JP3919459B2 - Hollow ready-made concrete pile, method for forming space in pile head into which curable material flows, and space forming tool - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hollow ready-made concrete pile, a method of forming a space in a pile head into which a curable material flows, and a space forming tool used therefor, and more particularly, during the construction of a ready-made pile by a pre-boring method, The present invention relates to a hollow ready-made concrete pile, a space forming method, and a space forming tool applied to a technique for forming a space for reinforcing bars in a pile head while discharging the curable material flowing into the outside.
[0002]
[Prior art]
As one of the methods for constructing ready-made piles, a pre-boring method is known in which a ready-made pile is built in a previously excavated pile hole. In this pre-boring method, generally, the ready-made pile built in the pile hole is integrated with the ground with a filling liquid such as cement milk.
[0003]
As a method that belongs to the pre-boring method, when a hole is drilled with an auger, a cement-based hardener is injected into the soil in the pile hole, mixed and stirred to create a soil cement, and this method is used as a filling material. Has been. According to this construction method, there is an advantage that the amount of soil discharged by excavation is small and the generation of industrial waste can be suppressed. For such a ready-made pile built in a pile hole filled with soil cement, an open-ended pile is usually used in order to facilitate the construction and establishment of the pile and to reduce the amount of soil removed.
[0004]
In the case of an open-ended pile, the soil cement flows into the pile by being built into the pile hole, and the pile is filled with the soil cement, so the amount of overflow is small. However, another problem arises in the case of an open-ended pile. It is a problem that pile head treatment, that is, the inside of the pile is in a state filled with hardened soil cement, so that a space for reinforcing bar connection to the structure foundation must be formed in the pile head .
[0005]
Conventionally, several techniques for forming a space for bar arrangement in a pile head have been proposed. For example, Japanese Patent Application Laid-Open No. 11-1923 discloses a technique in which a cylindrical bag body or two upper and lower annular bag bodies are attached to the outer periphery of the cylinder body, and the bag body is inflated and closely attached to the inner periphery of the pile head. . According to this technology, the curable material that flows into the inside of the pile due to the erection of the pile is discharged to the outside through the cylinder, and after the curable material is cured, the bag is removed, and the curable material clogged inside the cylinder By removing the material together with the cylinder, a space is formed in the pile head. Japanese Laid-Open Patent Publication No. 2000-54373 discloses a technique of making a cylinder body with reinforcing bars in order to facilitate the removal of the curable material clogged in the cylinder body.
[0006]
However, in each of the above conventional techniques, the fluid is supplied to the inflatable bag to close the space between the cylinder and the inner periphery of the pile. For this reason, the installation for supplying a fluid to a bag body is required, and the time and prior preparation process of supplying a fluid and expanding a bag body at the time of construction are needed. Therefore, it takes time to remove the bag as well. Also, it is difficult to say that the forming tool itself forming the space is inexpensive to manufacture.
[0007]
In order to solve the problem of such an inflatable bag body, the applicant described in Japanese Patent Application No. 2000-230770, “When a hollow ready-made pile was built in a pile hole filled with a curable material, A space forming tool for forming a space for reinforcing bars inside the pile head while discharging the curable material flowing into the hollow ready-made pile to the outside, and between the inner periphery of the hollow ready-made pile at the lower end An outer tube that is provided with a non-expandable annular closing member for closing the inner tube and a lid for closing the upper end of the pile head at the upper end and is fitted to the inner tube Proposed a space forming tool characterized by comprising a double tube. However, the following difficulties were found in the space forming tool.
[0008]
That is, when the pile is built, the curable material (soil cement) rises and flows into the hollow portion of the pile, thereby applying a large pressure to the lower part of the apparatus. In particular, when the ground is highly viscous, the soil cement does not flow smoothly into the pipe and may become clogged at the lower part of the apparatus, and in this case, a larger rising pressure is applied to the lower part of the apparatus. Such a phenomenon also occurs in the case of gravel layer ground, and as a result, the device may be pushed from below and jump out onto the pile head.
[0009]
The ring closing member is closely attached to the inner circumference of the pile and has a function of fixing the double pipe to the inner circumference of the pile by friction, and a function of preventing the soil cement from flowing into the space between the double pipe and the inner circumference of the pile. Together. A large rising pressure of the soil cement also acts on this annular closing member, and the annular closing member may not be able to withstand the pressure and may break down and the soil cement may flow into the space.
[0010]
In addition, when the pile is lifted, impact vibration may be applied to the pile by hitting it with another pile or heavy machinery, and the friction of the annular closing member is cut off by such impact vibration, and the inner pipe is displaced. There is. In addition, when the pile is built, if the verticality is corrected or the pile is not inserted properly, the pile may be lifted once, but if the soil cement enters the lower part of the device, the pile will rise. As the soil cement descends, a suction effect on the device is generated, which may cause the device to slip off. On the other hand, in the case of a concrete pile, since it is usually formed by centrifugal molding, the inner periphery is not a perfect circle, and there are irregularities instead of a smooth surface, so the adhesion of the annular closing member is improved. There is a limit.
[0011]
[Problems to be solved by the invention]
The present invention has been made based on the technical background as described above, and achieves the following object.
An object of the present invention is to provide a hollow ready-made concrete pile and a space forming method capable of holding the device at a fixed position on the inner periphery of the pile and reliably preventing a curable material from flowing into the space to be formed. And providing a space forming tool.
[0012]
[Means for Solving the Problems]
The present invention employs the following means in order to achieve the above object.
That is, according to the present invention, an annular plate having a hole having a diameter smaller than the inner diameter of the pile hollow portion is fixed at an inner peripheral position at a predetermined distance from the upper end of the pile head by embedding the outer peripheral portion in the pile body. It is in the featured hollow ready-made concrete pile.
[0013]
Further, the present invention is a hollow prefabricated concrete annular plate having a hole of inner diameter smaller than the inner diameter of the pile hollow portion from pile head upper end to the inner circumferential position of a predetermined distance, which is fixed by embedding its outer peripheral portion to the pile body A pipe body having a lid at the upper end and forming an annular space between the inner periphery of the pile head is inserted into the pile, and the lower end is supported by the annular plate and communicates with the hole. And installed so that the space between the pipe body and the top of the pile head is closed by the lid body,
The hollow ready-made concrete pile is built in a pile hole filled with a hardenable material, and the hardenable material flowing into the hollow ready-made concrete pile is discharged to the outside through the pipe body. There is a method of forming a space in the pile head into which water flows.
[0014]
[0015]
Furthermore, the invention, when it built up to Kuiana filled hollow prefabricated concrete pile with a curable material, while discharging a curable material flows into the hollow prefabricated concrete pile to the outside, the pile head A space forming tool for forming a space for reinforcing bars,
An annular plate having a hole with a diameter smaller than the inner diameter of the pile hollow part, the outer peripheral part being embedded in the pile body and fixed to the inner circumference position of a predetermined distance from the upper end of the pile head of the hollow ready-made concrete pile,
Wherein a tube body forming an annular space between the hollow prefabricated concrete pile inside is inserted with the peripheral in pile head, the lid is provided for closing the space between the pile head upper to the upper end And a tube having a lower end supported by the annular plate and communicating with the hole.
[0016]
More specifically, the annular plate is attached to a reinforcing bar cage disposed inside the pile body before the pile body is formed.
[0017]
According to this invention, the tubular body for discharging the curable material is supported by the annular plate fixed to the inner periphery of the pile head. For this reason, the rising pressure of the curable material is received by the annular plate, and since the large rising pressure does not act on the tube body, the tube body is held at a fixed position on the annular plate. In addition, since this annular plate has a function of closing the space between the lower end portion of the tubular body and the inner periphery of the pile head, the inflow of the curable material into the annular space is reliably prevented.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an axial cross-sectional view showing a pile head of a hollow ready-made pile used for forming a space. For example, a hollow ready-made pile 1 such as a PHC pile has a metal (steel) end plate 2 at the upper end of the pile head, and a predetermined distance from the end plate 2 (a distance of 1.5 to 2D when the pile diameter is D). The annular plate 3 is fixed to the inner peripheral position where the The diameter of the hole 4 opened in the center of the annular plate 3 is smaller than the inner diameter of the hollow ready-made pile 1, and thus the annular plate 3 is fixed so as to protrude in the radial direction from the inner periphery of the hollow ready-made pile 1. A metal plate such as a steel plate is preferably used as the annular plate 3 because of its robustness, but may be a plastic plate or a wood plate. The thickness varies depending on the material and the expected pressure. For example, in the case of a steel plate, the thickness is about 1.5 mm, and the outer diameter must be large enough to bite into the pile body.
[0019]
The annular plate 3 is embedded in the pile body as the hollow ready-made pile 1 is manufactured. 2 is an axial cross-sectional view showing a manufacturing process of a hollow ready-made pile, and FIG. 3 is a cross-sectional view taken along the line AA in FIG. Hollow ready-made piles are usually manufactured by centrifugal molding. The reinforcing bar 5 (see FIG. 2) arranged inside the pile body has a plurality of PC bars 6 as main bars and a spiral bar 7 arranged on the outer periphery thereof. It is manufactured in a cylindrical shape.
[0020]
The annular plate 3 is disposed inside the PC bar 6 arranged in a cylindrical shape, and is fixed to the PC bar 6 by a binding wire 8. For this reason, a plurality of holes 9 for passing the binding wire 8 are provided in the outer peripheral portion of the annular plate 3. The rebar cage 5 to which the annular plate 3 is attached is placed in a mold frame in the same manner as in a normal manufacturing method, and concrete is cast and molded, and after being removed from the mold, it is cured to produce a PC pile. As shown in FIG. 4, a notch 10 for receiving the PC bar 6 may be provided on the outer periphery of the annular plate 3. If it does in this way, the attachment positioning of the annular board 3 and the fixing operation | work by the binding wire 8 will become easy.
[0021]
The space forming tool according to the present invention includes a tubular body 11 and a lid body 12 shown in FIG. The tube 11 is made of a metal tube, a hard plastic, or the like that can withstand the pressure of soil cement. The lid 12 is integrally attached to an outer tube 13 that is detachably fitted to the outer periphery of the tube 11. A packing 15 made of rubber or the like is provided at the lower end of the tube body 11.
[0022]
FIG. 6 is an axial cross-sectional view showing a state in which the tubular body 11 is inserted and installed inside the hollow ready-made pile 1. The tube body 11 is placed on the annular plate 3 so that the lower end portion thereof communicates with the hole 4 of the annular plate 3. In this state, the packing 15 is in close contact with the annular plate 3 and the gap between the annular plate 3 disappears. On the other hand, the lid 12 is placed on a step 16 formed between the end plate 2 and the periphery of the pile body, and the lid 12 closes the top of the pile head. In this way, an annular space 18 is formed between the tubular body 11 and the inner periphery of the pile head. As will be described later, the ready-made pile 1 is built in the pile hole while rotating, but the rotating bracket 17 used for this is engaged with the upper end of the tubular body 11, and the tubular body 11 is raised when the pile is built. To prevent.
[0023]
FIG. 8 is a cross-sectional view showing a pile construction method using the space forming tool. The pile hole 20 in which the hollow ready-made pile 1 is built is filled with a curable material, that is, a soil cement 21 obtained by mixing and stirring the excavated earth and sand and cement milk. The curable material may be cement milk instead of soil cement.
[0024]
The hollow ready-made pile 1 in which the tubular body 11 is inserted and installed as shown in FIGS. 6 and 7 is built in the pile hole 21 while being rotated via the rotating metal fitting 17. As shown in FIG. 8 (a), the soil cement 21 rises and flows into the hollow ready-made pile 1, and the soil cement 21 rises through the inside of the tubular body 11 and is externally attached. To be discharged. At this time, since the rising pressure of the soil cement 21 is received by the annular plate 3, the large rising pressure does not act on the tube body 11, and the tube body 11 is held at a fixed position on the annular plate 3. In addition, since the annular plate 3 has a function of closing between the lower end portion of the pipe body 11 and the inner periphery of the pile head, the inflow of the soil cement 21 into the annular space 18 is reliably prevented. In addition, when the soil cement 21 flows into the pipe body 11, an ascending force due to viscous friction with the soil cement 21 acts on the pipe body 11, but the upper end of the pipe body 11 is shown in FIGS. Thus, the tubular body 11 does not rise.
[0025]
Next, after hardening of the soil cement 21, as shown in FIG.8 (b), the root cutting 22 circumference | surroundings around a pile head are performed and the cover body 12 is extracted. And as shown in FIG.8 (c), the reinforcing steel cage | basket | car 23 for couple | bonding a structure foundation and the hollow ready-made pile 1 is inserted and arrange | positioned in the annular space 18. As shown in FIG. The pipe-shaped body 11 and the core-shaped hardened soil cement 24 clogged in the pipe body 11 may be removed, but if it is not removed, the labor and processing can be saved, and the amount of concrete placed in the pile head space can be saved. Can be achieved. In this case, the lid body 12 can be reused.
[0026]
FIG. 9 is a cross-sectional view showing another embodiment. In this embodiment, a tubular portion 25 is provided on the inner periphery of the annular plate 3, and the tubular body 11 is fitted and fixed to the outer periphery (or inner periphery) of the tubular portion 25 with a screw 26. The cylindrical portion 25 may be formed integrally with the annular plate 3 in advance or may be attached to the annular plate 3 later as a separate part.
[0027]
10 is a cross-sectional view showing still another embodiment, and FIG. 11 is a cross-sectional view taken along the line BB of FIG. In this embodiment, a plurality of protrusions 27 protruding in the radial direction are provided at the lower end of the tube body 11. On the other hand, the inner periphery of the annular plate 3 is provided with a notch 28 through which the protrusion 27 can pass. A flange plate 29 is provided on the outer periphery of the lower end portion of the tube body 11, and a packing 30 made of rubber or the like is provided on the lower surface thereof. The tube body 11 is fitted into the hole 4 when the projection 27 passes through the notch 28, and the projection 27 is engaged and fixed to the lower surface of the annular plate 3 by appropriately rotating the tube body 11. In this state, the packing 30 is in close contact with the annular plate 3.
[0028]
FIG. 12 is a cross-sectional view showing still another embodiment. In this embodiment, an annular rubber 31 whose outer edge is curved inward is provided at the lower end of the tube body 11. The flange plate 29 and the packing 30 are provided on the outer periphery of the lower end portion of the tube body 11 in the same manner as the embodiment shown in FIGS. The tubular body 11 passes through the hole 4 while reducing the diameter of the annular rubber 31, and is engaged and fixed to the lower surface of the annular plate 3 by returning to the original shape after the passage.
[0029]
According to each of the embodiments shown in FIGS. 9 to 12, since the pipe body 11 is fixed to the annular plate 3, the pipe body 11 does not rise due to the inflow of the soil cement. It is not necessary to press the upper end of the metal plate with the rotary fitting 17.
[0030]
The above embodiments are merely examples, and the present invention can be modified in various ways. For example, although the straight pile is shown in the said embodiment, the joint pile which has a some node part in a pile outer periphery may be sufficient. Moreover, this invention is applicable also in the case of not only a PHC pile but RC pile, PC pile, and SC pile.
[0031]
【The invention's effect】
As described above, according to the present invention, since the tubular body for discharging the curable material is supported by the annular plate fixed to the inner periphery of the pile head, the rising pressure of the curable material is received by the annular plate. As a result, a large rising pressure does not act on the tube. Therefore, the tube body is securely held in place on the annular plate. In addition, since this annular plate has a function of closing the space between the lower end portion of the tubular body and the inner periphery of the pile head, the inflow of the curable material into the annular space is reliably prevented.
[Brief description of the drawings]
FIG. 1 is an axial sectional view showing a pile head of a hollow ready-made pile according to the present invention used for forming a space.
FIG. 2 is an axial sectional view showing a manufacturing process of a concrete pile.
FIG. 3 is a cross-sectional view taken along line AA in FIG.
FIG. 4 is a view showing another embodiment of the annular plate.
FIG. 5 is a perspective view showing a tube constituting the space forming tool according to the present invention.
FIG. 6 is an axial sectional view showing a state in which the tubular body is installed on the inner periphery of the pile head.
FIG. 7 is a plan view of the same state.
FIG. 8 is a cross-sectional view showing a space forming method associated with pile construction.
FIG. 9 is a cross-sectional view showing another embodiment.
FIG. 10 is a cross-sectional view showing still another embodiment.
11 is a cross-sectional view taken along line BB in FIG.
FIG. 12 is a cross-sectional view showing still another embodiment.
[Explanation of symbols]
1: hollow ready-made pile 2: end plate 3: annular plate 4: hole 11: tube body 12: lid body 13: outer tube 15: packing 16: stepped portion 17: rotating metal fitting 18: annular space 20: pile hole 21: soil cement

Claims (4)

Hollow ready-made concrete , characterized in that an annular plate having a hole with a diameter smaller than the inner diameter of the hollow part of the pile at an inner peripheral position at a predetermined distance from the upper end of the pile head is fixed by embedding the outer peripheral part in the pile body Pile. 2. The hollow ready-made concrete pile according to claim 1, wherein the annular plate is attached to a reinforcing bar cage disposed inside the pile body before the pile body is formed. An annular plate having a hole with an inner diameter smaller than the inner diameter of the hollow part of the pile at an inner peripheral position at a predetermined distance from the upper end of the pile head is placed inside the hollow ready-made concrete pile fixed by embedding the outer peripheral part in the pile body. A pipe body that has a lid in the part and forms an annular space between the inner periphery of the pile head is inserted, the lower end of the pipe is supported by the annular plate and communicates with the hole, and the pipe is covered by the lid Installed so that the space between the body and the top of the pile head is closed,
Curable material hollow like an anchor for prefabricated concrete pile in Kuiana filled with curable material, characterized in that it discharged to the outside through the tube body curable material flowing into the hollow prefabricated concrete pile by like an anchor A method of forming a space in the pile head into which water flows. When a hollow ready-made concrete pile is built into a pile hole filled with a hardenable material, the space for bar arrangement in the pile head is discharged while discharging the hardenable material flowing into the hollow ready-made concrete pile outside. A space forming tool for forming
An annular plate having a hole whose diameter is smaller than the inner diameter of the pile hollow portion, the outer peripheral portion being embedded in the pile body and fixed to the inner peripheral position at a predetermined distance from the pile head upper end of the hollow ready-made concrete pile,
It is a tubular body that is inserted into the hollow ready-made concrete pile and forms an annular space with the inner periphery of the pile head, and a lid for closing the upper end of the pile head is provided at the upper end. And a tubular body having a lower end supported by the annular plate and communicating with the hole.

Images