JPH08209686A - Pile head processing tool and pile head processing construction method for cast-in-place pile - Google Patents

Abstract

PURPOSE: To reduce pressure to a cap as much as possible, and smoothly pass them when a stabilizing liquid to fill up to prevent a collapse of an excavating hole wall and excessive spring water are pushed up by containing slime or the like at concrete placing time and overflow by passing through the inside of the cap and a clearance between the cap and a casing, by eliminating removing work of slime-mixed concrete of an inner cylinder after concrete is placed and cured, and preventing generation of an accumulating layer such as slime under a bottom surface by placing of concrete. CONSTITUTION: An inner cylinder 2 into which a concrete placing tremie pipe can be freely inserted, is surrounded at a prescribed interval with an outer cylinder 3. The upper ends of both cylinders 2 and 3 are locked and installed by an annular top plate 1, and the lower ends are locked and installed by an annular bottom plate 6, respectively, and a double cylindrical cap main body A is formed. Plural pile main reinforcement holes 8 are bored at prescribed intervals in the bottom plate 6 of this cap main body A, and gas-liquid bleeding holes 5 and 9 are opened and formed in the top plate 1 and the bottom plate 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a pile head treatment tool and a pile head treatment method for crown-inserting the pile head of a reinforced basket in cast-in-place reinforced concrete piles to be constructed underground in various civil engineering construction works. .

[0002]

2. Description of the Related Art Conventionally, in civil engineering and construction work, foundation piles are buried by various construction methods, but in recent years, they are mainly constructed by the cast-in-place concrete pile construction method.

In this cast-in-place concrete pile method, a circular excavation hole is first formed up to a supporting ground in the ground by an earth drill method or the like, and a reinforcing bar cage in which the main reinforcement of the pile is assembled into a cage is built in the excavation hole, Next, a tremie pipe is inserted from above the reinforced basket, concrete is discharged from the tip of the tremie pipe, and concrete is poured from the lower end of the drilling hole to construct a reinforced concrete pile.

At this time, the cast concrete forms a surplus concrete portion of about 1 m beyond the upper end of the reinforced basket. After backfilling the gravel and gravel in the upper excavation hole of this surplus concrete part, concrete is cured.

After curing, excavation is carried out to remove gravel and gravel, and the surplus concrete portion is scraped off to expose the main reinforcing bar of the above-mentioned reinforcing bar cage, and the foundation work of the building is constructed on the basis of the main reinforcing bar of the pile.

[0006] This surplus concrete part is chipped,
Conventionally, it has been a problem as a pollution source such as noise, vibration, and dust, and it has also been a cause of damage to the main reinforcement of piles, work accidents and occupational diseases. In addition, the material cost of the extra concrete,
It was also a major cause of high costs such as chipping work and an increase in construction period.

Therefore, the invention disclosed in Japanese Patent Laid-Open No. 61-186616 has been proposed as a means for omitting the hanging work. The present invention is a method of suctioning and removing concrete from a viscous concrete in a surplus portion that has not yet solidified immediately after concrete is poured through a tremie pipe by a suction hose connected to a powerful vacuum pump. Of course, this construction method is possible only when there is a casing fitted in the excavation hole, and is not necessarily applicable depending on the situation of the construction site. Rather, there is a risk of causing borehole collapse.

Further, in the above-mentioned construction method, instead of eliminating the surplus concrete portion, the main reinforcement of the pile is bent due to gravel and gravel during backfilling, and a large heavy machine is used for excavating the surplus concrete portion after curing. There was a defect that the head was damaged and it took time to repair it, and it was a method of practical lack.

Therefore, a pile head rebar cap as disclosed in Japanese Patent Application Laid-Open No. 58-153816 has been developed mainly for the purpose of preventing damage to the main reinforcement of the pile due to the above-mentioned chipping work of the overfilled concrete portion. .

This cap has a through hole into which a tremie tube can be removably attached, and has a donut-shaped closed double structure having two compartments or a similar structure centering on this through hole. Holes are formed in the annular bottom plate and top plate.

A connecting bolt is screwed into this cap through a hole formed in the bottom plate or the top plate, and a sleeve joint having a rear end attached to the upper end of the main bar of the reinforcing bar basket is connected to the connecting bolt. The cap and the rebar cage are firmly connected, and a tremie pipe is introduced into the through hole for concrete pouring.

The concrete is cast into the reinforced basket until the cap device placed on the upper part of the reinforced basket is embedded. After that, the gravel and gravel is backfilled in the upper excavation hole in which the rebar cage is buried, and the concrete is cured. After curing, remove the gravel, scrape off the concrete covering the cap, remove several screws to open the closed state of the cap, then remove the connecting bolt from the sleeve joint, remove the cap, It has been proposed that a threaded portion at the lower end of the anchor bar is screwed into this sleeve joint so that the anchor bar is connected and erected to the pile main bar.

According to this proposal, although the surplus concrete portion is smaller than before, the chipping work is still indispensable, and the structure of the cap itself is complicated, and especially the connecting work of the two compartments is inevitable. Therefore, it is a laborious work to attach and remove the side plate for closing the cap. In addition, the method of screwing the anchor bar into the sleeve joint and extending the pile main bar to a predetermined height is a method that is generally unstable because of problems with strength and is extremely unstable as a rule of thumb, and an unexpected accident may occur. Therefore, many technical problems remain.

In addition to the above, a pile head treating tool for cast-in-place piles (hereinafter abbreviated as a cap body) has been proposed by the inventor of the present application previously disclosed in Japanese Patent Laid-Open No. 1-232020. There is a processing cap.

The cap body of this proposal is disclosed in the above-mentioned Japanese Patent Laid-Open No.
Unlike the shallow donut-shaped cap composed of complicated two compartments described in Japanese Patent Publication No. 8-153816, an inner cylinder (tremy tube introduction tube) with upper and lower surfaces opened as a through hole through which a tremie tube can be freely inserted. , It is formed by a simple double cylinder consisting of an outer cylinder (upper cap) that connects the outer circumference of the top plate and the bottom plate on the outside, and multiple pile main holes are drilled near the peripheral edge of the bottom plate (planned cutting plate). (The name in parentheses is the name stated in the publication).

That is, since the cap body intended by the proposal is set to a size substantially corresponding to the extra concrete portion, as compared with the shallow cap (apparatus) disclosed in Japanese Patent Laid-Open No. 58-153816, it is far from that. It is formed on a deep cylinder, and the pile main bar is inserted through the pile main hole to the top plate of this cylinder, and the tremie pipe is penetrated through the inner cylinder to perform concrete pouring. Part is not generated at all, and the gravel and gravel is directly backfilled in the excavation hole above the cap to cure the concrete.

After the curing, if the floor is excavated to remove the gravel, the cap is immediately exposed without the chipping work. Therefore, it is sufficient to protect the pile rebar if the cap is carefully removed. However, since the slime-mixed concrete that fills the inner cylinder is left behind, appropriate measures are taken while removing the pile rebar together with the cap, and at the same time, dirt such as accumulated slime is washed and the cast-in-place concrete pile construction is completed. To do.

[0018]

A cap for treating pile heads of cast-in-place piles is disclosed in the above-mentioned Japanese Patent Laid-Open No. 1-32 developed by the present inventor.
As described in Japanese Patent Publication No. 2020, in addition to the purpose of protecting the original pile head, it is of great significance to eliminate the need for chipping work by eliminating the formation of excess concrete part inevitable with the conventional method. Eliminating the pollution and sanitation problems caused by the construction, the economic effects such as shortening the construction period and saving concrete were also great.

However, in this method, since the soil and gravel are backfilled and cured while the concrete is cast on the upper surface of the inner cylinder, the slime-mixed concrete in the inner cylinder must be removed after the curing. Of course, the removal work was extremely simple, and it was possible to remove it by simply making a hole in the part of the concrete to be cut off and causing a crack with the arrow head or a crack with an eyeon and lifting it with a rope, but it is useless as much as possible. It is preferable to omit such work.

Further, since the bottom plate of the cap is flat, a deposit layer of slime or the like is formed below the bottom surface when pouring concrete, and a stabilizing liquid to prevent collapse of the borehole wall and excess spring water are generated. When it is pushed up including slime when pouring concrete and overflows inside the cap and through the gap between the cap and the casing, the pressure on the cap is as small as possible and a means for smooth passage is required. Therefore, it is an object of the present invention to solve these problems associated with the close-closed cap that is closed except for the conventional main hole of the pile.

[0021]

In order to effectively achieve the above object, the present invention has the following structure. That is, in the pile head treating tool for cast-in-place pile according to the present invention as defined in claim 1, the inner cylinder 2 into which the tremy pipe 16 for concrete placement can be freely inserted is surrounded by the outer cylinder 3 at predetermined intervals, and both cylinders are surrounded. The upper ends of 2, 3 are attached to the annular top plate 1 and the lower ends thereof are attached to the annular bottom plate 6, respectively, to form a double cylindrical cap body A. A plurality of main pile holes 8 are formed by the above, and gas-liquid vent holes 5 (9) are formed in the top plate 1 and the bottom plate 6.

A pile head treating tool for cast-in-place piles according to a second aspect of the present invention has the structure according to the first aspect, wherein the inner cylinder 2 and the outer cylinder 3 have the same length and the top plate 1 is provided. Further, the bottom plate 6 has a structure in which it is attached to the upper and lower ends of the cylinders 2 and 3 in a horizontal plate shape.

In the pile head treating tool for cast-in-place pile according to the present invention as defined in claim 3, a plurality of gas-liquid drain holes 5 are formed near the outer peripheral edge of the top plate 1 of the outer cylinder 3, and An upper tremie port 4 into which a concrete placing tremie pipe 16 can be freely inserted is bored in the center of the top plate 1, and the upper tremie port 4 is engaged with the lower side of the upper tremie port 4 and the outer cylinder 3 is 2% to 3%. % In the cap body A formed by penetrating the inner cylinder 2 having a short open upper and lower surfaces to form a double cylinder, approximately equal intervals are provided in the flat region 6a of the outer cylinder 3 near the outer peripheral edge of the bottom plate 6. A plurality of main pile holes 8 are formed in the bottom of the bottom plate 6, and a plurality of slits 9 are radially cut into the periphery of the lower tremie port 7 formed in the center of the bottom plate 6.
Are formed at substantially equal intervals and leave the flat region 6a,
Further, the slit piece 9a generated by each slit 9 is bent obliquely upward, and the tip of this slit piece 9a is fixed to the inner cylinder 2
It is formed by being fixedly attached to the lower edge of the.

A pile head treating tool for cast-in-place piles according to a fourth aspect of the present invention has the structure according to the first, second or third aspect, and the top plate 1 or / and the bottom plate 6 is a net body. Alternatively, it is made of punching metal.

A pile head treating tool for cast-in-place piles according to a fifth aspect of the present invention has the structure according to the first, second, third or fourth aspect, in which the cap main body A is attached to the rebar cage 14. At the same time, the cap body A and the rebar cage 14 are tied and fixed with a cord 23 such as a detachable chain, wire or string, and the rebar cage 14 is built in the excavation hole 17 by the pile head treatment method. is there.

Further, the pile head treating method using the pile head treating tool for cast-in-place pile according to the present invention as defined in claim 6,
Using the pile head treatment tool for cast-in-place pile described in 2, 3, 4 or 5, the cap body A is staked and fixed to the rebar cage 14 by stat welding, and the cap body A is built in the excavation hole 17. The tremie pipe 16 is drilled through the inner cylinder 2 of the
The drilling bucket 1 attached to the kerry bar 19 immediately after the concrete is continuously placed from the bottom of the drilling hole 17 to the top surface of the inner cylinder 2.
It is a pile head processing method in which the slime-mixed concrete filled in the inner cylinder is removed by rotating 8.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described. As shown in FIGS. 1 to 7, the top plate 1 of the outer cylinder 3
A circular upper tremie port 4 into which a concrete pouring tremie pipe 16 can be freely inserted is bored in the center of the upper end of the upper tremie port 4 and the upper open tremie port 4 is slightly shorter than the outer cylinder 3 and is open vertically. When the inner cylinder 2 is penetrated, the cap body A excluding the bottom surface of the double cylinder is formed. A plurality of gas-liquid vent holes 5 are appropriately formed near the periphery of the top plate 1 of the outer cylinder 3 in the previous term.
At the center of the bottom plate 6 of the outer cylinder 3, a lower tremie port 7 having a shape similar to the upper tremie port 4 is formed.

Further, near the periphery of the bottom plate 6, main pile holes 8 for inserting the main pile bars 11 forming the reinforcing bar cage 14 are formed at substantially equal intervals, and at the intermediate position of each main pile hole 8. The slits 9 are formed by cutting the flat plate 6a radially outward from the lower tremie opening 7 and having a proper width near the outer peripheral edge and having an appropriate width.

The slit piece 9a thus formed is bent obliquely upward, and the tip of the slit piece 9a is welded to the peripheral edge of the lower end of the inner cylinder 2 to complete the cap body A of the present invention. As a characteristic of the external structure, a bottom space 10 having a reverse dish shape having a radial gap is formed on the bottom surface of the cap body A, and the effect is that the gap between the slit 9 and the gas-liquid of the top plate 1 at the time of concrete pouring. With the hole 5, it becomes possible to smoothly flow air or muddy water between the outer cylinder 3 and the inner cylinder 2,
The pressure from the lower side was reduced, and impurities such as slime and latance accumulated in the vicinity of the bottom plate in the past, forcing the formation of a deposited layer. However, the present invention alleviated these drawbacks.

Now, the rebar cage 14 having the cap body A of the present invention inserted and fixed therein is installed in the excavation hole 17, and the tremie pipe 16 is provided.
The concrete is continuously cast from the bottom of the drill hole 17 to construct the reinforced concrete pile. However, as a result of repeated experiments by the present inventor, it is indispensable to place concrete over the inner cylindrical top surface. However, by using the excavation method immediately after the completion of the pouring, for example, the excavation bucket 18 or the slime bucket is attached to the kelly bar 19, and the rotation of the kelly bar 19 makes it possible to easily remove the concrete mixed with the slime.

Subsequently, the upper surface of the cap body A is covered with an appropriate lid, and after the casing 13 is lifted up, gravel and gravel is backfilled and cured by a conventional method. After completion of curing, floor excavation is performed to remove debris, the cap body A is exposed, and appropriate mechanical means such as fusing with a gas burner and a power shovel are taken, so that the cap body A can be easily separated from the rebar cage 14. it can. According to the present invention, as described above,
No chipping work is required, protection of the pile main bar 11 can be sufficiently fulfilled, all the conventional technical problems are solved, and a great economic effect is brought about.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 is a perspective view of a cap body A of the present invention, FIG. 2 is a partially cutaway perspective view thereof, FIG. 3 is a plan view of a bottom plate 6 of an outer cylinder 3, and FIG. 4 is a partially cutaway vertical sectional view of a cap body A. 5 and 6 are explanatory views showing a usage state, FIG. 7 is an explanatory view showing a state of removing the inner cylinder slime-mixed concrete after the concrete is cast, and FIG. 8 is another embodiment of the cap body A of the present invention. 9 is a partially cutaway perspective view showing an example, FIG. 9 is a partially cutaway perspective view showing another embodiment of the cap body A of the present invention, and FIG. 10 is a part showing another embodiment of the cap body A of the present invention. FIG. 11 is a cutaway perspective view, and FIG. 11 is a perspective view of another embodiment of the cap body A of the present invention.

As shown in FIGS. 1 to 3, the cap body A
Is an annular top plate 1 with an upper tremie opening 4 in the center
And an inner cylinder 2 joined to the inner peripheral edge of the top plate 1, and the top plate 1.
The outer cylinder 3 is joined to the outer peripheral edge of the inner cylinder 2, and the annular bottom plate 6 is formed with a lower tremie port 7 in the center. The inner peripheral edge of the bottom plate 6 is joined to the inner peripheral surface of the inner cylinder 2, The peripheral edge has a double cylindrical shape joined to the bottom peripheral surface of the outer peripheral cylinder 3.

The inner cylinder 2 is usually shorter than the outer cylinder 3 by 2% to 3%. Although it is set in relation to the diameter difference between the upper tremie port 4 and the lower tremie port 7, the size of the gap between the slits 9 is also taken into consideration.

The size of the cap body A is the diameter of the rebar cage 14 which is set according to the scale of the excavation hole 7 (see FIG. 6).
It is determined by the thickness and the number of main pile reinforcements 11. Further, the exposed head portion 14a of the rebar cage 14 (which serves as a base for constructing the foundation of the building) in the excavation hole 17 is usually 40 times or more the diameter of the main pile reinforcement 11, and the exposed head portion 14a is formed by the conventional method. The height of the cap body A of the present invention may be adjusted according to the size of the exposed head portion 14a.

The material used for the cap body is preferably a mild steel plate having a thickness of 1.6 mm to 3.2 mm in consideration of protection against backfilling and re-drilling and removal means after the re-drilling. Of course, the material is not limited to a steel plate, and it may be formed of a synthetic resin material or another metal material. The cap body A is created in the following order.

As shown in FIG. 2, a circular top plate 1 and a bottom plate 6 having the same diameter are prepared, and a tremy pipe 16 for concrete placing (see FIG. 6) can be freely inserted into the center of the top plate 1 to provide a circular upper tremy. A port 4 is bored, and a plurality of gas / liquid vent holes 5 are bored near the outer peripheral edge of the top plate 1. The diameter and number of the gas-liquid drain holes 5 may be changed as appropriate depending on the size of the top plate 1. Generally, a diameter of 10 mm to 20 mm and 4 to 8 are suitable.

Further, as shown in FIG. 3, a flat area 6a having an appropriate width (usually around 90 mm) is provided near the outer peripheral edge of the bottom plate 6, and the pile main bar 11 forming the rebar cage 14 is inserted into the flat area 6a. The main hole 8 of the pile is drilled at substantially equal intervals.
It is preferable that the diameter of the main pile hole 8 is set to 1.3 to 1.5 times the thickness of the main pile 11 to be inserted so that a certain margin can be maintained.

Next, a lower tremie port 7 similar to that of the top plate 1 is bored in the center of the bottom plate 6, but the diameter of this tremie port is made 2% to 5% smaller than that of the upper tremie port 4. That is, slits 9 are formed in the lower tremie mouth 7 by cutting the slits 9a radially and at substantially equal intervals while leaving the flat area 6a on the periphery, and each slit piece 9a is bent obliquely upward to form an angle θ with the flat area. When tilted at 25 to 30 degrees,
Its tip edge has almost the same diameter as the upper tremie port, and by welding this tip edge to the peripheral edge of the lower end opening of the inner cylinder 2, a reverse dish-shaped space having a radial cross section shown in FIG. It can be formed on the bottom surface.

With this structure, the cap body A is integrated into a double cylinder, and the bottom surface of the cap body A has a shallow inverted dish-like space as described above, and the gap between the slit 9 and the pile main bar 8 is large. In order to generate, the inner cylinder 2 during construction
Air and muddy water flow between the outer cylinder 3 and the outer cylinder 3, and the pressure of the gas or liquid that is pushed up from the excavation hole 17 together with the gas-liquid vent hole 5 of the top plate 1 is effectively eliminated. It is also possible to obtain the effect that the slime deposit layer is not formed on the bottom surface of the inverted dish shape as described above.

The cap main body A is prepared by preparing each main part based on the above-mentioned basic structure. Generally, the inner cylinder 2 is first hung on the central lower surface of the top plate 1, and the bottom of the bottom is formed at the lower end of the inner cylinder 2. The tremie port 7 is attached, and finally the outer cylinder 3 is attached to the outer peripheral edges of the top plate 1 and the bottom plate 6. The welding in the present invention employs stat-welding for all welding, and it is considered that a gap is formed in the cap body A as much as possible, and the removal of the cap body A after placing concrete is facilitated.

The combination of the cap main body A and the reinforcing bar cage 14 is such that the main pile bar 11 is inserted through the main pile hole 8 formed in the bottom plate 6 of the main cap body A until it reaches the top plate.
(Refer to FIG. 5) After that, the reinforcing bar cage 14 is formed while winding the horizontal bar 15 around the pile main bar 11 by stat welding, and finally, the horizontal bar 15 close to the bottom plate 6 of the cap body A is stat welded to the bottom plate in some places. Then it is fixed and completed.

In any case, after the cap body A is inserted and fixed to the rebar cage 14 by an appropriate means, the rebar cage 14 is built in the excavation hole 17 as shown in FIG. 6, and the secondary slime treatment is carried out if necessary. Etc., the tremie pipe 16 is built through the inner cylinder 2, concrete is continuously poured from the bottom of the excavation hole 17, and the concrete is poured where the top surface of the inner cylinder 2 of the cap body A is exceeded. Complete the setup.

Immediately after the concrete pouring is completed, as shown in FIG. 7, the excavation bucket 18 or the slime bucket is attached to the kelly bar 19 depending on the situation of the construction site.
The slime-mixed concrete filled in the inner cylinder 2 is removed to the bottom of the cap by the rotation of the kelly bar 19. The casing 13 which protects the drill hole 17 after completion
Is removed, a suitable lid is put on the cap body A, and the gravel and gravel is backfilled, and then concrete curing is performed for a required period.

When the curing is completed, the foundation floor is excavated to remove the gravel and gravel again, and the pile head cap main body A exposed there is first subjected to mechanical work such as a power shovel and the like.
The outer cylinder 3 and the inner cylinder 2 can be successively torn and peeled off. That is, the above-mentioned stat welding is successful, and the bottom plate 6 can be easily removed by fusing the slit portions at 2 to 3 places with a gas burner. Since the stat welding is used for manufacturing the cap body A, the manufacturing time is shortened, the removal work is facilitated, and the economic effect can be enhanced accordingly.

Thus, the head of the pile main bar 11 protected by the cap body A is safely exposed, the intended purpose is achieved, and finally, unnecessary substances such as concrete residue, slime, and leitance are washed with high pressure water. Then, the pile head treatment work is completed.

FIG. 8 shows a cap body A showing another embodiment. The top plate 1 of this embodiment is made of punching metal and has a large number of holes 5a. Air and muddy water that have flowed in between the inner cylinder 2 and the outer cylinder 3 can be smoothly circulated through the holes 5a. Further, the main plate hole 8 is formed in the bottom plate 6 as in the above embodiment.
And the slit 9 is formed. The lengths of the inner cylinder 2 and the outer cylinder 3 are the same as those in the above-mentioned embodiment.
Alternatively, the inner cylinder 2 and the outer cylinder 3 may have the same length. In the case of the same size, the bottom plate 6 is provided at the lower ends of the inner cylinder 2 and the outer cylinder 3 in a horizontal plate shape. The method of using the cap body A is the same as that of the above-mentioned embodiment, and the description thereof is omitted. In addition to the punching metal described above, any member may be used as long as it has no problem in terms of strength, safety, and cost, as long as it is a mesh member and a member that has been processed to allow gas and liquid to flow therethrough.

Next, FIG. 9 shows a cap body A showing another embodiment, in which the slit 9a is formed in the top plate 1.
Is formed so that air and muddy water that have flowed in between the inner cylinder 2 and the outer cylinder 3 at the time of construction can be smoothly circulated from the slit 9a. The rest of the configuration is the same as that of the above-mentioned embodiment, and the explanation is omitted.

Next, FIG. 10 shows a cap body A showing still another embodiment. In this embodiment, a gas / liquid vent hole 5 is formed in a top plate 1, and a bottom plate 6 is formed in the slit 9 together with a main muscle hole 8. Corresponding hole 5c is formed. The rest of the configuration is the same as that of the above-mentioned embodiment, and the explanation is omitted.

The inner cylinder 2 and the outer cylinder 3 of each of the above-described embodiments may have the same length, or the inner cylinder 2 may be shorter than the outer cylinder 3. Although forming the main hole 8 in the bottom plate 6 is common to each of the embodiments, the slits and holes formed in the top plate 1 and the bottom plate 6 are not limited to those in the above-mentioned embodiments, and have various shapes and numbers. Can be freely changed to any shape as long as the shape allows gas and liquid to escape.

In FIG. 11, the engaging portion 20 is provided on the outer peripheral surface of the outer cylinder 3 of the cap main body A (the figure shows an example) of various embodiments as described above. In this embodiment, a bolt 20a is attached as a locking portion 20 by screwing it into a screw hole provided in the outer cylinder 3. One end of a locking wire 21 (connecting member) made of wire or string is tied to each of the bolts 20a.

When the cap body A is put on the rebar cage 14, the other end of the locking wire 21 is attached to the transverse bar 15 of the rebar cage 14.
The cap body A is fixed to the rebar cage 14 by tying to.
As a result, even if an upward lifting force of gas and liquid acts on the cap body A at the time of construction, the cap wire A is fixed by the locking wire rod 21 together with the action of the slits and the gas / liquid drain hole described above. It is possible to more surely prevent upward lifting.

FIG. 12 is a view showing a construction method of another embodiment, in which two chains 23a and 23b are used as the cords 23 for fixing the cap body A to the head of the rebar cage 14 by fixing it.
Using. That is, one chain 23a is hung along the outer peripheral surface of the outer cylinder 3 of the cap body A attached to the head of the rebar cage 14, and the chain 23a is hooked on the lateral bar 15 of the rebar cage 14 to further The hooks 24a and 24b on both ends of the chain 23a are locked to the same chain 23a by extending upward along the inner peripheral surface of the chain 23a.
Similarly, the other chain 23b is also provided at a position facing the above chain 23a as shown in the drawing. In addition, line 2
As the wire 3, other than the chain, any wire, string, thick wire, or any other material that can be hooked to the horizontal bar 15 of the rebar cage 14 to fix the cap body A may be used.

In this way, the cap body A is rebar cage 1
Fix at 4. As a result, even if the cap body A is lifted upward by gas and liquid at the time of construction as in the case of the above-mentioned embodiment, it is fixed by the chains 23a and 23b together with the above-mentioned action of the slits and gas and liquid drain holes. It is possible to more reliably prevent the cap body A from being lifted up.

In the cap body A of this embodiment,
When the casing 13 (see FIG. 7) is pulled out after the concrete is poured, the casing 13 is unlikely to be caught by the large number of bolts 20a (see FIG. 11) as in the above-described embodiment and difficult to pull up.

[0056]

As described above, in the pile head treating tool for cast-in-place piles according to the present invention as described above, no chipping work is required after concrete curing, which causes a pollution source or an industrial accident. Can be eliminated altogether. In addition, the slime layer deposited under the bottom of the cap body is also eliminated, and the air and muddy water that rises up during concrete pouring can smoothly pass through the cap body and flow out, making concrete pouring work easier. It will get better.

Further, in the pile head treating tool for cast-in-place pile according to the present invention, since the top plate and the bottom plate are formed into horizontal plates and are attached to the inner cylinder and the outer cylinder, the cap body is provided. Can be easily processed and manufactured.

Further, the pile head treating tool for cast-in-place pile of the present invention according to claim 3 presents a shallow inverted dish-like space on the bottom surface of the cap body, and moreover, the slit and the gap between the pile main bar and the main pile hole are formed. Since it is formed, air and muddy water flow between the inner cylinder and the outer cylinder during construction through these slits and gaps, and push up from the excavation hole along with the gas-liquid vent hole drilled in the top plate. The pressure of gas or liquid can be eliminated. Further, since the bottom plate is formed in an inverted dish shape, a slime deposit layer is not formed.

Further, in the pile head treating tool for cast-in-place pile of the present invention as defined in claim 4, the ceiling plate and / or the bottom plate is formed of a net or punching metal, so that the ceiling plate and / or the bottom plate is exposed to air. It is possible to eliminate the work of performing the drainage process, and it is possible to manufacture the cap body at a lower cost.

In the pile head processing method using the pile head processing tool for cast-in-place pile according to the present invention, the cap body and the rebar cage can be connected by the connecting member at the time of construction. It is possible to more surely prevent the main body from being lifted up by the gas and liquid pushing up from the drill hole.

In the pile head treatment method using the pile head treatment tool for cast-in-place piles according to the sixth aspect of the present invention, the head of the main reinforcement of the reinforcing bar cage is protected by the cap body. It does not damage the parts, and the gas-liquid pressure holes (including slits) formed in the top and bottom plates of the cap body allow the gas-liquid pressure from the bottom to escape, making the construction work of cast-in-place pile safe and safe. It can be done efficiently and smoothly.

[Brief description of drawings]

FIG. 1 is a perspective view of a cap body.

FIG. 2 is a partially cutaway perspective view of a cap body.

FIG. 3 is a plan view of the bottom plate of the outer cylinder before bending.

FIG. 4 is a partially cutaway vertical sectional view of a cap body.

FIG. 5 is an explanatory diagram of a usage state of the cap body.

FIG. 6 is likewise an explanatory view of a usage state.

FIG. 7 is an explanatory diagram for removing concrete in the inner cylinder.

8 is a partially cutaway perspective view showing another embodiment of the cap body A. FIG.

9 is a partially cutaway perspective view showing another embodiment of the cap body A. FIG.

10 is a partially cutaway perspective view showing another embodiment of the cap body A. FIG.

11 is a perspective view of another embodiment of the cap body A. FIG.

FIG. 12 is a perspective view of an essential part of another embodiment during construction.

[Explanation of symbols]

 A Cap body 1 Top plate 2 Inner cylinder 3 Outer cylinder 4 Upper tremie port 5 Gas-liquid vent hole 6 Bottom plate 6a Flat area 7 Lower tremie port 8 Pillar main hole 9 Slit 9a Slit piece 10 Bottom space 11 Pillar main bar 12 Plate edge 13 Casing 14 Reinforcing bar cage 15 Horizontal bars 16 Tremy tube 17 Drilling hole 18 Bucket 19 Kelly bar 21 Rope 21a chain 21b chain

Claims (6)

[Claims] 1. An inner cylinder 2 into which a concrete placing tremie pipe 16 can be freely inserted is surrounded by an outer cylinder 3 at a predetermined interval, and the upper ends of both cylinders 2 and 3 are annular top plates 1,
The lower ends of the cap body A are attached to each other by an annular bottom plate 6 to form a double-cylindrical cap body A. Further, a plurality of main pile holes 8 are formed in the bottom plate 6 of the cap body A at predetermined intervals. A pile head treatment tool for cast-in-place piles, characterized in that gas-liquid drain holes 5 (9) are formed in the top plate 1 and the bottom plate 6. 2. The inner cylinder 2 and the outer cylinder 3 have the same length, and the top plate 1 and the bottom plate 6 are attached to the upper and lower ends of the cylinders 2 and 3 in a horizontal plate shape. 1. A pile head treatment tool for in-place pile driving. 3. A plurality of gas / liquid drain holes 5 are formed near the outer peripheral edge of the top plate 1 of the outer cylinder 3, and a concrete placing tremie pipe 16 can be freely inserted into the center of the top plate 1. A double cylinder having an upper upper tremie port 4 formed therein, which is engaged with the lower side of the upper tremie port 4 and which has an upper and lower open inner cylinder 2 shorter than the outer cylinder 3 by 2% to 3%. In the cap body A formed by forming a plurality of main pile holes 8 at substantially equal intervals in a flat area 6a near the outer peripheral edge of the bottom plate 6 of the outer cylinder 3, and further in the center of the bottom plate 6. A plurality of slits 9 cut radially are formed on the periphery of the lower tremie opening 7 formed in
Are formed at substantially equal intervals and leave the flat region 6a,
Further, the slit piece 9a generated by each slit 9 is bent obliquely upward, and the tip of this slit piece 9a is fixed to the inner cylinder 2
A pile head treatment tool for cast-in-place piles, which is formed by being fixedly attached to the lower edge of the pile. 4. The pile head treating tool for cast-in-place piles according to claim 1, 2 or 3, wherein the top plate 1 and / or the bottom plate 6 is formed of a mesh or punching metal. 5. The rebar cage 14 is capped with the cap body A, and the cap body A and the rebar cage 14 are bound and fixed by a cord 23 such as a detachable chain, wire or cord. The pile head treatment method using the pile head treatment tool for cast-in-place pile according to any one of claims 1 to 4, wherein the pile head treatment tool is built in the excavation hole 17. 6. The cap body A is staked and fixed to the rebar cage 14 by stat welding and built in the drill hole 17, and then the tremie pipe 16 is built in the drill hole 17 through the inner cylinder 2 of the cap body A. After performing continuous concrete pouring from the bottom of the excavation hole 17 to the top surface of the inner cylinder 2, the inner cylinder is immediately filled by rotating the excavation bucket 18 attached to the kelly bar 19. The pile head treatment method using the pile head treatment tool for cast-in-place pile according to any one of claims 1 to 4, wherein the removed slime-mixed concrete is removed.