JP4522211B2 - Joint structure of vertical member and horizontal member - Google Patents

Description

  The present invention relates to a horizontal member of a vertical member caused by a shearing force at a joint between a vertical member receiving a high axial force and a horizontal member connected thereto, such as a column member and a foundation (footing), a pile and a foundation, a column member and a beam member. It is related with the junction part structure of the vertical member and horizontal member which suppress the crack and crushing in the interface surface.

  Acts on vertical members such as joints between vertical members receiving high axial forces and horizontal members connected to them, such as column members and foundations (footings), piles and foundations, column members and beams, bearing walls and beams and foundations. In a joint that alternately receives a compressive force and a tensile force due to the horizontal shearing force, cracking is likely to occur in the concrete attached to the reinforcing bar due to the yielding of the reinforcing bar on the pulling side as the deformation of the vertical member progresses.

  Once cracked concrete has been damaged, it can no longer bear the axial compressive force, and is easily crushed when subjected to compressive force due to shear force. The ability is extremely reduced.

  For such concrete collapse such as column members, for example, as shown in FIG. 5, the reinforcing effect of concrete is increased by closely inserting shear reinforcement bars including core bars around the main bars in the material axis direction, The method of increasing the toughness of the concrete, and as shown in FIG. 6, the core rebar is additionally arranged at the central part on the cross section of the column member, and the core rebar is burdened with a part of the compressive force. Although there is a way to mitigate, concrete crushing may occur due to damage caused by cracking due to tensile force as described above, so either method can prevent crushing due to cracking. Not effective.

  In addition, there is a method of interposing an intermediate member that bears compressive force between the vertical member and the horizontal member, and reducing the load on the concrete by sharing the compressive force acting on the concrete to the intermediate member and suppressing crushing. Yes (see Patent Documents 1 and 2).

Also, a compressive force support member is embedded under the base plate fixed to the surface by anchor bolts fixed in the concrete of the horizontal member, and the lower surface of the base plate is brought into contact with the upper end of the compressive force support member to change from the base plate to the horizontal member. There is a method of suppressing crushing by sharing the compressive force acting on the concrete of the horizontal member and the compressive force support member (see Patent Document 3).
JP 2002-61282 JP JP 2002-138469 A JP-A-7-305356

  In the methods of Patent Documents 1 and 2, the reinforcing bars that bear the tensile force are arranged across the two members to be joined to each other, and the edges of both the concrete are not cut, so the reinforcing bars bear the tensile force. It is difficult to prevent concrete crushing due to cracks because there is no means to prevent the occurrence of cracks in concrete.

  The method of patent document 3 is joining of a steel column base and foundation concrete, and there is no reinforcing bar which bears tensile force in concrete in the column base side, and the problem of the crack of concrete by adhesion of a reinforcing bar does not occur. Therefore, it cannot be applied to the joining of concrete members which are intended to prevent crushing by preventing cracks.

  From this background, the present invention proposes a joint structure between a vertical member and a horizontal member that suppresses cracking and crushing of the vertical member due to the shearing force at the boundary surface with the horizontal member and increases the deformability of the vertical member. .

In the present invention, at the joint between the vertical member and the horizontal member where the reinforcing bars are continuously arranged across the reinforced concrete vertical member and the horizontal member of the reinforced concrete structure, in the vertical member, the boundary surface with the horizontal member, or The vertical member side embedded material is arranged up to the vicinity, the horizontal member side embedded material is arranged in the horizontal member to the boundary surface with the vertical member or the vicinity thereof, and the end surfaces of both embedded materials are brought into contact with each other, and the vertical member By placing the side buried material and the horizontal member side buried material in a state where the compressive force transmitted from the vertical member to the horizontal member can be shared with the concrete, the tensile force due to the shearing force acting on the vertical member is borne on the vertical member side buried material. Without preventing the cracking of the concrete in the vertical member, preventing or suppressing the concrete crushing due to the crack, increasing the deformability of the vertical member .

  In the vertical member, the vertical member side embedded material is arranged up to the boundary surface with the horizontal member and the vicinity thereof, and in the horizontal member, the horizontal member side embedded material is arranged up to the boundary surface with the vertical member and the vicinity thereof and separated from each other. Thus, the vertical member side embedded material and the horizontal member side embedded material do not bear the tensile force due to the shearing force.

  The vertical member side embedded material in the vertical member does not bear the tensile force due to the shearing force, so that cracking of the concrete due to adhesion of the vertical member to the concrete when the tensile force is applied is prevented or suppressed, and the occurrence of the crack Concrete crushing due to concrete damage due to is prevented or suppressed.

  Further, the end surfaces of the vertical member side embedded material and the horizontal member side embedded material are in contact with each other, so that the compressive force due to the shearing force received by the vertical member is transmitted from the vertical member side embedded material to the horizontal member side embedded material, and the concrete of the vertical member Since the compressive force that should be borne is reduced, the collapse due to the concrete bearing the compressive force is prevented or suppressed. In order to efficiently transmit the shearing force due to the contact between the two embedded materials, it is appropriate to position the shafts of the vertical member side embedded material and the horizontal member side embedded material on the same line.

  The collapse of the vertical member due to the adhesion of the embedded material on the vertical member side in the vertical member and the collapse of the vertical member due to the compressive force of the concrete may be prevented or suppressed, which may cause the concrete of the vertical member to collapse. Even if the vertical member is deformed by shearing force, the ability to bear the compressive force in the axial direction of the concrete is maintained, so that the deforming ability of the vertical member is improved and the energy absorbing ability is also improved accordingly.

  The position of the vertical member side embedded material and the horizontal member side embedded material on the horizontal section of the vertical member is such that the axes of both embedded materials are substantially on the same line, etc. The end surface of the vertical member side embedded material and the horizontal member side If the end faces of the buried material are in a position where they are in contact with each other, the shearing force is transmitted between the buried materials, so there is no particular problem.

  However, since concrete crushing starts at the peripheral part on the horizontal cross section of the vertical member, the vertical member side embedded material and the horizontal member side embedded material are placed on the peripheral part on the horizontal cross section of the vertical member as described in claim 2. If arranged, the vertical member tries to start deformation by the shearing force, and at the same time, the compressive force that the concrete of the vertical member should bear is effectively borne by the horizontal member-side burying material located in the peripheral part. The effect of preventing or suppressing crushing by bearing the compressive force is enhanced, and the deformability and energy absorption capability of the vertical member are further improved.

  The vertical member-side embedded material can transmit the reaction force when transmitting the compressive force to the horizontal member-side embedded material to the surrounding concrete, and the horizontal member-side embedded material transmits the compressive force transmitted from the vertical member-side embedded material to the horizontal member. It is fixed in the concrete with a fixing material so that it can be transmitted to the surrounding concrete while burdening it. Or adhesion with concrete is ensured by taking fixing length.

  For example, when the vertical member is a column member, both the vertical member side embedded material and the horizontal member side embedded material are arranged facing the material axis direction of the vertical member. When the compression force is transmitted between the vertical members, it is necessary to secure a sufficient fixing length of the horizontal member side embedded material in the horizontal member while ensuring a sufficient fixed length of the vertical member side embedded material in the vertical member. If this is difficult, the cross-sectional area of the horizontal member-side embedded material is made larger than the cross-sectional area of the vertical member-side embedded material as described in claim 3 to increase the adhesion area of the horizontal member-side embedded material to the concrete. Thus, transmission of the compressive force between the horizontal member-side embedded material and the concrete is achieved.

  The vertical member side embedded material is arranged in the vertical member to the boundary surface with the horizontal member and the vicinity thereof, and the horizontal member side embedded material is arranged in the horizontal member to the boundary surface with the vertical member and the vicinity thereof. Since the vertical member side embedded material and the horizontal member side embedded material do not bear the tensile force due to the shearing force, the vertical member side embedded material adheres to the concrete of the vertical member that bears the tensile force. It is possible to prevent or suppress the cracking of concrete due to the crack, and to prevent or suppress the concrete collapse due to the damage of the concrete due to the occurrence of the crack.

  In addition, by bringing the end faces of the vertical member side embedded material and the horizontal member side embedded material into contact with each other, the compressive force due to the shearing force is transmitted from the vertical member side embedded material to the horizontal member side embedded material, so the concrete of the vertical member bears. The compressive force that can be reduced can be reduced, and the crushing caused by the concrete bearing the compressive force can also be prevented or suppressed.

  As a result, in addition to preventing crushing due to cracks, the possibility that the concrete of the vertical member will collapse will be reduced, and the ability to bear the axial compressive force of the concrete will continue regardless of the progress of the deformation of the vertical member. The deformation capacity and energy absorption capacity of the vertical member are improved.

  In claim 2, by placing the vertical member side embedded material and the horizontal member side embedded material in the peripheral part on the horizontal cross section of the vertical member, simultaneously with the start of the deformation of the vertical member, the compressive force that the concrete of the vertical member should bear Since it can be borne by the horizontal member-side embedded material in the peripheral portion, the effect of preventing or suppressing crushing due to the compressive force of the concrete increases, and the deformability and energy absorption capability of the vertical member are further improved.

  According to claim 3, the horizontal member-side embedded material is made larger in the horizontal member than the vertical member-side embedded material so that the cross-sectional area of the horizontal member-side embedded material is larger than that of the vertical member-side embedded material. Even when it is difficult to secure a sufficient fixing length, it is possible to transmit a compressive force between the horizontal member-side embedded material and the concrete.

  The present invention relates to a reinforced concrete vertical member A and a reinforced concrete horizontal member B, in which the reinforcing bar 1 is continuously arranged and joined to each other at the joint between the vertical member A and the horizontal member B in FIGS. 3, the vertical member-side embedded material 2 is disposed in the vertical member A up to or near the boundary surface with the horizontal member B, and the boundary surface with or near the vertical member A is disposed in the horizontal member B. The horizontal member-side embedded material 3 is disposed until the end surfaces of both the embedded materials 2, 3 are brought into contact with each other, thereby suppressing the cracking and crushing of the concrete at the boundary surface between the vertical member A and the horizontal member B due to the shearing force. It is the junction structure to do.

  The vertical member A and the horizontal member B are a column member and a foundation (footing), a pile and a foundation, a column member and a beam member, a load-bearing wall, a beam and a foundation, respectively, and the vertical member A receives a particularly high compressive force. For example, each part is not asked. Whether it is made of cast-in-place concrete or precast concrete, in the case of reinforced concrete, steel reinforced concrete, steel pipe concrete (CFT), or any combination, vertical member A and horizontal member B Sometimes prestressing concrete.

  Steel materials such as reinforcing bars, steel bars, PC steel, and shaped steel are mainly used for the vertical member-side embedded material 2 and the horizontal member-side embedded material 3, but each embedded material 2, 3 is assumed to bear no tensile force. Any material can be used as long as it has compressive rigidity that does not deform due to the burden of compressive force and has adhesion to concrete.

  In FIG. 1, the vertical member A embedded material 2 and the horizontal member side embedded material 3 are arranged at the central portion of the vertical member A on the horizontal cross section in a portion where the vertical member A is a column member and the horizontal member B is a foundation or a beam member. Shows the case. 2 (a) and 2 (b) show cross sections taken along lines xx and yy in FIG. 1, respectively.

  The vertical member-side embedded material 2 and the horizontal member-side embedded material 3 are arranged so that the respective axes face the material axis direction of the vertical member A, and the respective axes are located substantially on the same line. The reinforcing bar 1 is continuously arranged across the vertical member A and the horizontal member B, and is restrained by the shear reinforcing bar 4 in the vertical member A which is a column, and is fixed in the horizontal member B.

  In the vertical member A, the vertical member-side embedded material 2 only needs to be fixed to the concrete to such an extent that it can bear the reaction force when the compressive force is transmitted from the vertical member A to the horizontal member B. From this surface, the fixing length of the vertical member A, that is, the total length of the vertical member-side burying material 2 is determined, but it may be fixed by a fixing material such as an anchor.

  Similarly, in the horizontal member B, the horizontal member-side burying material 3 is fixed to the concrete so that the compressive force transmitted from the vertical member A can be shared with the concrete. Although the fixing length of the member A is determined, it may be fixed by a fixing material such as an anchor.

  In the case of adhesion, in the horizontal member B, it may be difficult to secure a sufficient fixing length in the direction of formation (height direction) of the horizontal member B. The material 3 is given a larger cross-sectional area than the vertical member side embedded material 2 (Claim 3). In this case, since the cross-sectional area of the horizontal member-side burying material 3 is larger than that of the vertical member-side burying material 2, there is an advantage that it is possible to cope with an arrangement error in each concrete.

  FIG. 3 is similar to FIG. 1 in that the vertical member A is a column member and the horizontal member B is a beam member or a base, and the vertical member side embedded material 2 and the horizontal member side embedded material 3 are arranged on the horizontal section of the vertical member A. The case where it arrange | positions to a peripheral part (Claim 2) is shown. 4 (a) and 4 (b) show cross sections along line xx and line yy in FIG. 3, respectively.

  In the case of FIG. 3, the compressive force that the concrete should bear on the periphery of the vertical cross section of the vertical member A is simultaneously applied to the horizontal member side simultaneously with the start of deformation of the vertical member A regardless of the acting direction of the shearing force acting on the vertical member A. Since the burying material 2 bears, there is an advantage that the effect of preventing or suppressing collapse due to the concrete bearing the compressive force is high.

When the vertical member is a column member and the horizontal member is a foundation or a beam member, a vertical cross-sectional view showing a case where the vertical member side embedded material and the horizontal member side embedded material are arranged in the central portion on the horizontal cross section of the vertical member It is. (a) is the xx sectional view taken on the line of FIG. 1, (b) is the yy sectional view. When the vertical member is a column member and the horizontal member is a foundation or a beam member, a vertical sectional view showing a case where the vertical member side embedded material and the horizontal member side embedded material are arranged in the peripheral portion on the horizontal cross section of the vertical member It is. (a) is the xx sectional view taken on the line of FIG. 3, (b) is the yy sectional view. (a) is a vertical cross-sectional view showing the conventional method for increasing the restraining effect of concrete by inserting shear reinforcement bars densely around the main bars in the axial direction, (b) is a horizontal cross-sectional view of (a). is there. (a) is a longitudinal sectional view showing a conventional method in which a core rebar is arranged at the center of the cross section of the column member, and a part of the compressive force is applied to the core rebar, and (b) is a diagram of (a). It is a horizontal sectional view.

Explanation of symbols

A ... Vertical member, B ... Horizontal member, 1 ... Rebar, 2 ... Vertical member side embedded material,
3 …… Embedded material on the horizontal member side, 4 …… Shear reinforcement

Claims (3)

At the joint between the vertical member and the horizontal member where the reinforcing bar is continuously laid across the reinforced concrete vertical member and the horizontal member of the reinforced concrete structure, the concrete of the vertical member due to shearing force at the boundary surface between the horizontal member and the horizontal member It is a joint structure that suppresses cracking and crushing,
In the vertical member, a vertical member side embedded material is disposed up to or near the boundary surface with the horizontal member, and in the horizontal member, the horizontal member side embedded material is disposed up to the boundary surface with the vertical member or in the vicinity thereof. And the end faces of both the vertical member side embedded material and the horizontal member side embedded material are in contact with each other, and the vertical member side embedded material and the horizontal member side embedded material are transmitted from the vertical member to the horizontal member. Joint structure of a vertical member and a horizontal member in a state where compressive force can be shared with concrete .
  The joint structure of a vertical member and a horizontal member according to claim 1, wherein the vertical member-side embedded material and the horizontal member-side embedded material are arranged in a peripheral portion on a horizontal section of the vertical member. The joint structure of a vertical member and a horizontal member according to claim 1 or 2, wherein a cross-sectional area of the horizontal member-side embedded material is larger than a cross-sectional area of the vertical member-side embedded material.

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