JP4154487B2 - Foundation pile construction method, foundation pile - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, foundation piles constituting the foundation of the building relates to the construction how the foundation pile.
[0002]
[Prior art]
Conventionally, the so-called cast-in-place pile method has been adopted in which foundation piles are excavated at the site, piles are sunk in the hole, and concrete is filled in the pile hole.
[0003]
[Problems to be solved by the invention]
In the cast-in-place pile method, there are problems such as excavation of pile holes at the construction site and embedding work of reinforcing bars, and the quality control of the concrete to be placed becomes complicated.
[0004]
Therefore, various methods using reinforced concrete and other ready-made piles have also been proposed, but the integrity of the pile holes and ready-made piles cannot be maintained, and the proof stress is considered only for the outer diameter of the ready-made piles to be buried, There was a problem that a large yield strength according to the hole diameter of the pile hole could not be expected.
[0005]
[Means for Solving the Problems]
However, the present invention solves the above-mentioned problems because the ready-made hollow pile in which the reinforcing bar is integrally connected is buried in the concrete in the pile hole to constitute the foundation pile.
[0006]
That is, this invention
(1) After excavating a pile hole having an expanded bulb with a drilling rod, the drilling rod is pulled up,
(2) Subsequently, a stirring rod is inserted into the hollow portion, and a ready-made concrete pile integrally connected with a reinforcing bar at the lower end is lowered into the pile hole, and the stirring head of the stirring rod protrudes below the ready-made concrete pile. And stirring the inside of the expanded bulb with the stirring head, injecting cement milk into the bulb portion from the discharge port of the stirring head, replacing the mud soil in the expanded bulb portion with cement milk ,
(3) Next, after the ready-made concrete pile is sunk at a predetermined position or while being laid , the concrete is discharged from the bottom of the pile hole to the ground while discharging the concrete from the discharge port of the stirring head. It is the construction method of the foundation pile characterized by pulling up the stirring rod through the part, replacing the cement milk with concrete, and filling the pile hole with concrete.
[0007]
In addition, in the above, a foundation pile in which a ready-made concrete pile is integrally connected to a lower end of a reinforcing bar and a short steel pipe or a disk-shaped ring is attached to the lower end of the reinforcing bar to protect the reinforcing bar. This is the construction method.
[0008]
In another invention, in a pile hole having a bottomed bulb part, a ready-made concrete pile having a reinforcing bar is continuously provided at the lower end , and the bottomed bulb part of the pile hole and the hollow part of the ready-made hollow pile are filled with concrete. It is a foundation pile, and the ready-made concrete pile is a short steel pipe or a disk shape that continuously connects a reinforcing bar to the lower end of the ready-made concrete pile having a hollow portion, and protects the reinforcing bar at the lower end of the reinforcing bar. The concrete is composed of a ring with a stirring rod protruding downward through the hollow portion of the ready-made concrete pile, and the mud in the bottom expansion bulb is stirred to discharge the stirring head. A foundation pile characterized in that the mud soil is replaced with cement milk discharged from an outlet, and then the cement milk is replaced with concrete discharged from a discharge port of the stirring head . Furthermore, in the above, it is a foundation pile in which the shaft reinforcing bar of the ready-made pile is protruded downward to form a protruding part, and a helical reinforcing bar is connected to the protruding part to constitute a reinforcing bar.
[0009]
In the above, the ready-made hollow piles are preferably various concrete piles (reinforced concrete piles, PC piles, etc.) used in the medium excavation method, but if they have hollow parts, composite piles of steel pipe and concrete may be used. it can.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
A shaft rebar of a ready-made concrete pile having a hollow portion is protruded downward to form a protrusion, and a helical rebar is connected to the protrusion to form an integrated rebar rod to obtain a ready-made hollow pile.
[0011]
After excavating the pile hole having the expanded bulb portion with the excavation rod, the excavation rod is pulled up. Then, the ready-made hollow pile which put the stirring rod in the hollow part descend | falls in a pile hole, the front-end | tip of a pile is located in the vicinity of a bottomed bulb part, and a ready-made hollow pile is hold | maintained here. The stirring head of the stirring rod is projected below the ready-made pile, cement milk is injected into the expanded bulb part, the inside of the bulb part is stirred, and the ready-made hollow pile is set in place. While discharging concrete from the bottom of the pile hole to the ground from the discharge port of the stirring head of the stirring rod, the stirring rod is pulled up through the hollow portion of the ready-made hollow pile. Cement milk is replaced with concrete, and concrete is filled into the pile holes. After the concrete is solidified, the ready-made hollow pile will be built with the concrete in the pile hole.
[0012]
[Action]
Since the reinforcing bar was formed in the lower end part of a ready-made hollow pile, the lower end part of a ready-made hollow pile becomes integral with the concrete with which the lower end part of the pile hole was filled. Moreover, concrete is filled in the hollow part of a ready-made hollow pile in a pile hole axial part. Therefore, it is possible to construct a field-built pile having the same strength as the field-built pile according to the hole diameter of the pile hole with the concrete in the pile hole and the hollow ready-made pile.
[0013]
[Example 1]
The structure of the ready-made hollow pile of this invention is demonstrated based on FIG.
[0014]
The shaft rebars 2 and 2 of the ready-made concrete pile main body 1 are protruded downward, and the protrusions 3 and 3 of the shaft rebars 2 and 2 are connected by the spiral rebar 4 to constitute the ready-made hollow pile 6 of the present invention.
[0015]
In the above description, the protrusions 3 and 3 of the shaft rebars 2 and 2 and the helical rebar 4 are used as the rebar rod 5. Further, in the ready-made hollow pile 6, the distance L from the lower end 1a of the ready-made concrete pile body 1 to the lower end 5a of the reinforcing bar 5 depends on the ground conditions and the load that the pile should bear, but the outer diameter of the ready-made hollow pile 6 D is usually about 1D to 1 m, and when the lower end 1a of the ready-made concrete pile body 1 is positioned at the bottom 23 of the pile hole 20 excavated by the lower end 5a of the reinforcing bar 5, the excavated pile hole 20 The height is such that it is located within the expanded bottom bulb portion 22.
[0016]
In the said Example, the short steel pipe 8 which protects the reinforcing bar 5 can also be welded to the lower end 5a of the reinforcing bar 5 (FIG. 3 (a)). Moreover, it can change to the short steel pipe 8 and can also be set as a disk-shaped ring (not shown).
[0017]
Moreover, in the said Example, although the axial reinforcement 3 of the ready-made concrete pile main body 1 was protruded below and the reinforcing bar rod 5 was comprised, the reinforcing bar rod 5 and the ready-made concrete pile main body 1 can also be comprised by another member. That is, the shaft reinforcing bars 11 are projected on the lower surface of the end plate 10, and the spiral reinforcing bars 4 are provided around the shaft reinforcing bars 11, 11 to constitute the reinforcing bar rod 12 (FIG. 3B). . The end plate 10 of the reinforcing bar 12 is connected to the lower end plate 9 of the ready-made concrete pile body 1 to constitute the ready-made hollow pile 6. In this case, if the reinforcing bar 12 is attached to the lower end plate 10 of a general ready-made concrete pile 1, the ready-made hollow pile of the present invention can be configured.
[0018]
Moreover, in the said Example, although the ready-made concrete pile main body 1 was made into the straight pile, it can also be set as the node pile which provided the annular ribs 13 and 13 over the lower end part or the full length (FIG.3 (c)).
[0019]
[Example 2]
Based on FIG. 1, the Example of the foundation pile of this invention and its construction method is described.
[0020]
(1) The excavation rod 15 having the excavation head 16 at the lower end is rotated forward to excavate the shaft portion 21 of the pile hole 20 (FIG. 1A). The excavation head 16 is configured to be swingable on a head body 17 having an excavation blade at a lower end portion, and attached with swinging arms 18 and 18 having an excavation blade at a lower end portion. Further, the excavating rod 15 is provided with conveying means (spiral splash, screw, etc.) for lifting excavated soil to the ground, and drums for kneading excavated mud to prepare pile hole walls and prevent collapse ( Not shown).
[0021]
(2) Subsequently, the excavation rod 15 is inverted, and the bottomed bulb portion 22 of the pile hole 20 is excavated with the swinging arms 18 and 18 that are swung in reverse (FIG. 1 (b)). When the excavation of the pile hole 20 is completed, the excavation rod 15 is pulled up to the ground while discharging a pile periphery fixing liquid (cement milk or the like) into the pile hole 22.
[0022]
(3) Next, the stirring rod 24 is accommodated in the hollow portion 7 of the ready-made hollow pile 6, and the ready-made hollow pile 6 and the stirring rod 24 are lowered into the pile hole 20. The stirring rod 24 has, at its lower end, an agitating head 25 having swinging stirring arms 26 and 26 and a concrete discharge port 27. The stirring rod 24 incorporates a conveyance pipe corresponding to the discharge port 27, but a common pipe for concrete and cement milk can be provided, or a dedicated pipe can be provided separately.
[0023]
(4) In the state where the lower end 5a of the ready-made hollow pile 6 (the lower end of the reinforcing bar) is located on the upper portion of the bottomed bulb portion 22 of the pile hole 20, the descent of the ready-made hollow pile 6 is stopped and held at this position. The stirring head 25 of the stirring rod 24 is protruded downward from the ready-made hollow pile 6 to stir the inside of the bottomed bulb portion 22 of the pile hole 20 and to inject cement milk into the bottomed bulb portion 22 (FIG. 1C). Here, the mud in the expanded bulb portion 22 is replaced with cement milk.
[0024]
(5) Next, after the ready-made hollow pile 6 is sunk in the bottom 23 of the pile hole 20, the concrete rod 28 is discharged from the discharge port 27 of the stirring head 25, and the hollow portion 7 of the ready-made hollow pile 6 is attached to the stirring rod 24. Then, it is pulled up on the ground 29 (FIG. 1 (d)). By injecting the concrete 28, the cement milk in the expanded bulb portion 22 is replaced with the concrete 28.
[0025]
(6) After the concrete 28 is solidified, the concrete 28 is filled in the bottomed bulb portion 22 of the pile hole 20 and the hollow portion 7 of the ready-made hollow pile 6, and the outer periphery of the shaft portion 21 of the pile hole 20 and the ready-made hollow pile 6. A foundation pile 31 filled with a pile periphery fixing liquid 30 is constructed between the two (FIG. 1 (e)).
[0026]
In the said Example, the various ready-made hollow piles (FIG. 3 others) of the said Example 1 can also be used for the ready-made hollow pile 6 (not shown).
[0027]
Further, in the above embodiment, after sinking the prefabricated hollow pile 6 to the bottom 23 of Kuiana 20, but from the stirring head 25 discharging the concrete 28, the hollow portion of the prefabricated hollow pile 6 while discharging the concrete from the stirring head 25 The ready-made hollow pile 6 can also be laid down while pulling up the stirring head 25 through 7 (not shown).
[0028]
Moreover, in the said Example, since cement milk was discharged from the stirring rod 24, mud was replaced with cement milk once, and cement milk was further replaced with concrete, the quality of concrete can be improved.
[0029]
【The invention's effect】
Since this invention sinks a ready-made hollow pile having a reinforcing bar at the lower end in the pile hole and fills the pile hole with concrete, it is possible to construct a concrete pile that is structurally integrated in the pile hole. There is an effect that can be expected to withstand strength according to.
[0030]
In addition, since a ready-made hollow pile is set in the pile hole, the set-up work is easier than the set-up of reinforcing steel rods, and the amount of concrete placed on the construction site can be greatly reduced. Has the effect of simplifying and improving efficiency.
[Brief description of the drawings]
1A to 1E are schematic longitudinal sectional views for explaining an embodiment of the present invention.
FIG. 2 is a ready-made hollow pile according to an embodiment of the present invention, in which (a) represents a longitudinal sectional view and (b) represents a bottom view.
FIGS. 3A to 3C are longitudinal sectional views of another embodiment of the ready-made hollow pile of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ready-made concrete pile main body 2 Shaft rebar 3 Shaft rebar protrusion 4 Spiral rebar 5 Reinforcing bar 5a Lower end of reinforcing bar 6 Ready-made hollow pile 7 Hollow part (Pre-made hollow pile)
9 Bottom plate (Precast concrete pile body)
10 End plate (rebar bar)
11 shaft rebar (rebar rod)
12 Reinforcing rod 15 Excavation rod 16 Excavation head 20 Pile hole 21 Pile hole shaft 22 Expanded bulb part 23 Pile hole bottom 24 Agitation rod 25 Agitation head 27 Discharge port (agitation head)
28 Concrete 29 Ground 31 Foundation pile

Claims (4)

(1) After excavating a pile hole having an expanded bulb with a drilling rod, the drilling rod is pulled up,
(2) Subsequently, a stirring rod is inserted into the hollow portion, and a ready-made concrete pile integrally connected with a reinforcing bar at the lower end is lowered into the pile hole, and the stirring head of the stirring rod protrudes below the ready-made concrete pile. And stirring the inside of the expanded bulb with the stirring head, injecting cement milk into the bulb portion from the discharge port of the stirring head, replacing the mud in the expanded bulb portion with cement milk ,
(3) Next, after the ready-made concrete pile is sunk at a predetermined position or while being laid , the concrete is discharged from the bottom of the pile hole to the ground while discharging the concrete from the discharge port of the stirring head. A construction method of a foundation pile characterized by pulling up the stirring rod through a section, replacing the cement milk with concrete, and filling the pile hole with concrete. The foundation pile according to claim 1, wherein the ready-made concrete pile is formed by continuously connecting a reinforcing bar to the lower end, and welding a short steel pipe or a disk-shaped ring to protect the reinforcing bar to the lower end of the reinforcing bar. How to build. In a pile hole having an expanded bulb part, a foundation pile in which a ready-made concrete pile with a reinforcing bar is continuously installed at the lower end is filled with concrete in the expanded bulb part of the pile hole and the hollow part of the ready-made hollow pile,
The ready-made concrete pile is formed by continuously connecting a reinforcing bar to the lower end of the ready-made concrete pile having a hollow portion, and welding a short steel pipe or a disk-shaped ring to protect the reinforcing bar to the lower end of the reinforcing bar. Configure
The concrete is agitating head of a stirring rod protruding downward through a hollow portion of the ready-made concrete pile, stirring the mud in the bottomed bulb, and the mud with cement milk discharged from the discharge port of the stirring head A foundation pile characterized in that the cement milk is replaced with concrete discharged from the discharge port of the stirring head. The foundation pile according to claim 3, wherein a shaft reinforcing bar of the ready-made pile is protruded downward to form a protruding portion, and a helical reinforcing bar is connected to the protruding portion to form a reinforcing bar rod.

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