JPH07268866A - Method for treating top of cast-in-place concrete pile - Google Patents

Abstract

PURPOSE:To facilitate work, guarantee a high quality, and reduce cost by eliminating noise and vibration caused by a drill for a long period of time, avoiding damage to a pile body, precluding excessive load leading to falling down of a crane, and preventing inferior concrete from mixing into concrete of the pile body. CONSTITUTION:A cage of reinforcing bar 3 is set in a pile bore 1 and concrete 5 is placed up to an extra-filling level, and before curing of the cast concrete starts, a ring-shaped jig 8 having a perforated plate shape with rough holes or a wheel shape is inserted into the cast concrete as deep as a crown level 6 of top of a pile, in a horizontal state. After curing of the cast concrete has started, before the concrete is completely cured, the jig is pulled up and extra- filled concrete 7 on the jig is removed and the concrete on the jig is washed with water so that the concrete may not be cured to separate cement therefrom, which cement is carried out together with surplus soil of a net pile.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating a pile head of a cast-in-place concrete pile which facilitates removal of overfilled concrete.

[0002]

2. Description of the Related Art As is well known, cast-in-place concrete piles, which are the foundations of piles of structures, are made by excavating deep into the ground to construct a reinforcing bar cage in a pile hole filled with mud, and underwater concrete. However, since the concrete on the pile head is deteriorated by the leitance, slime, and muddy water, the cast concrete will be 500 to more than the design pile head.
Overfilling is made about 1000 mm higher, and the overfilling portion is removed later. By the way, as the conventional means for removing the excess portion, there are the following various processing methods. A method of excavating the surrounding soil after the setting concrete is hardened, exposing the pile head, and crushing with a concrete crusher (breaker) that uses compressed air. A cover is attached to the reinforcing bars in the extra part in advance to prevent adhesion of the placed concrete, and a rock drilling machine or a static crushing agent (expansion due to hydration in concrete causes expansion of the concrete and inhibits hardening of the concrete, resulting in cracking. After separating the surplus portion at a predetermined height, the heavy concrete equipment such as a crane is used to pull out the concrete block in the surplus portion. At the top of the rebar cage built in the pile hole, attach a protective pipe to prevent concrete adhesion to each main bar,
Install a flat edged pipe below it at right angles to the main bar,
After placing concrete in the pile hole, apply hydraulic pressure to the edge cutting pipe to deform the pipe from a flat shape to an expanded shape such as a round shape, and cut the excess concrete, and then the excess A method of pulling up concrete (JP-A-58-213916). After placing the edge cutting pipe on the end of the main bar located in the pile head surplus portion of the reinforcing bar cage built in the pile hole and placing concrete to the pile head surplus portion to form the pile, A method in which a surplus concrete is removed by hammering an arrow into a hole previously formed on the side to remove the surplus concrete (Japanese Patent Application Laid-Open No. Sho-2004-2006).
63-308113). Inside the upper part of the rebar cage built in the pile hole, with the steel plate curing ring (cylindrical body) having a diameter slightly smaller than the inner diameter of the rebar cage and having a vertical length corresponding to the extra concrete thickness , Pour concrete, insert the rotating ring into the curing ring before hardening the concrete, remove the surplus concrete in the curing ring with the bucket, then pull out the curing ring and leave the remaining residual A method of picking up concrete (JP-A-58-80020). Fill the bucket in the extra part of the cast concrete,
A method of pulling out the bucket together with concrete pieces after the cast concrete has hardened to a predetermined strength (Japanese Patent Laid-Open No. Sho 60)
-62328). The remaining portion of the surplus will be removed later. Inside the upper part of the reinforced basket built in the pile hole, a bucket with a hole in the bottom plate is arranged at a predetermined height, and when placing concrete, excess concrete flows into the bucket from the hole in the bottom plate, A method of pulling out the bucket when the concrete is in a semi-hardened state (JP-A-62-50515). In addition, also in this case, the remaining portion of the excess will be removed later. By taking measures to prevent concrete from adhering to the concrete on the upper part of the reinforced cage built in the pile hole, and by loading the buried member in the pile head extra part before or after placing concrete, the extra concrete at this position is surrounded. Method to reduce the excess area by forcibly moving to the excess area, and after hardening the cast concrete, remove the excess concrete and the embedded member by removing the excess concrete around the embedded material (special Kaihei 1-219214 publication).

[0003]

However, these conventional techniques still have the following problems. a. In the above case, noise and vibration are generated when the excess concrete is crushed, which causes a slack for a long time and has a great adverse effect on the surrounding environment. In addition, the pile body may be damaged. b. In the above cases, the concrete block to be removed (about 2 tons when the pile diameter is 1500 mm) is pulled out by the crane, so if the insulation with the reinforcing bar and the occurrence of cracks are not complete, an excessive load will be applied to the crane. May cause the crane to tip over. In addition, when carrying out out-of-site as a method of disposing of the pulled out concrete lumps, it is necessary to consider fixing the transportation vehicle and the load so that the load does not drop during transportation. Furthermore, crushing work will occur at the disposal site. c. In the cases of (1) to (4) above, bad concrete, which is extra concrete, moves unintentionally when a bucket or the like is inserted, or bad concrete does not flow as desired due to the presence of a bucket, etc. Poor concrete may be mixed in or left under the surplus portion, and rather deteriorate the quality. Also, the work is not easy,
High cost. The present invention seeks to solve these problems.

[0004]

In order to achieve the above object, the invention of claim 1 is one in which a reinforcing bar cage is installed in a pile hole and concrete is poured up to a surplus portion before hardening of the cast concrete is started. Then, insert a ring-shaped jig having a coarse mesh or a wheel shape into the poured concrete in a horizontal posture to the top level of the pile head, and after hardening of the poured concrete, before hardening In addition, the ring-shaped jig is pulled up to remove excess concrete on the jig.

In the invention of claim 2, a reinforcing bar cage is installed in the pile hole, concrete is poured up to the surplus portion, and before the hardening of the concrete is started, the concrete is poured into the concrete. Insert a coarse plate-shaped or wheel-shaped ring-shaped jig in a horizontal posture to the top level of the pile head, and pull up the ring-shaped jig after the setting concrete has begun and before it has completely hardened. It is characterized in that the surplus concrete on the jig is removed, and the surplus concrete on the jig is washed with divided water so as to separate the cement, and the cement is carried out together with the excavated soil of the next pile.

[0006]

With the above construction, in any of the first and second aspects of the invention, the ring-shaped jig is inserted into the liquid concrete which has not yet been cured, and therefore the insertion of the ring-shaped jig is impossible. Occasionally, it will drop into the cast concrete under its own weight in a liquid-cut state, and thus will not push the defective concrete downward into the concrete of the pile. Also, after the start of the hardening of the poured concrete,
The ring-shaped jig that is pulled up before it is not completely hardened cuts off the soft concrete placed on it from the surroundings, and at that time, it does not spill due to the degree of hardening.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawings relate to an embodiment of the present invention. FIGS. 1 to 6 show the steps, and FIGS. 7 and 8 show the ring jig used. The steps will be sequentially described below. 1. Process of FIG. 1 A pile hole 1 having a required depth is excavated in the ground, and a cylindrical reinforcing casing 2 reaching the pile head to be constructed at the mouth of the pile hole 2
, And fill the inside of the pile hole with muddy water (not shown). Next, the reinforced cage 3 is built in the pile hole 1, the tremie pipe 4 is inserted, and the underwater concrete 5 is placed. At that time, the required height h is higher than the pile head top level 6. Hit extra concrete 7. The muddy water is made to overflow with the pouring of the underwater concrete 5, and is finally removed. 2. Step of FIG. 2 Immediately after the underwater concrete 5 is placed, that is, before the hardening is started, the ring-shaped jig 8 in a horizontal posture is hung by the wire 9.
Is inserted into the extra concrete 7 from above by its own weight using a crane, in particular, inside the reinforcing bar cage 3. As shown in FIGS. 7 and 8, the ring-shaped jig 8 has a wheel-shaped main body 10 formed of a thin steel strip and having an outer diameter slightly smaller than that of the rebar cage 3, and the rebar is provided on the upper surface of the main body. A cross-shaped reinforcing material 11 utilizing the above is additionally provided, and when it is inserted into the overfilled concrete 7, since the concrete is still liquid, it intrudes by its own weight in a state of cutting the liquid. 3. Step of FIG. 3 The inserted ring-shaped jig 8 is positioned at the pile head top end level 6 and the suspended wire 9 is attached to the casing 2 so as not to move until before the hardening of the concrete is started. It hangs on the support material 12 that is provided at the top and holds it. 4. Process of Fig. 4 After a certain period of time has passed after the hardening of the cast concrete and before the cast concrete has not completely hardened,
The supporting material 12 is removed, the hook of the crane is hung on the wire 9, and the buried ring-shaped jig 8 is lifted up, and the surplus concrete 7 in the upper part inside the rebar cage 3 placed on the ring-shaped jig is removed. At this time, the concrete on top is
There is no eye spillage due to the degree of hardening. 5. Process of FIG. 5 On the ground, the extra concrete 7 placed on the ring-shaped jig 8 is separated by water washing so as not to harden to separate the cement, and the cement is carried out together with the excavated soil of the next pile. The aggregate 13 separated from the cement by the divided water washing can be reused. 6. Process of Fig. 6 Pull out the casing 2 fitted in the mouth of the pile hole and cut the ground to a level equal to or slightly lower than the top level 6 of the pile head. In addition, the remaining part of the extra embankment concrete 7 that slightly remains outside the upper end of the reinforcing bar cage 3 is picked up and eliminated.

[0008]

EFFECTS OF THE INVENTION In either of the inventions of claim 1 and claim 2, (1) after placing concrete up to the surplus portion in the pile hole and before starting the hardening, the concrete is placed in the surplus concrete. Since a coarse plate-shaped or wheel-shaped ring-shaped jig is inserted in a horizontal position, it can be lowered into the pouring concrete by its own weight while cutting the liquid, and it can be easily and easily inserted. Make sure that the surplus concrete, which is concrete, does not flow as desired due to the insertion member and does not inadvertently push downward when the ring-shaped jig descends, and mixes into the concrete of the pile body. There is no such thing. (2) Since most of the surplus concrete is removed before it is completely hardened, there is very little fragrance and it can be finished easily, and it is possible to suppress the generation of noise and vibration in an extremely short time, which has an adverse effect on the surrounding environment. There is little damage to the pile. (3) Since the soft concrete before complete hardening is removed by the ring jig, the crane will not be overloaded and the crane will not fall. (4) No need to upgrade large-scale facilities and equipment. (5) Overall, the construction period can be shortened, high quality can be secured, and cost can be reduced. And so on. Further, in the invention of claim 2, the surplus concrete on the removed jig is subjected to split water washing treatment in an uncured state, the cement is separated so as not to harden, and the cement is carried out together with the excavated soil of the next pile. Therefore, it does not require special consideration for out-of-site removal, does not require crushing work at the disposal site, can be treated as industrial waste properly, quickly and easily, can be carried out, and can be disposed of. Since the aggregate is separated, it can be reused.

[Brief description of drawings]

FIG. 1 is an explanatory sectional view of a first step showing an embodiment of a method for treating a pile head of a cast-in-place concrete pile of the present invention.

FIG. 2 is an explanatory sectional view of a second step of the same example.

FIG. 3 is an explanatory sectional view of a third step of the same example.

FIG. 4 is an explanatory sectional view of a fourth step of the example.

FIG. 5 is an explanatory cross-sectional view of a fifth step of the same example.

FIG. 6 is an explanatory sectional view of a sixth step of the same example.

FIG. 7 is an enlarged plan view of a ring-shaped jig used in the same example.

FIG. 8 is an enlarged front view of the ring-shaped jig.

[Explanation of symbols]

 1 ... Pile hole 2 ... Casing 3 ... Reinforcing bar cage 4 ... Tremy pipe 5 ... Underwater concrete 6 ... Pile head top level 7 ... Extra concrete 8 ... Ring jig 9 ... Wire 10 ... Main body 11 ... Cross-shaped reinforcement 12 … Support material 13… Aggregate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor ▲ Sugi ▼ Masae Hon 10-10 Hashimotocho, Naka-ku, Hiroshima-shi, Hiroshima Stock company Takenaka Corporation Hiroshima branch (72) Inventor Hiraiwa ▲ Takashi ▼ Kure, Hiroshima Ichihirodai Shinkai 3-4-17 Sanyo Engineering & Civil Engineering Co., Ltd. (72) Inventor Satoshi Kamata 3-4-17 Sanyo Engineering & Engineering Co., Ltd. Kure, Hiroshima Prefecture

Claims (2)

[Claims] 1. Reinforcing bar cages are installed in the pile holes and concrete is poured up to the surplus portion, and before the start of hardening of the cast concrete, coarse-grained platters or wheel shapes are placed in the cast concrete. Insert the ring-shaped jig in the horizontal position to the top level of the pile head and pull up the ring-shaped jig after the start of hardening of the cast concrete and before it is completely hardened. A method for treating pile heads of cast-in-place concrete piles, which is characterized by eliminating. 2. Reinforcing bar cages are installed in the pile holes and concrete is poured up to the surplus portion, and before the hardening of the cast concrete begins, coarse-grained platters or wheel shapes are placed in the cast concrete. Insert the ring-shaped jig in the horizontal position to the top level of the pile head and pull up the ring-shaped jig after the start of hardening of the cast concrete and before it is completely hardened. The method for removing piles of cast-in-place concrete piles, which comprises removing the cement, separating the cement by separating water so as not to harden the surplus concrete on the jig, and removing the cement together with the excavated soil of the next pile.