction force of the ground acts on the lid member 3 in the direction of closing the lid member 3, and the opening does not open. The hollow interior can be made empty for a substantial volume until it penetrates to a predetermined depth (FIG. 11A).

  Next, a step of introducing the powdered solidified material 40 into the hollow tube 1 from the opening 51 on the ground side of the hollow tube 1 is performed (FIG. 11B). In this step, the tip of the hollow tube 1 is closed by the lid member 3, and the inside of the hollow tube 1 is empty. The powdered solidified material can be introduced into the hollow tube as a plurality of bag bodies 40 packed in a bag, so that an accurate amount of the solidified material can be uniformly introduced into the ground in the depth direction, and handling is easy. This is preferable. In addition, each bag body 40 packed in a bag can be connected to adjacent bag bodies with a connecting member and put into a hollow tube in a state of being connected in a zigzag manner. It is preferable in that it can be easily recovered. That is, for example, if a claw is formed in the linear portion near the shaft 4 of the lid member 3 of the hollow tube structure 10 so as to protrude inward, each bag 40 is moved when the claw moves upward. Since it breaks along the depth direction, all the bag bodies 40 can be easily recovered simply by pulling the bag body 40 close to the ground surface to the ground. The connecting member for connecting the bag body 40 may be a thread-like or belt-like member. Moreover, the strength of the connection members may be such that when the bag body 40 close to the ground surface is lifted to the ground, all the bag bodies 40 can be collected without breaking all the connection members in the middle.

  Next, the hollow tube 1 is pulled up to the ground surface while rotating in the reverse direction, and the solidified material 40 is left in the ground from the tip opening 52 of the hollow tube 1. When the hollow tube 1 is rotated in the reverse rotation direction (counterclockwise direction in FIG. 1), the hollow tube 1 rotates by a predetermined angle until the arc-shaped split spacer 5 contacts the protrusion 25 of the rotating body 20. . The pivot support position 4 of the lid member 3 is similarly moved by the rotation of the hollow tube 1. Then, since the distance between the shaft support position 4 and the guide rod member 33 is constant, the guide rod member 33 is guided by the guide member 24 in conjunction with the movement, and the inside of the guide long hole 23 is opposite to the hollow tube 1. Move to the side (outside). Thereby, a pair of half disk-shaped lid main-body parts 31 mutually space apart, and open the opening of the hollow tube 1 (refer FIG.2, FIG8 and FIG.9). When the hollow tube 1 is further rotated in the same direction from this state, the reaction force of the ground acts on the lid member 3 in the direction in which the lid member 3 is opened, and the opening is not closed. If the hollow tube structure 10 is pulled up at a predetermined speed in this state, the powdery solidified material can be left behind in the ground (FIGS. 11C and 11D).

  When leaving a plurality of bags packed in the ground in the ground, as described above, the bag 40 is broken by the nail attached to any one of the distal end portions of the hollow tube structure 10, and the bag 40 It is preferable that the columnar body of the powdered solidified material is left in the ground.

  Next, a step (FIG. 11 (E)) of mixing and mixing the solidified material and the local board is performed by penetrating the ground stirring and mixing device into the ground. The underground stirring and mixing device 50 used in the process is the hollow tube structure 10 or a device prepared separately from the hollow tube structure 10. The hollow tube structure 10 used in the penetration step of the first step has the wing member 22 of the rotating body 20 and can be used for stirring and mixing the solidified material and the local board. Further, when the hollow tube structure 10 has a stirring blade different from the blade member 22 of the rotating body 20, the stirring efficiency in this step is further improved. As an apparatus prepared separately from the hollow tube structure 10, a known stirring apparatus including a stirring blade and a rod which is equipped with the stirring blade at the tip and can be penetrated and pulled up into the ground can be mentioned.

  The underground stirring and mixing device 50 is inserted while rotating from the ground, and sufficiently mixes the columnar body of the powdered solidified material and the surrounding soft soil (local soil). As a result, the solidified material and the soft soil are hardened by the moisture contained in the soft soil, and an improved pillar is formed in the ground.

The perspective view of the front-end | tip part of the hollow tube structure of the state in which the cover member of this example was closed. The perspective view of the front-end | tip part of the hollow tube member which comprises the hollow tube structure of FIG. The perspective view of the rotation body which comprises the hollow tube structure of FIG. The perspective view of the front-end | tip part of the hollow tube structure of the state in which the cover member of this example was opened. The figure which looked at the hollow tube structure of FIG. 1 from the top. The figure which looked at the hollow tube structure of FIG. 1 from the bottom. The figure which looked at the hollow tube structure of FIG. 1 from the front. The figure which looked at the hollow tube structure of Drawing 4 from the top. The figure which looked at the hollow tube structure of Drawing 4 from the bottom. The figure which looked at the hollow tube structure of Drawing 4 from the front. The simplification figure explaining each process of the formation method of the columnar solidification pile of this example.

Explanation of symbols

1 Hollow tube 2 End flange 3 Lid member 4 Shaft (axial support position)
DESCRIPTION OF SYMBOLS 5 Arc-shaped half spacer 6 Ring-shaped window part 7 Cover member storage space 8 Notch part 10 Hollow pipe structure 20 Rotating body 21 Ring member 22 Wing member 23 Guide long hole 24 Guide member 25 Protrusion 30 Stirring blade

Claims (10)

A lid member having a pair of half-disc-shaped lid main body portions attached to the distal end surface of the hollow tube is attached so as to rotate along the opening surface of the distal end.
A rotating body that is rotatable within a predetermined angle with respect to the hollow tube at a tip portion and a peripheral surface portion of the hollow tube and has a pair of wing members is attached.
A guide rod member formed in the lid member is inserted into a guide elongated hole formed in the longitudinal direction of the pair of wing members, and the pair of half-disc-shaped members are interlocked with the rotation of the hollow tube. A hollow tube structure characterized in that the lid body is rotated to open and close the opening at the tip of the hollow tube.   The rotating body includes an annular member that freely swings around the hollow tube within a predetermined angle, a pair of wing members extending outward from the annular member, and a longitudinal side surface of the wing member. 2. The hollow tube structure according to claim 1, further comprising a guide member that forms the guide elongated hole having a predetermined length between the blade member and the blade member.   3. The hollow tube structure according to claim 1, wherein the guide bar member is erected upward from an arm member extending outward from a pair of half-disc-shaped lid main body portions. .   The rotation of the rotating body within a predetermined angle with respect to the hollow tube is such that notches having a predetermined circumferential length and a radial length are formed on both sides of the peripheral surface of the hollow tube in which the annular member is loosely fitted. The arc-shaped split spacer is attached as described above, and a protrusion formed on the inner peripheral surface of the annular member of the rotating body so as to extend toward the center of the rotating body is positioned in the notch. The hollow tube structure according to claim 2 or 3.   When the hollow tube is penetrated into the ground by forward rotation, the end faces of the halved disc-shaped linear portions abut each other to form a substantially disc shape, thereby closing the opening of the tip, 5. The inside according to claim 1, wherein when the lid body is pulled out by reverse rotation, the half-disc-shaped lid main body portions are separated from each other to open the distal end opening of the hollow tube. Empty tube structure.   The hollow tube structure according to claim 1, further comprising a stirring blade attached to the hollow tube.   A step of penetrating the hollow tube of the hollow tube structure according to any one of claims 1 to 6 to a predetermined depth while being rotated forward in the ground, from an opening on the ground side of the hollow tube into the hollow tube A step of feeding a powdered solidified material, a step of pulling the hollow tube to the ground while rotating it in the reverse direction, a step of leaving the solidified material in the ground from the tip opening of the hollow tube, A method for forming a columnar solidified pile, characterized by performing a step of mixing inside and stirring and mixing the solidified material and the local board.   The method of forming a columnar solidified pile according to claim 7, wherein the powdered solidified material is put into a hollow tube as a plurality of bags packed in a bag.   The columnar solidified pile according to claim 8, wherein each bag body packed in a bag is inserted into a hollow tube in a state where the adjacent bag bodies are connected to each other by a connecting member and connected in a zigzag manner. Forming method.   9. The underground stirring and mixing device is the hollow tube structure or a device prepared separately from the hollow tube structure. Of forming solid columnar solid piles.

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