JP2016169535A - Column beam connection structure and construction method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a column beam connection structure and a construction method thereof, which enable efficient construction of a column beam structure in which a long period beam and a short period beam are disposed in parallel.SOLUTION: A long period beam (6), which bears long period load such as self-weight of an architectural structure, and a short period beam (8), which bears a short period load such as an earthquake load, are disposed in parallel. A joint body (10) that supports the long period beam and the short period beam is disposed on a column (4). The joint body is formed by half-precast concrete method. A joint lower body (12) that is a precast concrete member comprises: a body (30) that is slightly larger rectangle than the column in plan view; and a convexity (32) that swelled upward in the vicinity of a side of the body. A top face of the convexity constitutes a first support face (36) that supports the long period beam, and a part adjacent to the convexity of the body constitutes a second support face (38) that supports the short period beam. The first support face is located higher than the second support face.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a joint structure between a beam and a column arranged in parallel and a construction method thereof in a building, and in particular, a column beam joint in which at least one beam is joined to a column in a joint mode different from other beams. It relates to the structure and its construction method.

  The load acting on the building is classified into a long-term load and a short-term load depending on the time during which the load acts. The long-term load includes a fixed load composed of the weight of the building itself, a loaded load composed of the weight of a person, furniture, and the like, and always acts for a long period of time. Short-term loads include earthquake loads and wind loads, and their action time is short. Many buildings are designed so that they will not be damaged by long-term loads, but they will be damaged while short-term loads, especially those caused by large earthquakes, are allowed to collapse. Designed to prevent.

  In reinforced concrete buildings, a rigid frame structure in which columns and beams are rigidly joined is widely used. In a rigid frame structure, the beam rigidly joined to the column bears both long-term and short-term loads.

  On the other hand, in Patent Document 1, a beam is separated into a long-term beam that bears a long-term load (“beam member for long-term load”) and a short-term beam that bears a short-term load (“beam member for seismic load”). A structure is disclosed. Although the long-term beam and the short-term beam are arranged in parallel to each other, the manner of joining with the columns is different. The long-term beam is designed and constructed to be simply supported by the column, i.e., considered to be pinned to the column. Long-term beams support loads such as floor slabs, but since they are pin-joined with columns, they do not receive the load even if the columns vibrate due to an earthquake. On the other hand, the short-term beam is designed and constructed so as to be fixedly supported by the column, that is, to be regarded as rigidly connected to the column. Short-term beams do not bear loads such as floor slabs, but bear earthquake loads.

  By the way, in order to shorten the construction period, a concrete member manufactured in advance in a factory, that is, a precast concrete (hereinafter referred to as “PCa”) member may be used for a reinforced concrete column or beam. For example, Patent Document 2 discloses a joint made of PCa (“precast concrete member”) for joining a PCa beam to a PCa column. This joint has a cross shape in plan view and is installed on the top of the PCa column. The four ends of the cross shape extend outward from the side surface of the PCa column, and further, the reinforcing bars that serve as the main bars of the beam protrude from the concrete surface on the tip side. After this reinforcing bar is connected to the main reinforcing bar of the PCa beam, concrete is placed in the connecting portion.

JP 2011-6859 A JP 62-6034 A

  Even in a building having a long-term beam and a short-term beam described in Patent Document 1, the construction period can be shortened by using the PCa column and the PCa beam. However, the joint described in Patent Document 2 is for rigidly joining the PCa column and the PCa beam, and cannot be pin-joined. When constructing without using joints, it is necessary to position both the long-term beam and the short-term beam arranged in parallel at the column-to-column connection between the long-term beam and the short-term beam made of PCa. It is preferable that both ends of the long-term beam have a shape in which the lower part is notched, so that the height of the support surface for supporting the long-term beam and the short-term beam at the column beam joint is different. Therefore, the work at the construction site was complicated.

  The present invention has been made in view of such a background, and provides a column beam joint structure and a construction method thereof that can be efficiently constructed in a column beam structure in which a long-term beam and a short-term beam are arranged in parallel. For the purpose.

  A certain aspect of the present invention includes a joint body (10) provided to support a beam at a predetermined portion of a pillar (4), and a long-term beam (6) made of precast concrete that is simply supported by the joint body. A column beam connection structure (2) of a column beam structure having a short-term beam (8) made of precast concrete, which is arranged in parallel in the width direction with respect to the long-term beam and fixedly supported by the joint body The joint body includes a first support surface (36) for supporting the long-term beam and a second support surface (38) for supporting the short-term beam. ), And the first support surface is provided at a position higher than the second support surface. The term precast concrete (PCa) includes full precast concrete and half precast concrete unless otherwise specified. The terms simple support and fixed support represent not a theoretical or ideal simple support and fixed support but a substantial simple support and fixed support, that is, a support state that can be regarded as a simple support or a fixed support in a design calculation.

  According to this structure, although arrange | positioned in parallel, the position adjustment of a height direction can be performed only by putting the long-term beam and short-term beam from which a support mode, ie, the shape of a connection part mutually differs, in a joint lower body. Moreover, since the convex part (32) produced by the difference in height between the first support surface and the second support surface shows an indication of the position in the width direction of the long-term beam and the short-term beam, the position adjustment in the width direction is easy. Become. Thus, since the position adjustment of a long-term beam and a short-term beam is easy, efficient construction becomes possible.

  Another aspect of the present invention is characterized in that, in the above configuration, the first support surface protrudes outward from the side surface of the column.

  According to this configuration, the long-term beam can be placed on the joint lower body so as not to interfere with the main bar of the column.

  According to another aspect of the present invention, in the above configuration, the joint body is formed by placing concrete integrally with at least a part of the floor slab (16) supported by the long-term beam. (14) is further included.

  According to this configuration, since the end portion of the long-term beam is reliably pressed by the upper joint body, it is possible to prevent the long-term beam from being lifted by vertical movement during an earthquake. Moreover, since the construction of on-site concrete for the joint upper body and the floor slab is performed integrally, an increase in the construction time for constructing the joint upper body can be suppressed.

  Another aspect of the present invention is characterized in that, in the above configuration, the long-term beam is provided with a projecting piece (24) protruding in the width direction at the intermediate portion so as to support the short-term beam at the time of temporary installation.

  According to this configuration, the short-term beam is stable in the temporary state, and it is possible to reduce the possibility that the short-term beam will fall when the short bar main bar is joined or when the joint upper body is constructed.

  Another aspect of the present invention is characterized in that, in the above configuration, the short-term beam is provided in a pair on both sides in the width direction of the long-term beam.

  According to this structure, the force at the time of an earthquake can be transmitted evenly between the column and the short-term beam, and an unnecessary twist can be prevented from being applied to the column.

  Another aspect of the present invention is characterized in that, in the above configuration, the short-term beam is provided so as to be separated from the floor slab.

  According to this configuration, it is possible to more reliably prevent a long-term load such as the weight of the floor slab from being applied to the short-term beam.

  According to another aspect of the present invention, in the above-mentioned configuration, the main bar (26) of the short-term beam is connected to the main bar of another short-term beam supported on the opposite side of the joint body across the joint body. It is characterized by being.

  According to this configuration, since the concrete placement of the joint portion between the short-term beams adjacent in the longitudinal direction can be performed integrally with the joint upper body, the construction efficiency can be increased.

  Further, according to another aspect of the present invention, a long-term beam (6) made of precast concrete is simply supported by a joint body (10) disposed on the top of a column member (4), and the joint body is made of precast concrete. The long-term beam and the short-term beam are joined to the column member so that the short-term beam (8) is fixedly supported, on the column member constructed up to just below the column-beam joint, A step of installing a precast concrete joint lower body (12) forming a part of the joint body, and an end of the long-term beam on a first support surface (36) formed in the joint lower body Placing the short-term beam on a second support surface (38) formed at a position lower than the first support surface of the joint lower body, the long-term beam and the short-term beam In order to join the beam to the column member, Characterized by a step of constructing a Joint upper body forming part (14) of the Joint body by Da設 concrete on the lower body.

  According to this structure, although arrange | positioned in parallel, the position adjustment of a height direction can be performed only by putting the long-term beam and short-term beam from which a support mode and the shape of an edge part mutually differ in a joint lower body. Moreover, since the convex part (32) produced by the difference in height between the first support surface and the second support surface shows an indication of the position in the width direction of the long-term beam and the short-term beam, the position adjustment in the width direction is easy. Become. Thus, since the position adjustment of a long-term beam and a short-term beam is easy, efficient construction becomes possible.

  ADVANTAGE OF THE INVENTION According to this invention, in the column beam structure by which the long-term beam and the short-term beam are arrange | positioned in parallel, the column beam junction structure which can be constructed efficiently, and its construction method can be provided.

Schematic plan view of the beam-column joint structure according to the embodiment The perspective view of the joint lower body which concerns on embodiment Sectional view along line III-III in FIG. Sectional drawing along the IV-IV line in FIG. Schematic front view showing the construction procedure of the column beam structure according to the embodiment

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, a beam-column joint structure 2 according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a column having a column member 4 made of PCa, a long-term beam 6 made of PCa, a short-term beam 8 made of PCa, and a joint 10 that joins the long-term beam 6 and the short-term beam 8 to the column member 4. 3 is a schematic plan view of a beam joint structure 2. FIG. The joint body 10 includes a joint lower body 12 and a joint upper body 14, but the joint upper body 14 is still connected to the right column member 4, the long-term beam 6, and the short-term beam 8 in the drawing. The state where it is not constructed is shown, and the left part shows the state after the joint upper body 14 is constructed. The floor slab 16 (see FIG. 5) is not shown. 2 is a perspective view of the joint lower body 12, and FIGS. 3 and 4 are cross-sectional views taken along lines III-III and IV-IV in FIG. 1, respectively. In addition, in the cross section, illustration of a known form of reinforcing bar and PC tendon which is not particularly mentioned in the specification is omitted.

  The column member 4 is reinforced concrete made of PCa, and a main reinforcement 18 (see FIG. 5) protrudes from the upper end of the top concrete surface. The protruding main reinforcement 18 penetrates the joint body 10 and is connected to a column member 4 (not shown) installed in the upper layer. The column member 4 has a rectangular shape in a plan view, and the column width and column column are substantially constant. The column member 4 can be made of reinforced concrete on site instead of PCa.

  The long-term beam 6 is bridged between a pair of column members 4 adjacent to each other. The long-term beam 6 is prestressed prestressed concrete made of PCa, and has a rectangular shape in a cross section perpendicular to the longitudinal direction. Both ends of the long-term beam 6 have a shape in which the lower side is notched, a tapered surface 20 that goes upward as it goes toward the end surface in the longitudinal direction, and a horizontal placement surface that is located on the end surface side of the tapered surface 20 22 is formed. The main bar (not shown) of the long-term beam 6 does not protrude from the end face of the concrete in the longitudinal direction. Projecting pieces 24 projecting on both sides in the width direction are formed in the middle portion of the long-term beam 6 in the longitudinal direction. The projecting piece 24 is made of reinforced concrete formed integrally with the main body of the long-term beam 6, and supports the short-term beam 8 during temporary installation.

  The short-term beams 8 are arranged in parallel on both sides in the width direction with respect to one long-term beam 6 so as to form a pair, and are bridged between the column members 4. Each of the pair of short-term beams 8 is the same as each other. The short-term beam 8 is reinforced concrete made of PCa, has a rectangular shape in a cross section orthogonal to the longitudinal direction, and its width and height are substantially constant. The upper surface of the short-term beam 8 is at a position lower than the upper surface of the long-term beam 6, and the short-term beam 8 is separated from the floor slab 16 (see FIG. 5). The lower surface of the short-term beam 8 is preferably at the same or higher position as the lower surface of the long-term beam 6. A main bar 26 protrudes from both longitudinal end faces of the short-term beam 8, and the main bar 26 extends to a main bar 26 of another short-term beam 8 that extends to the opposite side to the column member 4 by a mechanical joint 28. It is joined. Instead of the mechanical joint 28, other known joint means may be used.

  The joint body 10 is a member formed by a half precast method, and has a jointed lower body body 12 made of PCa and a joint upper body body 14 made of on-site concrete. The column member 4 supports the long-term beam 6 and the short-term beam 8 through the joint body 10.

  As shown in FIG. 2, the joint lower body 12 includes a rectangular flat plate-shaped main body 30 and convex portions 32 that bulge upward in a rectangular parallelepiped shape from the centers of the four sides of the upper surface of the main body 30. The size of the rectangle of the main body 30 is slightly larger than the rectangle of the column member 4, and in a state where the joint lower body 12 is installed on the head of the column member 4, the four sides of the main body 30 correspond to the corresponding column members 4. It arrange | positions so that it may extend in parallel with the side surface of this, and the outer side rather than the side surface. The main body 30 is provided with a hole 34 penetrating in the vertical direction for inserting the main reinforcement 18 (see FIG. 5) of the column member 4. Each of the convex portions 32 has the same shape and faces the convex portion 32 provided on the opposite side of the main body 30. Further, the side surface facing the outside in the convex portion 32 constitutes a flat surface continuous with the side surface of the main body 30. The upper surface of the convex portion 32 constitutes a first support surface 36 that supports the long-term beam 6, and the portion sandwiching the convex portion 32 near the side of the upper surface of the main body 30 is the second support surface 38 that supports the short-term beam 8. Configure. As shown in FIG. 3, the first support surface 36 supports the placement surface 22 of the long-term beam 6. As shown in FIG. 4, the second support surface 38 supports the lower surface of the end portion of the short-term beam 8. The first support surface 36 and the second support surface 38 may be in direct contact with the placement surface 22 of the long-term beam 6 and the lower surface of the end portion of the short-term beam 8, respectively. You may support through concrete. 2, the joint lower body 12 may further include corner protrusions 40 that bulge upward from the four corners of the upper surface of the main body 30 into a rectangular parallelepiped shape. Since the corner convex part 40 is provided in the position which pinches | interposes the short-term beam 8 in cooperation with the convex part 32, positioning of the short-term beam 8 becomes easy.

  As shown in FIGS. 1, 3, and 4, the joint upper body 14 covers the joint lower body 12 and the end portions of the long-term beam 6 and the short-term beam 8 placed on the joint lower body 12. Thus, it is formed by placing concrete. As will be described later, the joint upper body 14 is formed by placing concrete integrally with the floor slab 16 (see FIG. 5E), but in FIGS. 1, 3 and 4, the floor slab 16 is formed. Is omitted.

  The floor slab 16 (see FIG. 5E) is formed by placing concrete so as to be integrated with the long-term beam 6. Further, the lower surface of the floor slab 16 is separated from the upper surface of the short-term beam 8. Therefore, the floor slab 16 is supported by the long-term beam 6 but is not supported by the short-term beam 8. The positional relationship between the floor slab 16 and the PCa portion of the long-term beam 6 may be such that the lower surface of the floor slab 16 and the upper surface of the PCa portion of the long-term beam 6 coincide with each other. The PCa portion may be intruded. Further, the PCa portion of the long-term beam 6 is separated from the lower surface of the floor slab 16 so that the long-term beam 6 is completed by the half precast method, and is integrally cast with the joint upper body 14 and the floor slab 16. The upper part of the long-term beam 6 may be formed of concrete.

  The end of the long-term beam 6 in the longitudinal direction does not significantly protrude toward the center axis direction of the column member 4 with respect to the joint body 10, and at least from the main bar 18 (see FIG. 5) of the column member 4. Is also preferably arranged outside. In the present embodiment, the end portion of the long-term beam 6 in the longitudinal direction is joined to the joint body 10 outside the side surface of the column member 4. Thus, the long-term beam 6 has a short length of entry into the joint 10 at the end, and further has a shape in which the lower side of the end is notched and has a small vertical dimension. And the joint 10 can be regarded as a pin joint substantially. In other words, the long-term beam 6 is simply supported by the joint body 10. Even if the column member 4 vibrates due to an earthquake or the like, the force in the horizontal direction from the column member 4 is not transmitted to the long-term beam 6 because the pin joint portion rotates. Therefore, the long-term beam 6 has an extremely low risk of being damaged by an earthquake or the like. Moreover, since the edge part of the long-term beam 6 is covered with the joint upper body 14, even if the long-term beam 6 moves up and down at the time of an earthquake, the lifting is prevented. The long-term beam 6 supports the floor slab 16 and transmits the load to the column member 4.

  On the other hand, in the short-term beam 8, the main bar 26 is connected across the joint body 10 to the main bar 26 of another short-term beam 8 supported on the opposite side of the joint body 10. Therefore, the connection between the short-term beam 8 and the joint 10 can be regarded as a rigid connection. In other words, the short-term beam 8 is fixedly supported by the joint body 10. Therefore, the short-term beam 8 is integrated with the column member 4 and functions so that a horizontal load from the column member 4 caused by an earthquake or the like is transmitted and resists the horizontal force. On the other hand, since the short-term beam 8 is separated from the floor slab 16, it does not bear a long-term load. When a large-scale earthquake occurs, the building is designed and constructed so that the building can be prevented from collapsing even if the short-term beam 8 is damaged.

  Even if the short-term beam 8 is damaged by the earthquake, the long-term beam 6 is not damaged. Therefore, only the short-term beam 8 needs to be repaired. At that time, since the long-term load is supported by the long-term beam 6, the short-term beam 8 can be repaired while continuing to use the building. Even if the concrete is cracked in the short-term beam 8 and the main reinforcement 26 remains strained, the strength is sufficient to withstand earthquakes of the same scale, so the short-term beam 8 is repaired immediately after the damage. There is no need. Even if it is a case where there are many rights holders regarding the building, such as apartment buildings, and it takes time to obtain the consent of the owner, The risk of continuous use can be kept low.

  Moreover, since the long-term beam 6 and the short-term beam 8 are arranged in parallel so as to substantially overlap in the horizontal direction orthogonal to the longitudinal direction, it is possible to suppress the narrowing of the internal space of the building.

  Although the long-term beam 6 and the short-term beam 8 are arranged in parallel, the shapes of the end portions thereof are different, so that the height of the joining position to the joint body 10 is different. The joint lower body 12 has a convex portion 32 so as to correspond to the difference in height of the joint position, thereby supporting the first support surface 36 for supporting the long-term beam 6 and the short-term beam 8. A step is formed between the second support surface 38 and the second support surface 38. Therefore, when the long-term beam 6 and the short-term beam 8 are installed on the joint lower body 12, it is not necessary to adjust the height, and the construction efficiency is increased.

  Next, with reference to FIG. 5, the construction method of the column beam junction structure 2 which concerns on embodiment is demonstrated. FIG. 5 shows the construction situation of the column beam structure on the outer periphery of the building, and the long-term beam 6 and the short-term beam 8 are not installed on the near side in the direction orthogonal to the paper surface. For convenience of illustration and description, the relative dimensions between the members, the protruding amount in the width direction of the joint lower body 12, and the like are different from the actual ones.

  As shown in FIG. 5 (a), after the column member 4 is erected, the worker is placed on the top of the column member 4 so that the main bar 18 of the column member 4 is inserted into the hole 34 of the joint lower body 12. The joint lower body 12 is installed. Grout is injected into the gap between the main reinforcement 18 and the hole 34 to fix the joint lower body 12 to the column member 4.

  Next, as shown in FIG. 5B, the mounting surfaces 22 (see FIG. 3) at both ends of the long-term beam 6 come into contact with the first support surface 36 (see FIG. 3) of the joint lower body 12. In addition, the long-term beam 6 is bridged between a pair of adjacent column members 4. Note that a spacer may be installed between the first support surface 36 and the placement surface 22 so that the on-site concrete may wrap around between them.

  Next, as shown in FIG. 5 (c), the short-term beam 8 is arranged so that the lower surfaces of both ends of the short-term beam 8 are arranged on the second support surface 38 (see FIG. 4) of the joint lower body 12. Is bridged between a pair of adjacent column members 4. Spacers (not shown) are installed between the lower surfaces of both ends of the short-term beam 8 and the second support surface 38. In addition, you may make both contact | abut, without providing a spacer. The side face of the both ends of the short-term beam 8 facing the long-term beam 6 side and the side face of the convex portion 32 of the joint lower body 12 are spaced apart by a predetermined distance. Note that the width and position of the convex portion 32 of the joint lower body 12 are provided in advance so as to correspond to the position of the short-term beam 8, and the side surface and the joint facing both sides of the short-term beam 8 toward the long-term beam 6 side. The position in the width direction of the short-term beam 8 may be determined by contacting the side surface of the convex portion 32 of the lower body 12. Further, since the intermediate portion of the short-term beam 8 is supported by the projecting piece 24 of the long-term beam 6, a stable temporary state can be maintained. In addition, compared to a conventional single beam that supports both long-term loads and short-term loads, the single long-term beam 6 and the two short-term beams 8 that are separated in function are lighter, so that a large size is required for installation. There is no need to use lifting equipment.

  Next, as shown in FIG. 5 (d), the main bar 26 exposed from the end portion of the short-term beam 8 is moved from the end portion of another short-term beam 8 disposed on the opposite side of the joint lower body 12. The exposed main reinforcement 26 is joined by a mechanical joint 28. Grout is injected into the gap between the mechanical joint 28 and the main reinforcement 26. In the short-term beam 8 in which another short-term beam 8 is not installed on the opposite side, the exposed main bar 26 is processed by a known method so that the short-term beam 8 is rigidly joined to the joint 10. Is done.

  Next, after the formwork (not shown) is installed, as shown in FIG. 5E, the end of the long-term beam 6 and the end of the short-term beam 8 including the joined main reinforcement 26 are embedded. The concrete upper body 14 and the floor slab 16 are integrally formed by casting concrete. The floor slab 16 may be formed by installing a PCa plate instead of a formwork and placing concrete on the PCa plate.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. The number of long-term beams and short-term beams spanned between a pair of adjacent columns may be changed. In this case, the arrangement of the convex portions of the joint lower body is also changed as appropriate. For example, one short beam may be used. The column beam connection structure according to the present invention can be applied not only to a middle column and an outer peripheral column of a building but also to a corner column. In the short-term beam, joining with another short-term beam adjacent in the longitudinal direction may be performed between a pair of column members, and a bar arrangement may be provided in the upper part of the column members.

2 ... Column beam connection structure, 4 ... Column members, 6 ... Long-term beam 6 ... Short-term beam, 10 ... Joint body, 12 ... Bottom joint body, 14 ... Upper part of joint, 16 ... Floor slab, 24 ... Projection piece, 26 ... Main bar of short-term beam, 32 ... Convex part, 36 ... First support surface, 38 ... Second Support surface

Claims (8)

A joint provided to support the beam at a predetermined part of the column;
A long-term beam made of precast concrete that is simply supported by the joint body;
A column beam connection structure of a column beam structure having a short-term beam made of precast concrete arranged in parallel in the width direction with respect to the long-term beam and fixedly supported by the joint body,
The joint has a joint lower body made of precast concrete including a first support surface that supports the long-term beam and a second support surface that supports the short-term beam, and the first support surface is the A column beam connection structure characterized by being provided at a position higher than the second support surface.   The column beam connection structure according to claim 1, wherein the first support surface protrudes outward from a side surface of the column.   The said joint body further has a joint upper body formed by placing concrete integrally with at least a part of a floor slab supported by the long-term beam. Column beam connection structure.   4. The column beam connection structure according to claim 1, wherein the long-term beam includes a projecting piece projecting in the width direction so as to support the short-term beam at the time of temporary installation at an intermediate portion.   5. The column beam connection structure according to claim 1, wherein the short-term beam is provided in a pair on both sides in the width direction of the long-term beam.   6. The column beam connection structure according to claim 1, wherein the short-term beam is provided so as to be separated from the floor slab.   The main bar of the short-term beam is connected to the main bar of another short-term beam supported on the opposite side of the joint body so as to straddle the joint body. Column beam connection structure described in any one. The long-term beam made of precast concrete is simply supported by the joint arranged at the top of the column member, and the long-term beam made of precast concrete is fixedly supported by the joint. And a method of joining the short-term beams,
A step of installing a joint lower body made of precast concrete that forms a part of the joint body on the pillar member constructed up to just below the beam-column joint,
Placing the end of the long-term beam on a first support surface formed in the lower joint body;
Placing the short-term beam on a second support surface formed at a position lower than the first support surface of the joint lower body;
In order to join the long-term beam and the short-term beam to the column member, placing concrete on the joint lower body and constructing a joint upper body forming a part of the joint body; A method characterized by comprising.

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