JP2005042424A - Structure for joining steel pipe and reinforcing bar together - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure for joining a steel pipe and a reinforcing bar together, which is excellent in structural performance and cross-sectional efficiency of a joint, which can be easily manufactured by virtue of a simple shape of a joint member, and which can enhance workability and quality reliability by eliminating field welding. <P>SOLUTION: A hoop 2 with a diameter larger than an outside diameter of the steel pipe 1 is arranged around an upper end of the steel pipe 1. The reinforcing bar 3 is arranged as an anchoring bar between the upper end of the steel pipe 1 and the hoop 2. A protrusion 4 for preventing displacement is protrusively provided on the outside surface of the steel pipe 1. Concrete 5 is continuously infilled into the steel pipe 1, at the upper end of the steel pipe 1, and around the hoop 2 and a lower end side 3a of the reinforcing bar 3, so that the lower end side 3a of the reinforcing bar 3 can be integrally joined to the upper end of the steel pipe 1. Additionally, an upper end side 3b of each reinforcing bar 3 is raised above the steel pipe 1 by a predetermined length, so as to be anchored into a reinforced concrete member b. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a joining structure between a steel pipe and a reinforcing bar, and is applied to, for example, a joining part between a steel pipe member or a concrete-filled steel pipe member and a reinforced concrete or a steel reinforced concrete member at a pile head or a column base.

  Conventionally, steel pipe members or concrete-filled steel pipe members and reinforced concrete members or steel reinforced concrete members are joined by welding the reinforcing bars to the steel pipes and fixing the reinforcing bars to the reinforced concrete members or steel reinforced concrete members. There is a method of embedding and fixing a reinforcing bar to a reinforced concrete member or a steel reinforced concrete member.

  Taking a pile head joint as an example, as shown in FIG. 9, a method of inserting a reinforcing bar 41 (steel bar method) inside the steel pipe 1, and a reinforcing bar 51 is welded to the outer periphery of the steel pipe 1 as shown in FIG. 10. There are a method (shaving bar method) and a method (coupler method) in which a connecting tool provided with a screw hole is attached to the outer periphery of a steel pipe as described in Patent Document 1, and a screw rebar is screwed to this.

  However, in the reinforcing bar method, the reinforcing bar arrangement space is narrowed, so that the reinforcing bars are overcrowded and inferior in workability. Moreover, since the reinforcing bars are arranged inside the steel pipe, the cross-sectional efficiency against bending is poor.

  In the barbed reinforcement method, the reinforcing bars are generally welded on-site from the viewpoint of transportation efficiency and work efficiency during construction. However, it is difficult to always ensure an appropriate working environment (which is also affected by weather conditions) and a welding posture in field welding, and the quality of the welded part obtained in such an environment is not limited to reliability.

  Further, in the beard bar system, the force acting on the reinforcing bar is transmitted to the steel pipe by fillet welding, so that the weld length increases, making it difficult to automate welding and inferior in economic efficiency.

  The coupler method described in Patent Document 1 has problems in welding workability and welding quality, similar to the whiskers method, and an increase in cost due to the use of a dedicated coupler is inevitable.

  In addition, in the above-mentioned method, when filling concrete into a steel pipe and designing as a concrete-filled steel pipe member that is a composite cross section of both, use a steel pipe with a rib provided on the inner surface to increase adhesion, Alternatively, it is necessary to provide a function of preventing the misalignment between the filled concrete and the steel pipe by, for example, forming an inner protrusion by welding a steel strip to the inner wall surface of the steel pipe end.

  In order to solve such a problem, in Patent Document 2, a ring-shaped pile head member in which a hub having substantially the same outer diameter as the steel pipe is projected from the jaw portion is welded to the end portion of the steel pipe pile, and the jaw portion of the pile head member is obtained. Has proposed a method of providing a through hole for attaching a reinforcing bar and mechanically connecting the reinforcing bar to the through hole.

Further, in Patent Document 3, a base plate having a reinforcing bar fixed in advance is fixed to the outer periphery of a hollow pile head of a steel pipe pile, and a pile head cap having a conical cross-sectional shape convex downward is provided inside the pile head. Welded ones are listed.
Japanese Patent Laid-Open No. 62-153418 Japanese Patent Laid-Open No. 10-046604 JP 2000-220152 A

  The invention described in the above-mentioned Patent Document 2 is such that a pile head member for attaching a reinforcing bar to a pile head can be butt welded to a steel pipe pile, but the cross-sectional shape of the pile head member provided with a hub is complicated. Therefore, manufacturing requires either forging / casting or cutting of the steel sheet, which is costly.

  Further, high dimensional accuracy is required for the jaw portion that comes into contact with the nut when the rebar is screwed and the hub portion to which the steel pipe is butt welded. That is, the nut contact portion needs to be flat in order to transmit the force of the reinforcing bar evenly to the pile head member, while the hub portion does not cause a mistake due to a dimensional error of the steel pipe or a gap in the groove. Therefore, the flatness and roundness of the butt portion are required, and these portions need to be finished by machining.

  Further, in the invention described in Patent Document 2, when the reinforcing bar is attached to either the outer side or the inner side of the steel pipe, when a force acts on the reinforcing bar, the joint portion between the pile head member and the steel pipe end is deformed out of plane. Since the resistance to is weak, the part tends to be deformed. Furthermore, in the type in which the reinforcing bars are attached only to the outside of the steel pipe, it is necessary to separately displace the filled concrete and the steel pipe.

  The invention described in Patent Document 3 is based on the premise that the inside of the pile head is hollow, and resists the force transmitted from the reinforcing bar even when a flat pile head cap is provided inside the pile head. In order to do this, it is necessary to increase the thickness of the base plate, which is uneconomical.

  In addition, when a pile head cap with a conical section shape is provided, the steel pipe wall tends to be deformed by the force transmitted from the reinforcing bar (welding the cone-shaped pile head cap and the steel pipe). And the steel pipe wall surface below the base plate is deformed) and machining is also difficult.

  Furthermore, since the invention described in Patent Document 3 has a pile head cap, the pile head having a large moment cannot be made of a composite structure of steel pipe and concrete, and the thickness of the steel pipe from the viewpoint of securing the proof strength of the pile. Is large and uneconomical.

  The invention of the present application is intended to solve the above-described problems in the prior art, and is excellent in structural performance and cross-sectional efficiency at the joint, and the joining member is simple in shape and easy to manufacture. The purpose is to provide a steel pipe-reinforcing joint structure capable of improving workability and quality reliability.

  In the joining structure of the steel pipe and the reinforcing bar according to claim 1 of the present application, a hoop bar having a diameter larger than the outer diameter of the steel pipe is arranged around the end part of the steel pipe, and the end part of the steel pipe and the hoop bar One end side of the reinforcing bar is arranged between the ends, and concrete is continuously filled around the end of the steel pipe, the hoop bar and the one end side of the reinforcing bar.

  As a specific application object of the present invention, for example, a pile head joint that integrates a pile head of a steel pipe pile (including a steel pipe winding cast-in-place pile) and a reinforced concrete footing or the like via a reinforcing bar, a steel pipe, or concrete Column base joint that integrates the column base of the filled steel pipe structure and the reinforced concrete foundation via the reinforcing bar, and the column head of the steel pipe or concrete filled steel pipe structure and the beam made of reinforced concrete or steel reinforced concrete are integrated via the reinforcing bar However, the present invention is not limited to this, and it is not limited to these, but it is possible to join steel pipe members (including concrete-filled steel pipe members) and concrete members (including reinforced concrete members, steel-framed reinforced concrete members). In order to transfer stress smoothly between the steel pipe member and the concrete member, It is widely applicable as a structure for joining the.

  In the case of a concrete-filled steel pipe, concrete is usually filled over the entire length of the steel pipe, but when a hollow steel pipe is used, the concrete is filled over a certain range only at the end on the side where the hoop and rebar are arranged. But you can. In addition to the circular steel pipe, a square steel pipe or the like can be used as the steel pipe member, and the hoop bars may be arranged in a spiral shape.

  The steel pipe and rebar joint structure according to claim 2 of the present application is characterized in that, in the steel pipe and rebar joint structure according to claim 1, one end side of the rebar is arranged at a position away from the hoop. It is what.

  Since the one end side of the reinforcing bar is arranged in this way, the filling property of the concrete around the one end side of the hoop and the reinforcing bar can be remarkably enhanced.

  The steel pipe and rebar joint structure according to claim 3 of the present application is characterized in that, in the steel pipe and rebar joint structure according to claim 1, one end side of the hoop and rebar is arranged in a cage shape. To do.

  Since the one end side of the hoop and the reinforcing bar is arranged in a basket shape, it is possible to secure the same amount of hoop as the double pipe type outer pipe. In addition, the effect can be doubled by arranging a hoop muscle having a diameter larger than that of the hoop muscle in a concentric manner on the outside of the hoop muscle.

  The joining structure of the steel pipe and the reinforcing bar according to claim 4 of the present application is the joining structure of the steel pipe and the reinforcing bar according to any one of claims 1 to 3, wherein a supporting member is attached to at least one end of the reinforcing bar. It is characterized by this.

  Since the supporting member is attached to one end side of the reinforcing bar, the pulling resistance force on the one end side of the reinforcing bar is remarkably increased, so that the fixing length on the one end side of the reinforcing bar can be shortened. In this case, as the reinforcing bar, for example, a screw reinforcing bar or the like is arranged, and as the supporting member, for example, a fixing nut or the like that is screwed to the screw reinforcing bar can be used.

  The steel pipe and rebar joint structure according to claim 5 of the present application is the steel pipe and rebar joint structure according to any one of claims 1 to 4, wherein protrusions are provided outside and / or inside the end of the steel pipe. It is characterized by being.

  For example, the protrusion can be formed by bending a steel strip into an arc shape by fillet welding or partial penetration welding, or simply a bead. Further, the shape of the protrusion and the mounting method are not limited to these. In addition, when the adhesion force of concrete is very large, there is no need to have a protrusion.

  The steel pipe and rebar joint structure according to claim 6 of the present application is the steel pipe and rebar joint structure according to any one of claims 1 to 5, wherein the steel pipe is provided at the end of the steel pipe and / or inside the steel pipe. An overhanging ring-shaped member is attached.

  By projecting the ring-shaped member as described above at the end of the steel pipe, when a force acts on the reinforcing bar, the protrusion of the part protruding inside the steel pipe across the pipe wall of the steel pipe Since it receives force and resists overall deformation, the periphery of the joint between the ring-shaped member and the steel pipe is unlikely to be deformed out of plane. Moreover, the protrusion of the part which protruded inside the steel pipe functions as a shift | offset | difference with the concrete in a steel pipe.

  In the first aspect of the invention, the reinforcing bars are arranged outside the steel pipes constituting the concrete-filled steel pipe member or the steel pipe member, thereby preventing overcrowding and improving the cross-sectional efficiency against bending.

  Further, since the reinforcing bars as fixing bars can be attached using the adhesive force of concrete, on-site welding can be eliminated, and there are no problems in workability and quality as compared with the case of welding.

  In addition, since no special metal fittings are used unlike the coupler method, the cost increase is small, and a structure for joining rebars to the steel pipe member for smooth stress transmission between the steel pipe member and the concrete member As widely applicable.

  In the second aspect of the present invention, particularly, one end side of the reinforcing bar is arranged at a position away from the hoop reinforcement, so that the filling property of the concrete around the one end side of the hoop reinforcement and the reinforcing bar can be remarkably improved. .

  In the invention according to claim 3, in particular, one end side of the hoop and the reinforcing bar is arranged in a basket shape by binding each intersection portion with a wire or the like, so that the hoop is equivalent to a double tube type outer tube. The amount can be secured. In addition, the effect can be doubled by arranging a hoop muscle having a diameter larger than that of the hoop muscle in a concentric manner on the outside of the hoop muscle.

  In the invention described in claim 4, in particular, since the supporting member is attached to at least one end side of the reinforcing bar, the pulling resistance force at one end side of the reinforcing bar is remarkably increased, so that the fixing length at one end side of the reinforcing bar is shortened. Therefore, the construction can be performed extremely rationally and economically.

  In the invention according to the fifth aspect, since the protrusion is provided on the outer side and / or the inner side of the steel pipe end portion, the rigidity of the steel pipe upper end portion can be remarkably increased by integrating the steel pipe and the concrete.

  In the invention of claim 6, the ring-shaped member projecting to the outside and / or inside of the steel pipe is attached to the end of the steel pipe so that when a force acts on the reinforcing bar, the pipe wall of the steel pipe is sandwiched. Since the protrusion of the part protruding to the inside of the steel pipe receives the reaction force from the concrete and resists the entire deformation, the periphery of the joint between the ring-shaped member and the steel pipe is less likely to be deformed out of the plane. The protrusion of the protruding part functions as a deviation stop with the concrete in the steel pipe.

  FIG. 1 shows an embodiment in which the joint structure of a steel pipe and a reinforcing bar of the present application is applied to a pile head joint, and structurally a joint between a concrete-filled steel pipe member a and a reinforced concrete member b. It has become.

  To explain, a hoop bar 2 having a diameter larger than the outer diameter of the steel pipe 1 is arranged around the upper end part of the steel pipe 1, and a reinforcing bar 3 is arranged as a fixing bar between the upper end part of the steel pipe 1 and the hoop bar 2. Further, a protrusion 4 for preventing slippage is provided on the outer surface of the steel pipe 1.

  Moreover, the concrete 5 is continuously filled in the steel pipe 1 and around the upper end portion of the steel pipe 1, the hoop bars 2, and the lower end side 3 a of the reinforcing bar 3, so that the lower end side 3 a of the reinforcing bar 3 is made of the steel pipe 1. It is integrally joined to the upper end.

  A plurality of hoop bars 2 are arranged at predetermined intervals in the axial direction of the steel pipe 1, and a plurality of reinforcing bars 3 are arranged at predetermined intervals in the circumferential direction of the steel pipe 1. In particular, each reinforcing bar 3 has a lower end side 3a arranged between the steel pipe 1 and the hoop reinforcing bar 2, and an upper end side 3b of each reinforcing bar 3 is raised above the steel pipe 1 for a predetermined length, and a reinforced concrete member b. It is fixed inside.

  Further, the protrusion 4 for preventing slippage is attached to increase the adhesion force of the concrete 5 to the steel pipe 1. For example, the band plate is bent into a circular ring and welded to the outer surface of the steel pipe 1. And it protrudes at predetermined intervals in the axial direction of the steel pipe 1.

  With such a configuration, the reinforcing bar 3 functions as a fixing bar to the reinforced concrete member b, and the stress generated in the reinforcing bar 3 on the reinforced concrete member b side is transmitted to the concrete-filled steel pipe member a side through the adhesive force with the concrete 5. Is done.

  Further, the hoop bars 2 resist the shearing force generated by the bending bending moment of the concrete-filled steel pipe member a at the joint between the concrete-filled steel pipe member a and the reinforced concrete member b.

  FIG. 2 shows another embodiment in the case where the joining structure of the steel pipe and the reinforcing bar of the present application is applied to the pile head joint, and structurally joining the concrete-filled steel pipe member a and the reinforced concrete member b. Has become a department.

  In the case of FIG. 1, in particular, each hoop bar 2 and the lower end side 3a of the reinforcing bar 3 are arranged in a basket shape by binding each intersection part with a binding line such as a number line, and further on the outside thereof, the hoop bar 2 The hoop 6 having a larger diameter is doubled in a concentric manner with the hoop muscle 2. By being configured in this way, it is possible to ensure the same amount of hoop muscle as that of the outer tube of the double tube method.

  FIG. 3 shows another embodiment when the joining structure of the steel pipe and the reinforcing bar of the present application is applied to the pile head joint, and structurally the joining of the concrete-filled steel pipe member a and the reinforced concrete member b. Has become a department.

  In this case, the arrangement form of the hoop bars 2 and the reinforcing bars 3 is not particularly different from the case of FIG. 1, but a plurality of reinforcing bars 7 apart from the reinforcing bars 3 are formed in the circle of the steel pipe 1 inside each reinforcing bar 3. The bars are arranged at predetermined intervals in the circumferential direction, the lower end side 6a of each reinforcing bar 6 is arranged in the steel pipe 1, and the upper end side 6b is fixed in the reinforced concrete member b.

  A plurality of protrusions 4 for preventing slippage are provided on the inner surface of the steel pipe 1. Such a configuration is effective when the outer reinforcing bar 3 alone is insufficient as a fixing bar.

  FIG. 4 shows another embodiment in the case where the joint structure of the steel pipe and the reinforcing bar of the present application is applied to the pile head joint, and structurally, the joint between the steel pipe member c and the reinforced concrete member b It has become.

  In this case, the arrangement of the hoop bars 2 and the reinforcing bars 3 is not particularly different from the case of FIG. 1, but the bottom cover 8 is attached inside the upper end of the steel pipe 1, and the concrete 5 in the steel pipe 1 is Only the part above the bottom lid 8 is filled. Further, a protrusion 4 is provided on the inner surface of the upper end portion of the steel pipe 1 so as to prevent deviation.

  In this case, the bottom cover 8 is welded and joined to the steel pipe 1 to play a role of preventing the deviation between the concrete 5 and the steel pipe 1. In addition, when the strength is insufficient with only the bottom cover 8, a protrusion 4 is separately provided on the inner wall surface of the steel pipe 1 as a stopper for displacement.

  By being comprised in this way, the rigidity of the upper end part of the steel pipe 1 increases significantly, and especially the axial force (compression force) from the reinforced concrete member b side can be smoothly transmitted to the steel pipe member a.

  FIG. 5 shows another embodiment when the joining structure of the steel pipe and the reinforcing bar of the present application is applied to the pile head joint, and it is structurally joined between the concrete-filled steel pipe member a and the reinforced concrete member b. Has become a department.

  In the example of FIG. 1, the arrangement interval of the hoop muscles 2 is particularly changed, and the hoop muscles 2 are intensively arranged at the positions effective for shear reinforcement in this way. Can be arranged economically and economically.

  FIG. 6 shows another embodiment in the case where the joining structure of the steel pipe and the reinforcing bar of the present application is applied to the pile head joint, and structurally the concrete filled steel pipe member a and the steel reinforced concrete member b It is a junction.

  FIG. 7 shows another embodiment when the joining structure of the steel pipe and the reinforcing bar of the present application is applied to the pile head joint, and it is structurally joined between the concrete-filled steel pipe member a and the reinforced concrete member b. Has become a department.

  In the example of FIG. 1, a threaded reinforcing bar is particularly arranged as the reinforcing bar 3, and a fixing nut 9 is screwed to the end of the lower end side 3 a of each reinforcing bar 3 as a supporting member.

  In all of the examples of FIGS. 1 to 6, the stress transmission of the rebar 3 to the steel pipe 1 is performed by the adhesion force between the concrete 5 and the rebar 3. In this embodiment, the fixing nut 9 Since the support pressure and the adhesion force are accumulated, the fixing length of the lower end side 3a of the reinforcing bar 3 can be shortened.

  The reduction of the fixing length of the reinforcing bar 3 can greatly reduce the amount of excavated soil at the pile head joint, for example, and is very effective in terms of cost. Furthermore, if the fixing nut 9 is attached to the end portion of the upper end side 3b of the reinforcing bar 3 as a supporting member, the fixing length of the upper end side 3b of the reinforcing bar 3, that is, the fixing length of the reinforced concrete member b side can be shortened.

  8 (a) and 8 (b) show another embodiment in the case where the joining structure of the steel pipe and the reinforcing bar of the present application is applied to the pile head joint, and the concrete filled steel pipe member a is structurally. And a reinforced concrete member b.

  In the example of FIG. 1, a ring-shaped member 10 that extends horizontally on both the outside and the inside of the steel pipe 1 is attached to the upper end portion of the steel pipe 1.

  The ring-shaped member 10 is formed, for example, by cutting a part of a single steel plate into a continuous band shape and a ring shape, and is protruded by welding or the like to the upper end portion of the steel pipe 1. By being configured in this manner, the ring-shaped member 10 also has an effect of preventing the concrete 5 in the steel pipe 1 from slipping in addition to the effect of preventing the concrete 5 outside the steel pipe 1 from slipping.

  Further, when the concrete 5 outside the steel pipe 1 is about to come out, the protrusion (inner peripheral side) 10a of the portion protruding to the inside of the steel pipe 1 comes into contact with the inner concrete 5, and a leverage reaction force acts on the protrusion 10a. 1 The additional moment at the upper end is reduced. Further, when this method is combined with the inner rod method, the projection 4 protruding from the inner surface of the steel pipe 1 as shown in FIG. 3 can be used, which is very efficient.

  In the present invention, when stress is applied to the reinforcing bar 3, the protrusion (inner peripheral side) 10 b of the ring-shaped member 10 that protrudes to the inside of the steel pipe 1 receives the reaction force from the concrete 5 and deforms as a whole. Therefore, the periphery of the joint between the ring-shaped member 10 and the steel pipe 1 is hardly deformed out of plane.

  In addition, although the above embodiment is a case where this invention is applied to a pile head junction part, as above-mentioned, it can apply also to a column base part and others.

It shows one embodiment when the joint structure between the steel pipe and the reinforcing bar of the present application is applied to the pile head joint, (a) is a vertical cross-sectional view, (b) is an explanatory diagram in which bending force acts on the reinforcing bar, (C) is a partial vertical sectional view of the upper end portion of the steel pipe. It is a vertical sectional view showing other embodiments at the time of applying the joining structure of a steel pipe and a reinforcing bar of this application to a pile head joined part. It is a vertical sectional view showing other embodiments at the time of applying the joining structure of a steel pipe and a reinforcing bar of this application to a pile head joined part. It is a vertical sectional view showing other embodiments at the time of applying the joining structure of a steel pipe and a reinforcing bar of this application to a pile head joined part. It is a vertical sectional view showing other embodiments at the time of applying the joining structure of a steel pipe and a reinforcing bar of this application to a pile head joined part. It is a vertical sectional view showing other embodiments at the time of applying the joining structure of a steel pipe and a reinforcing bar of this application to a pile head joined part. It is a vertical sectional view showing other embodiments at the time of applying the joining structure of a steel pipe and a reinforcing bar of this application to a pile head joined part. The other embodiment at the time of applying the joining structure of the steel pipe and rebar of this application to a pile head joined part is shown, (a) is a vertical sectional view and (b) is the partially expanded view. The joining structure of the steel pipe and reinforcing bar by the reinforcing bar method in the conventional pile head junction part is shown, (a) is a horizontal sectional view, (b) is a vertical sectional view. It shows the joint structure of a steel pipe and a reinforcing bar by a whistle reinforcement method in a conventional pile head joint, (a) is a horizontal sectional view, (b) is a vertical sectional view, and (c) is a detail of a welded portion of a reinforcing bar. It is a figure (horizontal cross section).

Explanation of symbols

a ... concrete-filled steel pipe member, b ... reinforced concrete member, c ... steel pipe member, 1 ... steel pipe, 2 ... hoop reinforcement, 3 ... fixing reinforcement (rebar), 4 ... detent for protrusion
5 ... concrete, 6 ... hoop, 7 ... fixation (rebar), 8 ... bottom plate,
9: Fixing nut (supporting member), 10: Ring-shaped member.

Claims (6)

  A hoop bar having a diameter larger than the outer diameter of the steel pipe is arranged around the end of the steel pipe, and one end of the reinforcing bar is arranged between the end of the steel pipe and the hoop bar, and at least the A joint structure of a steel pipe and a reinforcing bar, wherein concrete is continuously filled around one end side of the end part of the steel pipe, the hoop bar and the reinforcing bar.   The joining structure of a steel pipe and a reinforcing bar according to claim 1, wherein one end side of the reinforcing bar is arranged at a position away from the hoop reinforcing bar.   2. The steel pipe-reinforcing joint structure according to claim 1, wherein one end side of the hoop and the reinforcing bar is arranged in a basket shape.   The joint structure of the steel pipe and the reinforcing bar according to any one of claims 1 to 3, wherein a supporting member is attached to at least one end of the reinforcing bar.   The protrusion structure is provided in the outer surface and / or inner surface of the edge part of a steel pipe, The joining structure of the steel pipe and reinforcing bar in any one of Claims 1-4 characterized by the above-mentioned.   The steel pipe and reinforcing steel joint structure according to any one of claims 1 to 5, wherein a ring-shaped member projecting to the outside and / or the inside of the steel pipe is attached to an end of the steel pipe.

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