JP2014190128A - Compaction device and compaction method for cast-in-place concrete pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device that enables concrete to be infilled into a clearance part on the backside of a casing by making the concrete inside a cage also flow.SOLUTION: A compaction device comprises a horizontal girder, a hanging material and a vibrator. The horizontal girder, which is a long material for being almost horizontally laid at an upper end of a casing, supports the vibrator in a hanging state. The vertical hanging material directly and indirectly connects the horizontal girder and the vibrator together. When the horizontal girder is laid at the upper end of the casing, the vibrator at a lower end of the hanging material is positioned near a lower end of the casing.

Description

  The present invention relates to a compaction device and a compaction method for cast-in-place concrete piles.

In the construction of cast-in-place concrete piles, a steel pipe as a casing is installed in order to prevent collapse of the inner wall portion of the drilling hole, particularly the inner wall portion of the surface layer portion.
Since this casing is unnecessary after the concrete is placed, it is pulled out and reused before the concrete solidifies.
In this case, if there is a gap on the outside of the casing, concrete that has not yet solidified flows into the gap when the casing is pulled out.
Since the concrete placed in the drilling hole becomes less fluid as time elapses, the concrete inside the reinforcing rods becomes difficult to move, so only the concrete that has not yet solidified outside the reinforcing rods flows into the gap. End up.
Therefore, as shown in FIG. 10, when the pile head a is dug after the concrete is hardened, there is a possibility that only the concrete on the outside of the reinforcing bar b will be a greatly lowered concrete pile, and the pile head has insufficient surplus f. It is also expected that defective construction such as a gap d, a pile cross-sectional defect g, or a gap portion d that is not filled with concrete will occur.
As a method of dealing with such poor construction of the pile head, it is conceivable to insert a vibrator from above after placing the concrete to give vibration to the concrete of the pile head. There is a possibility of deteriorating the quality of the concrete of the pile head by, for example, winding a certain stabilizing liquid or unhealthy concrete of the surplus part in the lower healthy part.
Patent Documents 1 and 2 are submitted for reference, and the inventions described in these documents are countermeasures against defects in the pile head due to the fluidity of the concrete to be placed, It is not a countermeasure against defects in the pile head that occurs when concrete flows into the surrounding gaps during drawing.

Japanese Patent No. 431625 Japanese Patent No. 4181617

As described above, the conventional concrete compaction apparatus and method have the following problems.
<1> The method of attaching the vibrator to the tip of the tremmy tube requires connecting or disconnecting a short tube to the tremmy tube, which makes the wiring process of the vibrator cumbersome and greatly increases the work time. It will be.
<2> It is not preferable to vibrate the reinforcing bar directly like a device for attaching a vibrator to the reinforcing bar.
<3> In a structure in which a vibrator is loosely inserted into a cylindrical body called a guide portion as in the invention described in Patent Document 2, the vibrator is pulled out of the guide portion by a concrete placing pressure, or the vibrator and the guide portion. There is a possibility that the concrete is not filled in between, and the trace of the raising and lowering of the guide portion remains as a cylindrical defect in the concrete.
<4> As described above, none of the countermeasures is a countermeasure against a phenomenon caused by a gap around the casing. That is, there remains a problem that the conventional technique and procedure cannot cope with the problem caused by the gap around the casing.

In order to solve the above-described problems, the cast-in-place concrete pile compaction apparatus according to the present invention includes a horizontal girder for laying substantially horizontally on the upper end of the casing, and a vertical direction provided substantially at the center of the horizontal girder. When the horizontal girder is installed on the upper end of the casing, the vibrator at the lower end of the hanger is Further, it is configured to be positioned near the lower end of the casing.
The cast-in-place concrete pile compaction method of the present invention uses the above compaction device, installs the casing, places the reinforcing bar rods in the drilled holes, and then attaches the horizontal girder of the compaction device to the casing. Place the above-mentioned device almost horizontally at the upper end, insert the treme tube from the guide tube, place concrete into the drilling hole, and start the vibrator with the concrete not yet solid raised to the top of the casing. The casing is pulled out together with the above device while shaking.

Since the cast-in-place concrete pile compaction apparatus and compaction method of the present invention are as described above, at least one of the following effects can be obtained.
<1> The vibrator can be positioned in the vicinity of the lower end of the casing only by installing the horizontal girder of the apparatus of the present invention on the upper end of the casing. Therefore, as the casing is pulled up, it is possible to continue to give vibration to the concrete that has not yet solidified inside the reinforcing bar rod near the lower end of the casing.
<2> Because of that, even if there is a gap around the casing, the concrete that has not yet solidified inside the reinforcing bar is pushed out and the casing is pulled up while filling the gap. There will be no lack of concrete and missing sections of piles.
<3> Since the vibrator according to the present invention is not attached to the reinforcing bar rod, it does not directly vibrate the reinforcing bar rod. Also, no special jigs or foreign objects for attaching the vibrator to the reinforcing bar are left in the concrete.
<4> Since there is no gap that is loosely inserted between the vibrator and the suspension material, there is no possibility that air or muddy water is involved and a defect is generated inside.
<5> When the vibrator is installed such that the vibrator installation position can be fixed around the suspension material, the vibrator can be arranged at an effective vibration position according to the diameter of the reinforcing bar rod.
<6> For the same reason as described above, the apparatus of the present invention can be used as it is even if the diameter of the reinforcing bar and the pile diameter are different.
<7> When the vibrator is arranged close to the inside of the reinforcing bar rod, the concrete is arranged close to the lower end of the casing, so that the concrete flows more efficiently into the gap on the back surface of the casing. Can be expected.

Explanatory drawing of the Example of the compaction apparatus of the cast-in-place concrete pile of this invention. Explanatory drawing of the other Example of the apparatus of this invention. Explanatory drawing of the Example which attached the protective material. Explanatory drawing of the stage which installed the casing and the reinforcing bar rod in the construction process using the apparatus of the present invention. Explanatory drawing of the stage which installed the tremy tube and the compaction device. Explanatory drawing of the stage where concrete that has not yet set is placed. Explanatory drawing of the stage which removed the tremy tube. Explanatory drawing of the step which operates a vibrator, pulling out a casing. Explanatory drawing of completed cast-in-place concrete pile. Explanatory drawing of the cast-in-place concrete pile completed by the conventional construction method.

  Hereinafter, preferred embodiments of a compaction device and a compaction method for a cast-in-place concrete pile according to the present invention will be described in detail with reference to the drawings.

<1> Preconditions The cast-in-place concrete pile compaction apparatus A according to the present invention fills a hole with a stable liquid while preventing the collapse of the ground with a casing P, drills the ground, and reinforces the reinforcing bar in the hole. This is a compacting device A used for a construction method in which a concrete G is placed in a drilling hole with a tremely tube T suspended from a gutter G.

<2> Overall Configuration The compacting device A of the present invention includes a horizontal girder 1, a vibrator 2, a suspension member 3, and a guide tube 4.
A configuration in which the upper end of the suspension member 3 is directly attached to the horizontal girder 1 (FIG. 1) or a configuration in which the hanger 3 is attached to the horizontal girder 1 via the guide cylinder 4 (FIG. 2) can be employed.
In the following, expressions such as “horizontal” and “vertical” are expressions for explanation assuming a state of actual use, and do not mean horizontal and vertical in a physical sense.

<3> Horizontal Girder The horizontal girder 1 is a long member such as H-shaped steel.
The length is at least equal to or larger than the diameter of the casing P installed for the target pile.
At the time of construction, the horizontal girder 1 is used by being installed substantially horizontally on the upper end of the casing P.
The horizontal girder 1 can also be composed of a plurality of long materials.
If the stopper 11 protrudes from the lower surface of the horizontal girder 1, the positional relationship with the casing P can always be secured. As a result, the guide cylinder 4 described later can always be positioned at the center of the casing P.

<4> Guide cylinder A guide cylinder 4 is provided in the approximate center of the horizontal beam 1.
The guide tube 4 can employ a configuration in which a steel pipe or the like penetrating in the vertical direction is welded to the horizontal beam 1.
This guide cylinder 4 is a cylinder used when the tremy tube T is disposed inside the drilling hole.
For this purpose, the inner diameter of the guide tube 4 is formed larger than the outer diameter of the tremmy tube T on which the concrete C is placed.
Thus, if the guide tube 4 is formed of a steel pipe and serves as a guide and is positioned at the center of the horizontal girder 1, the suspension member 3 can be arranged concentrically with the reinforcing bar rod G inside the reinforcing bar rod G. The vibrator can be arranged effectively and economically.
As will be described later, when the upper part of the suspension member 3 is directly fixed to the guide tube 4, the guide tube 4 also guides the position of the suspension member 3.
The guide tube 4 is not limited to a steel pipe, but can be configured as a frame in a cross-girder shape, a ladder shape, or a polygonal shape so that an opening is formed by a member of the horizontal girder 1.

<5> Hanging material From the horizontal girder 1 installed horizontally, the vibrator 2 is suspended through the hanging material 3 arranged vertically.
The vibrator 2 can also employ a structure in which one or a plurality of vibrators 2 are attached to one suspension member 3.
The suspension member 3 is not a flexible member such as a wire, but is a long member having a certain degree of rigidity, such as a round pipe or a steel plate.
Since it has a certain degree of rigidity, the vibrator 2 attached to the lower end of the vibrator may rise due to the pressure of the concrete C that has not yet solidified and rises from the bottom during placement, or may move horizontally. In addition, vibration can be applied to the concrete C that has not yet solidified at a fixed position.
For this purpose, the positions of the plurality of suspension members 3 are preferably restricted by one horizontal fixing ring 31 or the like at the lower part.

<5-1> Hanging material mounting structure 1 (FIG. 1)
In this structure, the upper end of the suspension member 3 is directly attached to the horizontal beam 1.
In that case, a structure in which the upper part of the suspension member 3 is directly welded to the horizontal girder 1 or a structure in which the upper part of the suspension member 3 is attached via a bracket 32 attached to the horizontal girder 1 can be employed.
A plurality of suspension members 3 are attached to the horizontal member 1.
The attachment positions of the suspension members 3 are arranged such that when the horizontal girder 1 is installed on the upper end of the casing P, all the suspension members 3 are positioned at equal intervals inside the reinforcing bar rod G. ("Near the inner surface of the reinforcing bar" will be described later)

<5-2> Hanging material mounting structure 2 (FIG. 2)
In this structure, the upper end or upper portion of the suspension member 3 is indirectly attached to the horizontal member 1.
For this purpose, the upper end or upper part of the suspension member 3 is welded to the side surface of the guide tube 4 and attached to the horizontal beam 1 via the guide tube 4.
The attachment position of the suspension member 3 is that when the horizontal girder 1 is installed on the upper end of the casing P, the suspension member 3 is arranged so that all the suspension members 3 are located at equal intervals inside the reinforcing bar rod G. Is the same.

<6> Positional relationship with reinforcing bar rod It is desirable that the suspension material 3 be arranged as close to the inner surface of the reinforcing rod rod G as possible and not in contact with the reinforcing rod rod G.
If it arrange | positions in this way, it will install the vibrator 2 in the position close | similar to the inner surface of the casing P as a result, and the effect which flows concrete into the clearance gap D of the back surface of the casing P improves.
The position close to the inner surface of the reinforcing bar rod G varies depending on conditions, but a position of about 100 to 200 mm is effective, and when approaching further, the vibrator 2 or an expansion mechanism described later hits the reinforcing bar rod G and the vibrator 2 Inconveniences that make it difficult to raise.

<7> Positional relationship with casing The distance between the horizontal girder 1 and the vibrator 2, that is, the installation depth of the vibrator 2 is given a certain relationship.
That is, when the horizontal girder 1 is installed on the upper end of the casing P, the vibrator 2 at the lower end of the suspension member 3 is configured to be positioned near the lower end of the casing P.
Then, when the compacting device A of the present invention is pulled up integrally with the casing P while driving the vibrator 2 with the horizontal girder 1 installed on the upper end, the vibrator 2 is always located near the lower end of the casing P, It is possible to continue to give vibration mainly to the concrete C that has not yet solidified near the lower end.
The “near the lower end” of the casing P differs depending on conditions, but when viewed in a side view, it means a position of about 500 mm to 1000 mm in the vertical direction from the lower end line of the casing P. That is, it is a substantial influence range of vibration of the vibrator.

<8> Expansion mechanism (Fig. 2)
When the vibrator 2 is directly fixed and connected to the suspension member 3, the position of the vibrator 2 cannot be changed, and the vibrator 2 is always located on the vertical line of the suspension member 3 and near the lower end thereof. However, when the installation position is appropriate for the target pile, the object of the present invention can be sufficiently achieved.
However, the vibrator 2 is not directly connected to the suspension member 3 but is indirectly attached via an expansion mechanism such as the link mechanism 5, and the vibrator 2 is installed and fixed at a peripheral position off the vertical line of the suspension member 3. It is also possible to configure so as to be able to.
The adjustment of the position of the vibrator 2 can be performed on the ground immediately before the compacting device A of the present invention is suspended in the casing P, or can be performed in advance at a factory or the like.
Therefore, even if the four-bar linkage mechanism 5 such as a pantograph is used as the expansion mechanism, it is not remotely operated after being suspended in the casing P. Such a simple structure can be adopted.
By adopting such a configuration, changes according to the pile diameter can be easily performed manually.

<9> Protective material (Figure 3)
A protective material 6 can also be provided so that the vibrator 2 is not caught by the reinforcing bar G particularly when it is lifted.
For this purpose, for example, as shown in FIG. 3, protective members 6 such as a warp that is curved in the vertical direction can be attached to a plurality of locations on the outer periphery of the fixing ring 31 that groups the suspension material 3 group.
Alternatively, in the vicinity of the lower end of each suspension member 3, that is, a position immediately above the vibrator 2, an arc-shaped reinforcing bar or a warp-like plate can be attached as a protective member 6 in the vertical direction.
Alternatively, an annular pipe or ring can be attached to the outer periphery of the fixed ring 31 or the suspension member 3 as the protective member 6 with its central axis positioned horizontally.
In the case where the expansion mechanism is provided, the same effect can be achieved even if a sled-like plate is hung on the outermost side of the bent link.
The protective material 6 can be formed of a hard resin having high durability and a small friction coefficient.

<10> Usage Method Next, a usage method of the compaction device A will be described.

<11> Precondition (Fig. 4)
Casing P has already been installed around the top of the hole by earth drill method, boring hole method, all-casing method, reverse circulation method, etc. Is a state where a reinforcing bar rod G is also installed.

<12> Preparation Step Vibrator 2 is attached in the vicinity of the lower end of each of a plurality of suspension members 3 attached to horizontal girder 1 on the ground.
If the position of the vibrator 2 can be adjusted, the position of the vibrator 2 is adjusted using an expansion mechanism such as the link mechanism 5 at that stage, and is fixed in advance with a bolt or the like.

<13> Installation of horizontal girder (Fig. 5)
At the upper end of the casing P, the horizontal girder 1 is installed almost horizontally.
Then, the vibrator 2 group suspended directly from the horizontal girder 1 via the suspension member 3 is located inside the reinforcing bar rod G and in the vicinity of the lower end of the casing P.
Furthermore, like the above-mentioned Example, it can also arrange | position in the state close | similar to the lower end of the casing P, and the vibrator 2 group inside the reinforcing bar rod G so that it does not contact the reinforcing rod rod G.
Since this stage is before placing concrete, the vibrator 2 is not operating.

<14> Placing concrete (Figure 6)
The tremmy tube T is suspended through the inside of the guide tube 4.
Then, the concrete C is supplied from the upper end of the tremy pipe T into the tremy pipe T through a concrete pump or the like.
In this way, the concrete C which has not yet solidified from the lower end of the tremy tube T is discharged into the hole and filled up while pushing up the stabilizing liquid.
The concrete C is continuously placed while the tremy pipe T is pulled up. When the upper end of the concrete C which has not yet solidified reaches a predetermined position above the casing P, the concrete placement is stopped, and the tremy pipe T is removed from the guide tube 4. Pull out and remove. (Fig. 7)

<15> Pulling up the casing (FIG. 8)
If the concrete C, which has not yet hardened to a predetermined height inside the casing P, is filled, the use of the casing P is finished, and the casing P is pulled out and removed.
When the vibrator 2 is actuated when the casing P is pulled out, the vibrator 2 ascends integrally with the casing P while maintaining a state in which the vibrator 2 is always located near the lower end of the casing P.
Therefore, it is possible to sequentially fill the gaps D that are hidden outside the casing P with the concrete C that has not yet solidified, without any bias.
Thus, when the gap D is generated on the back side of the casing P, it makes sense to use the apparatus of the present invention.
The vibrator 2 is raised by pulling up the casing P. However, when the protective material 6 is installed, there is no inconvenience that the vibrator 2 hits the reinforcing bar G or becomes tangled.

<16> Filling in the gap portion The filling state when the gap portion D exists on the back side of the casing P will be described in comparison with the conventional method.
As described above, conventionally, the vibrator is operated at a timing different from the lifting of the casing P, in which the casing P is pulled up after the vibrator is operated.
Therefore, in the conventional method, as shown in FIG. 10, only the concrete that has not yet solidified located on the outer periphery of the reinforcing bar 籠 b flows into the gap d, but the inner concrete surrounded by the reinforcing bar 籠 b is Since it cannot move so much at the time of pulling up, the defect | deletion g part of a pile cross section and surplus insufficient f part will generate | occur | produce around.
On the other hand, in the apparatus of the present invention, the vibrator 2 is always located in the vicinity of the lower end of the casing P and inside the reinforcing bar rod G, and the vibrator 2 is approached to the inner side of the reinforcing rod rod G in a state where both are not in contact with each other. It can also be positioned.
Therefore, when there is a gap D in the wall surface in the pile hole where the casing P is pulled up, the concrete C which has not yet solidified inside the reinforcing bar G is also subjected to vibration and given sufficient fluidity. Therefore, the concrete C that has not yet solidified is pushed out from the inside of the reinforcing bar G to the external gap D, and fills the gap D. (Fig. 9)
In this way, when the apparatus A of the present invention is used, only the concrete that has not yet solidified located outside the reinforcing bar b flows out as in the conventional method shown in FIG. 10, and the concrete surface of the pile head is inclined. A concrete pile having a solid head without a cross-sectional defect that maintains a horizontal placement surface is completed without causing inconveniences such as a lack of surplus f and occurrence of a cross-sectional defect g.

1: Horizontal girder 2: Vibrator 3: Suspension material 4: Guide tube 5: Link mechanism 6: Protective material A: Compaction device of the present invention P: Casing C: Concrete G: Rebar rod T: Tremy tube D: Gap

Claims (8)

A horizontal girder for laying substantially horizontally on the upper end of the casing;
A guide tube penetrating in the vertical direction, provided substantially at the center of the horizontal beam,
A suspension material with an upper end attached to a horizontal girder,
Consists of a vibrator attached to the lower end of the suspension material,
When the horizontal girder is installed on the upper end of the casing, the vibrator at the lower end of the suspension member is configured to be positioned near the lower end of the casing,
A compaction device for cast-in-place concrete piles. The compaction device according to claim 1,
The upper end of the suspension material is directly attached to the horizontal girder,
A compaction device for cast-in-place concrete piles. The compaction device according to claim 1,
The upper end of the suspension material is attached to a horizontal girder via a guide tube,
A compaction device for cast-in-place concrete piles. The compaction device according to claim 1,
The vibrator is directly connected by the suspension material, and the vibrator is configured to be always located on the vertical line of the suspension material,
A compaction device for cast-in-place concrete piles. The compaction device according to claim 1,
The vibrator is connected indirectly by the suspension material,
The vibrator is configured so that its position can be fixed outside the vertical line of the suspension material,
A compaction device for cast-in-place concrete piles. The compaction device according to claim 1,
When a horizontal girder is installed on the upper end of the casing,
The vibrator is characterized in that it is configured to be located further inside than the reinforcing bar rod installed inside the casing,
A compaction device for cast-in-place concrete piles. The compaction device according to claim 1,
When a horizontal girder is installed on the upper end of the casing,
The vibrator is configured to be located in a location that is close to and not in contact with the inner surface of the reinforcing bar,
A compaction device for cast-in-place concrete piles. Using the compaction device according to claim 1,
After placing the rebar rods in the hole drilled by installing the casing,
Install the above device with the horizontal girder of the compaction device placed almost horizontally on the upper end of the casing,
Insert the treme tube from the guide tube and place concrete in the drilling hole.
In a state where the concrete that has not yet solidified is raised to the upper part of the casing, the casing is pulled out together with the above device while vibrating the vibrator,
Method of compacting cast-in-place concrete piles.

Images