JP2530160Y2 - Pile for rotary burial method with pre-boring - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pile for a pre-boring combined rotary burial method, which is capable of firmly fixing a lower end portion of a pile to a foundation.

[0002]

2. Description of the Related Art As one of the construction methods for constructing a pile foundation on the ground, a rotary burying method combined with pre-boring has become widespread nationwide as a method capable of coping with vibration and noise regulations.

[0003] An example of this method will be described first with reference to FIG.
As shown in (1), the construction ground is excavated while jetting water or cement milk as the excavating liquid from the tip head b of the excavation rod a, and the soil and the cement milk are mixed by the stirring blade c.
After reaching the predetermined depth, the support layer d is excavated by injecting the root consolidation solution to form the pile insertion hole e. Thereafter, the vertical movement of the excavation rod a is repeated to mix and mix the gravel and the cement milk in the support layer d, and as shown in FIG. 11, a concrete or mortar-like solidified portion f is built in the support layer d. Then, as shown in FIG.
Is suspended and set on a rotating cap of an auger, and the pile is embedded while rotating around the axis or the pile g is buried under its own weight and rotated and buried in the support layer d as shown in FIG. The lower end portion h of the pile was fixed to the portion f.

[0004]

SUMMARY OF THE INVENTION In the hollow pile fixed in the rooting portion f in this way, the lower end of the pile is made of a concrete material or a mixture of cement milk and gravel. It is in a state of being temporarily closed by a hardened material of a mortar-like material (hereinafter, the concrete-like material and the mortar-like material are collectively referred to as a concrete-like material) in which sand is mixed. The load applied to the pile was supported by the frictional force acting on the pile surface acting between the pile and the consolidation part and the supporting force at the lower end face of the pile.

However, although the lower end of the pile is in a closed state as described above, it is merely a hardened concrete-like material serving as a lid.
For this reason, the closed portion and the inner peripheral surface of the pile main body are poorly integrated, and the closed portion is easily separated from the pile main body. Further, the closed portion was merely a hardened concrete product and had low strength, so that cracks were easily formed. For this reason, it was hardly expected that the pile supporting capacity would increase due to the blockage. Therefore, it is difficult to firmly fix the lower end portion of the pile to the root compaction portion, and the pile may not be able to sufficiently support the required load.

The present invention is based on the fact that the lower end portion of the pile is closed at the root fixing portion by the steel-reinforced concrete or mortar closing portion integrated with the lower end portion of the pile. To provide a pile for the rotary burial method with pre-boring that can solve the above-mentioned problems by making the anchoring to the part more firm and making the pile sufficiently support the required load on the entire lower end face of the pile. It is intended for.

[0007]

In order to solve the above problems, the present invention employs the following means. The pile (hereinafter referred to as a pile) 1 for the pre-boring combined rotary burial method according to the present invention is:
Lower end opening edge part 3 of hollow pile with open upper and lower ends
In addition, the closed steel part 5 is provided so that it protrudes into the hollow part of the pile. The closed steel part 5 has an opening through which a concrete-like material or a mortar-like material flows into the hollow portion of the pile.

The concrete structure of the closed steel part 5 is as follows. The lower end is welded to a steel plate 6 fixed to the lower end of the pile, and projects upward at a predetermined distance from the inner peripheral surface of the pile in the hollow part of the pile. A required number of three or more vertical streaks 9 provided at required intervals; and an annular ring streak 10 connecting the vertical streaks to each other by welding at least at a portion near the upper end and a portion near the lower end thereof. An example is one in which the central opening of the closed steel part 5 allows the concrete or mortar to flow into the hollow part of the pile. As an example of the ring streaks 10,
One example is the one in which a certain overlap margin is provided in a free state, and the diameter of the ring streak is adjustable by increasing or decreasing the overlap margin.

[0009]

In order to fix the lower end of the pile 1 to the foundation by rotating and embedding the pile 1 according to the present invention, for example, the construction ground is excavated by the conventional method shown in FIG. The existing pile insertion hole 2 is formed. Thereafter, similarly to the case shown in FIG. 11, the up and down movement of the drilling rod is repeated to mix and mix the sand or gravel in the support layer and the cement milk, and the concrete or mortar-like root consolidation section 33 is moved to the support layer 34. To build.

Thereafter, as in the case shown in FIG. 12, the pile 1 is buried in the pile insertion hole 2 while being rotated around the axis. At this time, since the closed steel part 5 has an opening (an opening between the reinforcing bars such as a central opening), the concrete-like material sequentially flows into the hollow portion 23 of the pile through the opening. When the lower end portion 32 of the pile is fixed to the bolster 33, the lower end portion 32 of the pile is firmly closed by the closed portion 35 of steel-reinforced concrete or mortar as shown in FIG. State.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1 and FIG. 2, the pile 1 according to the present invention is embedded in a pile insertion hole 2 formed in the construction ground by performing pre-boring while injecting a drilling fluid while being rotated around an axis. It is a hollow pile with open upper and lower ends, and a closed steel part 5 is fixed to the lower end opening edge portion 3.

The closed steel portion 5 is provided so as to protrude into the hollow portion of the pile, and the lower end 7 is welded to a steel plate 6 fixed to the lower end of the pile, and protrudes upward in a slightly inclined state. Four of the vertical streaks 9 are arranged in a circular shape at an equal angular pitch, and these four vertical streaks 9, 9, 9, 9 are ring-shaped upper ring streaks at their upper and lower end portions. 10a and a lower ring streak 10b are integrated by welding and formed in a cylindrical cage shape with an open central portion. The vertical bars 9 and the ring bars 10a and 10b are preferably formed using deformed reinforcing bars in order to increase the adhesive strength of the concrete.

The closed steel part 5 having such a structure is formed by a cage steel reinforcing bar 12 having a cylindrical cage shape as shown in FIG.
After the formation, the cage reinforcing bar 12 is preferably fixed to the plate 6 by welding.

An example of the procedure for manufacturing the car reinforcing bar 12 will be described. First, the lower reinforcing bar 9 is arranged so as to surround the vertical reinforcing bar 9 only at a position near the lower end of the circular vertical reinforcing bars 9, 9, 9, 9. A semi-finished car reinforcing bar 15 as shown in FIG. 4 where the ring bar 10b is welded is formed. Thereafter, as shown in FIG. 5, this is temporarily attached to the lower end opening edge portion 3 of the pile, and between the outer peripheral portion 19 of the upper ring streak 10a to be welded to the portion near the upper end of the vertical streak 9 and the inner peripheral surface portion 17 of the pile. The diameter of the upper ring streak 10a is determined so that a gap g of, for example, about 3 cm is generated. After that, the semi-finished car reinforcing bar 15 is temporarily removed from the lower end opening edge portion 3 of the pile, and the upper ring bar 10 set to a required diameter is removed.
"a" is fixed by welding so as to surround the vertical streak at a portion near the upper end of the vertical streak 9, thereby forming a cage iron bar 12 having a cylindrical shape as shown in FIG. These welding operations are performed at a construction site or at a factory. In particular, in this embodiment, a trapezoidal plate-shaped claw fitting 20 for trapezoidal plate, which is usually fixed to the plate 6 at the lower end of the pile, is integrally welded to the lower end of each longitudinal bar 9 of the car reinforcing bar 12. At the same time, the cage rebar 12 is fixed to the plate 6 and the claw fitting 20 is also fixed to the plate 6.

FIGS. 6 to 8 show another embodiment of the cage bar 12, and the claw fitting 2 is provided at the lower end of the vertical bar.
0 is not fixed, and the lower end 7 of the vertical streak 9 is welded to the plate 6 between the claw fittings 20 welded to the plate 6. The upper ring streaks 10a shown in FIG. 7 and the upper and lower ring streaks 10a and 10b shown in FIG.
Has a certain overlap margin 21 in the free state, and the diameter of the ring streaks can be adjusted by increasing or decreasing this overlap margin. In addition,
In the cage steel bar exemplified above, the upper and lower ring bars 10
a, 10b surround the vertical streaks 9;
a and 10b may be attached inside each vertical streak 9.

In the closed steel part 5 using the cage steel bar 12 manufactured as described above, when the pile is rotatably buried,
As shown in FIG. 9, the concrete-like material
Can flow into the hollow portion 23 of the pile through the central opening 22 or the opening between the reinforcing bars (the inflow state is indicated by an arrow).

[0017]

Advantageous Effects of the Invention The pile according to the present invention has the following excellent effects because it employs a structure in which the closed steel portion having an opening is provided at the opening edge of the lower end of the pile. When the pile is rotatably buried in a pile insertion hole formed by pre-boring, a concrete-like material (a concrete-like material obtained by mixing cement milk and gravel, a mortar-like material obtained by mixing cement milk and sand) )But,
It flows smoothly into the hollow part of the pile through the opening of the closed steel part. For this reason, the pile of the present invention can be buried in the same manner as a conventional hollow pile.

In a state where the lower end of the pile is fixed to the foundation, the lower end of the pile can be closed by a steel-reinforced concrete or mortar closing portion integrated therewith. Therefore, the lower end portion of the pile can be firmly closed, as if a pre-built closed pile having a lower end closed was buried. Therefore, the lower end of the pile can be more firmly fixed to the reinforced portion than in the case of the conventional hollow pile, and the required load can be stably supported by the pile in the entire lower end face of the pile. In other words, a highly reliable pile driving foundation can be constructed.

[Brief description of the drawings]

FIG. 1 is a front view showing a pile according to the present invention in an embedded state.

FIG. 2 is a perspective view showing a state in which a closed steel member is fixed to a lower end of a pile.

FIG. 3 is a perspective view illustrating a procedure for forming a closed steel part.

FIG. 4 is a perspective view showing a semi-finished car rebar.

FIG. 5 is a cross-sectional view showing a state in which a semi-finished car reinforcing bar is temporarily attached to an opening edge portion of a lower end of a pile.

FIG. 6 is a perspective view showing another example of the cage rebar forming the closed steel part, which is welded to the lower end of the pile.

FIG. 7 is a perspective view showing another example of a car reinforcing bar.

FIG. 8 is a perspective view showing another example of a car reinforcing bar.

FIG. 9 is a cross-sectional view showing a state in which a lower end portion of the pile is closed by a steel material-reinforced concrete closing portion.

FIG. 10 is an explanatory diagram illustrating a step of forming a pile insertion hole in the ground.

FIG. 11 is an explanatory diagram for explaining a step of constructing a rooted portion in a support layer at a lower end of a pile insertion hole.

FIG. 12 is an explanatory diagram illustrating a process of embedding a pile in a pile insertion hole.

FIG. 13 is an explanatory diagram illustrating a state in which a lower end portion of a pile is fixed to a root compaction portion.

[Explanation of symbols]

 Reference Signs List 1 pile 2 pile insertion hole 3 lower edge opening edge of pile 5 closed steel part 6 plate 9 longitudinal streak 10 ring streak

Claims (2)

(57) [Scope of request for utility model registration] To 1. A lower end opening edge portion of the pile forming a hollow that upper and lower ends are open (3), closed steel section (5), it is provided as to protrude into the hollow portion of the pile, the closure Steel
Part (5) is a steel plate (6) fixed to the lower end of the pile
The lower end is welded to the inside of the pile.
Longitudinal streaks protruding upward to separate the required distance from the part (9)
The required number of three or more provided at required intervals,
The vertical streaks should be at least
Annular ring streak (1
0), and the integrated steel part (5)
The central opening of the concrete or mortar
A pile for a rotary burial method combined with pre-boring, wherein the pile is made to flow into a hollow portion of the pile. 2. The ring muscle (10) is in a free state.
It has a certain overlap allowance and increases this overlap allowance
Or the diameter of the ring streaks can be adjusted by decreasing it
The pile according to claim 1, wherein the pile is used for a rotary burial method with pre-boring.