JPWO2012147690A1 - Synthetic pile and method for manufacturing synthetic pile - Google Patents

Abstract

In a synthetic pile combining a PHC pile and a steel pipe, a synthetic pile capable of clarifying the roles of axial stress, bending stress and shear stress, and a method for manufacturing the synthetic pile are provided. A synthetic pile comprising a PHC pile 1, a steel pipe 2 provided in a concentric arrangement with a clearance on the outer periphery of the PHC pile 1, and a filler 3 filled in the gap, the steel pipe 2 being The upper end portion is joined to the foundation of the structure so as to be able to transmit a horizontal force, and the lower end portion thereof is edge-cut from the PHC pile 1. The filler 3 is made of a material having strength and rigidity capable of preventing local buckling of the steel pipe 2 even when bending deformation occurs in the steel pipe 2 and having lower strength and rigidity than the PHC pile 1.

Description

The present invention, concrete strength is 85N / mm ² or more (preferably 100 N / mm ² or more) of concrete piles to exert high strength (hereinafter, referred to as PHC pile.), To ensure a gap on the outer periphery of the PHC pile It belongs to the technical field of a synthetic pile comprising a steel pipe provided in a concentric arrangement and a filler filled in the gap and a method for manufacturing the synthetic pile, and more specifically, supports a high-rise structure or a super-high-rise structure. The present invention relates to a synthetic pile suitable for the above and a method for producing the synthetic pile.

Concrete piles (including PHC piles) can retain large axial stress (compressive force), but they are brittlely broken against horizontal forces (bending stress and shear stress), so structures (especially high-rise structures) It is difficult to sufficiently withstand the horizontal resistance when used as the foundation of high-rise buildings).
On the other hand, steel pipe piles have high bending strength and shear strength, but in order to maintain a large axial stress, a thick-walled pile must be used, which is economical. There is also a problem that local buckling occurs when the pile diameter increases.

Then, as one of the methods for compensating these problems, there is a concrete pile with an outer shell steel pipe (hereinafter referred to as SC pile as appropriate) formed by combining a concrete pile and a steel pipe.
This SC pile is manufactured integrally by injecting high-strength concrete into the hollow portion of the steel pipe and centrifugally forming (centrifugal compaction), and resists axial stress, bending stress and shear stress as a unit.
This SC pile has the advantages of a concrete pile that is strong against axial stress and the strength of a steel pipe that is strong against bending stress and shear stress. Even if a large bending deformation occurs, the concrete prevents local buckling of the steel pipe. Since it is restrained by the steel pipe, there is an advantage of having a large toughness, and its demand has been increasing in recent years.

However, as described above, since the SC pile is configured to integrally resist axial stress, bending stress, and shear stress, it is necessary to bend the concrete pile constituting the SC pile in addition to axial stress. Stress and shear stress are also borne. Specifically, when a horizontal force (short-term load) such as an earthquake is applied to the structure, the concrete pile bears the axial stress (long-term vertical load) of the structure, 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 destructive property of the concrete pile was unknown.
Therefore, the SC pile has a problem that the role sharing (function sharing) that the concrete stress is borne by the concrete pile and the steel pipe is borne by the bending stress and the shear stress is not clear.
In a building structure, a high-rise structure or a super-high-rise structure requires a secondary design (holding horizontal strength method, time history response analysis), and evaluates not only the allowable stress level of the structure but also ultimate strength, toughness, etc. Is an important design item. Therefore, there is a problem that it is difficult to design a pile member whose performance as a member is unknown (ambiguous) and cannot be designed with a certain design policy.
In short, as for the SC pile, since the role sharing (function sharing) that the concrete pile bears the axial stress and the steel pipe bears the bending stress and shear stress is not clear, the performance of the pile body that can sufficiently cope with the secondary design There was no guarantee.

By the way, the invention which constructs a pile using a concrete pile and a steel pipe together besides the SC pile mentioned above is disclosed variously (for example, refer to patent documents 1-5).
However, the inventions according to Patent Documents 1 to 5, as described below, are not intended to clarify the division of roles of axial stress, bending stress, and shear stress. There is still no pile with a structure that can clarify the role sharing that the concrete pile bears, and the bending stress and shear stress bear the steel pipe.

JP-A-9-170232 JP-A-61-176717 JP-A-5-280046 JP-A-7-11636 JP 2010-265702 A

In the above-mentioned Patent Document 1, a core pile (concrete pile) that reaches the support layer and receives the tip resistance force is installed at the center of the steel pipe pile with a slight gap between the steel pipe pile and preloading. The gap between a given core pile and steel pipe pile is filled with a viscoelastic body, and the peripheral frictional resistance when the core pile receives an overload is transmitted to the ground via the viscoelastic body and the steel pipe pile. (Refer to the description of claim 1 and FIG. 1).
However, the technology according to Patent Document 1 aims to provide a highly reliable pile that can be effectively and economically designed and constructed for a practical load support function of the pile, and a core pile and a steel pipe pile. Therefore, the steel pipe pile is not a configuration that can actively resist horizontal force from the building or the ground.
Therefore, the pile according to Patent Document 1 may cause local buckling when a large bending deformation occurs in the steel pipe pile, and is implemented with a configuration utilizing the characteristics (advantages) of the steel pipe pile that is strong in bending strength and shear stress. However, it is impossible to expect the strength (proof strength) to be able to share the role that the axial stress is borne by the concrete pile and the bending stress and shear stress are borne by the steel pipe.

In Patent Document 2, a pile main body embedded in the ground from the ground surface, a frame body (steel pipe) provided so as to surround at least the outer peripheral surface of the pile main body, and between the frame main body and the frame body. A seismic isolation pile comprising an interstitial viscous material is disclosed (refer to the description of claim 1, FIG. 1, etc.).
However, since the technology according to Patent Document 2 is implemented with a configuration in which a viscous material is interposed between the pile body and the steel pipe, the steel pipe can positively resist horizontal force from the building or the ground. It is not a configuration.
Therefore, the seismic isolation pile according to Patent Document 2 may cause local buckling when a large bending deformation occurs in the steel pipe, similarly to Patent Document 1, and has the characteristics of a steel pipe that is strong in bending strength and shear strength. It is not implemented in a configuration that makes full use of it, and it is impossible to expect strength (proof strength) that can be shared so that axial stress is borne by concrete piles, and bending stress and shear stress are borne by steel pipes.

Since the foundation pile concerning the above-mentioned patent documents 3 is carried out in the composition where a foundation pile and a steel pipe pinch a vibration isolator between, the steel pipe is in the composition which resists the horizontal force from a building or the ground positively Clearly not.
Therefore, the foundation pile according to Patent Document 3 is also likely to cause local buckling when large bending deformation occurs in the steel pipe, as in Patent Documents 1 and 2, and the steel pile pile that is strong in bending strength and shear strength. It is not implemented in a configuration that takes advantage of the characteristics, and it is impossible to expect strength (proof strength) that can be shared so that axial stress is borne by concrete piles, and bending stress and shear stress are borne by steel pipes.

In Patent Document 4, a steel pipe is fitted into an existing pile placed in a place where an existing building is removed in a remodeling work of a building, and a high-strength mortar is provided in a gap between the steel pipe and the existing pile. A pile using an existing pile formed by filling them together is disclosed (see the description of claim 1).
However, the technology according to Patent Document 4 is an invention that increases the strength of a pile when reusing an existing pile, and since the gap portion is filled with high-strength mortar, the steel pipe is used as a part of the pile. It is required to function. Therefore, the new pile completed by filling with high-strength mortar is only what expected the function of a normal pile.

In Patent Document 5, a donut-shaped end plate is fixed to both ends of a steel pipe, and after peeling means is formed on the inner surface of the steel pipe, concrete is poured into the steel pipe, and centrifugal molding is performed to inject the inner surface of the peeling means. A steel pipe-covered concrete pile is disclosed which is formed by forming a cylindrical concrete portion on the side and fixing both end faces of the cylindrical concrete portion to the inner surface of the end plate (claims 1 and 1). Etc.).
However, although the technique according to Patent Document 5 is provided with a peeling means between the outer surface of the concrete and the inner surface of the steel pipe, the both ends of the concrete and the both ends of the steel pipe are fixed via end plates. Therefore, there is almost no difference in performance from the SC pile, which resists as a unit against axial stress, bending stress and shear stress.
Therefore, in the steel pipe covered concrete pile according to Patent Document 5, as in the case of the SC pile described above, the axial stress is borne by the concrete pile, and the bending stress and the shear stress are borne by the steel pipe (function sharing). Problems that cannot be solved remain unresolved.

In short, the technology for constructing a pile using a concrete pile and a steel pipe in combination is disclosed in various ways as described in Patent Documents 1 to 5 in addition to the SC pile. However, axial stress, bending stress, and shear stress are disclosed. There is still no stake that can clarify the division of roles.
Therefore, as long as the division of roles is not clear, it was not possible to guarantee the performance of the pile body enough to cope with the secondary design (the retained horizontal strength method, time history response analysis).

An object of the present invention is to provide a synthetic pile that can clarify the role sharing between axial stress, bending stress, and shear stress in a synthetic pile in which a PHC pile and a steel pipe are combined, and a method for manufacturing the synthetic pile. .
A further object of the present invention is to guarantee the performance of a pile body that can sufficiently cope with the secondary design (holding horizontal strength method, time history response analysis), and not only low-rise structures but also high-rise structures or super-high-rise structures. It is providing the synthetic pile applicable also to the foundation pile of this, and the manufacturing method of this synthetic pile.

As a means for solving the problems of the background art, the composite pile according to the invention described in claim 1 includes a PHC pile, a steel pipe provided in a concentric arrangement with a clearance on the outer periphery of the PHC pile, A synthetic pile consisting of a filler filled in the gap,
The upper end of the steel pipe is joined so as to be able to transmit a horizontal force with the foundation of the structure, and the lower end of the steel pipe is edged with the PHC pile.
The filler is made of a material having strength and rigidity capable of preventing local buckling of the steel pipe even when bending deformation occurs in the steel pipe, and having strength and rigidity smaller than those of the PHC pile.

  The invention described in claim 2 is the composite pile according to claim 1, wherein an upper portion of the gap is closed by a flat plate member provided at an upper end opening of the steel pipe, and the flat plate member is an upper end of the PHC pile. Or the upper end of the steel pipe.

  According to a third aspect of the present invention, in the composite pile according to the first aspect, the upper portion of the gap is closed with a large-diameter end plate whose end plate at the upper end of the PHC pile is larger in diameter than the pile diameter. It is characterized by.

  The invention described in claim 4 is the composite pile according to any one of claims 1 to 3, wherein the steel pipe is shorter than the PHC pile and has a length that can effectively resist the horizontal force. It is characterized by having.

  The invention described in claim 5 is the synthetic pile described in any one of claims 1 to 4, wherein the filler is cement milk, mortar, resin mortar, or asphalt concrete.

The invention described in claim 6 is the composite pile according to any one of claims 1 to 5, wherein the strength of the filler is about ²⁰ to 50 N / mm ² .

  The invention described in claim 7 is the composite pile described in any one of claims 1 to 6, wherein the PHC pile is a support pile.

  The invention described in claim 8 is the composite pile according to any one of claims 1 to 7, wherein the structure is a high-rise structure or a super-high-rise structure.

The manufacturing method of the synthetic pile which concerns on the invention described in Claim 9 consists of a PHC pile, the steel pipe provided in a concentric arrangement | positioning, ensuring a clearance gap on the outer periphery of a PHC pile, and the filler with which the said clearance gap is filled. A method for manufacturing a synthetic pile,
On the flat part, the PHC pile and the steel pipe are erected vertically in a concentric arrangement, and the gap formed between the outer peripheral surface of the PHC pile and the inner peripheral surface of the steel pipe, from above, Filling the steel pipe with a filling material made of a material having strength and rigidity that can prevent local buckling of the steel pipe even if bending deformation occurs in the steel pipe, and having strength and rigidity smaller than the PHC pile, The filler is cured.

  The invention described in claim 10 is the method for manufacturing a composite pile according to claim 9, wherein the composite pile has the PHC on a flat portion in a composite pile manufacturing pit having a predetermined width and depth. The pile and the steel pipe are manufactured by standing vertically in a concentric arrangement.

  The invention described in claim 11 is the synthetic pile manufacturing method according to claim 9 or 10, wherein a peeling plate is placed on the upper surface of the flat portion, and the PHC pile, the steel pipe, Are vertically arranged in a concentric arrangement.

  The invention described in claim 12 is the synthetic pile manufacturing method according to claim 9 or 10, wherein the steel pipe is a bottomed steel pipe having a flat plate member joined to the bottom thereof, and the bottomed steel pipe is After standing upright on the flat part in the vertical direction, the PHC pile is dropped into the steel pipe in a concentric arrangement with the steel pipe and is raised upright on the flat plate member.

  The invention described in claim 13 is the synthetic pile manufacturing method according to claim 9 or 10, wherein the PHC pile is joined to a plate member having a diameter larger than the pile diameter at an end plate of one end thereof, After the flat plate member is directed downward on the flat portion, the steel pipe is dropped so as to surround the PHC pile in a concentric arrangement with the PHC pile, and is vertically raised on the flat plate member. It is characterized by that.

  The invention described in claim 14 is the synthetic pile manufacturing method according to claim 9 or 10, wherein the PHC pile is a large-diameter end plate whose end plate is larger in diameter than the pile diameter. After the large-diameter end plate is directed downward on the flat portion in a vertical direction, the steel pipe is dropped so as to surround the PHC pile in a concentric arrangement with the PHC pile, and is placed on the large-diameter end plate. It is characterized by standing in the vertical direction.

  The invention described in claim 15 is the synthetic pile manufacturing method according to any one of claims 9 to 14, wherein the outer peripheral surface of the PHC pile or the inner peripheral surface of the steel pipe is positioned concentrically. An interval holding member is provided.

The composite pile according to the present invention has the following effects.
1) Since the upper end of the steel pipe 2 is joined to the foundation of the structure so as to be able to transmit a horizontal force (short-term load) such as an earthquake, and the lower end of the steel pipe 2 is cut off from the PHC pile 1, the steel pipe 2 The axial load of the friction resistance generated in the steel pipe 2 itself is sufficient, and the load of the axial stress (long-term vertical load) of the structure is small. Therefore, the steel pipe 2 can be configured to bear exclusively the bending stress and shear stress resulting from the horizontal force.
In addition, the properties of the filler 3 filling the gap formed by the PHC pile 1 and the steel pipe 2, that is, the strength and rigidity capable of preventing local buckling of the steel pipe 2 even if bending deformation occurs in the steel pipe 2. The steel pipe 2 can positively resist the bending stress and the shear stress without causing local buckling due to the characteristics made of a material having lower strength and rigidity than the PHC pile 1.
In short, the steel pipe 2 constituting the composite pile 10 (20, 30, 40) according to the present invention mainly acts on bending stress and shear stress and prevents local buckling, so that its bending performance is sufficient. Toughness performance.
2) On the other hand, regarding the PHC pile 1 that bears the axial stress (long-term vertical load) of the structure, when the horizontal force is generated in the structure, the steel pipe 2 resists the bending stress and shearing force. Since the filler 3 effectively absorbs the energy of the bending stress and shearing force, the transmission of bending stress and shearing force to the steel pipe 2 and the PHC pile 1 located inside the filler 3 is small. Moreover, since the said filler 3 has rigidity (vertical rigidity) smaller than the PHC pile 1, the structure which bears most vertical loads of a structure only with the PHC pile 1 is realizable. Since the PHC pile 1 is high in strength, it can sufficiently bear the vertical load of the structure.
3) Therefore, the synthetic pile 10 (20, 30, 40) according to the present invention is a rational use of the advantages of the PHC pile 1 that is extremely resistant to axial stress and the steel pipe 2 that is resistant to bending stress and shear stress. As a result, the PHC pile 1 exclusively bears the axial stress, and the steel pipe 2 exclusively bears the bending stress and the shear stress. Therefore, it is possible to realize the composite pile 10 (20, 30, 40) with a clear role assignment.
In addition, the steel pipe 2 does not need to withstand a vertical load and can prevent local buckling. Therefore, even a relatively thin steel pipe (commercially available) can sufficiently exhibit its performance and is economical.
4) Therefore, the roles of axial stress, bending stress, and shear stress can be clarified, so that the performance of pile bodies that can sufficiently cope with the secondary design (holding horizontal strength method, time history response analysis) can be guaranteed. It is also possible to design structural important items such as the allowable stress level, ultimate strength and toughness evaluation of the structure, and the synthetic pile that can favorably support not only low-rise structures but also high-rise structures or super-high-rise structures. Can be realized.

The synthetic pile manufacturing method according to the present invention has the following effects.
5) In the state where the PHC pile 1 and the steel pipe 2 are erected in the vertical direction, the filler 3 can be filled into the gap formed by the PHC pile 1 and the steel pipe 2 from above. And can be evenly filled. Therefore, it is excellent in workability and can manufacture the high-quality synthetic pile 10 (20, 30, 40).
6) Further, when the synthetic pile 10 (20, 30, 40) is manufactured in a synthetic pile manufacturing pit having a predetermined width and depth, the height work can be reduced by the depth of the pit. The working efficiency of the filling work of the filler 3 and the lifting work of heavy machinery can be enhanced.

A is an elevation view showing a synthetic pile according to the first embodiment, B is a cross-sectional view taken along line B-B of A, and C is a plan view of the synthetic pile of A. FIG. AC is a work process figure which showed the manufacturing method of the synthetic pile concerning Example 1 in steps. A is an elevation view showing a composite pile according to Example 2, B is a cross-sectional view taken along line B-B of A, and C is a plan view of A composite pile. AC is a work process figure which showed the manufacturing method of the synthetic pile concerning Example 2 in steps. A is an elevational view showing a composite pile according to Example 3, B is a cross-sectional view taken along line B-B of A, and C is a plan view of the composite pile of A. FIG. AC is a work process figure which showed the manufacturing method of the synthetic pile concerning Example 3 in steps. A is an elevation view showing a composite pile according to Example 4, B is a cross-sectional view taken along line B-B of A, and C is a plan view of A composite pile. AC is a work process figure which showed the manufacturing method of the synthetic pile concerning Example 4 in steps.

  Next, an example of a synthetic pile and a manufacturing method of a synthetic pile concerning the present invention is described based on a drawing.

1A-C show an embodiment of a synthetic pile according to the present invention.
This synthetic pile 10 is composed of a PHC pile 1, a steel pipe 2 provided in a concentric arrangement with a clearance on the outer periphery of the PHC pile 1, and a filler 3 filled in the gap, and is built in the ground 6. And the foundation of the structure (not shown) is constructed thereon.
The upper end of the steel pipe 2 is joined to the foundation of the structure so that a horizontal force can be transmitted, and the lower end of the steel pipe 2 is edged with the PHC pile 1. There are various means for joining the upper end of the steel pipe 2 to the foundation of the structure. For example, a reinforcing steel bar protruding upward is welded to the outer peripheral surface of the upper end of the steel pipe 2 and a basic concrete is placed. Then, the upper end portion of the steel pipe 2 and the foundation of the structure are joined so that a horizontal force can be transmitted.
The filler 3 is made of a material having strength and rigidity capable of preventing local buckling of the steel pipe 2 even when bending deformation occurs in the steel pipe 2 and having lower strength and rigidity than the PHC pile 1.

  Incidentally, FIG. 1 has shown the Example in the case of applying the synthetic | combination pile 10 to the support layer S with the deep depth from the ground 6 (for example, about 30 m) as a support pile. In this case, a normal PHC pile 1 is added below the synthetic pile 10. Moreover, although the PHC pile 1 which comprises the said synthetic | combination pile 10 and the upper end part of the steel pipe 2 are arrange | equalized with the same height and it has implemented with the structure protruded from the upper surface of the ground 6, it is not limited to this. According to the construction method of the foundation of the structure built on the upper part, for example, it can also be carried out in alignment with the height of the ground level. The structure may be a low-rise structure, a high-rise structure, or a super-high-rise structure. The synthetic pile 10 can also be implemented with a configuration that does not reach the support layer S. The same technical idea is applied to the following Examples 2 to 4.

The PHC pile 1 constituting the composite pile 10 is provided with ring-shaped end plates 1a at both ends in the axial direction, and preferably has a strength (Fc) of 100 N / mm ² or more capable of supporting a large vertical load. Used for. The PHC pile 1 preferably has an outer diameter (D) of about 600 to 1400 mm and a length (L) of about 10 to 20 m.
Of course, 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 or the properties of the ground 6.

The steel pipe 2 constituting the composite pile 10 is a commercial product having an outer diameter (D) of about 620 to 1600 mm, a thickness (t) of about 9 to 25 mm, and a length (L) of about 5 to 15 m. Preferably used.
Specifically, when the PHC pile 1 having an outer diameter of about 600 mm is used, the steel pipe 2 having an outer diameter of about 620 to 800 mm is used. When the PHC pile 1 having an outer diameter of about 1400 mm is used, the outer diameter is 1420. The steel pipe 2 is arranged in a concentric arrangement in which a gap (diameter) for filling the filler 3 from the outer peripheral surface of the PHC pile 1 is secured about 10 to 100 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, about 5 times the diameter of the pile of the PHC pile 1 is preferable, but the design is appropriately changed according to the properties of the ground 6.
However, the length of the steel pipe 2 is preferably shorter than that of the PHC pile 1. The reason for this is not only economical, but when the depth to the support layer S is deep and it is necessary to add a normal PHC pile 1 and a synthetic pile 10 manufactured in a factory or the like, This is because smooth addition work that does not get in the way can be performed.
Further, the gap for filling the filler 3 is not limited to about 10 to 100 mm, and the design is appropriately changed according to the level of horizontal force (bending stress and shear stress) acting on the composite pile 10. The

The filler 3 constituting the synthetic pile 10 is densely filled in the gap formed by the outer peripheral surface of the PHC pile 1 and the inner peripheral surface of the steel pipe 2 over almost the entire length of the steel pipe 2.
The filler 3 is made of a material having a lower strength and rigidity than the PHC pile 1 (as a guide, a strength of about ²⁰ to 50 N / mm ² ). Of course, it is necessary to have a certain toughness and strength and rigidity to prevent local buckling of the steel pipe 2.
As the filler 3 according to the present embodiment, cement milk, mortar, resin mortar, asphalt concrete, or closely packed sand having a relative density of 80% or more is preferably used. If a resin mortar having plastic performance is used as the filler 3, the function as an energy absorbing material can be further expected. Moreover, if it is the said sand of close packing, the compression characteristic is high and volume compression can also be prevented by the dilatancy effect with respect to the shear stress which generate | occur | produces between the steel pipe 2 and the PHC pile 1.
In addition, these fillers 3 are properly used depending on the size of the gap to be filled. For example, a material having good fluidity such as cement milk is suitably used when the gap is as narrow as about 10 mm, and mortar is suitably used when the gap is as wide as about 50 mm.
The filler 3 made of such material effectively absorbs the bending stress (bending moment) and shear stress of the steel pipe 2 by having a material smaller than the strength and rigidity of the PHC pile 1 and adjacent PHC. The structure which makes it difficult to transmit to the pile 1 is realizable. Moreover, since the said filler 3 has rigidity (vertical rigidity) smaller than the PHC pile 1, the structure which bears most vertical loads of a structure only with the PHC pile 1 is realizable.

The synthetic pile 10 according to the present invention can be constructed at the site, or can be manufactured in advance at a factory or the like and carried into the site. However, since about several tens of the synthetic piles 10 are usually used, it is preferable to manufacture in advance at a factory or the like in consideration of labor saving in field work and being not affected by the weather.
When constructing the synthetic pile 10 on-site, as an example, the steel pipe 2 is built by a medium digging method using an excavator, the steel pipe 2 is positioned at a predetermined depth, and then the PHC pile is placed in the hollow portion. 1 is installed in a concentric arrangement with the steel pipe 2, and it is built with appropriate addition until its tip reaches the support layer S. Next, the filler 3 is densely filled from above into the gap (groove portion) formed by the inner peripheral surface of the steel pipe 2, the outer peripheral surface of the PHC pile 1 and the ground located at the lower end of the steel pipe 2. Thereafter, the upper end portion of the steel pipe 2 is joined to the foundation of the structure so that a horizontal force can be transmitted.

  When the synthetic pile 10 is manufactured in a factory or the like, as shown in steps in FIGS. 2A to 2C, a release plate 5 having a diameter larger than that of the steel pipe 2 is placed on the upper surface of the flat portion 7 such as ground or concrete. The steel pipe 2 is erected on the upper surface of the peeling plate 5 with a heavy machine or the like in the vertical direction (FIG. 2A). Subsequently, one PHC pile 1 is placed concentrically with the steel pipe 2 and dropped into the steel pipe 2 with a heavy machine or the like, and is vertically raised on the peeling plate 5 (FIG. 2B). Subsequently, from above, the filler 3 is filled to the same height as the steel pipe 2 in the gap formed between the inner peripheral surface of the steel pipe 2 and the outer peripheral surface of the PHC pile 1, The synthetic pile 10 is manufactured by curing (FIG. 3C). After curing, the synthetic pile 10 can be easily peeled off from the peeling plate 5 by lifting it with a heavy machine or the like. In addition, a manufacturing procedure is not limited to this, After raising the said PHC pile 1, you may make the steel pipe 2 stand up.

  Thus, the synthetic pile 10 manufactured in a factory or the like is carried to the site and built by a medium digging method using an excavator. When the depth from the ground 6 to the support layer S is as deep as about 20 to 40 m, it is added to the uppermost stage of the penetrated PHC pile 1 and installed. Thereafter, the upper end portion of the steel pipe 2 constituting the synthetic pile 10 is joined to the foundation of the structure so as to be able to transmit a horizontal force.

Conventionally, piles are often manufactured in a state of being placed sideways, and it has been difficult to uniformly fill the filler between the steel pipe and the PHC pile. For this reason, although the device which inclines a pile and raises a filling property was given, it was difficult for positioning work etc. of a pile, and it was not able to raise manufacturing efficiency. In particular, when a cement-based material such as cement milk or mortar is used as the filler, it is difficult to evenly fill, and it is necessary to ensure fluidity, and there are concerns about the occurrence of voids due to breathing.
In this regard, according to the method for manufacturing the synthetic pile 10 having the above-described configuration, the steel pipe 2 and the PHC pile 1 are vertically erected in the gap formed by the steel pipe 2 and the PHC pile 1 from above. Since the filler 3 can be filled, it can be filled easily, surely and evenly. Therefore, it is excellent in workability and a high quality synthetic pile 10 can be manufactured.

Specifically, for the method of filling the gap 3 with the filler 3, for example, the filler 3 can be simply dropped from above the gap and filled, or an injection tube is inserted to the lower end of the gap. Also, more reliable filling can be achieved. It is of course possible to provide a sensor inside the gap and perform automatic injection management. It is preferable from the viewpoint of work that the pipe diameter of the injection pipe is properly used according to the size of the gap. Examples 2 to 4 described below have the same technical idea.
About the method of positioning the PHC pile 1 and the steel pipe 2 in a concentric arrangement, when an interval holding member (not shown) such as a separator or a spacer is provided on the outer peripheral surface of the PHC pile 1 or the inner peripheral surface of the steel pipe 2 Smooth positioning work can be performed. For example, as shown in FIGS. 2A to 2C, when the steel pipe 2 is raised first, the spacing member is provided on the outer peripheral surface of the upper end portion of the steel pipe 2 or the outer peripheral surface of the lower end portion of the PHC pile 1. . When the PHC pile 1 is raised first, the spacing member is provided on the outer peripheral surface of the upper end portion of the PHC pile 1 or the outer peripheral surface of the lower end portion of the steel pipe 2. Examples 2 to 4 described below have the same technical idea.
Further, when the synthetic pile 10 is manufactured in a synthetic pile manufacturing pit having a predetermined width and depth, the height work can be reduced by the depth of the pit, and the filling work of the filler 3 and heavy machinery It is possible to increase the work efficiency of the lifting work. The width of this synthetic pile manufacturing pit is appropriately changed in design according to the number of synthetic piles 10 to be manufactured, and the depth is preferably about the height of the steel pipe 2 in terms of filling work. Examples 2 to 4 described below have the same technical idea.

3A-C show different embodiments of the composite pile according to the present invention.
The composite pile 20 according to the second embodiment is different from the first embodiment in that the flat plate member 2a that closes the upper end opening is joined to the upper end opening of the steel pipe 2 such as welding (full circumference fillet welding). The difference is that they are integrally joined by means. Since the forms of the PHC pile 1, the steel pipe 2, the filler 3, and the like are the same as those in the first embodiment, the same reference numerals are given and the description thereof is omitted as appropriate.
In short, the second embodiment uses the synthetic pile 20 manufactured in advance in a factory or the like, and the flat plate member 2a is provided to improve the efficiency of the filling work of the filler 3 and the quality of the synthetic pile 20. It was.

As shown in FIGS. 4A to 4C in a stepwise manner, the method for manufacturing the synthetic pile 20 according to the second embodiment includes the steel pipe 2 and a bottomed steel pipe in which the flat plate member 2a is joined and integrated at the bottom. 2 and the bottomed steel pipe 2 is erected in the vertical direction on the upper surface of the flat portion 7 by a heavy machine or the like (FIG. 4A). Subsequently, one PHC pile 1 is dropped into the steel pipe 2 by a heavy machine or the like in a concentric arrangement with the steel pipe 2, and is erected on the flat plate member 2a in the vertical direction (FIG. 4B). Subsequently, the filler 3 is equivalent to the steel pipe 2 from above in a gap (groove) formed between the inner peripheral surface of the steel pipe 2, the outer peripheral surface of the PHC pile 1, and the upper surface of the flat plate member 2a. The synthetic pile 20 is manufactured by filling up to a height and curing the filler 3 (FIG. 3C).
Thus, the synthetic pile 20 manufactured at a factory or the like is carried to the site and built by a medium digging method using an excavator. When the depth from the ground 6 to the support layer S is as deep as about 20 to 40 m, it is added to the uppermost stage of the penetrated PHC pile 1 and installed. Thereafter, the upper end of the steel pipe 2 constituting the composite pile 20 is joined to the foundation of the structure so as to be able to transmit a horizontal force.

According to the method for manufacturing the composite pile 20 having the above-described configuration, the filler 3 and the PHC pile 1 are erected in the vertical direction in the gap formed by the steel pipe 2 and the PHC pile 1 from above. Can be filled in a simple, reliable and even manner as in the first embodiment. Therefore, it is excellent in workability and a high quality synthetic pile 20 can be manufactured.
Moreover, according to the synthetic pile 20 which concerns on this Example 2, although the flat plate member 2a is provided in the upper-end opening part of the steel pipe 2 compared with the said Example 1, other structures are completely the same as the said Example 1. The same is true (see FIGS. 1A-C and FIGS. 3A-C in contrast). Therefore, the composite pile 10 according to the second embodiment has the same effects as the synthetic pile 10 according to the first embodiment.

5A-C show different embodiments of the composite pile according to the present invention.
Compared with the first embodiment, the composite pile 30 according to the third embodiment is provided with a flat plate member 4 that closes the opening at the upper end opening of the steel pipe 3, and the flat plate member 4 is connected to the PHC pile. It is different in that it is integrally joined to the upper end of the joint by a joining means such as welding. Since the forms of the PHC pile 1, the steel pipe 2, the filler 3, and the like are the same as those in the first embodiment, the same reference numerals are given and the description thereof is omitted as appropriate.
In short, the third embodiment uses a synthetic pile 30 manufactured in advance in a factory or the like, and the flat plate member 4 is provided in order to improve the efficiency of the filling work of the filler 3 and the quality of the synthetic pile 30. It was.

The manufacturing method of the synthetic pile 30 which concerns on this Example 3 joined integrally the flat plate member 4 larger diameter than a pile diameter to the end plate 1a of one end part, as shown in steps in FIG. The PHC pile 1 is erected in the vertical direction on the upper surface of the flat portion 7 with a heavy machine or the like with the flat plate member 4 facing downward (FIG. 6A). Subsequently, the steel pipe 2 is dropped with a heavy machine or the like so as to surround the PHC pile 1 in a concentric arrangement with the PHC pile 1, and is erected on the flat plate member 4 in the vertical direction (FIG. 6B). At this stage, the lower end portion of the steel pipe 2 and the flat plate member 4 may be joined. Subsequently, the filler 3 is equivalent to the steel pipe 2 from above in a gap (groove) formed between the outer peripheral surface of the PHC pile 1, the inner peripheral surface of the steel pipe 2, and the upper surface of the flat plate member 4. The synthetic pile 30 is manufactured by filling up to a height and curing the filler 3 (FIG. 6C).
Thus, the synthetic pile 30 manufactured at a factory or the like is carried into the site and built by a medium digging method using an excavator. When the depth from the ground 6 to the support layer S is as deep as about 20 to 40 m, it is added to the uppermost stage of the penetrated PHC pile 1 and installed. Thereafter, the upper end portion of the steel pipe 2 constituting the composite pile 30 is joined to the foundation of the structure so that a horizontal force can be transmitted.
The flat plate member 4 integrally joined to the PHC pile 1 is a disk shape having a size that matches the outer peripheral surface shape of the steel pipe 2 when viewed from the plane direction. It is not limited to this. As long as the steel pipe 2 can be covered, it may be larger than the outer diameter of the steel pipe 2 or may be implemented similarly in a rectangular shape.

According to the method for manufacturing the composite pile 30 having the above-described configuration, the filler 3 is formed from above into the gap formed by the PHC pile 1 and the steel pipe 2 while the PHC pile 1 and the steel pipe 2 are erected in the vertical direction. Can be filled in a simple, reliable and even manner as in the first embodiment. Therefore, it is excellent in workability and a high quality synthetic pile 30 can be manufactured.
Moreover, according to the synthetic pile 30 which concerns on this Example 3, compared with the said Example 1, although the flat plate member 4 is provided in the upper-end opening part of the steel pipe 2, other structures are completely the same as the said Example 1. The same is true (see FIGS. 1A-C and FIGS. 5A-C in comparison). Therefore, the composite pile 30 according to the third embodiment has the same effects as the synthetic pile 10 according to the first embodiment.

7A-C show different embodiments of the composite pile according to the present invention.
The synthetic pile 40 according to the fourth embodiment is different from the first embodiment in that the end plate 1a at one end of the PHC pile 1 is a large-diameter end plate 1a ′ having a larger diameter than the pile diameter. . Since the forms of the PHC pile 1, the steel pipe 2, the filler 3, and the like are the same as those in the first embodiment, the same reference numerals are given and the description thereof is omitted as appropriate.
In short, the fourth embodiment uses the synthetic pile 40 manufactured in advance in a factory or the like, and the large-diameter end plate 1a ′ increases the efficiency of the filling operation of the filler 3 and the quality of the synthetic pile 40. Provided for.

The manufacturing method of the synthetic pile 40 which concerns on this Example 4 is PHC which used the end plate 1a of the one end part as the large diameter end plate 1a 'larger diameter than a pile diameter, as shown in steps in FIG. The pile 1 is erected in the vertical direction on the upper surface of the flat portion 7 with a heavy machine or the like with the large-diameter end plate 1a ′ facing downward (FIG. 8A). Subsequently, the steel pipe 2 is dropped with a heavy machine or the like so as to surround the PHC pile 1 in a concentric arrangement with the PHC pile 1, and is erected in the vertical direction on the large-diameter end plate 1a ′ (FIG. 8B). At this stage, the lower end portion of the steel pipe 2 and the large-diameter end plate 1a ′ may be joined. Subsequently, the filler 3 is placed from above into the gap (groove) formed between the outer peripheral surface of the PHC pile 1, the inner peripheral surface of the steel pipe 2, and the upper surface of the large-diameter end plate 1 a ′. 2 to a height equivalent to 2, and curing the filler 3 to produce a synthetic pile 40 (FIG. 8C).
Thus, the synthetic pile 40 manufactured in a factory or the like is carried to the site and built by a medium digging method using an excavator. When the depth from the ground 6 to the support layer S is as deep as about 20 to 40 m, it is added to the uppermost stage of the penetrated PHC pile 1 and installed. Thereafter, the upper end portion of the steel pipe 2 constituting the composite pile 40 is joined to the foundation of the structure so that a horizontal force can be transmitted.

According to the manufacturing method of the synthetic pile 40 having the above-described configuration, the filler 3 is formed from above into the gap formed by the PHC pile 1 and the steel pipe 2 in a state where the PHC pile 1 and the steel pipe 2 are erected in the vertical direction. Can be filled in a simple, reliable and even manner as in the first embodiment. Therefore, it is excellent in workability and a high quality synthetic pile 40 can be manufactured.
Moreover, according to the synthetic pile 40 which concerns on this Example 4, although the end plate 1a of the upper end part of the PHC pile 1 is formed in the large diameter end plate 1a 'compared with the said Example 1, other structures Is exactly the same as in Example 1 above (see FIGS. 1A-C and FIGS. 7A-C in comparison). Therefore, the synthetic pile 40 according to the fourth embodiment has the same effects as the synthetic pile 10 according to the first embodiment.

  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 are usually made by those skilled in the art without departing from the technical idea thereof. I will mention that just in case.

DESCRIPTION OF SYMBOLS 1 PHC pile 1a End plate 2 Steel pipe 2a Flat plate member 3 Filler 4 Flat plate member 5 Release plate 6 Ground 7 Flat part 10, 20, 30, 40 Composite pile S Support layer

Claims (15)

A composite pile composed of a PHC pile, a steel pipe provided in a concentric arrangement with a clearance on the outer periphery of the PHC pile, and a filler filled in the gap,
The upper end of the steel pipe is joined so as to be able to transmit a horizontal force with the foundation of the structure, and the lower end of the steel pipe is edged with the PHC pile.
The filler is characterized by having a strength and rigidity capable of preventing local buckling of the steel pipe even when bending deformation occurs in the steel pipe, and made of a material having lower strength and rigidity than the PHC pile, Synthetic pile.   The upper portion of the gap is closed by a flat plate member provided at the upper end opening of the steel pipe, and the flat plate member is joined to the upper end portion of the PHC pile or the upper end portion of the steel pipe. The synthetic pile described in item 1.   2. The composite pile according to claim 1, wherein an upper portion of the gap is closed with a large-diameter end plate in which an end plate of an upper end portion of the PHC pile is larger in diameter than a pile diameter.   The synthetic steel pile according to any one of claims 1 to 3, wherein the steel pipe is shorter than the PHC pile and has a length that can effectively resist the horizontal force.   The synthetic pile according to any one of claims 1 to 4, wherein the filler is cement milk, mortar, resin mortar, or asphalt concrete. The synthetic pile according to any one of claims 1 to 5, wherein the strength of the filler is about ²⁰ to 50 N / mm2.   The said PHC pile is a support pile, The synthetic pile as described in any one of Claims 1-6 characterized by the above-mentioned.   The synthetic pile according to any one of claims 1 to 7, wherein the structure is a high-rise structure or a super-high-rise structure. A method of manufacturing a synthetic pile comprising a PHC pile, a steel pipe provided in a concentric arrangement with a clearance provided on the outer periphery of the PHC pile, and a filler filled in the gap,
On the flat part, the PHC pile and the steel pipe are erected vertically in a concentric arrangement, and the gap formed between the outer peripheral surface of the PHC pile and the inner peripheral surface of the steel pipe, from above, Filling the steel pipe with a filling material made of a material having strength and rigidity that can prevent local buckling of the steel pipe even if bending deformation occurs in the steel pipe, and having strength and rigidity smaller than the PHC pile, A method for producing a synthetic pile, characterized by curing the filler.   The synthetic pile is manufactured by standing the PHC pile and the steel pipe vertically in a concentric arrangement on a flat part in a synthetic pile manufacturing pit having a predetermined width and depth. The manufacturing method of the synthetic | combination pile described in Claim 9.   The peeling plate is mounted on the upper surface of the flat portion, and the PHC pile and the steel pipe are erected in a vertical direction in a concentric arrangement on the upper surface of the peeling plate. A method of manufacturing synthetic piles.   The steel pipe is a bottomed steel pipe having a flat plate member joined to the bottom thereof, and the bottomed steel pipe is erected in a vertical direction on the flat portion, and then the PHC pile is disposed concentrically with the steel pipe. 11. The method for manufacturing a synthetic pile according to claim 9, wherein the synthetic pile is dropped into the steel pipe and raised in a vertical direction on the flat plate member.   The PHC pile is joined to a flat plate member having a diameter larger than the pile diameter on an end plate at one end thereof, and the flat plate member is faced downward to stand vertically on the flat portion. The method of manufacturing a synthetic pile according to claim 9 or 10, wherein the PHC pile is dropped so as to surround the PHC pile so as to surround the PHC pile and is erected in a vertical direction on the flat plate member.   The PHC pile is a large-diameter end plate having an end plate at one end larger than the pile diameter, and the steel pipe is erected vertically on the flat portion with the large-diameter end plate facing downward. The method of manufacturing a synthetic pile according to claim 9 or 10, wherein the PHC pile is dropped so as to surround the PHC pile in a concentric arrangement with the PHC pile, and is vertically erected on the large-diameter end plate. .   The space | interval holding member for positioning to a concentric arrangement | positioning is provided in the outer peripheral surface of the said PHC pile, or the inner peripheral surface of the said steel pipe, The any one of Claims 9-14 characterized by the above-mentioned. A method for manufacturing synthetic piles.

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