JP5192346B2 - Pile head processing method - Google Patents

Description

  The present invention relates to a pile head processing method, and more particularly to a method for removing surplus concrete when constructing a cast-in-place concrete pile.

  Cast-in-place concrete piles excavate holes in the ground, fill the holes with bentonite liquid, etc., suspend steel rods in the holes while preventing the collapse of the hole walls, and cast concrete upward from the bottom of the holes. Built. Since the cast concrete rises with impurities such as slime in the bentonite liquid, a portion having insufficient compressive strength is formed at the upper end of the concrete pile. Therefore, in the cast-in-place concrete pile, concrete is cast to a position higher than the design length to form a surplus portion, and after the concrete is hardened, the surplus portion is removed by a concrete crushing machine or the like. However, since the surplus portion is located inside the main bar, there is a problem that the efficiency of the removal work is poor and the work cost increases.

  In order to solve the above problems, Patent Document 1 discloses that a filler is filled in the main bar axis direction at the upper end of the reinforcing bar rod before or after the reinforcing rod rod is inserted into the hole formed in the ground. Pile head treatment material with inflated bag is attached, and then concrete is placed in the hole. After the concrete has hardened, the filler and pile head treatment material are removed, and then the pile head concrete is removed. A pile head treatment method has been proposed.

  However, in the method of Patent Document 1, since the bag body is only attached in the direction of the main muscle axis, the concrete around the main muscle is only removed when placing concrete, and the inner side surrounded by the main muscle and the bag body. A relatively large surplus portion is left behind. Therefore, the efficiency of the work of removing the surplus portion is only slightly improved, and the fundamental solution to the problem of increased work costs has not been reached.

Further, as a structure for joining a cast-in-place concrete pile with an upper structure, a joint is formed in a columnar shape having a diameter smaller than the pile diameter of the cast-in-place concrete pile, and a reinforcing cylinder is attached to this joint. It is described in. In this cast-in-place concrete pile, a reinforcing steel bar structure composed of main bars and band bars is used, and from this reinforcing steel bar structure, a connecting steel bar structure formed with a smaller diameter projects upward, It extends to the joint and footing. This connecting rebar structure is also composed of main bars (core rebars) and band bars, and the inside surrounded by the main bars is narrower than the inside of the reinforcing bar structure, so the removal work of the surplus portion is more It becomes even more difficult.
Japanese Patent Laid-Open No. 10-82048 JP 2005-290799 A

  In view of the current situation as described above, the object of the present invention is to improve the efficiency of the work of removing the surplus part after hardening the concrete when constructing the cast-in-place concrete pile, and to reduce the noise generated during the work of removing the surplus part. It is to provide a pile head processing method that can be suppressed.

In order to solve the above-mentioned problems, in the present invention, a plurality of reinforcing bars are fixed to a plurality of main reinforcing bars, a plurality of core reinforcing bars are fixed therein to form reinforcing bar rods, and the reinforcing bar rods are formed in the ground. In the method of constructing a cast-in-place concrete pile by inserting into the concrete and placing it inside, the inside of the rebar rod surrounded by a plurality of core rebars is filled with a fluid and inflated an annular bag body in the vertical direction After fixing the pipe body to the inside of the plurality of annular bags, the reinforcing rod is inserted into the hole formed in the ground, and the inside of the hole of the ground including a part of the pipe body is inserted. A pile head processing method is provided, in which concrete is placed on the pipe and the pipe is pulled out together with the concrete in the concrete when the concrete is hardened to a predetermined strength.
In the pile head processing method of the present invention, a lower annular plate that suppresses concrete pressure from below is provided on the lower side of the plurality of annular bag bodies fixed in the vertical direction inside the core reinforcing bar, and the annular bag on the upper side. It is preferable to provide an upper annular plate that prevents the body from lifting. The lower annular plate is preferably provided with a plurality of holes of a predetermined size, from which the impurities such as slime rising together with the concrete pass upward and are led to the gaps between the plurality of annular bags. Therefore, the surplus portion can be reduced.
In the pile head processing method of the present invention, it is preferable to fix an annular bag body on the outer peripheral surface of the tubular body so as to be superposed on the plurality of annular bag bodies in the reinforcing bar cage.
Further, in the present invention, a lower annular plate for suppressing concrete pressure from below is provided on the lower side of the plurality of annular bags fixed in the longitudinal direction inside the core reinforcing bar, and the outer circumferential surface of the tubular body is annular. It is preferable to provide a lifting presser member that prevents the bag body from lifting.
Still further, in the present invention, it is preferable to provide a constriction forming member for forming a constriction at the lower end of the concrete that protrudes in the inner peripheral direction at the lower end of the inner peripheral surface of the tubular body and hardens inside the tubular body.
Furthermore, in the present invention, it is preferable to provide a slit for relaxing the constrained state of the concrete that hardens inside the tubular body on the peripheral surface of the tubular body.

In order to solve the above-mentioned problem, in the present invention, a plurality of main bars and a plurality of band bars are combined to form a cylindrical reinforcing bar rod, and the reinforcing bar rod is inserted into a hole formed in the ground to provide concrete. In the construction method of constructing a cast-in-place concrete pile by placing a plurality of annular bags that are inflated by filling with fluid inside the plurality of main bars in the rebar rod, After inserting and fixing the pipe body inside the annular bag body, the rebar rod is inserted into a hole formed in the ground, and concrete is placed in the hole of the ground including a part of the inside of the pipe body. When the concrete is hardened to a predetermined strength, a pile head processing method is provided, wherein the pipe body is pulled out together with the concrete inside.
In the pile head processing method of the present invention, a lower annular plate that suppresses concrete pressure from below is provided on the lower side of the plurality of annular bags fixed in the longitudinal direction inside the main bars, and the annular bag body on the upper side. It is preferable to provide an upper annular plate that prevents the lifting of the upper plate. The lower annular plate is preferably provided with a plurality of holes of a predetermined size, from which the impurities such as slime rising together with the concrete pass upward and are led to the gaps between the plurality of annular bags. Therefore, the surplus portion can be reduced.
In the pile head processing method of the present invention, it is preferable to fix an annular bag body on the outer peripheral surface of the tubular body so as to be superposed on the plurality of annular bag bodies in the reinforcing bar cage.
According to the present invention, a lower annular plate for suppressing concrete pressure from below is provided below the plurality of annular bags fixed in the longitudinal direction inside the main bars, and the annular bag is provided on the outer peripheral surface of the tubular body. It is preferable to provide a lifting presser member that prevents the body from lifting.
Furthermore, in the present invention, it is preferable to provide a constriction forming member for forming a constriction at the lower end of the concrete that protrudes in the inner peripheral direction and hardens inside the tubular body at the lower end of the inner peripheral surface of the tubular body.
Furthermore, in the present invention, it is preferable to provide a slit for relaxing the constrained state of the concrete that hardens inside the tubular body on the peripheral surface of the tubular body.

In the pile head processing method of the present invention, a plurality of annular bag bodies are fixed in an inner vertical direction surrounded by core reinforcing bars in a reinforcing bar rod, and a pipe body is inserted inside the annular bag body, and the ground includes the inside of the pipe body. When concrete is placed in the holes of the pipe and the concrete is hardened to the specified strength, the pipe body is lifted upward by a crane or other hoisting machine, and thus the pipe body holds extra concrete inside. The annular bag body that has been removed in this state and surrounded by the core rebar is left with only an easily removed annular bag and impurities such as slime that have entered the gap.
Therefore, in the pile head processing method of the present invention, surplus concrete is left only on the outside of the core rebar, and removal work by a concrete crushing machine that generates noise is performed only on this surplus concrete. Since it is good, the labor of the removal work is greatly reduced compared to the conventional method, and the noise can be remarkably suppressed.
The pile head processing method of the present invention has the following effects.
(1) By fixing the annular bag body on the outer peripheral surface of the tubular body and polymerizing it on the plurality of annular bag bodies in the reinforcing bar cage, the annular bag body inside the reinforcing bar cage is provided by the amount of the annular bag body provided on the tubular body. In this way, the annular bag body that is not buried in the tube-side surplus can be used for other purposes.
(2) By providing the upper annular plate on the upper side inside the core rebar, the annular bag body can be prevented from being lifted. Alternatively, the annular bag body can be lifted on the outer peripheral surface of the tubular body. By providing the member, it is possible to prevent the annular bag body from being lifted. In particular, in the latter case, the lifting retainer member of the annular bag body can be made smaller in diameter than the upper annular plate, and the lifting retainer member can be diverted to other uses. It is possible to save the time and effort required for attaching the battery and to reduce the cost required for this.
(3) By providing a constriction forming member for forming a constriction at the lower end of the concrete that hardens inside the tubular body at the lower end of the inner peripheral surface of the tubular body, when the concrete hardens to a predetermined strength, When the pipe is pulled out together with the concrete inside it, the concrete can be easily cracked or broken at the constricted part and the concrete inside the pipe can be easily cut off. it can.
(4) A slit is provided on the outer peripheral surface of the tubular body to ease the restraint state of the concrete that hardens inside the tubular body. When the concrete attached to the inner peripheral surface of the pipe body is peeled off, the concrete can be easily detached from the inside of the pipe body.

Further, in the pile head processing method of the present invention, a plurality of annular bag bodies are fixed in an inner vertical direction surrounded by main bars in a reinforcing bar rod, and a tubular body is inserted inside the annular bag body, including the inside of the tubular body. When concrete is placed in the hole in the ground and the concrete has hardened to the specified strength, the pipe is lifted upward by a crane or other hoisting machine and removed. The ring bag that is removed while being held and surrounded by the main bars is left with an extremely easy to remove annular bag and impurities such as slime that have entered the gap.
Therefore, in the pile head processing method of the present invention, the surplus concrete is left only on the outside of the main bar, and the removal work by the concrete crushing machine that generates noise may be performed only on the surplus concrete that remains. Therefore, the labor of the removal work is greatly reduced as compared with the conventional method, and noise can be remarkably suppressed.
The pile head processing method of the present invention has the following effects.
(1) By fixing the annular bag body on the outer peripheral surface of the tubular body and polymerizing it on the plurality of annular bag bodies in the reinforcing bar cage, the annular bag body inside the reinforcing bar cage is provided by the amount of the annular bag body provided on the tubular body. In this way, the annular bag body that is not buried in the tube-side surplus can be used for other purposes.
(2) By providing the upper annular plate on the upper side inside the main bar, it is possible to prevent the annular bag body from being lifted. Alternatively, the annular bag body is held on the outer circumferential surface of the tubular body. By providing, it is possible to prevent the annular bag body from being lifted. In particular, in the latter case, the lifting presser member of the annular bag body can be made smaller in diameter than the upper annular plate, and this lifting presser member can be diverted, so that the trouble of attaching the upper annular plate to the main bar is difficult. And the cost required for this can be reduced.
(3) By providing a constriction forming member for forming a constriction at the lower end of the concrete that hardens inside the tubular body at the lower end of the inner peripheral surface of the tubular body, when the concrete hardens to a predetermined strength, When the pipe is pulled out together with the concrete inside it, the concrete can be easily cracked or broken at the constricted part and the concrete inside the pipe can be easily cut off. it can.
(4) A slit is provided on the outer peripheral surface of the tubular body to ease the restraint state of the concrete that hardens inside the tubular body. When the concrete attached to the inner peripheral surface of the pipe body is peeled off, the concrete can be easily detached from the inside of the pipe body.

  Hereinafter, although embodiment of this invention is described, this invention is not limited to this.

1A is a cross-sectional view of a cast-in-place concrete pile 10 to which the pile head processing method of the present invention is applied, FIG. 1B is a cross-sectional view taken along line AA in FIG. (c) is sectional drawing cut | disconnected by the BB line in Fig.1 (a).
First, the outline of the structure of the cast-in-place concrete pile 10 will be described with reference to FIGS. 1A to 1C. The cast-in-place concrete pile 10 includes a plurality of strips 12 around the plurality of main bars 11. The reinforcing bar 13 is fixed to the outer periphery of the core reinforcing bar 13 with a fixing tool (not shown) at the center of the inside of the main bar 11 to form a reinforcing bar 15, and the reinforcing bar 15 is placed on the ground. It is constructed by inserting concrete 16 by inserting it into the formed hole. In this case, the rebar 14a is attached in advance to the lower part of the core reinforcing bar 13, that is, the part disposed inside the main reinforcing bar 11 before placing concrete. The core rebar 13 protruding upward from the main reinforcement 11 is embedded in the concrete of the joint 17 and the foundation 18 constructed above the cast-in-place concrete pile 10.

The pile head processing method of the present invention is applied when forming the cast-in-place concrete pile 10 as described above. Hereinafter, the pile head processing method of the present invention will be described with reference to FIGS. .
2, FIG. 5 to FIG. 9 show only two main bars 11 and two core bars 13 on both sides for simplification of the drawings, the band 12 is shown by a dotted line, and the band 14a is Although omitted as appropriate, they are arranged in the same manner as in FIG.

In the pile head processing method according to the present invention, first, the forming process of the reinforcing bar 15 is performed.
As shown in FIG. 2, the rebar rod 15 is composed of a plurality of core rebars 13 and band bars 14 a, and the lower annular plate 19 is fixed to a predetermined height inside the core rebar 13 with a fixture such as a welding rebar. Install by (not shown). After the lower annular plate 19 is attached, the annular bag body 20 is attached over the plurality of stages, and the upper annular plate 21 is attached on the annular bag body 20. Thus, the annular bag 20 and the upper annular plate 21 are provided on the inner side surrounded by the core rebar 13b. And if the sheath pipe 23 (tube body) is suspended by a lifting machine (not shown) such as a crane and is inserted into the holes provided in the upper annular plate 21 and the annular bag body 20, the core rebar 13 is attached. The assembly 24 of FIG. 2 is formed.
On the other hand, a casing 26 is press-fitted into the ground 25 to excavate a hole 27, and the hole 27 is filled with a hole wall protective liquid such as bentonite liquid. The hoist is lifted and inserted, and temporarily placed so that the upper end of the main bar 11 protrudes from the hole 27. Then, an assembly 24 including the core rebar 13 of FIG. 2 is inserted into the inner side surrounded by the main reinforcing bar 11 and the band reinforcing bar 12 by a lifting machine and fixed by a fixing tool (not shown) such as a welding reinforcing bar. In this case, the reinforcing bar 15 is formed as shown in FIG.
The annular bag 20 is filled with a fluid (air or the like) at a predetermined timing in the process of assembling the reinforcing bar rods 13 and 14a and inflated.

Hereinafter, the configuration of each unit described above will be described.
Here, as shown in FIG. 3A, the lower annular plate 19 is provided with a hole 19a at the center, and a protrusion 19b for provisionally receiving the lower end of the sheath tube 23 is provided on the inner periphery of the hole 20a. It is done. The lower annular plate 19 has a plurality of holes 19c. The plurality of holes 19c allow impurities such as slime rising together with the concrete to pass upward, and the impurities pass into the gaps between the plurality of annular bags 20. It is for guiding. Further, the lower annular plate 19 is formed in such a size that the outer circumference dimension can be attached to the inner circumference of the core rebar 13 without a gap.
Further, as shown in FIGS. 4A and 4B, the annular bag body 20 is provided with a hole 20a in the center and has a fluid inlet 20b that can be opened and closed. It can be inflated by injecting a fluid such as. The central hole 20a is formed in such a size that the sheath tube 23 can be inserted through the hole 20a and the gap with the surface of the sheath tube 23 is minimized.
As shown in FIG. 3B, the upper annular plate 21 is provided with a hole 21a at the center. The hole 21a is sized to allow the sheath tube 23 to be inserted, and the gap with the surface of the sheath tube 23 is minimized. Formed to be.
When the sheath tube 23 is installed as shown in FIG. 2, the sheath tube 23 has a length that protrudes upward from the upper end of the core rebar 13.

In the step of forming the reinforcing bar rod 15 described above, the assembly 24 of FIG. 2 including the core reinforcing bar 13 is assembled first, and then the assembly 24 is integrated with the main reinforcing bar 11 and the band reinforcing bar 12. Otherwise, there is also a method of assembling the reinforcing bar assembly 28 composed of the main reinforcing bar 11, the reinforcing bar 12, the core reinforcing bar 13 and the reinforcing bar 14b as shown in FIG. In this method, after assembling the reinforcing bar assembly 28, the lower annular plate 19 is attached to a predetermined position surrounded by the plurality of core reinforcing bars 13, and a plurality of annular shapes are provided from the lower annular plate 19 toward the left side in FIG. The bag body 20 is attached, and the upper annular plate 21 is attached to the left side of the annular bag body 20.
6 is suspended in a hole 27 excavated in the ground 25 with a lifting machine, and temporarily placed so that the upper end of the main bar 11 protrudes from the hole 27. Then, the sheath tube 23 is lifted by a lifting machine, inserted into the respective holes of the upper annular plate 21 and the annular bag body 20 and placed on the projecting portion 19b of the lower annular plate 19, and then the annular bag body 20. 5 is filled with a fluid such as air, the reinforcing bar 15 shown in FIG. 5 can be formed.

After the reinforcing bar 15 is formed as shown in FIG. 5, the reinforcing bar 15 is suspended and installed in the hole 27 by a crane or the like. Then, the tremy tube 30 is inserted into the sheath tube 23 and extended to the bottom of the hole 27, and concrete is placed while the tremy tube 30 is gradually pulled up. When the placed concrete rises with impurities such as slime in the bentonite liquid and reaches a predetermined surplus height as shown in FIG. 7, the concrete placement is finished.
Impurities such as slime that rise with the concrete are contained in the extra-concrete concrete 31 formed on the outer periphery of the core rebar 13, while noro as an impurity passes through the plurality of holes 19 c formed in the lower annular plate 19. , It is absorbed in the gap between the annular bag bodies 20 provided on the outer periphery of the sheath tube 23.

When the concrete placement is finished, as shown in FIG. 8, the tremy tube 30 is extracted from the inside of the sheath tube 23, and then the casing 26 is extracted from the hole 27 so that the inside of the sheath tube 23 is filled with the extra concrete 32. To. When a predetermined time elapses after the concrete is placed and the concrete reaches a predetermined strength, the sheath tube 23 is lifted upward by a crane or the like.
As a result, as shown in FIG. 9A, the sheath tube 23 is extracted from the pile head with the extra concrete 32 held therein, and as shown in FIG. The extra concrete 32 is removed from the inside of the core rebar 13 at the pile head of the concrete pile 10. Inside the core rebar 13, a plurality of annular bag bodies 20 and the blades that have entered the gaps remain, but these annular bag bodies 20 can be easily removed if they are cut.
Therefore, in the pile head processing method of the present invention, it is only necessary to remove the surplus concrete 31 left outside the core rebar 13 with a concrete crushing machine, so this removal operation is extremely low noise compared to the conventional method. It becomes possible to implement efficiently.

  Moreover, the pile head processing method (henceforth a 2nd construction method) of this invention different from the said pile head processing method (henceforth a 1st construction method) is demonstrated using FIGS. 10-21. Here, in order to simplify the drawings, FIGS. 10 to 21 also show only two main reinforcing bars 11 and two core reinforcing bars 13 on both sides, the band 12 is indicated by a dotted line, and the band 14 is Although omitted as appropriate, they are arranged in the same manner as in FIG.

  In the second construction method, as shown in FIG. 10, the reinforcing bar assembly 28 composed of the main reinforcing bar 11, the reinforcing bar 12, the core reinforcing bar 13, and the reinforcing bar 14 b is assembled at the same time in a state of being laid down on the ground surface 29. In addition, the annular bag body 20 is filled with a fluid (air or the like) at a predetermined timing in the process of assembling the reinforcing bar 15 and is inflated. In addition, in this construction method, the first construction method, except that the configurations and the operational effects of the main reinforcement 11, the reinforcement 12, the core rebar 13 and the reinforcement 14b, the annular bag 20, and the sheath tube 23 are pointed out in the following description. It is the same as the case of. Then, a lower annular plate 19 is attached to a predetermined position surrounded by a plurality of core reinforcing bars 13 by a fixing tool 191 such as a welding reinforcing bar, and a plurality of annular bag bodies 20 are vertically arranged on the lower annular plate 19 ( Polymerization is performed over a plurality of stages (toward the left side of FIG. 10), and these annular bag bodies 20 are fixed to the lower annular plate 19 or the reinforcing bars using a string-like member 201 or the like. In this case, as shown in FIG. 11, a plurality of holes 190 through which the string-like member 201 is passed are formed along the inner peripheral edge of the lower annular plate 19, and as shown in FIG. A plurality of projecting pieces 211 having holes 210 for passing the string-like member 201 are provided along the inner periphery and the outer periphery of the body 20, and the annular bag body 20 on the lower annular plate 19 is placed inside the lower annular plate 19. A string-like member 201 is connected between each hole 190 on the circumferential side and each hole 210 on the inner circumferential side of the annular bag body 20, and each annular bag body 20 thereon is connected to each outer circumferential side of the annular bag body 20. It is preferable that the annular bag body 20 is bound by binding through the string-like member 201 between the hole 210 and the band reinforcement 14b. In this method, the upper annular plate 21 in the first method is not required for the core rebar 13. Instead of the upper annular plate 21, as shown in FIG. 13, a lifting presser member 231 that prevents the annular bag body 20 from lifting is fixed to a predetermined height of the outer peripheral surface of the sheath tube 23, and this lifting One or a plurality of annular bag bodies 20 (in the case where a plurality of annular bag bodies 20 are provided, are superposed in a plurality of stages in the vertical direction) are fixed with a string-like member 201 under the presser member 231, and the reinforcing bar 15 The annular bag body 20 can be polymerized on the plurality of annular bag bodies 20, and the annular bag body 20 can be lifted and pressed by a pressing member 231. Thus, by providing the annular bag body 20 in the sheath tube 23, the number of the annular bag bodies 20 can be reduced from the rebar rod 15 side by the number of the annular bag bodies 20 on the sheath tube 23 side. By doing so, the annular bag body 20 which is not buried in the surplus on the side of the sheath tube 23 can be diverted to others. In this case, since the lifting and holding member 231 of the annular bag body only has to hold the lifting of the annular bag body 20 inside the core rebar 13, the outer diameter of the upper annular plate 21 in the case of the first construction method. In addition, since the lifting presser member 231 can be diverted to other diameters, it is possible to save time and labor for attaching the upper annular plate 25 to the core rebar 13 in the first construction method. Can be reduced. Further, in the case of the sheath tube 23, a constriction forming member 232 for projecting inward by a predetermined dimension over the entire circumference at the lower end of the inner peripheral surface and forming a constriction at the lower end of the concrete cured inside the sheath tube 23 is provided. Provided. In this case, it is preferable to use a material having flexibility such as polyethylene foam for the member 232. For example, as shown in FIG. What is necessary is just to fix to the lower end of the internal peripheral surface of the pipe | tube 23 via adhesive means, such as an adhesive tape. By doing so, the constricted portion of the concrete that hardens inside the sheath tube 23 can be easily cracked due to the chipping of the concrete, as shown in FIG. Has sufficient cross-sectional area to occur. Further, in the case of this sheath tube 23, as shown in FIG. 16, a slit 233 is formed on the peripheral surface from the predetermined height to the lower end along the axial direction (of the sheath tube 23) and cured inside the sheath tube 23. The restraint state of the concrete to be relaxed is to be eased. In this case, slits 233 are formed at predetermined intervals on the peripheral surface of the sheath tube 23 at a plurality of positions at equal intervals (here, at two intervals of 180 °) from the vicinity of the center in the height direction to the lower end. In this manner, as shown in FIG. 17, the casing 26 is press-fitted into the ground 25 to excavate the hole 27, and the hole 27 is filled with the hole wall protective liquid such as bentonite liquid. 28 is suspended in a hole 27 excavated in the ground 25 with a lifting machine, and temporarily placed so that the upper end of the main bar 11 protrudes from the hole 27. Then, when the sheath tube 23 is lifted by a lifting machine, inserted into the respective holes of the respective annular bag bodies 20 and placed on the lower annular plate 19, the reinforcing bar 15 shown in FIG. 17 can be formed.

  As shown in FIG. 18, after the reinforcing bar 15 is formed, the reinforcing bar 15 is suspended and installed in the hole 27 by a crane or the like. Then, the tremy tube 30 is inserted into the sheath tube 23 and extended to the bottom of the hole 27, and concrete is placed while the tremy tube 30 is gradually pulled up. At this time, when the placed concrete rises together with impurities such as slime in the bentonite liquid and reaches a predetermined surplus height, the concrete placement is finished. Impurities such as slime that rise with the concrete are contained in the extra-concrete concrete 31 formed on the outer periphery of the core rebar 13, while noro as an impurity passes through the plurality of holes 19 c formed in the lower annular plate 19. , It is absorbed in the gap between the annular bag bodies 20 provided on the outer periphery of the sheath tube 23.

  When the concrete placement is finished, as shown in FIG. 19, the tremy tube 30 is extracted from the inside of the sheath tube 23, and then the casing 26 is extracted from the hole 27 so that the inside of the sheath tube 23 is filled with the extra concrete 32. To. When a predetermined time elapses after the concrete is placed and the concrete reaches a predetermined strength, the sheath tube 23 is lifted upward by a crane or the like as shown in FIG. At this time, the constriction forming member 232 at the lower end of the sheath tube 23 can be constricted at the lower end of the concrete 32 hardened inside the sheath tube 23, and the concrete 32 is easily broken or easily broken at the constricted portion. When the sheath tube 23 is pulled out together with the concrete 32 inside, the concrete tube 32 inside the sheath tube 23 can be easily cut by shaking the sheath tube 23 left and right. As shown in FIG. 20 (a), the sheath tube 23 is thus extracted from the pile head with the extra concrete 32 held therein, and as shown in FIG. 20 (b), cast-in-place concrete. The extra-concrete concrete 32 is removed from the inside of the core rebar 13 in the pile head of the pile 10. Inside the core rebar 13, a plurality of annular bag bodies 20 and the blades that have entered the gaps remain, but these annular bag bodies 20 can be easily removed if they are cut. On the other hand, although the concrete 32 is clogged inside the sheath tube 23, as shown in FIG. 20A, a slit 233 is provided on the outer peripheral surface of the sheath tube 23, and the concrete 32 is hardened inside the sheath tube 23. Therefore, the concrete 32 attached to the inner peripheral surface of the sheath tube 23 can be easily peeled off by applying a force or vibrating the sheath tube 23 in the outer peripheral direction. The concrete 32 can be easily detached from the inside. At this time, as shown in FIG. 21, it is preferable to employ a table D having a wedge-shaped portion D1 that can be inserted into the slit 233 of the sheath tube 23, and the suspended sheath tube 23 is connected to the slit 233 of the sheath tube 23. When the wedge-shaped portion D1 is inserted into the slit 233 of the sheath tube 23 while being combined with the wedge-shaped portion D1, and the wedge-shaped portion D1 is inserted into the slit 233 of the sheath tube 23, the slit 233 is pushed open by the wedge-shaped portion D1. The concrete 32 is easily peeled off from the peripheral surface, and the concrete 32 can be easily removed from the inside of the sheath tube 32.

  Therefore, also in the second construction method, it is only necessary to remove the surplus concrete 31 left outside the core rebar 13 by the concrete crushing machine, so this removal operation is extremely low noise and efficient compared to the conventional construction method. Can be implemented.

  In this construction method, the reinforcing bar assembly 28 including the main reinforcing bar 11, the reinforcing bar 12, the core reinforcing bar 13, and the reinforcing bar 14a is assembled at the same time. However, the process described in the first construction method may be adopted. Needless to say. Moreover, it is needless to say that the same effect can be obtained by applying the configuration of the sheath tube 23 employed in this construction method, that is, the constriction forming member 232 and the slit 233 in the same manner also in the first construction method.

  22 to 26 show a pile head processing method (hereinafter referred to as a third method) of the present invention which is different from the first and second methods. In the third construction method, the configuration of the cast-in-place concrete pile 40 is slightly different from that of the first and second methods. First, an outline of the configuration of the cast-in-place concrete pile 40 will be described. The cast-in-place concrete pile 40 is a so-called general pile, and a plurality of linear main bars 41 and an annular band bar 42 are combined to form a cylindrical reinforcing bar bar 45, and the reinforcing bar bar 45 is formed in a hole formed in the ground. It is constructed by inserting and placing concrete. The third construction method is applied when forming the cast-in-place concrete pile 40 as described above, and the third construction method will be described below with reference to FIGS. 22 to 26. 22 to 26, for the sake of simplification, only two main reinforcing bars 41 are shown on both sides, and the band 42 is shown by a dotted line.

  In the third construction method, a process of forming the reinforcing bar rod 45 is first performed. As shown in FIG. 22, a plurality of main bars 41 and band bars 42 are combined to form a cylindrical reinforcing bar rod 45, and a lower annular plate 49 is fixed to a predetermined height inside the main bar 41 and a fixing tool such as a welding bar. Attach with 491. After attaching the lower annular plate 49, the annular bag body 50 is attached over the plurality of stages, and the upper annular plate 51 is attached on the annular bag body 50. In this way, the annular bag body 50 and the upper annular plate 51 are provided inside the main bar 41. Then, the sheath tube 53 is suspended by a lifting machine (not shown) such as a crane and is inserted into the holes provided in the upper annular plate 51 and the annular bag body 50, whereby the assembly 54 of FIG. 22 is formed. Is done. In this way, as shown in FIG. 23, the casing 56 is press-fitted into the ground 55 to excavate the hole 57, and the hole 57 is filled with a hole wall protective liquid such as bentonite liquid, and then assembled in the hole 57 in advance. The rebar bar 45 is lifted and inserted by a lifting machine, and temporarily placed so that the upper end of the main bar 41 protrudes from the hole 57. The annular bag body 50 is filled with a fluid (air or the like) at a predetermined timing in the process of assembling the reinforcing bar rod 45 and inflated.

  In this construction method, the main reinforcing bar 41 and the band reinforcing bar 42 are combined to form a cylindrical reinforcing bar rod 45, and unlike the reinforcing bar rod 15 in the case of the first construction method, a lower annular plate is formed. 49, the basic structure of the annular bag 50, the upper annular plate 51, the sheath tube 53 and the like are the same as those of the first construction method.

  As shown in FIG. 24, after the reinforcing bar 45 is formed, the reinforcing bar 45 is suspended and installed in the hole 57 by a crane or the like. Then, the tremy pipe 30 is inserted into the sheath pipe 53 and extended to the bottom of the hole 57, and concrete is placed while the tremy pipe 30 is gradually pulled up. When the cast concrete rises with impurities such as slime in the bentonite liquid and reaches a predetermined surplus height, the concrete casting is finished. Impurities such as slime that rise with the concrete are contained in a large amount of extra-concrete concrete 61 formed on the outer periphery of the main bar 41, while noro as an impurity passes through a plurality of holes formed in the lower annular plate 49, and the sheath It is absorbed in the gap between the annular bag bodies 50 provided on the outer periphery of the tube 53.

  When the concrete placement is finished, as shown in FIG. 25, the tremy tube 30 is extracted from the inside of the sheath tube 53, and then the casing 56 is extracted from the hole 57 so that the inside of the sheath tube 53 is filled with the extra concrete 62. To. When a predetermined time elapses after the concrete is placed and the concrete reaches a predetermined strength, the sheath tube 53 is lifted upward by a crane or the like. As a result, the sheath tube 53 is extracted from the pile head with the extra concrete 62 held inside as shown in FIG. 26 (a), and is cast in place as shown in FIG. 26 (b). The extra concrete 62 is removed from the inside of the main bar 41 in the pile head of the concrete pile 40. Inside the main bar 41, a plurality of annular bag bodies 50 and noro that have entered the gaps remain, but these annular bag bodies 50 can be easily removed if they are cut.

  Therefore, in the third construction method, it is only necessary to remove the surplus concrete 61 remaining on the outside of the main bar 41 with a concrete crushing machine. Therefore, this removal operation is carried out efficiently with extremely low noise compared to the conventional construction method. It becomes possible to do.

  Also in the step of forming the reinforcing bar rod 45, as described in the first construction method, the reinforcing bar assembly 54 composed of the main bar 41 and the band bar 42 is assembled on the ground surface so that the reinforcing bar assembly 54 is laid down. After assembling, a lower annular plate 49 is attached to a predetermined position surrounded by a plurality of main bars 41, and fluid (air or the like) is previously filled from the lower annular plate 49 toward the left side (or right side) to expand. A plurality of annular bag bodies 50 may be attached, and the upper annular plate 51 may be attached to the left side (or right side) of the annular bag body 50. The reinforcing bar assembly 54 thus formed is suspended in a hole 57 excavated in the ground 55 by a lifting machine, and temporarily placed so that the upper end of the main bar 41 protrudes from the hole 57. Then, if the sheath tube 53 is lifted by a lifting machine, inserted into the respective holes of the upper annular plate 51 and the annular bag body 50 and placed on the lower annular plate 49, the reinforcing bar 45 can be formed. .

  Moreover, the pile head processing method (henceforth the 4th construction method) of this invention different from the said 3rd construction method is demonstrated using FIGS. 27-32. Here, in order to simplify the drawings in FIGS. 27 to 32, only two main bars 41 are shown on both sides, and the band 42 is shown by a dotted line.

  In the fourth construction method, as shown in FIG. 27, the rebar assembly 54 composed of the main bar 41 and the band bar 42 is assembled in a state of being laid down on the ground surface 29. In this case, the annular bag body 50 is filled with a fluid (such as air) at a predetermined timing in the process of assembling the reinforcing bar rod 45, and inflated. In addition, in this construction method, each structure of the main reinforcement 41, the band reinforcement 42, the annular bag 50, and the sheath tube 53 and the operation and effects thereof are the same as in the case of the third construction method, except in the following description. Then, a lower annular plate 49 is attached to a predetermined position surrounded by a plurality of main reinforcing bars 41 by a fixing tool 491 such as a welding reinforcing bar, and a plurality of annular bag bodies 50 are vertically arranged on the lower annular plate 49 (see FIG. 27) (toward the left side of 27), and the annular bag body 50 is fixed to the lower annular plate 49 or the reinforcing bar by using a string-like member 501 or the like. In this case, as described in the second construction method, a string-like member 501 is provided in each annular bag body 50, and the annular bag body 50 on the lower annular plate 49 is formed on the inner circumference by the string-like member 501. The annular bag body 50 is attached to the lower annular plate 49 on the side, and the annular bag bodies 50 thereon are attached to the straps 42 and the like on the outer peripheral side, and the annular bag bodies 50 are bound. In this construction method, the upper annular plate 51 is not necessary for the main reinforcement 41. Then, instead of the upper annular plate 51, as shown in FIG. 28, a lifting presser member 531 for preventing the lifting of the annular bag 50 is fixed to a predetermined height of the outer peripheral surface of the sheath tube 53. One or a plurality of annular bag bodies 50 are fixed to the lower part of the lifting and holding member 531 (in the case where a plurality of annular bag bodies 50 are provided, they are superposed in a plurality of stages in the vertical direction) and fixed with a string-like member 501, and a reinforcing bar The annular bag body 50 is configured so as to be superposed on the plurality of annular bag bodies 50 in the bag 45 and to be able to be pressed by the lifting pressing member 531. By providing the annular bag body 50 in the sheath tube 53 in this way, the number of the annular bag bodies 50 can be reduced by the number of the annular bag body 50 on the sheath tube 53 side from the rebar rod 45 side. By doing so, the annular bag body 50 which is not buried in the surplus on the side of the sheath tube 53 can be diverted to others. In this case, since the lifting and lowering member 531 of the annular bag only has to hold the lifting of the annular bag 50 inside the main bar 41, the outer diameter of the upper annular plate 51 in the case of the third construction method. In addition, since the lifting and pressing member 531 can be diverted to other diameters, it is possible to save the trouble of attaching the upper annular plate 51 to the main bar 41 in the third method and reduce the cost required for this. can do. Further, in the case of the sheath tube 53, a constriction forming member 532 for projecting inward by a predetermined dimension over the entire circumference at the lower end of the inner peripheral surface and forming a constriction at the lower end of the concrete cured inside the sheath tube 53 is provided. Provided. In this case, it is preferable to use a material having flexibility such as polyethylene foam for the member 532, and a structure in which a cylindrical shape is wrapped with a cylindrical shape, and is formed at the lower end of the inner peripheral surface of the sheath tube 53. What is necessary is just to fix through adhesive means, such as an adhesive tape (refer FIG. 14). In this way, the constricted portion of the concrete that hardens inside the sheath tube 53 is sufficiently broken so that if the sheath tube 53 is shaken to the left and right when the sheath tube 53 is pulled out, cracking can easily occur due to the concrete defect. It has an area (see FIG. 15). Furthermore, in the case of the sheath tube 53, a slit 533 is formed along the axial direction (of the sheath tube 53) from the predetermined height to the lower end on the peripheral surface, thereby relaxing the restraint state of the concrete that hardens inside the sheath tube 53. Like to do. In this case, slits 533 are formed at predetermined intervals on the peripheral surface of the sheath tube 53 at a plurality of positions at equal intervals (here, at two intervals of 180 °) from the vicinity of the center in the height direction to the lower end (FIG. 16). reference). In this way, as shown in FIG. 29, the casing 56 is press-fitted into the ground 55 to excavate the hole 57, and the hole 57 is filled with the hole wall protective liquid such as bentonite liquid. 54 is suspended by a lifting machine in a hole 57 excavated in the ground 55 and temporarily placed so that the upper end of the main bar 41 protrudes from the hole 57. Then, when the sheath tube 53 is lifted by a lifting machine, inserted into the respective holes of each annular bag body 50 and placed on the lower annular plate 49, the reinforcing bar 45 shown in FIG. 29 can be formed.

  As shown in FIG. 30, after the reinforcing bar 45 is formed, the reinforcing bar 45 is suspended and installed in the hole 57 by a crane or the like. Then, the tremy pipe 30 is inserted into the sheath pipe 53 and extended to the bottom of the hole 57, and concrete is placed while the tremy pipe 30 is gradually pulled up. At this time, when the placed concrete rises together with impurities such as slime in the bentonite liquid and reaches a predetermined surplus height, the concrete placement is finished. Impurities such as slime that have risen with the concrete are contained in a large amount of extra-concrete concrete formed on the outer periphery of the main bar 41, while noro as an impurity passes through a plurality of holes formed in the lower annular plate 49, and the sheath tube It is absorbed in the gap between the annular bag bodies 50 provided on the outer periphery of 53.

  When the concrete placement is finished, as shown in FIG. 31, the tremy tube 30 is extracted from the inside of the sheath tube 53, and then the casing 56 is extracted from the hole 57 so that the inside of the sheath tube 53 is filled with the extra concrete 62. To. When a predetermined time elapses after the concrete is placed and the concrete reaches a predetermined strength, the sheath pipe 53 is lifted upward by a crane or the like as shown in FIG. At this time, the constriction forming member 532 at the lower end of the sheath tube 53 can be constricted at the lower end of the concrete 62 cured inside the sheath tube 53, and the concrete 62 is easily broken or broken at the constricted portion. When extracting the sheath tube 53 together with the concrete 62 therein, the edge of the concrete 62 inside the sheath tube 53 can be facilitated by shaking the sheath tube 53 left and right. In this way, the sheath pipe 53 is extracted from the pile head with the extra concrete 62 held inside as shown in FIG. 32 (a), and cast in place as shown in FIG. 32 (b). The extra-concrete concrete 62 is removed from the inside of the main bar 41 in the pile head of the pile 40. Inside the main bar 41, a plurality of annular bag bodies 50 and noro that have entered the gaps remain, but these annular bag bodies 50 can be easily removed if they are cut. On the other hand, although the concrete 62 is clogged inside the sheath tube 53, as shown in FIG. 32A, a slit 533 is provided on the outer peripheral surface of the sheath tube 53, and the constrained state of the concrete 62 that hardens inside the sheath tube 53. Therefore, the concrete 62 attached to the inner peripheral surface of the sheath tube 53 can be easily peeled off by applying a force or vibrating the sheath tube 53 in the outer peripheral direction. The concrete 62 can be easily detached from the inside. At this time, it is preferable to employ a table having a wedge-shaped portion that can be inserted into the slit 533 of the sheath tube 53, while the suspended sheath tube 53 is combined with the slit 533 of the sheath tube 53 and the wedge-shaped portion. When the wedge-shaped portion is inserted into the slit 533 of the sheath tube 53 and the slit 533 is pushed open by the wedge-shaped portion, the concrete 62 is easily peeled off from the inner peripheral surface of the sheath tube 53, and the sheath tube The concrete 62 can be easily removed from the interior of 53 (see FIG. 21).

  Accordingly, even in the fourth method, only the surplus concrete 61 left outside the main bar 41 needs to be removed by a concrete crushing machine, so this removal operation is extremely low noise and efficient compared to the conventional method. It becomes possible to carry out.

  In this construction method as well, it goes without saying that the reinforcing bar assembly 54 composed of the main reinforcement 41 and the band reinforcement 42 may be formed by the process described in the third construction method. Of course, the configuration of the sheath tube 53 employed in this construction method, that is, the constriction forming member 532 and the slit 533 are applied in the same manner in the third construction method, so that the same effect can be obtained.

(A) is a cross-sectional view of a cast-in-place concrete pile to which the pile head processing method of the present invention is applied, (b) is a cross-sectional view taken along line AA in (a), and (c) is a cross-sectional view of B in (a). It is sectional drawing cut | disconnected by the -B line. It is the figure which showed the process of forming the reinforcing bar rod in this invention. (A) is a top view of a lower annular board, (b) is a top view of an upper annular board. (A) It is a top view of a cyclic | annular bag body, (b) is sectional drawing of the cyclic | annular bag body along the IVb-IVb line. It is the figure which showed one process implemented after the process of FIG. It is the figure which showed the process of forming a reinforcing bar rod by the method different from FIG. It is the figure which showed the process of placing concrete with a tremy pipe. It is the figure which showed the state after extracting a tremy tube. (A) is sectional drawing of the extracted sheath pipe, (b) is sectional drawing which shows the pile head after a sheath pipe is extracted. It is the figure which showed the process of forming the reinforcing bar rod in the pile head processing method (2nd method) of this invention. It is the figure which showed the lower annular board employ | adopted in a 2nd construction method. It is the figure which showed the cyclic | annular bag body employ | adopted in a 2nd construction method. The sheath pipe used for the pile head processing method (2nd construction method) of this invention is shown, (a) is the front view, (b) is the top view. It is the figure which showed the constriction formation member of the sheath pipe employ | adopted in a 2nd construction method. It is the figure which showed the effect | action of the constriction formation member of the sheath pipe employ | adopted in a 2nd construction method. It is the figure which showed the slit of the sheath pipe employ | adopted in a 2nd construction method. It is the figure which showed one process implemented after the process of FIG. 10 in a 2nd construction method. It is the figure which showed the process of placing concrete with a tremy pipe in the 2nd construction method. It is the figure which showed the state after extracting a tremy pipe | tube in a 2nd construction method. The state after extracting a sheath pipe in the 2nd construction method is shown, (a) is a sectional view of the extracted sheath pipe, (b) is a sectional view showing a pile head after a sheath pipe is extracted. It is. It is the figure which showed the process of removing concrete from the inside of a sheath pipe in a 2nd construction method. It is the figure which showed the process of forming the reinforcing bar rod in the pile head processing method (3rd method) of this invention. It is the figure which showed one process implemented after the process of FIG. 22 in a 3rd construction method. It is the figure which showed the process of placing concrete with a tremy pipe in the 3rd construction method. It is the figure which showed the state after extracting a tremy pipe | tube in a 3rd construction method. The state after extracting a sheath pipe in a 3rd construction method is shown, (a) is a sectional view of the extracted sheath pipe, (b) is a sectional view showing a pile head after a sheath pipe is extracted. It is. It is the figure which showed the process of forming the reinforcing bar rod in the pile head processing method (4th method) of this invention. The sheath pipe used for the pile head processing method (4th method) of this invention is shown, (a) is the front view, (b) is the top view. It is the figure which showed one process implemented after the process of FIG. 27 in a 4th construction method. It is the figure which showed the process of placing concrete with a tremy pipe in the 4th construction method. It is the figure which showed the state after extracting a tremy pipe | tube in a 4th construction method. The state after extracting a sheath pipe in the 4th construction method is shown, (a) is a sectional view of the extracted sheath pipe, (b) is a sectional view showing a pile head after a sheath pipe is extracted. It is.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Cast-in-place concrete pile 11 Main reinforcement 12 Band reinforcement 13 Core reinforcement 14a Reinforcement 15 Reinforcement rod 16 Concrete 19 Lower annular board 190 Hole 191 Fixing tool, such as a reinforcing bar for welding 20 Annular bag body 201 String-like member 21 Upper annular board 210 Hole 211 Projection piece 23 Sheath tube (tube)
231 Lifting presser member of annular bag body 232 Constriction forming member 233 Slit D1 Wedge-shaped part D stand 27 Hole formed in ground 31 Extra-concrete concrete 32 Extra-concrete concrete 40 Cast-in-place concrete pile 41 Main reinforcement 42 Band reinforcement 45 Reinforcement rod 49 Down Annular plate 491 Fixing tool such as a reinforcing bar for welding 50 Annular bag body 501 String-like member 51 Upper annular plate 53 Sheath tube (tube body)
531 Lifting and holding member for annular bag body 532 Constriction forming member 533 Slit 54 Reinforcing bar assembly 55 Ground 56 Casing 57 Hole formed in ground 61 Extra concrete 62 Extra concrete

Claims (10)

A place where a plurality of reinforcing bars are fixed to a plurality of main reinforcing bars, a plurality of core reinforcing bars are fixed therein to form a reinforcing bar rod, and the reinforcing bar rod is inserted into a hole formed in the ground and placed in concrete. In the method of building cast concrete piles,
A plurality of annular bag bodies filled with fluid and expanded in the inside of the rebar rod surrounded by a plurality of core rebars are fixed in the vertical direction, and a tubular body is inserted and fixed inside the plurality of annular bag bodies. After inserting the reinforcing bar rod into the hole formed in the ground, placing concrete in the hole in the ground including a part of the inside of the pipe, and when the concrete is hardened to a predetermined strength, the pipe Pile head processing method, characterized by extracting with the concrete inside.   An upper annular plate that provides a lower annular plate that suppresses concrete pressure from below on the lower side of the plurality of annular bags fixed in the longitudinal direction inside the core reinforcing bar, and prevents the annular bag from lifting up. The pile head processing method of Claim 1 characterized by the above-mentioned.   The pile head processing method according to claim 1, wherein an annular bag body is fixed to the outer peripheral surface of the tubular body on the plurality of annular bag bodies in the reinforcing bar so as to be polymerized.   A lower annular plate for suppressing concrete pressure from below is provided on the lower side of the plurality of annular bags fixed in the longitudinal direction inside the core rebar, and the annular bag is lifted on the outer peripheral surface of the tubular body. The pile head processing method according to claim 1 or 3, wherein a lifting presser member to prevent is provided. A method of constructing a cast-in-place concrete pile by combining a plurality of main reinforcing bars and a plurality of band reinforcing bars to form a cylindrical reinforcing bar and inserting the reinforcing bar into a hole formed in the ground and placing concrete. In
After fixing a plurality of annular bag bodies that are filled with fluid and inflated in the inside surrounded by a plurality of main bars in the reinforcing bar rods, and inserting and fixing a tubular body inside the plurality of annular bag bodies The rebar rod is inserted into a hole formed in the ground, concrete is placed in a hole in the ground including a part of the inside of the pipe, and when the concrete is hardened to a predetermined strength, the pipe is Pile head processing method characterized by extracting with the concrete inside.   A lower annular plate for suppressing concrete pressure from below is provided on the lower side of the plurality of annular bags fixed in the longitudinal direction inside the main bars, and an upper annular plate for preventing the annular bag from being lifted on the upper side. The pile head processing method according to claim 5, wherein the pile head processing method is provided.   The pile head processing method according to claim 5, wherein an annular bag body is fixed to the outer peripheral surface of the tubular body so as to be superposed on the plurality of annular bag bodies in the reinforcing bar.   A lower annular plate for suppressing the concrete pressure from below is provided on the lower side of the plurality of annular bags fixed in the longitudinal direction inside the main bars, and the annular bag is prevented from floating on the outer peripheral surface of the pipe body. The pile head processing method according to claim 5 or 7, wherein a lifting presser member is provided.   9. A constriction forming member for forming a constriction at a lower end of concrete that protrudes in an inner peripheral direction at the lower end of the inner peripheral surface of the tubular body and hardens inside the tubular body is provided. The pile head processing method described in any one.   The pile head processing method according to any one of claims 1 to 9, wherein a slit is provided on a peripheral surface of the tubular body for relaxing a constrained state of the concrete that hardens inside the tubular body.

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