JPH1129942A - Head part structure of cast-in-place steel pipe concrete pile, and its work execution method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the joining strength of a pile head part with a footing by arranging a lower part of an anchoring bar formed of high strength reinforcement close to an inner surface of a steel pipe, and extending an upper part to the construction position of the footing to improve the holding force of the anchoring bar. SOLUTION: A lock nut 32 is welded to an inner circumferential surface of a steel pipe 1 to be installed in the ground 7, a lower part of an anchoring bar 2 consisting of a threaded and knotted reinforcement is threaded therein, the interval (d) between the anchoring bar 2 and the steel pipe 1 is arranged to be within 1.5 times the diameter D of the anchoring bar 2, an upper part of the anchoring bar 2 is extended to the construction position of a footing, and the lock nut 31 as an anchoring member is threaded to an upper end. The anchoring bar 2 is a high strength reinforcement of >=490 N/mm<2> in yield point, and fixed to the steel pipe 1 before the concrete placement or after removing the chamber concrete after placement. The lower anchoring bar may be connected to the upper one at the position close to the upper end of the steel pipe 1 by a coupler. The holding force of the anchoring bar 2 is improved, and the joining strength of the pile head part with the footing can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pile head structure of a cast-in-place steel pipe concrete pile having a pile head made of a steel pipe concrete pile, and a method of constructing the pile head structure.

[0002]

2. Description of the Related Art In order to further improve the seismic resistance of a conventional cast-in-place concrete pile with the rise of building structures, as shown in FIG. A cast-in-place concrete pipe pile (composite cast-in-place pile) in which a pile head or the like subjected to shearing force is constituted by a steel pipe concrete pile 110 is used.

[0003] By the way, this steel pipe concrete pile 110
As the joint structure of the pile head consisting of
Conventionally, (1) rebar cage method (2) whiskers method (3) coupler method and the like have been proposed and put into practical use.

[0004] The steel pipe concrete pile 110 of the above (1) to (3)
In any case, the joint structure between the pile head made of and the footing 109 minimizes the protruding length of the steel pipe concrete pile 110 to the footing 109 and mainly serves as a reinforcing bar (hereinafter, referred to as “anchoring bar”). Is used for fixing.

[0005] Among them, the rebar cage method of (1) is shown in FIG.
As shown in (a), a pre-assembled reinforced basket 102a is inserted into a steel pipe 101 constituting a cast-in-place steel pipe concrete pile, and the upper end of the reinforced basket 102a is extended to a construction position of a footing 109. After being temporarily fixed, the concrete 106 is fixed by pouring the concrete 106 into the inside of the steel pipe 101, and the rebar basket 102a is used as a fixing bar.

In the beard streak method (2), as shown in FIG. 7 (b), it is fixed on the outer peripheral surface of a steel pipe 101 constituting a cast-in-place steel pipe concrete pile at substantially regular intervals by pre-installation or post-installation. The lower end of the streak 102b is welded, and the upper end of the fixing streak 102b is extended to the position where the footing 109 is constructed.

[0007] The coupler system of (3) is shown in FIG.
As shown in the figure, the coupler 103 is welded to the outer peripheral surface of the steel pipe 101 constituting the cast-in-place steel pipe concrete pile at substantially equal intervals, and after removing the excess concrete, the coupler 103 is fixed to the coupler 103 with a threaded reinforcing bar. The lower end of the streak 102c is screwed in, fixed by performing grout injection or tightening with a lock nut.
2c is extended to the construction position of the footing 109.

[0008]

[Problems to be Solved by the Invention] By the way, the above (1) to
Of the joining structures in (3), the reinforced cage method in (1) is the lowest cost and highly reliable structure, but it cannot be used alone due to the recent rise in building structures. It is usually used in combination with the beard streak method of (2) and the coupler method of (3), which requires welding work to fix the anchoring streaks, resulting in low work efficiency and workability. However, there is a problem that costs are required. In addition, in the case of this rebar cage method, the interval between the rebar cage 102a and the steel pipe 101 is usually set to about 3.0 to 3.5 times the diameter of the rebar, but due to its structure, the interval is set to be about 3.0 to 3.5 times. It was difficult to set accurately. Further, in the beard streak method (2) and the coupler method (3), the fixing streaks 102b and 102c are fixed to the outer peripheral surface of the steel pipe 101 directly or via the coupler 103, respectively, only by welding bonding force. For this reason, there is a limit in realizing the currently required improvement in the holding power of the anchoring bars for the steel pipe concrete pile 110 without increasing the cost.

The present invention has been made in view of the above-mentioned problems of the joint structure between a pile head and a footing made of a steel pipe concrete pile, and has realized an improvement in the holding force of anchoring bars to the steel pipe concrete pile without increasing the cost. It is an object of the present invention to provide a pile head structure of a cast-in-place steel pipe concrete pile and a construction method thereof.

[0010]

In order to achieve the above object, the pile head structure of the cast-in-place steel pipe concrete pile according to the present invention is provided on the inner peripheral surface of the steel pipe constituting the cast-in-place steel pipe concrete pile at substantially regular intervals. , The lower part of the anchoring muscle consisting of high-strength rebar,
The distance between the anchoring muscle and the steel pipe is set to be within 1.5 times the diameter of the anchoring muscle, and the upper part of the anchoring muscle is extended to the footing construction position.

The pile head structure of the cast-in-place steel pipe concrete pile has a structure in which the lower part of the anchoring bar made of high-strength steel is fixed to the inner peripheral surface of the steel pipe constituting the cast-in-place steel pipe concrete pile at substantially regular intervals. By setting the distance from the steel pipe to within 1.5 times the diameter of the anchoring bar, the number of anchoring bars can be increased as compared with the reinforced cage system, and the steel bar can be punched inside the steel pipe. The holding power of the anchoring streaks by the concrete to be provided can be improved. In addition, by using anchoring bars made of high-strength rebar, it is possible to reduce the number of anchoring bars required to join a pile head made of a steel pipe concrete pile and a footing with a required strength. In addition to the arrangement of the lower portion of the anchoring muscle with the spacing between the anchoring muscle and the steel pipe set within 1.5 times the diameter of the anchoring muscle, the clearance between adjacent anchoring muscles should be increased. Can be.

In this case, the anchoring muscle is constituted by a lower anchoring muscle and an upper anchoring muscle, and the lower anchoring muscle and the upper anchoring muscle are connected by a connecting member at a position near the upper end of the steel pipe. Can be. Here, when a screw bar is used as the fixing bar, a coupler can be used as the connecting member.

[0013] Thus, after constructing the cast-in-place steel pipe concrete pile and performing the work of removing the excess concrete, the upper setter is connected to the lower setter buried in the cast-in-place concrete pile via the connecting member. Therefore, the work of removing excess concrete can be efficiently performed, and the occurrence of accidents such as damage to anchoring bars during the removal of excess concrete can be prevented.

Further, a connection member having an outer peripheral surface formed in a deformed shape (including a "screw wiper") can be used.

[0015] Thereby, the integrity of the connection member and the concrete can be improved.

The high-strength rebar has a yield point of 490 N /
It is desirable to use a reinforcing bar of mm ² or more (according to JIS Z 2241).

As a result, the number of fixing streaks can be significantly reduced as compared with the case where a reinforcing bar (yield point: 390 N / mm ² ) which has been widely used in the past is used.

Further, a screw bar can be used as the fixing bar.

This makes it possible to simplify the work such as connection of anchoring streaks on site, thereby improving work efficiency and improving the integration with concrete.

Further, a fixing member can be provided at at least one end of the fixing streaks. Here, the fixing member is disposed at an upper end and / or a lower end of the fixing streaks. When a screw bar is used as the fixing streaks, a female screw member such as a lock nut or a coupler is used as the fixing member. Can be used.

Accordingly, the anchoring member serves as an anchor for the anchoring streaks, and the joining strength between the pile head made of steel pipe concrete pile and the footing can be improved.

Further, the connecting member or the fixing member provided at the lower end of the fixing streak can be welded to the inner peripheral surface of the steel pipe.

Thus, the anchoring streak can be fixed to the steel pipe with high reliability.

Further, in order to achieve the same object, the method of constructing a pile head of a cast-in-place steel pipe concrete pile according to the present invention employs a high-strength steel pipe at substantially equal intervals on the inner peripheral surface of a steel pipe constituting the cast-in-place steel pipe concrete pile. Concrete is cast in a state where the lower anchoring bar made of reinforcing steel is arranged with the distance between the lower anchoring bar and the steel pipe set to within 1.5 times the diameter of the lower anchoring bar, and a cast-in-place steel pipe concrete pile is constructed. After that, connect the upper anchoring bar made of high-strength steel to the connecting member arranged at the upper end of the lower anchoring bar,
The footing is constructed by extending the upper anchoring streaks to the footing construction position and casting concrete.

The method of constructing the pile head of the cast-in-place steel pipe concrete pile is to join the pile head composed of the steel pipe concrete pile and the footing with a required strength by using the anchoring bar composed of a high-strength steel bar. The number of anchoring muscles required can be reduced, and the lower part of the anchoring muscles can be arranged with the distance between the anchoring muscle and the steel pipe set within 1.5 times the diameter of the anchoring muscle. In addition, it is possible to increase the distance between the adjacent fixing streaks, thereby improving the work efficiency in the field. In addition, after constructing the cast-in-place steel pipe concrete pile and performing the work of removing the excess concrete, it is possible to connect the upper anchorage muscle to the lower anchorage buried in the cast-in-place steel pipe concrete via a connecting member, Therefore, the work of removing excess concrete can be efficiently performed, and the occurrence of accidents such as damage to fixing streaks during the removal of excess concrete can be prevented.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a pile head structure of a cast-in-place steel pipe concrete pile according to the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show a first embodiment of a pile head structure of a cast-in-place steel pipe concrete pile according to the present invention. The pile head structure of the cast-in-place steel pipe concrete pile is composed of an anchoring bar 2 made of a high-strength threaded rebar at substantially equal intervals on the inner peripheral surface of the steel pipe 1 constituting the cast-in-place steel pipe concrete pile installed in the ground 7.
Is arranged with the distance d between the anchoring muscle 2 and the steel pipe 1 set within 1.5 times the diameter D of the anchoring muscle, and the upper part of the anchoring muscle 2 is extended to the footing construction position. The configuration is as follows. A lock nut 31 as a fixing member can be screwed into an upper end portion of the fixing streak 2 extending to the footing construction position, and a lower end of the fixing streak 2 located in the steel pipe 1 as necessary. A lock nut 32 as a fixing member can be screwed into the portion. In addition, the fixing line 2
The lock nut 32 screwed to the lower end of the steel pipe 1 can be welded to the inner peripheral surface of the steel pipe 1 if necessary. In this case, after the lock nut 32 is welded to the inner peripheral surface of the steel pipe 1,
The lower end of the fixing streak 2 is screwed and fixed. Further, a fixing hoop 4 for fixing and holding the intermediate position of the anchoring streak 2 by temporary welding to the upper end surface of the steel pipe 1 is attached to the leg member 5.
Can be arranged through. Fixation of the anchoring muscle 2,
The holding can be performed using a member such as a pin.

In this case, as shown in FIG. 2, a spiral steel pipe having a projection 11 for improving the integrity with the concrete 6 cast inside the steel pipe 1 is formed on the inner peripheral surface of the steel pipe 1 as shown in FIG. It is desirable to use.

The anchoring bar 2 made of a high-strength threaded reinforcing bar has a yield point of 490 N / mm ² or more and a tensile strength of 620 N / mm ^2.
N / mm ² or more, more preferably a yield point of 685 N /
mm ² or more, a tensile strength of 860N / mm ² or more of rebar (JI
According to SZ2241. For example, it is desirable to use “High-strength screw control (USD685)” (trade name) manufactured by Kobe Steel, Ltd., whereby a reinforcing bar (yield point: 390 N / mm ² ), which has been widely used as a fixing bar, is conventionally used. Compared to the case of using a reinforcing bar, the number of anchoring bars is significantly increased (when using a reinforcing bar having a yield point of 685 N / mm ² or more, 4
0% or more), thereby improving the work efficiency and workability of the work of arranging the steel pipe 1 in combination with the fact that the distance s between the adjacent anchoring streaks 2 can be increased. Can be.

Further, as in this embodiment, the lock nuts 31 and 32 may be simply screwed to the fixing streaks 2 to the fixing member of the fixing streaks 2 made of a high-strength threaded reinforcing bar. , 32, a grout material can be injected and, as shown in FIG. 3, fixing plates 31c, 32c separately prepared can be tightened by lock nuts 31a, 32a and couplers 31b, 32b. . In this case, the fixing members do not necessarily need to be disposed at both ends of the fixing streaks 2, and may be disposed at only one of the upper end and the lower end. If necessary, a fixing member such as a coupler 32b attached to the lower end of the fixing streak 2 can be welded to the inner peripheral surface of the steel pipe 1.

In this embodiment, a high-strength threaded reinforcing bar is used as the anchoring bar 2, but an anchoring bar made of a high-strength bar (including deformed bar) is used. On the inner peripheral surface of the steel pipe 1, the distance d between the anchoring streaks and the steel pipe 1 can be set at substantially equal intervals within 1.5 times the diameter D of the anchoring streaks. Accordingly, the fixing streaks can be fixed to the inner peripheral surface of the steel pipe 1 by welding or the like.
The fixing of the anchoring muscle is performed before the steel pipe 1 is built in the borehole.
The work can be performed by a so-called post-installation method or by a so-called post-installation method after removing the excess concrete from the cast-in-place concrete pile. Also in this case, it is desirable to provide an appropriate fixing member on the fixing streak.

The pile head structure of the cast-in-place cast-pipe concrete pile is formed on the inner peripheral surface of the steel pipe 1 constituting the cast-in-place cast-in-place concrete pile installed in the ground 7, at substantially equal intervals, at the upper end, and further, if necessary. The lower end of the fixing bar 2 made of a high-strength threaded rebar in which lock nuts 31 and 32 as fixing members are screwed to the lower end, and the distance d between the fixing bar 2 and the steel pipe 1 is set to 1 of the diameter D of the fixing bar. Set and arrange within 5 times,
The upper end of the anchoring line 2 is extended to the footing construction position, and the intermediate position of the anchoring line 2 is fixed and held. Then, concrete is cast on the ground 7 including the inside of the steel pipe 1 to construct a footing.

As described above, by setting the distance between the anchoring bar 2 made of a high-strength threaded reinforcing bar and the steel pipe 1 within 1.5 times the diameter of the anchoring bar 2, the number of anchoring bars 2 can be reduced. And the holding power of the anchoring streaks 2 by the concrete poured into the steel pipe 1 can be improved,
The lock nuts 31 and 32 become anchors of the anchoring muscle 2,
The joint strength between the pile head made of steel pipe concrete pile and the footing can be improved.

The diameter of the anchoring bars 2, the number of the anchoring bars 2, the length of insertion of the anchoring bars 2 into the steel pipes 1 constituting the cast-in-place steel pipe concrete pile, the anchoring bars 2 extending upward from the steel pipes 1
Can be set in accordance with a joint structure between a pile head and a footing made of a steel pipe concrete pile, which is conventionally widely used.

Next, FIG. 4 shows a second embodiment of the pile head structure of the cast-in-place steel pipe concrete pile of the present invention. As shown in FIG. 4 (c), the pile head structure of this cast-in-place steel pipe concrete pile is composed of a lower anchoring bar 21 and an upper anchoring bar 22, and a lower anchoring bar consisting of a high-strength screw bar. The streaks 21 and the upper anchoring streaks 22 are connected to each other by a coupler 33 as a connecting member at a position near the upper end of the steel pipe 1 constituting the cast-in-place steel pipe concrete pile to be installed in the ground 7. The lower anchoring streaks 21 are arranged on the inner peripheral surface of the steel pipe 1 at substantially equal intervals, with the interval between the lower anchoring streaks 21 and the steel pipe 1 set within 1.5 times the diameter of the anchoring streaks. Starting from the point that the upper fixing streaks 22 are extended to the footing construction position, a lock nut as a fixing member is screwed to the upper end portion of the upper fixing streaks 22 extending to the footing construction position. In addition, if necessary, a lock nut as a fixing member can be screwed into a lower end portion of the lower fixing streak 21 located in the steel pipe 1. It is the same as the pile head structure of the cast-in-place steel pipe concrete pile of the embodiment. The coupler 33 as a connecting member screwed to the upper end of the lower fixing streaks 21 can be fixed by temporary welding to the inner peripheral surface of the steel pipe 1 as necessary. Further, as the coupler 33 as the connecting member, a coupler whose outer peripheral surface is formed in an irregular shape (including a “screw wiper”) can be used, thereby improving the integration between the coupler 33 and the concrete to be cast. be able to.

The pile head structure of the cast-in-place steel pipe concrete pile is constructed such that a connection member is provided on the inner peripheral surface of the steel pipe 1 constituting the cast-in-place steel pipe concrete pile installed in the ground 7 at substantially equal intervals and at the upper end thereof. The lower anchoring bar 21 made of a high-strength reinforcing bar provided with the coupler 33 is disposed with the distance between the lower anchoring bar 21 and the steel pipe 1 set within 1.5 times the diameter of the lower anchoring bar 21 and temporarily fixed. (FIG. 4 (a)). And coupler 33
By disposing a closing member 34 such as a temporary threaded screw, the upper opening of the coupler 33 is closed (FIG. 4 (b)), concrete 6 is cast, and the cast-in-place steel pipe concrete pile is removed. To construct. In this case, in addition to the above-mentioned temporary storage screw pieces, a closing member made of a synthetic resin, an easily removable irregular-shaped filler, or the like, is used as the closing member 34 in a state where the upper opening of the coupler 33 is closed. Any member that can prevent the provided concrete from entering through the upper opening of the coupler 33 can be used. In the case where a temporarily-inserted screw is used as the closing member 34, the temporarily-inserted screw is screwed into the coupler 33, and the lower end surface of the temporarily-inserted screw is brought into contact with the upper end surface of the lower fixing streak 21. There is an advantage that the lower fixing streaks 21 can be firmly fixed to the coupler 33, but the fixing between the lower fixing streaks 21 and the coupler 33 can also be performed by injecting a grout material or tightening with a lock nut. After constructing a cast-in-place steel pipe concrete pile and removing excess concrete, the closing member 3 closing the upper opening of the coupler 33 was removed.
4 and the upper anchoring bar 22 made of high-strength steel is connected to the lower anchoring bar 21 buried in the cast-in-place steel pipe concrete pile via a coupler 33, and the upper anchoring bar 22 is extended to the footing construction position. (FIG. 4C). Thereafter, concrete is cast on the ground 7 to build a footing.

As described above, the anchoring bars are constituted by the lower anchoring bars 21 and the upper anchoring bars 22, and the lower anchoring bars 21 and the upper anchoring bars 22 are formed in a place-punched steel pipe concrete pile in the ground 7. At the position near the upper end of the steel pipe 1, by connecting with a coupler 33 as a connecting member,
After constructing the cast-in-place steel pipe concrete pile and performing the work of removing excess concrete, it is possible to connect the upper anchoring muscle 22 via the coupler 33 to the lower anchoring muscle 21 buried in the in-place steel pipe concrete pile, Therefore, the work of removing excess concrete can be efficiently performed, and the occurrence of accidents such as damage to fixing streaks during the removal of excess concrete can be prevented.

Next, FIG. 5 shows a third embodiment of the pile head structure of the cast-in-place steel pipe concrete pile of the present invention. The pile head structure of this cast-in-place steel pipe concrete pile is the same as that of the second embodiment of FIG.
As shown in (c), the anchoring bar composed of the high-strength screw bar is composed of the lower anchoring bar 21 and the upper anchoring bar 22, and the lower anchoring bar 21 and the upper anchoring bar 22 are installed in the ground 7. Steel pipes that make up steel piles in place
Are connected by a coupler 33 as a connecting member at a position near the upper end. Then, the lower anchoring muscles 21 and the lower anchoring muscles 2 are provided on the inner peripheral surface of the steel pipe 1 at substantially equal intervals.
Starting from the point that the distance between the steel anchor 1 and the steel pipe 1 is set within 1.5 times the diameter of the anchoring streaks, and the upper anchoring streaks 22 are configured to extend to the footing construction position. Upper anchor muscle 2 extended to the footing construction position
A lock nut as a fixing member can be screwed into the upper end of the second fixing member 2, and a lock nut as a fixing member can also be screwed into the lower end of the lower fixing streak 21 located in the steel pipe 1 as necessary. The basic configuration, such as being able to be screwed, is the same as the pile head structure of the cast-in-place steel pipe concrete pile of the first and second embodiments. The coupler 33 as a connection member screwed to the upper end of the lower fixing streaks 21 can be fixed by temporary welding to the inner peripheral surface of the steel pipe 1 as necessary. Also, a coupler 3 as a connecting member
For the coupler 3, a coupler having an outer peripheral surface formed in an irregular shape (including a "screw wrap") can be used.
And the concrete to be cast can be improved.

The pile head structure of the cast-in-place steel pipe concrete pile has a lower anchoring bar made of high-strength rebar at substantially equal intervals on the inner peripheral surface of the steel pipe 1 constituting the cast-in-place steel pipe concrete pile installed in the ground 7. 21 is provided with the interval between the lower anchoring streak 21 and the steel pipe 1 set within 1.5 times the diameter of the lower anchoring streak 21, temporarily fixed, and made of foamed resin at the upper end of the lower anchoring streak 21. A curing cap 35 such as the one shown in FIG.
(A)). In this case, the temporary fixing of the lower fixing streaks 21 is performed, for example, by temporarily welding a fixing hoop (not shown) to an arbitrary position of the lower fixing streaks 21 and attaching the lower fixing streaks 21 via an appropriate spacer (not shown). It can be performed by temporarily welding to the steel pipe 1. After the concrete 6 is cast and a cast-in-place steel pipe concrete pile is constructed, the excess concrete is removed, the curing cap 35 is removed, and a coupler as a connection member is connected to the upper end of the lower anchoring streak 21. 33 is provided (FIG. 5B). afterwards,
Lower anchorage 21 buried in a steel-pipe concrete pile
Then, the upper anchoring bar 22 made of a high-strength reinforcing bar is connected via a coupler 33, and the upper anchoring bar 22 is extended to the footing construction position (FIG. 5C). In this case,
If necessary, the lower fixing streaks 21 and the upper fixing streaks 22 and the coupler 33 can be fixed by injecting a grout material or tightening with a lock nut. afterwards,
The footing is constructed by placing concrete on the ground 7.

As described above, the anchoring bars are constituted by the lower anchoring bars 21 and the upper anchoring bars 22, and the lower anchoring bars 21 and the upper anchoring bars 22 are constructed in a place-punched steel pipe concrete pile in the ground 7. At the position near the upper end of the steel pipe 1, by connecting with a coupler 33 as a connecting member,
After constructing the cast-in-place steel pipe concrete pile and performing the work of removing excess concrete, it is possible to connect the upper anchoring muscle 22 via the coupler 33 to the lower anchoring muscle 21 buried in the in-place steel pipe concrete pile, For this reason, the work of removing the excess concrete can be performed more efficiently, and it is possible to prevent the occurrence of an accident such as damage to the fixing streaks during the removal of the excess concrete.

[0041]

According to the pile head structure of the cast-in-place steel pipe concrete pile of the present invention, the anchoring bar composed of the high-strength rebar is provided at substantially equal intervals on the inner peripheral surface of the steel pipe constituting the cast-in-place steel pipe concrete pile. By arranging the lower portion so that the interval between the anchoring bar and the steel pipe is set to within 1.5 times the diameter of the anchoring bar, the number of anchoring bars can be increased as compared with the rebar cage method. In addition, it is possible to improve the holding power of the anchoring streaks by the concrete cast into the inside of the steel pipe. In addition, by using anchoring bars made of high-strength rebar, it is possible to reduce the number of anchoring bars required to join a pile head made of a steel pipe concrete pile and a footing with a required strength. In addition to the arrangement of the lower portion of the anchoring muscle with the spacing between the anchoring muscle and the steel pipe set within 1.5 times the diameter of the anchoring muscle, the clearance between adjacent anchoring muscles should be increased. Thus, the work efficiency and workability of the work of arranging the anchoring streaks can be improved, and the cost required for this can be reduced.

Further, the anchoring muscle is composed of a lower anchoring muscle and an upper anchoring muscle, and the lower anchoring muscle and the upper anchoring muscle are
At the position near the upper end of the steel pipe, a cast-in-place steel pipe concrete pile is constructed by connecting with a connecting member, and after removing excess concrete, the connecting member is connected to the lower anchorage buried in the cast-in-place steel pipe concrete pile. The upper anchoring streaks can be connected via, so that the work of removing excess concrete can be performed efficiently,
It is possible to prevent the occurrence of accidents such as damage to anchoring streaks during the work of removing the excess concrete.

In addition, by using a connecting member having an outer peripheral surface formed in an irregular shape, the integrity of the connecting member and concrete can be improved.

In addition, a yield point of 490 N / m
By using a reinforcing bar of m ² or more, the number of fixing bars can be significantly reduced as compared with the case of using a reinforcing bar (yield point: 390 N / mm ² ) which has been widely used in the past.

Further, by using a screw bar as the anchoring bar, the work such as connection of the anchoring bar on site can be simplified, the working efficiency can be improved, and the integration with concrete can be improved. Can be improved.

Further, by disposing the fixing member at at least one end of the fixing streak, the fixing member serves as an anchor of the fixing streak, and the joining strength between the pile head made of the steel pipe concrete pile and the footing can be improved.

Further, by welding the connecting member or the fixing member disposed at the lower end of the fixing streak to the inner peripheral surface of the steel pipe,
The fixing of the anchoring muscle to the steel pipe can be performed with high reliability.

Further, according to the method for constructing a pile head of a cast-in-place steel pipe concrete pile of the present invention, the pile head made of a steel pipe concrete pile and a footing are required by using an anchoring bar made of a high-strength rebar. While it is possible to reduce the number of anchoring streaks required for joining with strength,
This, together with the arrangement of the lower portion of the anchoring muscle with the spacing between the anchoring muscle and the steel pipe set within 1.5 times the diameter of the anchoring muscle, increases the interval between adjacent anchoring muscles. And work efficiency at the site can be improved.
In addition, after constructing the cast-in-place steel pipe concrete pile and performing the work of removing the excess concrete, it is possible to connect the upper anchorage muscle to the lower anchorage buried in the cast-in-place steel pipe concrete via a connecting member, For this reason, while being able to perform the work of removing excess concrete efficiently,
It is possible to prevent the occurrence of accidents such as damage to anchoring streaks during the work of removing the excess concrete.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a pile head structure of a cast-in-place steel pipe concrete pile according to the present invention, in which (a) is a longitudinal sectional view and (b) is a sectional view taken along line AA of (a). Figure, (c) is (a)
FIG. 7 is a sectional view taken along line BB of FIG.

FIG. 2 shows a steel pipe used for a pile head structure of a cast-in-place steel pipe concrete pile according to the present invention, wherein (a) shows a state where concrete is cast inside, and (b) shows a state before concrete is poured inside. Is shown.

FIG. 3 shows an example of disposing a fixing member with respect to a fixing streak;
(A) is a plan view, (b) is a front view, and (c) is a bottom view.

FIG. 4 is a longitudinal sectional view showing a construction process of a second embodiment of the pile head structure of the cast-in-place steel pipe concrete pile of the present invention.

FIG. 5 is a longitudinal sectional view showing a construction process of a third embodiment of a pile head structure of a cast-in-place steel pipe concrete pile according to the present invention.

FIG. 6 is a schematic diagram of a pile head structure of a cast-in-place steel pipe concrete pile.

FIG. 7 is a longitudinal sectional view showing a pile head structure of a conventional cast-in-place steel pipe concrete pile, in which (a) shows a reinforcing bar cage system, (b) shows a beard bar system, and (c) shows a coupler system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel pipe 2 Anchoring bar 21 Lower anchoring bar 22 Upper anchoring bar 31 Anchoring member (lock nut) 32 Anchoring member (lock nut) 33 Connecting member (coupler) 4 Fixed hoop 5 Leg member 6 Concrete 7 Ground

Claims (8)

[Claims] 1. An inner peripheral surface of a steel pipe constituting a cast-in-place steel pipe concrete pile, at substantially equal intervals, a lower portion of an anchoring bar made of a high-strength reinforcing bar, and an interval between the anchoring bar and the steel pipe is set to one of the diameters of the anchoring bar. .
A pile head structure of a cast-in-place steel tube concrete pile, wherein the pile head is set within 5 times, and an upper portion of the anchoring bar is extended to a footing construction position. 2. An anchoring muscle comprising a lower anchoring muscle and an upper anchoring muscle, and the lower anchoring muscle and the upper anchoring muscle are connected by a connecting member at a position near the upper end of the steel pipe. The pile head structure of the cast-in-place steel pipe concrete pile according to claim 1. 3. The pile head structure of a cast-in-place concrete pipe pile according to claim 2, wherein a connection member having an outer peripheral surface formed in an irregular shape is used. 4. The pile head structure of a cast-in-place steel tube concrete pile according to claim 1, wherein the anchoring bar is made of a high-strength reinforcing bar having a yield point of 490 N / mm ² or more. 5. The pile head structure of a cast-in-place steel pipe concrete pile according to claim 1, wherein the anchoring bar is made of a screw bar. 6. The fixing member according to claim 1, wherein a fixing member is provided at least at one end of the fixing streaks.
Pile head structure of cast-in-place steel pipe concrete pile described. 7. The cast-in-place concrete pipe pile according to claim 2, wherein the connecting member or the fixing member disposed at the lower end of the fixing stud is welded to the inner peripheral surface of the steel pipe. Head structure. 8. An inner peripheral surface of a steel pipe constituting the cast-in-place steel pipe concrete pile, a lower anchoring bar made of high-strength rebar is provided at substantially equal intervals, and an interval between the lower anchoring bar and the steel pipe is set to one of the diameters of the lower anchoring bar. After setting concrete within 5 times and laying it out and constructing a cast-in-place steel pipe concrete pile, connect the upper anchoring bar consisting of high-strength rebar to the connecting member arranged at the upper end of the lower anchoring bar. A method of constructing a pile head of a cast-in-place steel pipe concrete pile, comprising connecting, extending the upper anchorage to a footing construction position, placing concrete, and constructing a footing.