JP2014095254A - Pile head treatment method for cast-in-place pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pile head treatment method for a cast-in-place, capable of crushing concrete of an extra-fill part while preventing a broken-out section from being formed in a mountain-shaped section inside a group of main reinforcements even in the case of a large diameter cast-in-place pile, and capable of surely crushing concrete of an extra-fill part positioned outside the group of main reinforcements so as to peel them outward from the group of main reinforcements.SOLUTION: Edge cutting sleeves 5 for preventing adhesion of concrete are fitted to main reinforcements 3 of a pile head; and a plurality of static crushing cartridges 7 constituted by filling water-permeable containers with a hydration expansive crushing agent are circularly arranged along the inner peripheral surface of the group of main reinforcements inside the group of main reinforcements circularly arranged and at a position slightly higher than a pile top end of design, and fixed to the group of main reinforcements. Concrete is placed, in a state that a horizontal breaking auxiliary plate 8 for vertically separating concrete inside the group of main reinforcements is horizontally arranged and fixed to the group of main reinforcements. After the concrete is cured, the hydration expansive crushing agent is made to expand to crush and remove an extra-fill part above the horizontal breaking auxiliary plate.

Description

The present invention uses piles of pile crushing concrete using a static crushing cartridge in which a water-permeable container is filled with a hydrated expansion crushing agent (concrete part of pile head with poor quality of a pile head mixed with slime).
The present invention relates to a pile head processing method for cast-in-place piles for crushing and removing.

As a pile head treatment method for cast-in-place piles, which eliminates the need for chipping work of surplus parts with impact tools such as breakers and drills, it consists of a frame in which static crushing cartridges filled with hydrated expansion crushing agent are arranged in a water-permeable container A pile head crusher is attached to the pile head at a predetermined position using a main bar, and concrete is placed in the pile hole in this state. After the concrete is hardened, the hydrated expansion crushing agent is expanded. A technique for automatically crushing and removing the surplus portion is already known from Patent Document 1.

According to this method, it is possible to omit the crushing work of the surplus portion by the breaker and the drilling work of the static crushing agent injection hole by the drill, and there is an advantage that the pile head processing can be performed without generating noise and dust. .

However, in the above-described known technology, as described in FIGS. 2 to 4 of Patent Document 1, a plurality of static crushing cartridges having a linear shape are radially arranged inside the main muscle group of the pile head. It was arranged.

Therefore, when the hydrated expansion crushing agent of the static crushing cartridge is expanded, the surplus concrete located inside the main muscle group is finely crushed, and there is a concern that troublesome work of removing as crushing waste may occur. .

Further, in the above-described known technology, a foamed synthetic resin that can be bent in accordance with a circular reinforcing bar rod by forming a plurality of main muscle insertion holes in the thickness and forming a slit parallel to the main muscle insertion hole on one side. The outer edge and the inner edge of the group of main bars arranged in a circle are separated by the edge-cutting plate, because the steel edge-cutting plate is fitted into the main reinforcement above the top of the pile pile to prevent the concrete from adhering to the main reinforcement. Therefore, it is difficult to exert the crushing action due to the expansion of the static crushing cartridges radially arranged inside the main muscle group to the outside of the main muscle group. There is concern that the concrete on the outside will remain as a large lump on the outside.

As a solution to such a problem, the present inventor tried to arrange a plurality of static crushing cartridges in an arc shape and arrange them in a circular shape along the inner peripheral surface of the main muscle group. According to this, as shown in a schematic diagram to be described later, the crushing action due to the expansion of the static crushing cartridge can be exerted from the gap between the adjacent main muscles to the outside of the main muscle group. It was found that the concrete of the embankment could be crushed so as to be peeled away from the main reinforcing bar group, and that the concrete of the surging part could be crushed into a large lump that could be lifted and removed by heavy machinery inside the main muscle group.

However, when a plurality of static crushing cartridges are arranged in a circle along the inner peripheral surface of the main muscle group, for example, in a cast-in-place pile having a large diameter of 1800 mm or more, a pile generated by expansion of the static crushing cartridge It was found that the fracture surface on the center side became a mountain shape, and that most of the surging parts remained in the mountain shape on the pile center side.

JP 2002-285550 A

The present invention was made on the basis of the above-described new knowledge, and the object thereof is to arrange a plurality of static crushing cartridges in a circular shape along the inner peripheral surface of the main muscle group, By combining a horizontal break auxiliary plate for cutting up and down the concrete inside the main reinforcing bars, even in cast-in-place piles with a large diameter of 1800 mm or more, the fracture surface does not become chevron inside the main reinforcing bars. The concrete of the surplus part can be crushed into a large lump that can be lifted and removed by heavy machinery, and the concrete of the surplus part located outside the main muscle group can be reliably crushed so as to be peeled off from the main muscle group It is in providing the pile head processing method of a cast-in-place pile.

In order to achieve the above object, technical measures taken by the present invention are as follows. That is,
The pile heading method for a cast-in-place pile according to the first aspect of the present invention is a method in which a sleeve for edge cutting for preventing adhesion of concrete is fitted to a main bar of a pile head in a cast-in-place pile, while a group of main bars arranged in a circular shape. A plurality of static crushing cartridges, which are filled with a hydrated expansion crushing agent in a water-permeable container, are placed in a circular shape along the inner peripheral surface of the main muscle group at a position slightly higher than the design pile top. The concrete is placed and fixed in the state where the horizontal break auxiliary plate for cutting the concrete inside the main bar group up and down is horizontally placed and fixed to the main bar group. After that, expand the hydrated expansion crushing agent to crush and remove the upper surplus portion from the horizontal break auxiliary plate, remove the static crush cartridge and horizontal break auxiliary plate, and then finish to the design pile top As a feature That.

Invention of Claim 2 is the pile heading method of the cast-in-place pile of Claim 1, Comprising: The horizontal fracture | rupture auxiliary | assistant board is the opening for the tremey tube insertion formed in the center part, and its opening edge It is formed of an elastic plate having a notch formed radially at the part and a notch for forming a gap through which the concrete can pass between the horizontal fracture auxiliary plate formed at the outer peripheral edge and the main reinforcement group. It is characterized by that.

Invention of Claim 3 is the pile heading method of the cast-in-place pile of Claim 1 or 2,
The static crushing cartridge is arranged in two upper and lower stages.

Invention of Claim 4 is the pile heading method of the cast-in-place pile described in any one of Claims 1-3, Comprising: By binding a static crushing cartridge with the wire from the sleeve for edge cutting It is fixed to the main muscle group, and it is fixed to the main muscle group in a state of being sandwiched up and down by two upper and lower cross-girder reinforcing bars spanned across the main muscle group in the form of a cross beam.

Invention of Claim 5 is the pile heading method of the cast-in-place pile in any one of Claims 1-4, Comprising: The main reinforcement is made into the bundle reinforcement which bundled two deformed reinforcement, and the sleeve for edge cutting is It is characterized by having a cross-sectional shape that fits into a bundled reinforcing bar.

Invention of Claim 6 is a pile heading method of the cast-in-place pile in any one of Claims 1-5, Comprising: The sleeve for edge cutting is made into the cross-sectional shape which opened both upper and lower ends, The upper end opening is made. It is characterized by being configured to be closed with a cap.

According to the first aspect of the present invention, the plurality of static crushing cartridges are arranged in a circular shape along the inner peripheral surface of the main reinforcing bar group, and the horizontal for vertically cutting the concrete inside the main reinforcing bar group. By combining a break assist plate, even in cast-in-place piles with a large diameter of 1800 mm or more, the surplus cross section of the surplus portion due to expansion of the static crushing cartridge should not be chevron inside the main reinforcement group. The pile concrete can be crushed into large blocks that can be lifted and removed by heavy machinery, and the crushing action caused by the expansion of the static crushing cartridge extends from the gap between the main muscles to the outside of the main muscle groups. It can be reliably crushed so that the concrete of the embankment is peeled away from the main reinforcing bars.

That is, since a plurality of static crushing cartridges are arranged in a circular shape along the inner peripheral surface of the main muscle group, the static crushing cartridge expands as shown in the schematic diagram shown in FIG. When crushing the inner concrete, the crushing action due to the expansion of the static crushing cartridge can be exerted from the gap between the main bars (the area where there is no restriction by the main bars) to the outside of the main bar group. Therefore, along with the expansion of the static crushing cartridge to the outside, it is possible to reliably crush so that the concrete in the surplus portion located outside the main muscle group is peeled away from the main muscle group.

In addition, the concrete is placed in the pile hole in a state where the horizontal fracture auxiliary plate for horizontally cutting the concrete inside the main reinforcing bar group is vertically arranged inside the main reinforcing bar group.
Even for cast-in-place piles with a large diameter of 0 mm or more, the fracture surface of the surplus part due to expansion of the static crushing cartridge does not become a mountain shape, and the concrete of the surplus part located inside the main muscle group can be lifted and removed by heavy machinery It can be crushed into a large lump shape, and the crushed concrete of the surplus portion can be easily removed.

As described above, the surplus portion up to a position slightly higher than the design pile top is crushed and removed, so the amount of work for finishing chiseling to the design pile top after the removal of the static crush cartridge and the horizontal break auxiliary plate is completed. Therefore, the generation of noise and dust can be suppressed as much as possible.

According to invention of Claim 2, the horizontal fracture | rupture auxiliary | assistant board was formed in the opening for the tremey tube insertion formed in the center part, the cut radially formed in the opening edge part, and the outer periphery Since it is formed of an elastic plate with a notch for forming a gap through which concrete can pass between the horizontal fracture auxiliary plate and the main reinforcing bar group, when placing concrete while pulling up the tremy tube, good quality The extra concrete pushed up by the concrete spreads the opening edge of the horizontal break auxiliary plate located around the tremy tube, overflows above the horizontal break auxiliary plate,
Even from the cutout portion of the outer peripheral edge of the horizontal fracture assisting plate, it overflows above the horizontal fracture assisting plate.
Therefore, it is possible to prevent the surplus concrete from staying in the lower part of the horizontal fracture auxiliary plate.

According to invention of Claim 3, since the static crushing cartridge is arrange | positioned at 2 steps | paragraphs of upper and lower sides, even if the protrusion length of the main reinforcement which protrudes upwards from the pile top end of a design is long, on the outer side of a main reinforcement group It can be reliably crushed so that the concrete in the surplus portion located can be peeled away from the main reinforcement group.

According to the invention described in claim 4, since the static crushing cartridge is fixed to the main muscle group by bundling with a wire from above the edge cutting sleeve, it is not restricted by the planar shape or installation level of the horizontal fracture auxiliary plate. The static crushing cartridge can be attached to the cylinder, and it is easy to arrange the static crushing cartridge in a circular shape. In addition, the horizontal breakage auxiliary plate is fixed to the main reinforcing bar group in a state where it is sandwiched between the upper and lower two-level cross-girder reinforcing bars that are bridged across the main reinforcing bar group. When placing concrete, there is no possibility that the mounting position of the horizontal fracture auxiliary plate is shifted up and down, and high-precision construction is possible.

According to the fifth aspect of the present invention, the main reinforcing bar is a bundled reinforcing bar in which two deformed reinforcing bars are bundled, and the edge cutting sleeve has a cross-sectional shape that fits into the bundled reinforcing bars, so even if the number of the main reinforcing bars is large. The gap between the main muscle groups arranged in a circle can be secured widely, and the crushing action due to the expansion of the static crushing cartridge can be easily exerted from the gap between the main muscles to the outside of the main muscle group.

According to the sixth aspect of the present invention, since the edge cutting sleeve has a cross-sectional shape with both upper and lower ends opened, and the upper end opening is closed with the cap, the concrete from the upper end opening of the edge cutting sleeve Intrusion prevention is easy and reliable.

It is a partially cutaway perspective view of the principal part showing an embodiment of the present invention. It is a longitudinal cross-sectional view of the principal part. It is the sectional view on the AA line of FIG. It is a vertical side view explaining a process. It is a vertical side view explaining the process following FIG. It is a vertical side view explaining the process following FIG. It is a vertical side view explaining the process following FIG. It is a vertical side view explaining the process following FIG. It is a schematic diagram of the crushing action by expansion of a static crushing cartridge.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the figure, 1 is a reinforcing bar rod inserted into a pile hole 2 for cast-in-place pile construction, and is composed of a necessary number of main bars 3 and hoop bars 4. In the illustrated example, the main reinforcing bar 3 is a bundled reinforcing bar in which two deformed reinforcing bars are bundled. Even if the number of reinforcing bars of the main reinforcing bar 3 is large, the passage of the coarse concrete aggregate between the main reinforcing bars 3 and the arrangement of underground beams (not shown) To secure the necessary rebar clearance.

The main reinforcement 3 of the pile head in the cast-in-place pile is fitted with a foam cutting sleeve 5 made of foamed synthetic resin to prevent the adhesion of concrete to the upper part of the design top of the pile (a shown in FIG. 6). is there. In the illustrated example, since the main reinforcing bar 3 is a bundled reinforcing bar in which two deformed reinforcing bars are bundled, the edge cutting sleeve 5 has a cross-sectional shape that fits the bundled reinforcing bar as shown in FIGS. These edge-cutting sleeves 5 have a cross-sectional shape with both upper and lower ends opened, and the upper-end opening is configured to be closed with a cap 6 different from the sleeve.
You may produce in the cross-sectional shape which obstruct | occluded the upper end beforehand.

A distance H (inside the main group 3 of the main bars 3 arranged in a circular shape of the reinforcing bar 1 and a little from the designed pile top end a.
For example, at a high position b, a plurality of static crushing cartridges 7 in which a permeable container is filled with a hydrated expansion crushing agent are arranged in a circular shape along the inner peripheral surface of the main muscle 3 group. A horizontal breakage assisting plate 8 that is fixed to the group and that vertically cuts the concrete inside the main bar 3 group is arranged horizontally and fixed to the main bar 3 group.

More specifically, the static crushing cartridge 7 is fixed to the main muscle 3 group by bundling with a wire 9 such as a number wire from above the edge cutting sleeve 5. The horizontal breaking auxiliary plate 8 is fixed to the main bar 3 group in a state where both the upper and lower surfaces are sandwiched between two upper and lower narrow bar-shaped reinforcing bars 10 spanned across the main bar 3 group in a cross beam shape. In the illustrated example, the static crushing cartridges 7 are arranged in two upper and lower stages.
Depending on the length of the main bar above the pile top end a, the upper static crushing cartridge 7 may be omitted, or the static crushing cartridges 7 may be arranged in three or more stages.

The horizontal breaking auxiliary plate 8 is formed of an elastic plate such as a synthetic resin plate or a rubber plate, and has an opening 8a for insertion of a tremy tube formed in the center portion, and a notch formed radially at the opening edge portion thereof. 8
b, and a notch 8c for forming a gap through which the concrete can pass between the horizontal fracture auxiliary plate 8 formed on the outer peripheral edge and the main reinforcing bar group.

As described above, the static crushing cartridge 7 and the horizontal fracture auxiliary plate 8 are placed at predetermined positions of the reinforcing bar 1.
After removing the slime from the bottom of the pile hole 2, the reinforcing bar 1 is installed in the pile hole 2,
In this state, as shown in FIGS. 4 and 5, the concrete 12 is placed using the tremy pipe 11. 13 in the figure indicates muddy water (hole wall stabilizing solution).

The opening 8a at the center of the horizontal breakage assisting plate 8 is formed to have a slightly smaller diameter than the tremy tube 11, but the horizontal breakage assisting plate 8 is made of an elastic plate, and a radial notch is formed at the edge of the opening 8a. Since the 8b is formed, the opening edge portion is easily elastically deformed in the vertical direction by inserting and removing the tremy tube 11.

Accordingly, the pre-prepared concrete (poor quality concrete mixed with slime) 12a is lifted by the high-quality concrete 12, and the outer side of the opening 8a, the notch 8b, the notch 8c, and the main reinforcing bars 3 group in the horizontal fracture auxiliary plate 8 is lifted. As shown in FIG. 6, it passes through a hollow part (muddy water) etc. and is pre-prepared to a required height.

After the whole concrete 12 including the pre-cured portion is cured, the hydrated expansion crushing agent is expanded by reaction with the concrete moisture to crush and remove the upper surplus portion from the horizontal fracture auxiliary plate 8. The reaction rate is performed by controlling the rate of water immersion into the permeable container as usual.

In this embodiment, an edge-cutting sleeve 5 that prevents adhesion of concrete to the main reinforcement 3 of the pile head is fitted, while a plurality of static crushing cartridges 7 are arranged along the inner peripheral surface of the main reinforcement 3 group in a circular shape. As shown in the schematic diagram shown in FIG.
When the inner concrete of the surplus portion is crushed and the crushing action of the static crushing cartridge 7 is crushed, the crushing action by the expansion of the static crushing cartridge 7 may be exerted from the gap between the main bars 3 (the area where there is no restriction by the main bar 3) to the outside of the main bar 3 group. it can. Therefore, along with the expansion of the static crushing cartridge 7 to the outside, it is possible to reliably crush the extra-concrete concrete positioned outside the main reinforcing bar 3 group so as to peel away from the main reinforcing bar 3 group.

In addition, the concrete is placed in the pile hole 2 in the state where the horizontal fracture auxiliary plate 8 for vertically cutting the concrete inside the main bar 3 group is vertically arranged inside the main bar 3 group. Even in cast-in-place piles with a large diameter of 1800 mm or more, the fracture surface of the surplus portion due to expansion of the static crushing cartridge 7 does not become a mountain shape, and the surplus concrete located inside the main muscle group can be lifted and removed by heavy machinery Can be crushed into large blocks. Therefore, as shown in FIG. 7, for example, by embedding hanging brackets such as eyebolts at an appropriate time before the concrete is completely cured, the crushed surplus concrete is easily lifted by heavy machinery. It can be removed.

After crushing and removing the pre-cured portion in this way, after removing the static crushing cartridge 7 and the horizontal fracture auxiliary plate 8, the finishing crushing is performed up to the designed pile crest a, and as shown in FIG. Processing will be completed.

In the above-described embodiment, even when the number of reinforcing bars of the main reinforcing bars 3 is large, it is possible to secure a reinforcing bar clearance necessary for passing of the coarse concrete aggregate and the arrangement of underground beams (not shown) between the main reinforcing bars 3. Therefore, although the main reinforcing bar 3 is a bundled reinforcing bar having two deformed reinforcing bars, it can be implemented as a general reinforcing bar bar having one deformed reinforcing bar.

DESCRIPTION OF SYMBOLS 1 Reinforcement rod 2 Pile hole 3 Main reinforcement 4 Hoop reinforcement 5 Edge cutting sleeve 6 Cap 7 Static crushing cartridge 8 Horizontal fracture auxiliary plate 8a Opening 8b Notch 8c Notch 9 Wire 10 Cross-beam reinforcement 11 Tremy tube 12 Concrete 12a Preliminary concrete 13 Muddy water H Small distance (for example, 100mm)
a Designed pile top b Position slightly higher than the designed pile top

Claims (6)

A permeable container is placed inside the main bar group arranged in a circle and slightly higher than the design top of the pile while fitting a sleeve for preventing the adhesion of concrete to the main bar of the pile head in the cast-in-place pile. A plurality of static crushing cartridges filled with hydrated expansion crushing agent are arranged in a circular shape along the inner peripheral surface of the main muscle group and fixed to the main muscle group, and the concrete inside the main muscle group is moved up and down In a state where the horizontal breaking auxiliary plate for cutting the edge is horizontally arranged and fixed to the main muscle group,
After placing concrete and hardening the concrete, expand the hydrated expansion crushing agent to crush and remove the upper surplus part from the horizontal break auxiliary plate, remove the static crush cartridge and horizontal break auxiliary plate, and design A pile heading method for cast-in-place piles, characterized in that finishing is done to the top of the upper pile. A horizontal break assist plate is provided between the opening for treme tube insertion formed in the central portion, the notches formed radially on the opening edge, and the horizontal break assist plate formed on the outer peripheral edge and the main muscle group. The pile heading method for a cast-in-place pile according to claim 1, wherein the pile head is formed of an elastic plate having a notch for forming a gap through which concrete can pass. The method of pile heading of cast-in-place piles according to claim 1 or 2, wherein the static crushing cartridges are arranged in two upper and lower stages. The static crushing cartridge is fixed to the main muscle group by bundling it with a wire rod from the top of the edge-cutting sleeve, and the horizontal fracture auxiliary plate is sandwiched up and down by the upper and lower two-stage cross-bar rebars spanned across the main muscle group The pile heading method for a cast-in-place pile according to any one of claims 1 to 3, wherein the pile is fixed to the main muscle group. The cast-in-place pile according to any one of claims 1 to 4, wherein the main reinforcing bar is a bundled reinforcing bar in which two deformed reinforcing bars are bundled, and the edge cutting sleeve has a cross-sectional shape fitted to the bundled reinforcing bar. Pile head method. The pile head of a cast-in-place pile according to any one of claims 1 to 5, wherein the edge cutting sleeve has a cross-sectional shape opened at both upper and lower ends, and the upper end opening is closed with a cap. Reasoning method.

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