JP2013072184A - Connection member for pile head reinforcing bar, and pile head joint structure using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connection member that is reduced in weight while securing joining strength for a pile head part, and has a threadable engagement length easily confirmed without making a length of a male screw part formed at an end of a pile head reinforcing bar unnecessarily long, and a pile head joint structure using the same.SOLUTION: There is provided a connection member 1 which is provided in a plurality at suitable intervals along an outer peripheral surface of a steel pipe of a pile head part of a steel pipe concrete pile or a steel pipe pile, and has one end part of a pile head reinforcing bar 3 threadably engaged with a female screw part formed in a cylindrical body, and one end surface of the connection member 1 is formed on an inclined surface 14 inclined from the side of a steel pipe 2 to above the opposite side so that a length of a contact region 12 on a side contacting the outer peripheral surface of the steel pipe is set to be equal to or longer than a necessary welding length and a length of an opposite region 13 of the connection member 1 on the opposite side across an axis is set to be equal to or longer than a necessary threadably engagement length.

Description

  The present invention relates to a connection member for a pile head rebar for connecting a pile head rebar to a steel pipe outer peripheral surface of a pile head in a steel pipe concrete pile or a steel pipe pile (hereinafter sometimes simply referred to as a “connection member”) and the same. It relates to a pile head joint structure.

  Generally, a steel pipe pile or a steel pipe concrete pile and a footing (foundation concrete) are joined by fixing a plurality of pile head reinforcing bars provided on the pile head in the footing. In recent years, steel pipe piles or steel pipe concrete piles, for which demand has been increasing, have higher bending strength on the pile heads than other piles due to the high yield strength of the pile bodies, and occur in each pile head reinforcing bar. Tensile force also increases. As a pile head joint structure such as these steel pipe concrete piles, there is one in which a plurality of pile head reinforcing bars are directly welded at equal intervals along the steel pipe outer peripheral surface of the pile head. However, because the pile head rebar having a predetermined length is welded on site, there are problems in terms of workability, construction accuracy, welding management, etc., and from the point of weldability, the high strength material rebar is used as the pile head rebar. It is difficult to adopt. Therefore, as a pile head joint structure for solving such a problem, many welded connection members to which a lower end portion of a pile head rebar is screwed on a steel pipe outer peripheral surface of a pile head (for example, Patent Documents 1 and 2).

Japanese Patent Laid-Open No. 03-267422 JP 2002-013137 A

  However, since the above-mentioned pile head joint structure transmits stress between the pile head and the pile head rebar through the connecting member, particularly in the welded portion between the connecting member and the pile head, it resists a large tensile force. It needs to be strong enough to do it. Therefore, in order to ensure a sufficient welding amount, a connection member having a longer overall length than a general nut or the like is used. In addition, when the steel pipe thickness of a pile is thin, since the cross-sectional size of a welding part cannot be enlarged, the welding length to a steel pipe outer peripheral surface is lengthened, ie, the full length of a connection member is responded.

  From these facts, the connection member is longer than the necessary screwing length capable of sufficiently transmitting stress to the pile head rebar due to the joint strength with the pile head, so the weight increases, Accordingly, there is a problem that welding workability is poor. In addition, in the case of a connecting member in which the female screw portion is formed over the entire length inside the cylindrical body, the male screw portion formed at one end of the pile head reinforcing bar is also screwed over the entire length. Therefore, there is a problem that the formation range of the male screw portion becomes longer than necessary and the manufacturing cost increases.

  In addition, there are cases where the male screw part of the pile head rebar and the female screw part of the connecting member are formed slightly longer than the required screwing length in advance, but in this case, when performing construction inspection There is a problem that it is impossible to confirm at a glance whether or not the pile head rebar is screwed in with an appropriate length. In actuality, it takes a lot of work to measure the length of the pile head reinforcement after connection one by one to confirm that the necessary screwing length is secured.

  The present invention has been made to solve the above-described problems, and while ensuring the bonding strength to the pile head, the weight can be reduced and the length of the male screw portion formed at the end of the pile head reinforcing bar. It is an object of the present invention to provide a connection member for a pile head rebar that can easily check the screwing length without making the length longer than necessary, and a pile head joint structure using the connection member.

In order to achieve the object, a plurality of pile head reinforcing bar connection members according to the invention according to claim 1 are provided at appropriate intervals along a steel pipe outer peripheral surface of a pile head in a steel pipe concrete pile or a steel pipe pile. A connection member for a pile head rebar in which one end of a pile head rebar is screwed to a female screw portion formed inside, and the length of a portion on the side in contact with the outer peripheral surface of the steel pipe is equal to or longer than a necessary welding length, and The one end surface of the connecting member for pile head reinforcement is inclined from the steel pipe side toward the upper side on the opposite side so that the length of the opposite side portion across the axis is set to the required screwing length or more. It is formed on an inclined surface. With such a configuration, it is possible to reduce the weight while securing the amount of welding to the pile head, so that the welding workability is improved. Furthermore, since it is not necessary to lengthen the length of the external thread formed at the end of the pile head reinforcing bar more than necessary, it is possible to reduce the manufacturing cost and the screwing length at the time of construction inspection Can be easily confirmed.
Moreover, the connection member for pile head reinforcement of the invention which concerns on Claim 2 is a connection member for pile head reinforcement of Claim 1, The said inclined surface is a concave curved surface, It is characterized by the above-mentioned. With such a configuration, not only can the weight of the connecting member be further reduced, but also the length of the screwing range of the threaded portion of the pile head reinforcing bar and the connecting member can be reduced to a minimum, thereby reducing the manufacturing cost. Is possible.
Moreover, the connection member for pile head reinforcement of the invention which concerns on Claim 3 exists in the range in which the said inclined surface is formed in the connection member for pile head reinforcement of Claim 1 or Claim 2, Comprising: Steel pipe outer peripheral surface A slit is formed in a part on the side in contact with. With such a configuration, the weight of the connecting member can be further reduced, and the welded length to the pile head is increased by welding the inner peripheral edge of the slit to the outer peripheral surface of the steel pipe. Can do. Furthermore, even when the steel pipe thickness of the pile is thin, it is not necessary to lengthen the entire length of the connecting member to ensure the necessary welding length, and thus it is possible to reduce the manufacturing cost.
Moreover, the pile head joint structure using the connection member for pile head reinforcement of the invention which concerns on Claim 4 is the connection member for pile head reinforcement described in the claim of any one of Claims 1-3. A plurality of steel pipe concrete piles or steel pipe piles were provided at appropriate intervals along the steel pipe outer peripheral surface of the pile head, and one end of the pile head rebar was screwed to the female thread formed inside the connection member for the pile head rebar It is characterized by that.

  In the connection member for pile head reinforcing bars and the pile head joint structure using the same according to the present invention, the welding workability is improved because the weight can be reduced while securing the welding amount to the pile head. Furthermore, since it is not necessary to lengthen the length of the external thread formed at the end of the pile head reinforcing bar more than necessary, it is possible to reduce the manufacturing cost and the screwing length at the time of construction inspection Can be easily confirmed.

It is a figure which shows the pile head junction structure of Embodiment 1 which concerns on this invention. 3 is a diagram illustrating a configuration of a connection member according to Embodiment 1. FIG. It is a figure which shows the structure of the connection member of Embodiment 2. FIG. It is a figure which shows the other structure of the connection member of Embodiment 2. FIG. It is a figure which shows the structure of the connection member of Embodiment 3. It is a figure which shows the other structure of the connection member of Embodiment 3.

Next, Embodiments 1 to 3 of the connection member according to the present invention and the pile head joint structure using the connection member will be described.
Embodiment 1. FIG.
1A and 1B are diagrams showing a connection portion between a connection member 1 and a steel pipe 2 in the pile head connection structure of Embodiment 1, wherein FIG. 1A is a side view, FIG. 1B is a plan view, and FIG. It is an A line fragmentary sectional view. 2A and 2B are diagrams illustrating a configuration of the connection member 1 according to the first embodiment, in which FIG. 2A is a front view, FIG. 2B is a side view, and FIG. A plurality of connecting members 1 are provided by welding at appropriate intervals along the outer peripheral surface of the steel pipe 2 of the pile head in the steel pipe concrete pile or the steel pipe pile, and the pile head is formed on the female screw portion 11 formed inside the cylindrical body. A male screw portion 31 formed at one end of the reinforcing bar 3 is screwed. Since the connecting member 1 is welded in contact with the outer peripheral surface of the steel pipe 2, the length of the contact portion (welded portion) 12 is the maximum length h1 of the connecting member 1, and this is the required welding length. That's it. Here, the “required welding length” means the pile head rebar 3 and the steel pipe 2 without breaking the welded portion between the connecting member 1 and the steel pipe 2 even when a maximum stress assumed in advance is generated in the pile head. It is the welding length that can transmit stress between. Further, the connecting member 1 has the length of the facing portion 13 opposite to the contact portion 12 across the axis, that is, the minimum length h2 of the connecting member is not less than the necessary screwing length. Here, the “necessary screwing length” is a screwing length capable of transmitting the maximum stress applied to the pile head reinforcing bar 3 to the connecting member 1 without the pile head reinforcing bar 3 screwed to the connecting member 1 coming off. That is. The “necessary welding length” and the “necessary screwing length” are appropriately set according to the force acting on the pile head. Moreover, the lower end surface of the connecting member 1 is an inclined surface 14 that is inclined upward from the contact portion 12 on the steel pipe 2 side toward the opposite portion 13 on the opposite side.

  Therefore, according to the connection member 1 of the present embodiment, even if the length of the contact portion 12 welded to the outer peripheral surface of the steel pipe 2 is equal to or longer than the required welding length, the lower end surface is opposite to the steel pipe 2 side. Since it is the inclined surface 14 which inclines toward upper direction, the weight of the connection member 1 can be reduced, ensuring the welding amount with respect to a pile head, and welding workability | operativity improves. Further, when the male threaded portion 31 of the pile head reinforcing bar 3 is completely screwed into the female threaded portion 11 of the connecting member 1, as shown in FIGS. 1 (a) and 1 (c), the tip of the male threaded portion 31. Even if the portion does not exceed the lower end of the contact portion 12, it protrudes from the inclined surface 14 of the connecting member 1, so that the tip of the male screw portion 31 protruding from the inclined surface 14 is visually observed from the lateral direction or obliquely upward. In addition, it is possible to easily confirm the screwing length at the time of construction inspection. Moreover, since such visual observation is possible, since it is not necessary to lengthen the length of the external thread part 31 formed in the one end part of the pile head reinforcement 3 more than the maximum length h1 of the connection member 1, manufacturing cost is reduced. It becomes possible to reduce.

Embodiment 2. FIG.
3A and 3B are diagrams showing a connection member 1 ′ according to the second embodiment. FIG. 3A is a front view, FIG. 3B is a side view, and FIG. As shown in FIGS. 1 and 2, the connecting member 1 of the first embodiment has a lower end surface formed on a flat inclined surface 14, but the connecting member 1 'of the second embodiment has an inclined surface 14' of a steel pipe. It is characterized in that it is formed in a concave curved surface toward the part 12 'side that contacts the outer peripheral surface of No. 2. The features other than the inclined surface 14 ′ at the lower end surface are the same as those of the connection member 1 of the first embodiment.

  Therefore, according to the connection member 1 ′ of the present embodiment, the same effect as that of the connection member 1 of the first embodiment can be obtained, and the inclined surface 14 ′ of the lower end surface is formed into a concave curved surface, so that the required welding length is obtained. Further, the weight can be reduced as compared with the connecting member 1 of the first embodiment while ensuring the necessary screwing length. Thereby, the manufacturing cost of the connection member 1 ′ can be reduced and the welding workability and the like are improved. Further, as apparent from FIG. 3 (c), the inclined surface 14 ′ of the connecting member 1 ′ is formed in a concave curved surface directed toward the contact portion 12 ′, so that the female screw portion 11 ′ and the pile head The length h3 of the screwing range of the reinforcing bar 3 with the male screw portion 31 is shorter than the connecting member 1 of the first embodiment, and approaches the required screwing length (minimum length h2 of the connecting member 1 ′). Thereby, since the formation range of the external thread part 31 of the pile head reinforcement 3 can be further shortened, the manufacturing cost of the pile head reinforcement 3 can be reduced.

  4A and 4B are diagrams showing another example of the connection member 1 ′ according to the second embodiment. FIG. 4A is a front view, FIG. 4B is a side view, and FIG. 4C is a cross-sectional view taken along the line DD. The connecting member 1 ′ shown in FIG. 4 has a female screw portion 11 ′ formed in a range from the upper end surface to a position exceeding the necessary screwing length h 2, and has a screwing portion 11 a ′ at the tip. 3 is the same as that of the connecting member 1 ′ shown in FIG. According to this connection member 1 ′, when the pile head rebar 3 is screwed into the connection member 1 ′, the front end of the male screw portion 31 of the pile head rebar 3 hits the screwing portion 11 a ′ and stops. Therefore, at the time of construction, it is only necessary to screw the pile head rebar 3 until the tip of the male screw portion 31 comes into contact with the screwing portion 11a ', so that the workability is improved as compared with the connecting member 1' shown in FIG. Further, since the lower part of the female screw part 11 ′ is open, it is discharged even if foreign matter such as mud enters the female screw part 11 ′ as compared with the conventional connecting member in which the lower end part of the female screw part is closed. Cheap. In addition, the same screwing part 11a 'can also be provided in the connection member 1 of the first embodiment.

Embodiment 3. FIG.
The connection member 1 ″ of the third embodiment is characterized in that a slit is further provided to the connection members 1, 1 ′ of the first and second embodiments. In the following, the connection member 1 ′ of the second embodiment is compared with the connection member 1 ′. Although description will be given by providing a slit, it is of course possible to provide a slit for the connecting member 1 of the first embodiment. FIG. 5 is a diagram showing the connecting member 1 ″ of the third embodiment, (a) is a front view, (B) is a side view, (c) is a sectional view taken along line EE. As is clear from FIG. 5A, in the connecting member 1 ″, the slit 15 is formed in the contact portion 12 ″ that contacts the outer peripheral surface of the steel pipe 2 in the range where the inclined surface 14 ″ is formed on the lower end surface. As a result, the length of the portion that is in contact with the outer peripheral surface of the steel pipe 2 is the sum of the maximum length h1 of the connecting member 1 ″ and the length of the slit 15. Since the inner peripheral edge portion of the slit 15 can also be welded, the welding length of the connecting member 1 "to the steel pipe 2 is increased by that amount. As a result, the weight of the connecting member 1" is increased by the amount of the slit 15. Not only can this be further reduced, but it is only necessary that the sum of the maximum length h1 of the connecting member 1 "and the length of the slit 15 be equal to or greater than the required welding length, so the maximum length h1 of the connecting member 1" can be shortened. it can. Furthermore, even when the thickness of the steel pipe 2 is thin, it is not necessary to increase the maximum length h1 of the connecting member 1 "to ensure the necessary welding length, and thus it is possible to reduce the manufacturing cost. .

  6A and 6B are diagrams showing another example of the connection member 1 ″ according to the third embodiment, in which FIG. 6A is a front view, FIG. 6B is a side view, and FIG. In the connecting member 1 ″ of another example shown in FIG. 6, not only the inclined surface 14 ″ is provided on the lower end surface, but also the inclined surface 16 ″ is provided on the upper end surface, and the inclined surfaces 14 ″ and 16 ″ are formed. Each is provided with a slit 15. In this connecting member 1 ″, the inner peripheral edge portions of the slits 15 at the upper and lower two locations can be welded. Therefore, although the maximum length h1 of the connecting member 1 ″ is longer than that shown in FIG. Less than that. As a result, since the weight is reduced as compared with the conventional connecting member, the manufacturing cost can be reduced and the workability can be improved.

  In the present invention, the thickness t1 of the contact portion 12, 12 ′, 12 ″ of the connection member 1, 1 ′, 1 ″ that contacts the outer peripheral surface of the steel pipe 2 is constant over the entire length in terms of stress transmission. Although it is preferable, the lower end portions of the contact portions 12, 12 ′, 12 ″ may be processed obliquely by forming the inclined surface, and the thickness thereof may be changed. Further, the connection members 1, 1 ′, 1 may be changed. When the pile head rebar 3 is screwed to “a”, it may be separately fixed using a nut or the like for the purpose of preventing loosening. Moreover, the pile head reinforcement 3 can also apply the screw node reinforcement which does not need to give a screw process to an edge part, A round steel may be used not only in a deformed reinforcement. Furthermore, the external shape of the connection members 1, 1 ′, 1 ″ according to the present invention is not limited to a circular shape, and is not particularly limited to a hexagonal shape. Further, for example, the external shape as shown in FIG. In the case of the connecting member 1 that does not exist, the contact portion 12 hits the outer peripheral surface of the steel pipe 2 at one point, and it is difficult to weld the connecting member 1 to the steel pipe 2 in the vertical direction. In order to improve this, a V-shaped notch may be formed in the contact portion 12 of the connecting member 1 in advance.

  1, 1 ', 1 "... connecting member, 11, 11', 11" ... female screw part, 12, 12 ', 12 "... contact part, 13 ... opposing part, 14, 14', 14", 16 " ... inclined surface, 15 ... slit, 2 ... steel pipe, 3 ... pile head rebar, 31 ... male screw part.

Claims (4)

A pile head in which one end of a pile head rebar is screwed to a female thread part formed inside a tubular body, provided in plural at appropriate intervals along the steel pipe outer peripheral surface of the pile head in a steel pipe concrete pile or steel pipe pile A connecting member for reinforcing bars,
The pile head is set so that the length of the portion on the side in contact with the outer peripheral surface of the steel pipe is set to the required welding length or more and the length of the portion on the opposite side across the axis is set to the required screwing length or more. A connecting member for pile head reinforcing bars, wherein one end surface of the connecting member for reinforcing bars is formed on an inclined surface that is inclined upward from the steel pipe side to the opposite side.   The connection member for pile head reinforcing bars according to claim 1, wherein the inclined surface is a concave curved surface.   The connection member for pile head reinforcing bars according to claim 1 or 2, wherein the inclined surface is in a range formed, and a slit is formed in a portion on the side in contact with the outer peripheral surface of the steel pipe. Connection member for pile head reinforcement.   A plurality of pile head reinforcement connecting members according to any one of claims 1 to 3 are provided at appropriate intervals along a steel pipe outer peripheral surface of a pile head in a steel pipe concrete pile or a steel pipe pile. A pile head joint structure using a connection member for a pile head reinforcement, wherein one end of the pile head reinforcement is screwed to a female screw portion formed inside the connection member for a pile head reinforcement.

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