JP6703466B2 - Jig for preventing leakage of filler and method for manufacturing composite pile using the jig - Google Patents

Description

This invention is provided in a concentric arrangement with a concrete pile (hereinafter referred to as a PHC pile) exhibiting a high concrete strength of 85 N/mm ² or more and a gap between the outer periphery of the PHC pile and the heads thereof aligned. The present invention relates to a technical field of a composite pile including a steel pipe and a filler to be filled in the gap, and more specifically to a manufacturing method of the composite pile and a filler leakage prevention jig used in the method.

Although concrete piles (including PHC piles) can retain large axial stress (compressive force), they break brittlely against horizontal forces (bending stress and shear stress), so structures (especially high-rise structures) , It is hard to say that it can withstand the horizontal force when used as the foundation of a skyscraper.
On the other hand, the steel pipe pile has large bending strength and shear strength, but it has to be thick in order to retain a large axial stress, which is an economical problem. There is also a problem that local buckling occurs when the pile diameter becomes large.

Therefore, as one of the methods for compensating for these problems, there is a concrete pile with an outer shell steel pipe (hereinafter appropriately referred to as SC pile) which is a combination of a concrete pile and a steel pipe.
This SC pile is manufactured by pouring high-strength concrete into the hollow part of a steel pipe and integrally manufacturing it by centrifugal molding (centrifugal compaction), and integrally resists axial stress, bending stress, and shear stress.
This SC pile has the advantages of a concrete pile that is strong against axial stress and the advantages of a steel pipe that is strong against bending stress and shear stress, and even if a large bending deformation occurs, the concrete prevents local buckling of the steel pipe and the concrete Since it is constrained by a steel pipe, it has the advantage of having great toughness, and the demand for it has been increasing in recent years.

However, since the SC pile is configured to integrally resist axial stress, bending stress, and shear stress as described above, inevitably, in addition to the axial stress, the concrete pile constituting the SC pile is Bending and shear stresses will also be burdened. Specifically, when a horizontal force (short-term load) such as an earthquake is applied to a structure, the concrete pile is subjected to axial stress (long-term vertical load) of the structure and bending stress and shear stress. It was unclear how much the concrete pile inside the SC pile bears bending stress and shear stress. As a result, the fracture property of the concrete pile was unknown.
Therefore, the SC pile has a problem that it is not clear that the concrete pile bears the axial stress and the steel pipe bears the bending stress and the shear stress.
In a building structure, a secondary design (horizontal bearing capacity method, time history response analysis) is essential for high-rise structures or super-high-rise structures, and not only the allowable stress of the structure but also the ultimate strength and toughness of the structure are evaluated. Is an important item in design. Therefore, there is a problem in that it is difficult to design a pile whose performance as a member of the pile is unknown (ambiguous), and the design cannot be performed according to a reliable design policy.
In short, in the SC pile, the concrete pile bears the axial stress, and the steel pipe bears the bending stress and the shear stress. Therefore, the role of the pile is not clear. There was no guarantee.

By the way, in addition to the above-mentioned SC pile, various inventions which construct a pile using a concrete pile and a steel pipe together are disclosed (for example, refer to patent documents 1-5).
However, the inventions according to Patent Documents 1 to 5 do not have a purpose (issue) and a structure to clarify the role sharing of the axial stress, the bending stress, and the shear stress, and therefore the concrete pile bears the axial stress. However, the bending stress and the shear stress are not piles having a configuration in which the division of roles that the steel pipe bears can be clarified (for details, refer to the section of [Problems to be solved by the invention] according to Patent Documents 6 and 7 below. ).

Therefore, as shown in Patent Documents 6 and 7, the present applicant has developed a composite pile in which PHC piles and steel pipes are combined, which can clarify the role allotment of axial stress and bending stress and shear stress.
This composite pile is composed of a PHC pile, a steel pipe provided in a concentric arrangement with a gap provided on the outer periphery of the PHC pile, and a filler filled in the gap, and the PHC pile and the steel pipe are flattened. It is made to stand upright in the vertical direction on the upper surface of the peeling plate placed on top of it in a vertical direction, and a filler is added to the steel pipe from above in a gap formed between the outer peripheral surface of the PHC pile and the inner peripheral surface of the steel pipe. It is filled up to the same height, and the filling material is cured to be manufactured (see claim 1 of Patent Document 7).

JP-A-9-170232 Japanese Patent Laid-Open No. 61-176717 JP-A-5-280046 JP-A-7-11636 JP, 2010-265702, A Re-table 2012/147690 publication Japanese Patent No. 5805182

Incidentally, in the past, so-called synthetic piles were mainly manufactured in a state of being placed sideways, and it was difficult to evenly fill the filler between the steel pipe and the PHC pile. For this reason, although the pile material such as the PHC pile is inclined to improve the filling property, it is difficult to perform the positioning work and the like, and the manufacturing efficiency cannot be improved. In particular, when a cement-based material such as cement milk or mortar is used as the filler, uniform filling is difficult, it is necessary to secure fluidity, and there are concerns that voids may be generated due to breathing.

In view of such a problem, the composite pile according to Patent Document 7 developed by the present applicant is manufactured with the head of the PHC pile and the steel pipe facing downwards, which is the reverse of the actual use. That is, since the PHC pile and the steel pipe are erected concentrically on the peeling plate and filled with the filler from above, the filling work can be performed easily, reliably, and satisfactorily. It has excellent advantages such as being able to manufacture high quality synthetic piles.
However, if the PHC pile and the steel pipe are placed on the peeling plate and each of them is left to its own weight to fill the gap formed by the PHC pile and the steel pipe with the filler, the peeling plate, the PHC pile and the steel pipe are restrained at all. Since there is no filling structure, there is a concern that the filling material may leak between the peeling plate and the PHC pile or the steel pipe due to the filling pressure of the filling material, which may adversely affect the quality of the composite pile to be manufactured. There was not a little.
Therefore, it is obvious that if the leakage of the filler can be reliably prevented, a higher quality composite pile can be provided.

The present invention has been devised in view of the problems of the background art described above, and an object thereof is to ensure the leakage of the filler while maintaining the advantages of the invention according to Patent Document 7. It is an object of the present invention to provide a filler leakage prevention jig and a method for manufacturing a synthetic pile using the same, which can provide a higher quality synthetic pile by preventing the above.

As a means for solving the problems of the above-mentioned background art, a filler leakage prevention jig according to the invention described in claim 1 is concentrically arranged with a PHC pile and a gap between the outer circumference of the PHC pile and the heads aligned. A steel pipe provided in, and a filler leakage prevention jig used in a method for manufacturing a composite pile consisting of a filler filled in the gap,
A ring-shaped or disk-shaped flat plate portion that can be bolted to an end plate provided on the head of the PHC pile and closes the opening of the gap, and a cylinder that rises from the flat plate portion along the outer peripheral surface of the steel pipe. And a bolt mounting portion projecting from the outer peripheral surface of the cylindrical portion and capable of being bolted to the steel pipe.

According to a second aspect of the present invention, in the filling material leakage prevention jig according to the first aspect, a water blocking material such as a rubber packing that closes the opening of the gap is provided on the upper surface of the flat plate portion. Is characterized by.

According to a third aspect of the present invention, in the filling material leakage prevention jig according to the first or second aspect, the raised portion that is higher than the protrusion size of the bolt joined to the end plate provided on the head of the PHC pile. It is characterized by having.

According to a fourth aspect of the present invention, in the filler leakage prevention jig according to any one of the first to third aspects, the bolt attachment portion has a denden bolt that is rotatable in the axial direction of the steel pipe in advance. Alternatively, an eyebolt is provided.

The method for manufacturing a composite pile according to the invention described in claim 5 is a PHC pile, a steel pipe provided in a concentric arrangement with a gap secured on the outer periphery of the PHC pile and heads aligned, and a filler filled in the gap. A method of manufacturing a composite pile comprising
The flat plate part of the filler leakage prevention jig according to any one of claims 1 to 4 is bolted to an end plate provided on the head of the PHC pile, and the bolt mounting part and the outer circumference of the steel pipe are also attached. By bolt-joining the bolt mounting portion projecting on the surface with a bolt and a nut, the opening of the gap formed by the concentric PHC pile and the steel pipe is closed by the flat plate portion, and the filling material Vertically standing the PHC pile and the steel pipe in a concentric arrangement with the leakage prevention jig facing downward;
The filling material is filled into the gap from above, and after the filling material is cured, all the above-described bolt connection states are released and the filling material leakage prevention jig is removed.

According to the invention described in claim 6, in the method for manufacturing a composite pile described in claim 5, after removing all the bolt connection states described above, the bolt mounting portion projecting on the outer peripheral surface of the steel pipe is removed. Is characterized by.

The invention described in claim 7 is the method for manufacturing a composite pile according to claim 5 or 6, wherein the axial length of the steel pipe is shorter than the axial length of the PHC pile.

The invention described in claim 8 is the method for manufacturing a synthetic pile according to any one of claims 5 to 7, wherein the filler is cement milk, soil cement, mortar, resin mortar, asphalt concrete, or relative. The feature is that the sand is densely packed with a density of 80% or more.

The invention described in claim 9 is the method for manufacturing a composite pile according to any one of claims 5 to 8, wherein the filler causes local buckling of the steel pipe even if bending deformation occurs in the steel pipe. The filler is made of a material having strength and rigidity that can be prevented and smaller in strength and rigidity than the PHC pile.

According to the filler leakage prevention jig 20 and the method for manufacturing the composite pile 10 using the jig 20 according to the present invention, the following operational effects are exhibited.
(1) The PHC pile 1 and the steel pipe 2 can be integrally bolted together via the filler leakage prevention jig 20, and at the same time when the bolt joining work is completed, the PHC pile 1 and the steel pipe 2 are automatically joined. Can be positioned and fixed in a concentric arrangement. That is, since the concentric positioning operation, which is conventionally troublesome, can be performed easily, reliably, and quickly, the workability is excellent.
(2) In the filler 3 filled in the gap 3 formed by the PHC pile 1 and the steel pipe 2, the lower end portion of the gap S is closed by the flat plate portion 11 of the jig 20, and the inner diameter direction of the lower end portion Is reliably closed by the bolt joining effect between the PHC pile 1 and the flat plate portion 11 over the entire circumference thereof, and the bolt joining effect between the steel pipe 2 and the flat plate portion 11 over the entire circumference in the outer diameter direction of the lower end portion thereof. Since it is surely closed by the above, it is possible to surely realize a sealed state in which there is no risk of leakage (mainly liquid leakage) due to the filling pressure. If a water blocking material such as a rubber packing is attached to the flat plate portion 11 of the filling material leakage prevention jig 20 for implementation, a hermetically sealed state with higher airtightness can be realized. Therefore, a high quality synthetic pile can be realized.
(3) Since the filler leakage prevention jig 20 is mechanically joined to the PHC pile 1 and the steel pipe 2 only with bolts, after the filler 3 is cured, the joined state can be easily removed by removing the bolts. It can be canceled and can be promptly removed (recovered). Therefore, it is excellent in workability.

A is a vertical cross-sectional view showing a use state of the composite pile manufactured by the method for manufacturing a composite pile according to the present invention, B is a cross-sectional view taken along the line BB of A, and C is a cross-section of A. It is a top view. A is a front view showing a filling preparation step of the method for manufacturing a composite pile according to the present invention, and B is a sectional view thereof. 2A and 2B are enlarged views of the lower portion of FIGS. 2A and 2B, respectively. FIG. 3B is a sectional view taken along the line AA of FIG. 3A. A is a plan view showing an embodiment of a filler leakage prevention jig according to the present invention, B is a front view of the same, and C is a cross-sectional view taken along line CC of A. A is a bottom view of the filler leakage prevention jig according to FIG. 5, and B is a right side view of the same. It is explanatory drawing which showed an example of the attachment method to the PHC pile and the steel pipe of the filler leak prevention jig which concerns on this invention. FIG. 6 is a vertical sectional view showing another embodiment of the filler leakage prevention jig according to the present invention.

Next, an example of a method for manufacturing a composite pile according to the present invention and a filler leakage prevention jig used in the method will be described with reference to the drawings.

(Regarding the composite pile manufactured by the method for manufacturing a composite pile according to the present invention)
First, a composite pile manufactured by the method for manufacturing a composite pile according to the present invention will be described with reference to FIGS.
This composite pile 10 is filled with the PHC pile 1, a steel pipe 2 provided with a gap S (see FIGS. 2 to 4) on the outer periphery of the PHC pile 1 in a concentric arrangement with heads aligned, and the gap S filled. It is built in the ground G, and the foundation (not shown) of the structure is built on it.
The upper end of the steel pipe 2 is joined to the foundation of the structure in a structure capable of transmitting a horizontal force. There are various means for joining the upper end portion of the steel pipe 2 to the foundation of the structure. For example, a reinforcing bar (beard rebar) protruding upward is welded to the outer peripheral surface of the upper end portion of the steel pipe 2 and the basic concrete is placed. The upper end of the steel pipe 2 and the foundation of the structure are joined so that horizontal force can be transmitted.
Incidentally, FIG. 1 shows an embodiment in which the composite pile 10 is applied as a support pile to a support layer J having a deep depth from the ground G (for example, about 30 m). In this case, an ordinary simple PHC pile 1 is added below the composite pile 10. That is, the composite pile 10 is provided at the top of the support pile.
Although the top end of the composite pile 10 according to the illustrated example is configured to slightly project from the upper surface of the ground G, depending on the construction method of the structure foundation, for example, a level equivalent to the ground G level or lower than that. Of course, it is also possible to implement the configuration set to the level.
The structure may be a low-rise structure, a high-rise structure or an ultra-high-rise structure. The support piles including the composite piles 10 can of course be implemented with a configuration that does not reach the support layer J.

The PHC pile 1 constituting the composite pile 10 is preferably provided with ring-shaped end plates 1a at both ends in the axial direction thereof and has a strength (Fc) of 100 N/mm ² or more capable of supporting a large vertical load. Used for. The PHC pile 1 is generally manufactured with an outer diameter (D) of about 300 to 1200 mm and a length (L) of about 5 to 15 m.
The size of the PHC pile 1 is not limited to this, and the design can be appropriately changed according to the form of the structure to be supported, the property of the ground G, and the like.

The steel pipe 2 constituting the composite pile 10 preferably has an outer diameter (D) of about 400 to 1,400 mm, a wall thickness (t) of about 6 to 25 mm, and a length (L) of about 3 to 15 m. Be done.
Specifically, when using the PHC pile 1 having an outer diameter of about 600 mm, the steel pipe 2 having an outer diameter of about 700 to 800 mm is used, and when using the PHC pile 1 having an outer diameter of about 1200 mm, the outer diameter is 1300 to The steel pipes 2 are arranged in a concentric arrangement in which a gap S for filling the filling material 3 is secured in a range of 20 to 100 mm, for example, by using the steel pipes 2 of about 1400 mm.
The length of the steel pipe 2 is a length that can effectively resist the form of the structure supported by the composite pile 10 or the horizontal force (bending stress and shear stress) acting on the structure. As a guide, it is said that about 5 times the pile diameter of the PHC pile 1 is preferable, but the design may be appropriately changed according to the property of the ground G.
The axial length of the steel pipe 2 is preferably shorter than the axial length of the PHC pile 1. The reason is not only economical, but as shown in FIG. 1A, as shown in FIG. This is because, if it is necessary to add the replenishment, the steel pipe 2 can be smoothly replenished without interfering with the work.
The size of the gap S filled with the filling material 3 is not limited to about 20 to 100 mm, and may be appropriately determined according to the level of horizontal force (bending stress and shear stress) acting on the composite pile 10. The design is changed.

The filler 3 forming the composite pile 10 is densely filled in the gap S formed by the outer peripheral surface of the PHC pile 1 and the inner peripheral surface of the steel pipe 2 over substantially the entire length of the steel pipe 2.
As the filler 3 according to this embodiment, cement milk, soil cement, mortar, resin mortar, asphalt concrete, or densely packed sand having a relative density of 80% or more is preferably used. If a resin mortar having plasticity is used as the filler 3, the function as an energy absorbing material can be further expected. Further, if the densely packed sand is used, the compression characteristic is high, and the volume compression can be prevented against the shear stress generated between the steel pipe 2 and the PHC pile 1 by the diretansy effect.
Furthermore, it is preferable that the filler 3 be a material having lower strength and rigidity than the PHC pile 1 (strength of about ²⁰ to 50 N/mm ² as a standard). Further, it is preferable that the steel pipe 2 has a certain toughness and strength and rigidity that can prevent local buckling of the steel pipe 2.

The filler 3 made of the above-mentioned material has a material smaller than the strength and rigidity of the PHC pile 1 to effectively absorb the bending stress (bending moment) and the shear stress of the steel pipe 2, and the adjacent PHC piles. It is possible to realize a configuration in which it is difficult to transmit to 1. Further, since the filler 3 has a lower rigidity (vertical rigidity) than the PHC pile 1, it is possible to realize a configuration in which the PHC pile 1 alone bears most of the vertical load of the structure.

The composite pile 10 can be constructed on-site, or can be manufactured in advance in a factory or the like and carried into the site.

(About the filler leakage prevention jig used in the method for manufacturing a composite pile according to the present invention)
Next, a filling material leakage prevention jig used in the method for manufacturing a composite pile according to the present invention will be described based on FIGS. 2 to 6.
The filler leakage prevention jig 20 is preferably made of metal and can be bolted to the ring-shaped end plate 1a provided on the head of the PHC pile 1 to form the PHC pile 1 and the steel pipe 2. The ring-shaped flat plate portion 11 that closes the opening of the gap S, the cylindrical portion 12 that rises from the flat plate portion 11 along the outer peripheral surface of the steel pipe 2, and the steel pipe that is provided so as to project on the outer peripheral surface of the cylindrical portion 12. 2 and a bolt mounting portion 13 capable of being bolted.
In short, the filling material leakage prevention jig 20 according to the present invention is implemented with a configuration in which the flat plate portion 11 is provided with a bolt joining means with the PHC pile 1 and the cylindrical portion 12 is provided with a bolt joining means with the steel pipe 2. It
The flat plate portion 11 may be formed in a disc shape as shown in FIG. 8 in addition to the ring shape (see reference numeral 11').

<About the flat plate portion 11>
The ring-shaped flat plate portion 11 is implemented in such a size that it can be installed (surface touch) on the head of the PHC pile 1 and the steel pipe 2 that are positioned concentrically. By the way, the ring-shaped flat plate portion 11 according to the illustrated example is implemented with an inner diameter of 460 mm, an outer diameter of 808 mm, and a plate thickness of 19 mm, for example. In the present embodiment, as an example, a PHC pile 1 having a pile diameter (outer diameter) of 700 mm (inner diameter of 500 mm) and a steel pipe 2 having an outer diameter of 800 mm (thickness of 9 mm) have gaps S with respect to the flat plate portion 11 of this size. =41 mm is secured and they are placed in a concentric arrangement. That is, as shown in FIG. 3B and the like, the PHC pile 1 and the steel pipe 2 are placed between the inner diameter and the outer diameter of the ring-shaped flat plate portion 11.
By the way, on the inner diameter side (inner peripheral edge portion) of the ring-shaped flat plate portion 11, rising ribs 14 which are continuous in the circumferential direction (as an example, the height from the upper surface of the flat plate portion 11 is 40 mm) are formed.
Although not shown, in order to further enhance the effect of preventing leakage (mainly liquid leakage), the entire surface between the inner diameter and the outer diameter of the ring-shaped flat plate portion 11 or at least a portion corresponding to the gap S is provided. It is preferable that a water-blocking material such as a ring-shaped rubber packing that closes the opening of the gap S is attached and provided.

In addition, the flat plate portion 11 is well-balanced in a portion corresponding to a plurality of screw holes among the screw holes so that the flat plate portion 11 is joined using the screw holes provided in the end plate 1a of the PHC pile 1 in advance ( (5 in the illustrated example) and bolt through holes (through holes) 11a are provided (see FIG. 5A and the like). The existing screw holes of the end plate 1a are usually provided in a number corresponding to the PC steel wire installation position at a predetermined pitch (about 8 to 32 according to the pile diameter). Although the number of the bolt through holes 11a is five, of course, the number is not limited to this, and the flat plate portion 11 can be firmly fixed to the end plate 1a and the filling material 3 that fills the gap S can be formed. The design can be changed (increased or decreased) as long as the leakage can be prevented.

<About the cylindrical portion 12>
On the outer diameter side (outer peripheral edge portion) of the ring-shaped flat plate portion 11, a cylindrical portion 12 that rises in a substantially perpendicular direction is provided in a circumferentially continuous form by a joining means such as welding. The cylindrical portion 12 is provided for favorably positioning the steel pipe 2 that forms the outer periphery of the composite pile 10 and for firmly fixing the bolt mounting portion 13. By the way, the cylindrical portion 12 according to the illustrated example is implemented, for example, at a height of about 80 mm from the upper surface of the flat plate portion 11.

In the present embodiment, the cylindrical portion 12 has a rational configuration that also serves as the raised portion 15. That is, as shown in FIG. 3B, etc., the cylindrical portion 12 having an inner diameter of approximately 808 mm, an outer diameter of 832 mm, a wall thickness of 12 mm, and a height of approximately 120 mm is approximately the same as the outer diameter of the flat plate portion 11. Positioning the flat plate part 11 at a position slightly lower than the inner wall surface of the cylindrical part 12 (at a position where the raised dimension H (see FIG. 3B) is secured by 20 mm) when externally attached along the outer peripheral edge of the part 11. However, they are integrally joined by joining means such as welding.
The raised portion 15 is formed slightly higher than the head of the bolt 21 for bolting to the end plate 1a of the PHC pile 1 via the flat plate portion 11 so that the filler leakage prevention jig 20 is directed downward. When the jig 20 is installed on a flat part such as the ground, the jig 20 serves to maintain a stable horizontal posture without rattling, and also serves to prevent the damage of the bolt 21.
The raised portion 15 may be implemented by using the elongated cylindrical portion 12 having the role of raising the lower portion as described above, or may be provided separately from the cylindrical portion 12 as a matter of course. .. For example, a ring-shaped or square-shaped raised portion (rib) slightly higher than the head of the bolt 21 is provided on the lower surface of the flat plate portion 11, or protruding members such as square members and leg members are scattered in a well-balanced manner. It can also be carried out.

<About the bolt mounting part 13>
A bolt mounting portion 13 is provided on the outer peripheral surface of the cylindrical portion 12 so as to project therefrom. The bolt mounting portion 13 according to the present embodiment is provided at a total of four locations on the outer peripheral surface of the cylindrical portion 12 in a well-balanced manner (see FIG. 5A, etc.). The bolt mounting portion 13 according to the present embodiment is a so-called bracket made of two parallel metal plates. As an example, a pair of substantially rectangular metal plates having a length of 70 mm, a width of 75 mm, and a plate thickness of 9 m are The arms are arranged on the outer peripheral surface of the cylindrical portion 12 in a two-armed manner at intervals of about 20 mm and are integrally provided by a joining means such as welding. Each of the two metal plates is provided with a bolt through hole for allowing the bolt 16 to pass therethrough at a substantially central portion.
By the way, in the present embodiment, the denden bolts 18 (eye bolts are also possible) are arranged between two metal plates, and the bolt through holes provided in each metal plate and the bolt through holes (core holes) of the denden bolts. The bolts 16 are inserted through the three bolt through holes whose cores are aligned with each other, the washers are passed through both ends of the bolts 16, and nuts 17 are tightened. The steel pipe 2 is configured to be rotatable in the axial direction (vertical direction) with a hole (core hole) as a base point.

The bolt attachment portions 13 are provided at four locations in all directions, but of course the invention is not limited to this, and the filler 3 that can be well bolted to the steel pipe 2 and that fills the gap S. The design can be changed (increased or decreased) as long as the leakage can be prevented.
The length of the denden bolt 18 is, for example, about 130 mm from the hole core. However, the length is not limited to this, and the bolt attachment portion 19 (described later) provided on the steel pipe 2 side is in a good joint state. It is implemented with the proper length to achieve.

(Regarding the manufacturing method of the composite pile using the above-described filler leakage prevention jig according to the present invention)
Next, a method for manufacturing the composite pile 10 using the filler leakage prevention jig 20 having the above configuration will be described.
In the method for manufacturing the composite pile 10, first, the flat plate portion 11 of the filler leakage prevention jig 20 is bolted to the end plate 1a provided on the head of the PHC pile 1, and the bolt mounting portion 13 is used. The PHC pile 1 and the steel pipe 2 which are concentrically arranged are formed by bolt-joining the bolt mounting portion 19 projecting on the outer peripheral surface of the steel pipe 2 with a bolt (denden bolt 18) and a nut 22. The opening of the gap S is closed by the flat plate portion 11, and the PHC pile 1 and the steel pipe 2 are erected vertically in a concentric arrangement with the filler leakage prevention jig 20 facing downward (filling preparation step).
Then, the filling material 3 is filled into the gap S from above, and after the filling material 3 is cured, all the above-described bolt connection states are released and the filling material leakage prevention jig 20 is removed (filling). Work process).

<About the filling preparation process>
The filling preparation step is, in short, a step of integrally bolt-bonding the PHC pile 1 and the steel pipe 2 in a concentric arrangement through the filler leakage prevention jig 20.
That is, the filling material leakage prevention jig 20 (hereinafter, appropriately abbreviated as a jig 20) has an original role of preventing the leakage of the filling material 3 and also positions and fixes the PHC pile 1 and the steel pipe 2 in a concentric arrangement. Also plays a role.

There are various methods for bolting the jig 20 to the PHC pile 1 and the steel pipe 2. For example, in this embodiment, as shown in FIG. 7, an operator uses a nylon sling to attach the PHC pile 1 to the steel pipe 2 installed on a support (for example, H-shaped steel) 32 in a factory or on-site. The work is carried out by lifting it with a heavy machine and the like, and a supporting base (for example, H-shaped steel) 31 is also installed at both ends of the PHC pile 1 which has been penetrated.
Here, the height of the support base 31 is slightly higher than the height of the support base 32 (ideally, by the gap S to be formed), so that the PHC pile 1 and the steel pipe 2 are separated from each other. It is preferable that the arrangement is substantially concentric. In addition, it is preferable to dispose shift-preventing members (for example, square members) for preventing swing (rotation) on both sides of the PHC pile 1 and the steel pipe 2 on the support bases 31 and 32.

It should be noted that the steel pipe 2 is preliminarily welded with the same number (a total of four bolts in four directions in this embodiment) of bolt mounting portions 19 in a portion corresponding to the bolt mounting portions 13 provided on the jig 20 side on the outer peripheral surface thereof. It is provided by the joining means of.
In the present embodiment, as an example, the bolt attachment portion 19 uses a channel material (C-shaped steel) having a length (protruding dimension) of about 80 mm, a web of 75 mm and a flange of 40 mm, and the outer center of the web. A notch 19a capable of receiving the bolt shaft of the denden bolt 18 is formed in the portion (see FIGS. 3A and 4). By the way, the bolt attachment portion 19 may be attached to the steel pipe 2 at a suitable position such that the bolt attachment portion 19 has a shape corresponding to the curvature of the outer peripheral surface of the steel pipe 2.

Then, the jig 20 is fixed by joining the flat plate portion 11 to the end plate 1a provided on the head of the PHC pile 1 with bolts 21 (stopped at five points). After that, the PHC pile 1 having the jig 20 mounted on the head is moved to the steel pipe 2 side (or the steel pipe 2 is moved to the PHC pile 1 side) by using a heavy machine as necessary, and the jig 20 is used. The flat plate portion 11 of is contacted with the head portion of the steel pipe 2. Then, the heads of the PHC pile 1 and the steel pipe 2 are necessarily aligned with each other (see FIG. 3B for assistance).

Then, the bolt attachment work between the bolt attachment portion 13 provided on the jig 20 side and the bolt attachment portion 19 provided on the steel pipe 2 side is performed in a horizontal (horizontal) posture.
In this bolt joining work, first, the bolt mounting portion 13 and the bolt mounting portion 19 are aligned, and then the denden bolt 18 on the bolt mounting portion 13 side is attached to the corresponding steel pipe 2 side. The bolt mounting portion 19 is rotated until it abuts on the inner end of the cutout portion 19a. Then, the nut 22 is tightened by passing a washer at the tip of the denden bolt 18, so that the bolt mounting portions 13 and 19 are bolted (joined) to each other. In addition, it is preferable in terms of work that the washer and nut 22 be attached to the tip of the denden bolt 18 in advance.
By repeating this bolt joining work according to the number of the denden bolts 18 (bolt mounting portions 13), the jig 20 and the steel pipe 2 are bolt-joined, and thus, the concentric arrangement and the head portion are provided. The aligned PHC pile 1 and the steel pipe 2 are integrally bolt-bonded via the jig 20 (see FIGS. 2B and 3B for assistance).

Then, the material (PHC pile 1, steel pipe 2) of the above-mentioned sideways posture composite pile 10 is erected vertically using a heavy machine with a jig 20 facing downward on a flat part such as the ground.
Since the raised portion 15 is formed in the lower portion of the jig 20, the jig 20 can be installed on the flat portion while maintaining a stable horizontal posture without rattling, regardless of the presence of the bolt 21. ..

<Regarding processes such as filling work>
Next, the operation of filling (press-fitting) the filling material 3 from above is performed in the space of the cylindrical gap S formed by the PHC pile 1 and the steel pipe 2. This filling operation is carried out densely while appropriately adjusting the filling amount and the filling speed so that no unfilled portion occurs. Introducing a drop-filling method that uses a small-diameter injection pipe (sunny hose) that can be inserted into the gap 3, or installing a sensor inside the gap S to adopt automatic injection management. Is to be carried out appropriately. The filling operation is usually performed until reaching the same height as the steel pipe 2, but the filling operation is not limited to this.

In the filler 3 filled in the gap 3, the lower end of the gap S is closed by the flat plate portion 11 of the jig 20, and the lower end portion of the filler 3 and the PHC pile 1 are flat along the entire circumference in the inner diameter direction. It is surely closed by the bolt-joining effect with the portion 11, and is reliably closed by the bolt-joining effect between the steel pipe 2 and the flat plate portion 11 over the entire circumference in the outer diameter direction of the lower end portion thereof. It is possible to realize a sealed state in which there is no risk of leakage (mainly liquid leakage). If the waterproofing material such as the rubber packing is attached to the operation, a more airtight closed state can be realized.

Next, after waiting for the curing of the filling material 3 that is densely filled in the gap S where the lower end portion is in the sealed state, all the bolted states described above are released. Specifically, all the bolts 21 for fixing the 5 points are removed to release the joint state between the PHS pile 1 and the jig 20, and the denden bolts 18 for fixing the 4 points are loosened by rotating the nut 22 and rotated. The joined state between the steel pipe 2 and the jig 20 is released. Then, the jig 20 in which all the joined states are released is removed and collected.

Thus, a high-quality composite of the PHC pile 1, the steel pipe 2 provided in the concentric arrangement with the gap S secured on the outer periphery of the PHC pile 1 with the heads aligned, and the filler 3 filled in the gap S The pile 10 can be manufactured.
Note that the bolt mounting portion 19 provided on the outer peripheral surface of the steel pipe 2 may be left as it is when it is used as a suspension fulcrum when it is built in the ground G by a heavy machine when constructing a support pile in the field thereafter. You may cut it with a gas burner and remove it.

Although the embodiments have been described with reference to the drawings, the present invention is not limited to the illustrated examples, and includes a range of design changes and application variations that a person skilled in the art normally makes, without departing from the technical idea thereof. I will mention this just in case.

For example, the bolt mounting portion 13 on the PHC pile 1 side and the bolt mounting portion 19 on the steel pipe 2 side may be replaced with each other, and the bolt mounting portion 19 on the steel pipe 2 side may be configured to include the denden bolt 18. .. The structure of the bolt mounting portions 13 and 19 is not limited to the illustrated example, and each is made of a steel material having bolt through holes whose cores coincide with each other, and bolts are provided in the bolt through holes in the axial direction of the PHC pile 1 and the steel pipe 2. It can be carried out by passing through both ends of the bolt and tightening a washer with a nut.

Further, although the flat plate portion 11 of the jig 20 is formed in a ring shape, as shown in FIG. 8, it is needless to say that it is formed in a disc-shaped flat plate portion 11' having no hole formed in the central portion. it can.

Further, in the present embodiment, as shown in FIG. 7, the bolt joining work between the jig 20 and the PHC pile 1 and the steel pipe 2 is carried out in a horizontal posture, but the present invention is not limited to this, and as shown in FIG. As shown, a substantially columnar base member 33 is installed on a flat portion such as the ground, the jig 20 is placed on the base member 33, and the PHC pile 1 and the steel pipe 2 are suspended and supported by a heavy machine to achieve a vertical posture. It is also possible to carry out bolt joining work with. In this case, the form of the base member 33 is such that the outer diameter is smaller than the inner diameter of the PHC pile 1 and the height is such that a good work posture can be secured so that the worker can smoothly perform the work of joining the bolts 21. It is preferable to carry out.

In addition, if the manufacturing method of the composite pile 10 is performed in a composite pile manufacturing pit (not shown) having a predetermined width and depth, the work at high places can be reduced by the depth of the pit, and filling can be performed. It is possible to improve work efficiency such as the work of filling the material 3 and the work of lifting the heavy equipment. The size of the synthetic pile manufacturing pit is appropriately changed according to the number of synthetic piles 10 to be manufactured, and the depth is preferably about the height of the steel pipe 2 for the filling operation. This pit has the advantage that it can be expected to have a curing effect, such as improving work efficiency and keeping the temperature at a constant level above the ground level, so that the curing management can be performed more appropriately.

1 PHC pile 1a End plate 2 Steel pipe S Gap 3 Filler 10 Composite pile G Ground J Support layer 11 Flat plate part 11a Bolt through hole 12 Cylindrical part 13 Bolt mounting part 14 Rising rib 15 Raised part H Raised size 16 Bolt 17 Nut 18 Denden Bolt 19 Bolt mounting portion 19a Cutout portion 20 Filler leakage prevention jig 21 Bolt 22 Nut 31 Support base 32 Support base 33 Base member

Claims (9)

A filler leakage prevention jig used in a method for manufacturing a composite pile including a PHC pile, a steel pipe provided with a gap between the PHC pile and a concentric arrangement with heads aligned, and a filler filled in the gap. And
A ring-shaped or disk-shaped flat plate portion that can be bolted to an end plate provided on the head of the PHC pile and closes the opening of the gap, and a cylinder that rises from the flat plate portion along the outer peripheral surface of the steel pipe. And a bolt mounting portion projecting from an outer peripheral surface of the cylindrical portion and capable of being bolt-joined to the steel pipe, a filler leakage preventing jig. The filling material leakage prevention jig according to claim 1, wherein a water blocking material such as a rubber packing that closes the opening of the gap is provided on the upper surface of the flat plate portion. The filling material leakage prevention jig according to claim 1 or 2, further comprising a raised portion that is higher than a protruding dimension of a bolt joined to an end plate provided on the head of the PHC pile. The filler leakage prevention according to any one of claims 1 to 3, characterized in that a denden bolt or eyebolt rotatable in the axial direction of the steel pipe is provided in advance in the bolt mounting portion. jig. A method for manufacturing a composite pile, comprising: a PHC pile, a steel pipe provided with a concentric arrangement with a gap secured on the outer periphery of the PHC pile, with heads aligned, and a filler filled in the gap.
The flat plate part of the filler leakage prevention jig according to any one of claims 1 to 4 is bolted to an end plate provided on the head of the PHC pile, and the bolt mounting part and the outer circumference of the steel pipe are also attached. By bolt-joining the bolt mounting portion projecting on the surface with a bolt and a nut, the opening of the gap formed by the concentric PHC pile and the steel pipe is closed by the flat plate portion, and the filling material Vertically standing the PHC pile and the steel pipe in a concentric arrangement with the leakage prevention jig facing downward;
A method of manufacturing a composite pile, characterized in that the gap is filled with a filling material from above, and after the filling material is cured, all the above-described bolt connection states are released and the filling material leakage prevention jig is removed. Method. The method for manufacturing a composite pile according to claim 5, wherein the bolt mounting portion projecting on the outer peripheral surface of the steel pipe is removed after all of the above-described bolt connection states are released. The method for manufacturing a composite pile according to claim 5 or 6, wherein an axial length of the steel pipe is shorter than an axial length of the PHC pile. 8. The filler is cement milk, soil cement, mortar, resin mortar, asphalt concrete, or dense sand with a relative density of 80% or more, according to any one of claims 5 to 7, A method for manufacturing the described composite pile. The filler has strength and rigidity that can prevent local buckling of the steel pipe even if bending deformation occurs in the steel pipe, and is made of a material having lower strength and rigidity than the PHC pile. The method for manufacturing a synthetic pile according to any one of claims 5 to 8, which is characterized.

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