JP2006083586A - Inclined concrete pile driving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inclined concrete pile driving method for driving an inclined pile by a crane having no leader mounted thereon, without raising damage including cracking at all, the method being very excellent in safety and cost efficiency. <P>SOLUTION: The inclined concrete pile driving method is comprised of the following steps. In the first step, a work stand 2 having a guide 2a for guiding the concrete pile 1 so as to assume a necessary inclined angle, is prepared, and the concrete pile 1 is built into a sea bottom at the inclined angle, along the guide 2. In the following step, a protective pipe 3 having a hollow portion 3a with a length sufficient for covering the concrete pile 1 from a pile head 1a at least to the guide 2, and having a closed upper edge, is fitted onto the concrete pile 1 beginning from the pile head 1a, and then supported by the guide 2. In the final step, a hammer 4 hung by heavy equipment such as a crane 10 is mounted on a head of the protective pipe 3, and the concrete pile 1 is driven into the sea bottom down to a necessary depth by driving the hammer 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention belongs to the technical field of an inclined concrete pile placing method, and more specifically, relates to a method for placing an inclined concrete pile on the seabed using a heavy machine such as a crane not equipped with a leader.

  When constructing artificial ground such as a marine airport on the sea, in recent years, in order to effectively resist horizontal forces such as seismic forces, inclined piles (tilted piles) are placed on the submarine ground to support the artificial ground. Various techniques have been disclosed (see, for example, Patent Documents 1 to 3).

  In general, in order to place a slant pile on the seabed, as shown in FIG. 8, a crane f equipped with a leader e is used, and a slant pile g held by the leader e is suspended from a crane boom h. This is performed by hitting with a hammer i (see, for example, Patent Document 4). In addition, a reinforced concrete pile is preferably used for the slant pile g.

  The reinforced concrete pile is roughly divided into a PHC pile that gives high tension to the steel bar as the main reinforcement and compresses the concrete, and a deformed rebar that improves the adhesion to the concrete. RC piles that reinforce the steel are widely known. Incidentally, the symbol a in the figure indicates artificial ground, the symbol b indicates in the sea, the symbol c indicates a straight pile, and the symbol d indicates a submarine ground.

JP-A-7-90830 JP-A-7-90860 JP-A-8-170346 JP 2000-212959 A

When the inclined pile g is driven using the crane f equipped with the leader e, the following problems have occurred.
1) Since the construction work of the slant pile g cannot be performed by the crane f equipped with the leader e, the work efficiency is poor and the workability and the economical efficiency are poor because an auxiliary crane is required separately.
2) When a long leader e is used, it is very difficult to carry in and out the leader e, and it takes time and labor to attach and position the crane e to the crane boom h. It was bad.
3) When placing a large-diameter pile (tilted pile g), a large-diameter leader e must be used and the weight of the leader e increases accordingly. The work range of the crane f was narrow due to the fact that it could not be taken large, and the workability and economy were poor.
4) In the first place, the crane f equipped with the leader e is not suitable for pier construction because the work range (radius) is inevitably small.

  By the way, as a method of driving a pile, there is a method (so-called flying method) in which a crane f not equipped with a leader e is used without using the leader e (see FIG. 9). According to this flying construction method, since the slant pile g can be driven without using the leader e, the problems 1) to 4) are solved, and it is possible to carry out with excellent workability and economy.

  However, when the slant pile g is driven by this flying method, a large bending moment is generated at the contact portion X (FIG. 9) between the slant pile g and the guide j that supports the slant pile g. Aside from steel pipe piles, concrete piles such as PHC piles and RC piles, which are vulnerable to bending deformation, may cause cracks at the abutting portion X, and could not be carried out.

  Thus, conventionally, it has been recognized that the technique of placing an inclined concrete pile on the seabed ground by the flying method is very excellent in workability and economy, but has not been realized.

  The object of the present invention is to use a crane not equipped with a leader, and to incline an inclined concrete pile without causing any damage such as cracks. It is to provide a pile construction method.

As a means for solving the above-described problems of the prior art, the inclined concrete pile placing method according to the invention described in claim 1 is:
Preparing a work table with a guide for guiding the concrete pile to a required inclination angle, and building the concrete pile on the seabed at the inclination angle along the guide;
A step of fitting a cylindrical protective tube having a hollow portion of a length that wraps from the pile head of the concrete pile to at least the guide and having the upper end closed, and supporting the guide from the pile head of the concrete pile. ,
A hammer suspended by a heavy machine such as a crane is attached to the head of the protective tube, and the concrete pile is driven to a required depth by hitting with the hammer.

The construction method of the inclined concrete pile described in claim 2 is:
Preparing a work table with a guide for guiding the concrete pile to a required inclination angle, and building the concrete pile on the seabed at the inclination angle along the guide;
A step of fitting a cylindrical protective tube having a hollow portion of a length that wraps from the pile head of the concrete pile to at least the guide and having the upper end closed, and supporting the guide from the pile head of the concrete pile. ,
A hammer suspended by a heavy machine such as a crane is attached to the head of the protective tube, and by hitting with the hammer, the head of the protective tube is driven to a position directly above the guide, and then the protective tube is A process of pulling from the concrete pile,
A step of setting a short protective pipe on the pile head of the concrete pile, attaching the hammer to the head of the short protective pipe, and driving the concrete pile to a required depth by hitting with the hammer. It is characterized by that.

  The invention described in claim 3 is characterized in that, in the inclined concrete pile placing method described in claim 1 or 2, the concrete pile is a PHC pile or an RC pile.

  According to a fourth aspect of the present invention, in the method for placing an inclined concrete pile according to any one of the first to third aspects, the protective tube has a cross section substantially the same shape and the same size as the cross section shape of the concrete pile. It is characterized by a shape.

  The invention described in claim 5 is the inclined concrete pile placing method according to any one of claims 1 to 4, wherein the protective pipe is inserted at a required interval at the pile head insertion position of the concrete pile. It is characterized by having a peephole for confirming.

  According to the inclined concrete pile placing method according to the present invention, the inclined concrete pile is protected by a protective pipe from the pile head to the guide supporting the pile, and the so-called flying method is used. It is possible to perform the placing work without causing any damage such as cracks in the concrete pile. Therefore, since it is possible to perform the placing work safely and reliably using a crane that is not equipped with a leader, all of the above problems 1) to 4) can be solved, and it is very economical and easy to construct. Excellent implementation is possible.

  The construction method of the inclined concrete pile according to claim 2 is carried out as follows in order to place the inclined concrete pile without generating any cracks using a crane not equipped with a leader. .

  FIGS. 1-7 has shown the construction procedure of the construction method of the inclined concrete pile described in Claim 2 in steps.

  As shown in FIG. 1, first, a work table 2 provided with a guide 2a for guiding a concrete pile 1 to a required inclination angle is prepared on a pier on the sea as shown in FIG. The concrete pile 1 suspended by the wire rope 12 of the crane 10 is built on the seabed at the inclination angle along the guide 2a.

  The inclined concrete pile 1 penetrates the required length into the seabed ground d by its own weight action along the angle set by the guide 2a. Incidentally, the code | symbol 11 in a figure has shown the crane boom.

  As the concrete pile 1 according to the present embodiment, a PHC pile is suitably used, but the concrete pile 1 is not limited to this, and can be carried out substantially in the same manner with a concrete pile such as an RC pile (the invention according to claim 3). . In addition, the concrete pile 1 according to the present embodiment is a columnar concrete pile 1 having a diameter of about 60 cm and a length of about 25 m, but the size and shape are not limited thereto. Of course.

  Next, as shown in FIGS. 2A and 2B, a cylindrical protective tube 3 having a hollow portion 3 a long enough to wrap from the pile head 1 a of the concrete pile 1 to at least the guide 2 a and closed at the upper end. The concrete pile 1 is fitted from the pile head 1a and supported by the guide 2a.

  The protective tube 3 is preferably a steel pipe. The protective tube 3 according to the present embodiment uses a cylindrical protective tube 3 having an inner diameter of about 60 cm, an outer diameter of about 65 cm, a length of about 15 m, and a hollow portion 3 a having a length of about 12 m. Of course, the size and shape are not limited thereto. However, it is preferable that the protective tube 3 has a cross-sectional shape substantially the same shape and the same size as the cross-sectional shape of the concrete pile 1 (the invention according to claim 4). This is for placing the concrete pile 1 safely and reliably. In addition, the protective tube 3 is provided with a viewing hole (not shown) in the longitudinal direction for confirming the insertion position of the pile head 1a of the concrete pile 1 at intervals of about 1.5 to 2.0 m. (The invention according to claim 5).

  Next, as shown in FIG. 3, a hammer 4 suspended by a crane 10 (such as a heavy machine) is attached to the head of the protective tube 3, and the head of the protective tube 3 is hit by the hammer 4. Then, it is driven to the position directly above the guide 2a (so-called flying method).

  The inclined concrete pile 1 is covered and protected by the protective tube 3 without any gap from the pile head 1a to a position reaching at least the guide 2a. Therefore, the concrete pile 1 and the guide 2a are hit when the hammer 4 is hit. There is no possibility of damage such as cracks due to a large bending moment generated in the contact portion X (see FIG. 3). Therefore, the operation of placing the inclined concrete pile 1 can be performed safely and reliably.

  Thus, after the hammer 4 has driven the inclined concrete pile 1 safely and securely until the head of the protective tube 3 reaches a position directly above the guide 2a, the protective pipe 3 is protected as shown in FIG. The pipe 3 is pulled out from the concrete pile 1. As a guideline for pulling out the protective tube 2, it should be noted that the head of the protective tube 2 is located above the guide 2a and that the lower end of the protective tube 2 does not penetrate into the seabed ground d. .

  Next, as shown in FIG. 5, a short protective tube (Yatco) 5 is set on the pile head 1a of the concrete pile 1 and, as shown in FIG. A hammer 4 is mounted, and the concrete pile is driven to a required depth by hitting with the hammer 4 (the invention according to claim 2 above).

  The short protective tube 5 is preferably a steel tube, and functions in the same manner as a so-called Yatsuko. Incidentally, the short protective tube 5 according to this embodiment has a length of about 7 m, and the length of the portion of the concrete pile 1 that covers the pile head 1 a is about 1 m. Of course, the size of the short protective tube 5 is not limited to this. However, it is preferable that the short protective tube 5 has a cross-sectional shape substantially the same shape and the same size as the cross-sectional shape of the concrete pile 1 (invention of claim 4). In addition, the short protective tube 5 has a viewing hole (not shown) for confirming the insertion position of the pile head 1a of the concrete pile 1 at intervals of about 1.5 to 2.0 m in the length direction. It is drilled and carried out (the invention according to claim 5).

  Thus, after placing the inclined concrete pile 1 to the required depth (equivalent to the height dimension of the adjacent straight pile), as shown in FIG. 7, the short protective tube 5 is removed, The placing work for one inclined concrete pile 1 is completed.

  In addition, if it implements using the elongate protective tube 3 which formed the closed part of the upper end part of the said protective tube 3 as long as about 6 m in order to combine the function of the said short protective tube (Yatko) 5, the said short length It is also possible to carry out without using the protective tube 5 (invention of claim 1).

  Thus, according to the construction method of the inclined concrete pile mentioned above, the crane 10 which is not equipped with the leader is used, and the concrete pile 1 which is weak to bending deformation does not generate | occur | produce damages, such as a crack, at all. It can be placed safely and economically. Specifically, in placing one slant pile, a cost reduction of about 50% can be expected compared to the case of placing using a leader.

  Although the embodiments have been described with reference to FIGS. 1 to 7, the present invention is not limited to the embodiments of the illustrated examples, and design modifications that are usually performed by those skilled in the art without departing from the technical idea thereof, Note that it includes a range of application variations.

It is the elevation which showed the stage which built the concrete pile. A and B are elevational views showing step by step the process of inserting a protective tube into a concrete pile. It is the elevation which showed the step which hits the protection pipe which protects a concrete pile with a hammer. It is the elevation which showed the stage which pulled out the protection pipe from the concrete pile. It is the elevation which showed the stage which set the Yatco to the pile head of a concrete pile. It is the elevation which showed the stage which hits Yatco with a hammer. It is an elevational view showing the stage of removing the Yatco after placing the concrete pile to a desired depth. It is the elevation which showed the prior art. It is the elevation which showed the prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Concrete pile 1a Pile head 2 Work table 2a Guide 3 Protection tube 3a Hollow part 4 Hammer 5 Short protection tube (Yatco)
10 Crane 11 Crane Boom 12 Wire Rope X Abutting part between inclined pile and leader

Claims (5)

Preparing a work table with a guide for guiding the concrete pile to a required inclination angle, and building the concrete pile on the seabed at the inclination angle along the guide;
A step of fitting a cylindrical protective tube having a hollow portion of a length that wraps from the pile head of the concrete pile to at least the guide and having the upper end closed, and supporting the guide from the pile head of the concrete pile. ,
A process of attaching a hammer suspended by a heavy machine such as a crane to the head of the protective tube and driving the concrete pile to a required depth by hitting with the hammer,
An inclined concrete pile driving method characterized by comprising: Preparing a work table with a guide for guiding the concrete pile to a required inclination angle, and building the concrete pile on the seabed at the inclination angle along the guide;
A step of fitting a cylindrical protective tube having a hollow portion of a length that wraps from the pile head of the concrete pile to at least the guide and having the upper end closed, and supporting the guide from the pile head of the concrete pile. ,
A hammer suspended by a heavy machine such as a crane is attached to the head of the protective tube, and by hitting with the hammer, the head of the protective tube is driven to a position directly above the guide, and then the protective tube is A process of pulling from the concrete pile,
A step of setting a short protective tube on the pile head of the concrete pile, attaching the hammer to the head of the short protective tube, and driving the concrete pile to a required depth by striking with the hammer,
An inclined concrete pile driving method characterized by comprising:   The concrete pile is a PHC pile or an RC pile, and the method for placing an inclined concrete pile according to claim 1 or 2,   The construction method of the inclined concrete pile according to any one of claims 1 to 3, wherein the protective tube has a cross-sectional shape substantially the same shape and the same size as the cross-sectional shape of the concrete pile.   The inclined concrete pile according to any one of claims 1 to 4, wherein a peephole for confirming an insertion position of a pile head of the concrete pile is provided in the protective tube at a required interval. Construction method.

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