JPH0222810B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pile cap treatment method for cast-in-place concrete piles.

Conventionally, the pile cap of a cast-in-place concrete pile is formed with a concentration of poor concrete mixed with impurities such as slime, making it impossible to obtain the required strength. Pile head processing is performed by forming a high backfill section and, after hardening, using a breaker to scrape and remove the backfill section, but the workability is poor and requires a great deal of labor and time, increasing construction costs and construction time. Not only will this result in a prolonged period of
It had the disadvantage of generating pollution such as noise and vibration.

The present invention concentrically arranges a ring-shaped pipe injected with a static crushing agent and a ring-shaped tube in which a static crushing agent is not injected, on the horizontal dividing planned line between the pile main body portion and the extra pile portion, and A ring-shaped pipe injected with a static crushing agent is placed horizontally within the area where the heap part is formed, and static crushing is carried out at a predetermined position above or below the inner surface of the pipe that is within the area where the overfill part is formed and is surrounded by this pipe. After the pipe injected with the agent is erected so that it can return elastically to its predetermined position, concrete is poured, and after the required time has elapsed, cracks caused by the expansion pressure of the static crushing agent in the pipe on the horizontal dividing plan line are statically removed. By generating a crushing agent toward the pipe that has not been injected, the extra pile part is separated from the pile main body along the horizontal dividing plan line, and then the static of the ring-shaped pipe placed within the area where the extra pile part is formed is The surplus part is vertically divided into an inner part and an outer part by the expansion pressure of a crushing agent, and at the same time or after that, this inner part is divided by the expansion pressure of a static crushing agent of a pipe installed in the part. The purpose of this is to allow pile cap processing to be carried out efficiently without causing pollution such as noise and vibration.

The illustrated embodiment will be described below.

1 and 2 are ring-shaped steel sheath tubes, the outer sheath tube 1 has a slightly larger diameter than the hoop reinforcement 4 of the cage reinforcing bar 3, and the inner sheath tube 2 has a diameter of about 2 times the diameter of the sheath tube 1. /3 in diameter, and injection ports 2', 2' are provided at both ends, slanting outward and upward.

The sheath tubes 1 and 2 are arranged concentrically on the same surface, and connecting fittings 5 are placed at approximately 6 equal parts around each circumference.
are connected by tightening both ends with screws 6.

Then, the sheathed pipes 1 and 2 are fitted to the cage reinforcing bar 3 with the vertical reinforcement 7 located between the sheathed pipes 1 and 2, and the sheathed pipe 1 is fitted to the uppermost hoop reinforcement 4'. The connecting fitting 5 is placed horizontally on the outside, and the required portions of the connecting fitting 5 are tightened to the hoop muscle 4' with wire, adhesive tape, or the like.

Reference numeral 8 denotes a cylindrical insulating material made of foamed polyethylene, which is fitted into the portion of each longitudinal bar 7 extending upward from the hoop bar 4' and fixed with adhesive tape, string, or the like.

Reference numerals 9 and 10 are steel sheath tubes formed into a ring shape with a diameter slightly smaller than that of the hoop muscle 4, and injection ports 9', 9', 10', and 10' are provided at both ends thereof and are inclined outwardly and upwardly.

The sheath pipe 9 is fitted horizontally to the inner circumference of the cylindrical insulating material 8 and is spaced apart from the sheath pipe 2 by a predetermined distance.
Required portions of the periphery are fastened to the cylindrical insulating material 8 using adhesive tape, wire, or the like.

The predetermined interval may be at least wider than the interval between the sheath tube 1 and the sheath tube 2.

Further, the sheath tube 10 is fitted horizontally on the inner periphery of each cylindrical insulating material 8 at approximately the midpoint between the sheath tube 9 and the upper end of the vertical bar 7, and the required portions of the periphery are covered with the cylindrical insulating material. 8. Tighten with adhesive tape, wire, etc.

Reference numerals 11 to 18 denote straight steel sheathed tubes with injection ports 11' to 18' provided at one end, and the sheathed tubes 1,
2 and sheath tube 9, and between sheath tube 9 and sheath tube 1
0, four of them are horizontally hung in a grid pattern at predetermined positions above and below the inner surface surrounded by the sheath tubes 9 and 10.

That is, each of the sheath tubes 11 to 18 is horizontally suspended with coil springs 19, 19 attached to both ends tightly tied to the opposing cylindrical insulating material 8, and the coil springs 19, 19 are
Each coil spring 19 is tensioned in a pre-stretched state so that the sheath tubes 11 to 18 can be suspended above the sheath tubes 1 and 2 in the event that one of the sheath tubes 19 is accidentally broken.

A known static crushing agent in the form of slurry that develops expansion pressure after a predetermined period of time is injected into each of the sheath pipes 2, 9, 10, 11-18, and each injection port 2', 2',
9', 9', 10', 10', 11' to 18' are sealed with adhesive tape, and the sheath tube 1 is left empty.

The predetermined time for the expansion pressure of the static crushing agent to develop is different, and the time for sheath pipes 9 to 18 is longer than the time for sheath pipe 2, and the time for sheath pipes 9 and 10 is longer than that for sheath pipe 2. The time and the time for sheath tubes 11 to 18 are made the same length, or the time for sheath tubes 11 to 18 is
Make sure that the time for number 8 is longer. This time difference can be adjusted freely by setting the water ratio of the crushing agent separately if each sheath pipe has the same diameter, or by using different water ratios of the crushing agent with different diameters of each sheath pipe. can be determined.

Thus, each sheath tube 2, 9, 10, 11-1
The cage-shaped reinforcing bars 3 filled with static crushing agent 8 are inserted into pile holes or casing tubes (not shown).
With the sheath pipes 1 and 2 positioned on the horizontal dividing planned line 20 between the pile part and the pile main part, insert the tremie pipe (not shown) from the inside of the sheath pipe 2. ), and concrete 21 is poured to the required extra height.

When the tremie tube is inserted, the sheath tubes 11 to 1
8, it will move to an arbitrary position against the spring force of the coil spring 19, but if the tremie pipe is pulled out after concrete pouring, it will elastically return to the predetermined position.

After a predetermined period of time has elapsed since the concrete 21 was placed, the static crushing agent in the sheath pipe 2 buried at the horizontal dividing planned line 20 expands and an expansion pressure is developed, causing the outer sheath pipe 1 to expand. This combination of the fact that the horizontal cross-sectional area of only one part is missing and the sheath pipe 1 is empty and the pressure resistance strength is lower than that of other parts causes a horizontal crack 22 along the horizontal dividing planned line 20. occurs, and the extra heap portion 21a of the concrete 21 is separated from the pile body portion 21b.

In this case, the sheath tube 9 is opposed above the sheath tube 1, but the distance therebetween is wider than the distance between the sheath tube 1 and the sheath tube 2 as described above, so the crack is between the sheath tube 2 and the sheath tube 9. This occurs horizontally along the horizontal dividing planned line 20 as described above.

The extra heap portion 21a is the pile body portion 21b.
After the static crushing agent in the sheath pipes 9 and 10 buried in the remaining portion expands and an expansion pressure is generated, each vertical strip 7 is pushed outward, as if each A crack 23 occurs along the circumferential surface connecting the vertical bars 7, and a cylindrical inner part 21c corresponding to the inside of the longitudinal bar 7, in other words, the inside of the sheath tubes 9 and 10, and the outer part outside thereof. 21d, and at the same time, vertical cracks 24 are generated at approximately equal intervals in the outer portion 21d, thereby further dividing the outer portion 21d.

Further, at the same time or after the expansion pressure of the sheath pipes 9 and 10 due to the static crushing agent is developed,
Sheath pipe 11 buried in the inner part 21c
The expansion pressure of the static crushing agent ~18 is developed, and cracks 25 and 26 are generated horizontally on the surface along the sheath pipes 11-14 and the surface along the sheath pipes 15-18, and each sheath pipe A crack occurs along the surface connecting 11 to 18 and the sheath pipes 9 and 10,
The inner portion 21c is further divided by these.

In this case, the excess portion 21a is the pile body portion 21b.
Since the sheath tubes 9 to 18 have already been separated from
The pile body portion 21b will not be crushed by the expansion pressure of the static crushing agent.

After the root cutting, the extra heap portion 21a has already been separated from the pile body portion 21b along the horizontal dividing planned line 20, and the cylindrical insulating material 8 has been fitted to the vertical reinforcement 7, and the vertical reinforcement 7 is connected to the concrete 21. Not only are the parts 7 not in close contact with each other, but the inner part 21c and the outer part 21d are further divided, so that they can be easily removed by hand or by pulling them out using heavy machinery.

In addition, in the above embodiment, a case was explained in which two ring-shaped steel sheath pipes were placed each on the horizontal dividing planned line and within the reinforcement part formation range, but the sheath pipes on the horizontal dividing planned line were An appropriate number of three or more sheath pipes may be arranged depending on the dimensions, and one or three or more sheath pipes may be arranged in an appropriate number within the area where the extra sheath part is formed. The tube may be made of any suitable material other than metal, such as a synthetic resin tube or a paper tube.

Furthermore, the tube into which the static crushing agent is injected is preferably a sheathed tube, but it is not limited to this, and any tube other than a sheathed tube may be used as long as it does not absorb and reduce the expansion pressure of the static crushing agent. In addition, the static crushing agent may be injected before the sheath pipe is attached to the cage reinforcing bar.

As is clear from the above, according to the present invention, after the concrete is crushed by the expansion pressure of the static crushing agent to separate the extra pile from the pile main body, the extra pile is buried there. The ring-shaped pipe is divided into an inner part and an outer part by the expansion pressure of the static crushing agent, and the inner part is further divided by the expansion pressure of the static crushing agent of the pipe buried in the pipe. , it is possible to eliminate all at once the disadvantages of increasing construction costs, prolonging the construction period, noise pollution, etc. when the above-mentioned conventional extra-heavy portion is cut and crushed with a breaker.

In addition, when the expansion pressure of the static crushing agent in a pipe placed on the horizontal dividing planned line occurs, the horizontal cross-sectional area is missing only in the part between the spaces, and this pipe is empty and has a higher resistance than other parts. Combined with the decrease in pressure strength, not only can cracks be reliably generated along the horizontal separation planned line, but also the expansion pressure of the static crushing agent will increase after the excess pile is separated from the pile body. Since the pile is divided into an inner part and an outer part, and the inner part is further divided, there is no possibility of accidentally crushing the main body part of the pile.

Furthermore, the sheath tubes that divide the inner part are constructed so that they can elastically return to their predetermined positions, so even if the tremie tube comes into contact with each sheath tube during insertion, it can be freely moved against the elasticity. The concrete can be moved to the position shown in FIG. 1 without interfering with the insertion of the tremie pipe, and can be elastically returned to the predetermined position after concrete is poured.

Additional relationship After arranging the ring-shaped pipe injected with static crushing agent and the ring-shaped pipe without static crushing agent injected concentrically on the horizontal dividing plan line between the pile main body part and the extra pile part,
After concrete is poured and the required time has elapsed, cracks due to the expansion pressure of the static crushing agent are generated toward the pipes in which the static crushing agent has not been injected, thereby overfilling the concrete along the horizontal dividing planned line. The point where the section is separated from the pile main body section is the invention described in claim 1 of Patent No. 1468383 (Japanese Patent Publication No. 63-013490).
However, the present invention is an invention in which this point is the main part of the configuration, and the expansion pressure of the static crushing agent allows horizontal crushing. It is the same in that it separates the extra heap from the pile main body by creating cracks along the separation planned line, allowing efficient pile cap treatment without causing pollution such as noise and vibration. It accomplishes its purpose.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a perspective view of a sheathed pipe arranged on a horizontal dividing plan line, and FIG. 2 is a perspective view of the sheathed pipe shown in FIG. Fig. 3 is a perspective view of the main parts showing the state in which the cage reinforcing bars are attached, and Fig. 3 is a plan view showing the state in which the sheathed pipes are attached to the required parts of the cage reinforcing bars, with the sheathed pipes suspended horizontally in the shape of a grid above being omitted. , Fig. 4 is a cross-sectional view showing the state in which the reinforcement part is separated from the pile main body part along the horizontal dividing plan line at the line position in Fig. 3, and Fig. 5 is a cross-sectional view showing the state in which the reinforcement part is separated from the pile main part part along the horizontal division plan line. After that, it is further divided into an inner part and an outer part,
It is a perspective view showing a state in which these inner and outer parts are further divided. 21b...Pile main part, 21a...Extra pile part,
20...Horizontal dividing planned line, 1, 2, 9-18...
sheath tube.

Claims (1)

[Claims] 1. A ring-shaped pipe injected with a static crushing agent and a ring-shaped pipe without a static crushing agent are arranged concentrically on the horizontal dividing planned line between the pile main body part and the extra pile part, and the above-mentioned pile A ring-shaped pipe injected with a static crushing agent is placed horizontally within the area for forming the part, and static crushing is carried out at a predetermined position above or below the inner surface of the area surrounded by the pipe within the area for forming the overfill part. After the pipe injected with the agent is erected so that it can return elastically to its predetermined position, concrete is poured, and after the required time has elapsed, the static crushing agent's expansion pressure of the pipe placed on the horizontal dividing planned line causes By generating cracks in the direction of the pipe into which static crushing agent has not been injected, the extra pile portion is separated from the pile main body portion along the horizontal separation plan line, and then a ring is placed within the area where the extra pile portion is formed. The expansion pressure of the static crushing agent in the pipe vertically divides the excess portion into the inner and outer parts of the pipe, and at the same time or afterwards, the inner surface surrounded by the pipe or a predetermined area above and below it is divided. A pile cap processing method characterized in that the inner part is further divided by the expansion pressure of a static crushing agent of a pipe suspended horizontally at a certain position.