JP5452401B2 - Eccentric column beam frame and building composed of the same frame - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a building frame, and in particular, can reduce the size of a column protruding to the indoor side to effectively use the indoor area, and allows free joining and intersection of column beams to improve design flexibility. In particular, the present invention relates to a frame that can secure a large span and opening of the outer frame, and further, a frame that is suitable for use in combination with seismic isolation technology.

  Japanese Laid-Open Patent Publication No. H8-120781 (Patent Document 1) relates to a reinforced concrete tube structure. In the structure described in the official gazette, an outer peripheral tube composed of a number of wall-like columns and a continuous flat beam is arranged on the outer periphery of the building, and a core wall is arranged on the center of the building. A capital slab formed by increasing the thickness of the slab is provided on the portion surrounded by the core wall and the outer peripheral portion thereof for supporting the slab between the core wall and the outer peripheral tube. The slab between the core wall and the outer tube has a partially thick flat beam arranged in a substantially cross-beam shape as a whole of the slab, and the unbonded PC steel is particularly concentrated on the substantially cross-beam-shaped flat beam. It is a reinforced concrete tube structure with a flat slab structure in which wires are arranged in a suspended curve. Here, the tube structure is generally provided with a large number of columns at a predetermined pitch on the outer periphery of the building to form an outer peripheral tube, and an earthquake-resistant element such as a slit earthquake-resistant wall is arranged on the equipment core in the center of the building, It is a name referring to a structure in which a large beam is arranged between a column in the core and a column in the outer tube.

  According to the above-mentioned reinforced concrete tube structure, the beam height can be reduced and the floor height can be suppressed, and the core wall can be effectively used as a seismic element, and the slab from the slab to the core wall can be used. Shear force can be transmitted smoothly.

  However, from the viewpoint of effective use of the indoor area, the above reinforced concrete tube structure still has room for improvement. In other words, it is possible to effectively use the indoor area to some extent by simply flattening the cross section of the column of the frame facing the outside. However, in the case of a reinforced concrete structure, the beam main bar is arranged inside the column main bar. Therefore, there is a problem that the column cannot be made as small as the beam width. Also, if the beam is eccentric and attached to the column, the column will be twisted, and the proof strength of the column beam joint will be reduced. There is concern about damage.

Japanese Patent Laid-Open No. 8-120781

  The present invention aims to solve the above-mentioned problems of the prior art, and by making the column of the outer frame a wall shape, the dimension of the column protruding to the indoor side is reduced, and the indoor area is reduced. The frame that can be used effectively, the wall column of the outer frame is enlarged, the rigidity and proof stress of the wall column are increased, the cross-sectional performance is improved, and the seismic isolation structure that reduces the earthquake input is applied. Together, it is an object to provide a frame that can secure a large span and opening.

  In addition, the present invention goes further and does not necessarily join the column and the beam so that the column center and the beam center intersect, but allows a state in which only a part of the cross section of the column and the beam is bonded. This provides a frame that can increase the degree of freedom in frame design.

  In order to solve the above-described problem, in the present application, the frame includes a column beam, and at a joint portion of the column beam, one side surface of the column protrudes from one side surface of the beam, and the column We propose a column-to-beam frame with joint reinforcement bars that cross the joint surface of the column and the beam in the direction orthogonal to the main reinforcement and the beam reinforcement.

  In this specification, one side surface of a column protrudes from one side surface of a beam. When the frame is an outer frame of a building, the side surface of the beam inside the building is joined to the beam. However, in general, the opposite position relationship, that is, the side of the beam outside the building, is preferable. The arrangement | positioning located in the building outer side further than the side surface of the building outer side of the pillar joined to the said beam is not excluded. As an example of the bar arrangement in this case, at least one of the beam main bars is arranged inside the column main bar located at the outermost end, and at least one other of the beam main bars is located at the outermost end. If, for example, in the outer frame of a building, a total of four beam reinforcements are arranged at the four corners of the beam and a total of four column reinforcements are arranged at the four corners of the column, The two main bars inside the building are arranged inside the building than the two main bars inside the column building, and at the same time, the two main bars outside the building of the beam are arranged inside the building than the two main bars outside the building of the column It may be a positional relationship. Alternatively, all the main bars of the beam may be arranged outside the main bars of the column.

  By adopting the configuration as described above, when one side surface of the beam protrudes to the inside of the building rather than one side surface of the column, a large floor area inside the building can be secured. When one side surface of the projection protrudes from the one side surface of the beam to the inside of the building, a space where the beam does not protrude can be secured in the building. In addition, since it is not necessary to join the column beam so that the column center and the beam center intersect, the degree of freedom in frame design increases.

  In the frame according to the present invention, the width and thickness of the wall column head may be larger than the width and thickness of the leg. Here, the width means a dimension along a side surface having a larger outer dimension in a horizontal section of a wall column having a flat section. In the case of this structure, it is possible to increase the yield strength by providing a capital or a taper at the head to increase the volume of the column beam joint.

  The frame according to the present invention may be a frame composed of a structure other than a reinforced concrete structure. Although the frame based on this invention can be applied suitably to the frame of a reinforced concrete structure, a frame may be a steel frame reinforced concrete structure or a steel frame structure. Further, it may be a frame based on a precast structure or a frame based on a conventional structure. The frame may be a ramen structure or a ramen structure, or may be a ramen structure with a seismic wall.

  In the column beam joint portion of the frame, a joint reinforcing bar that restrains and reinforces the joint portion in a direction (out-of-plane direction) crossing the shearing force may be arranged. In particular, in the case of a reinforced concrete frame, the joint reinforcement of the column and beam is constrained by the joint reinforcement that intersects the virtual shear plane, and the integrity of the column and beam is increased, effectively improving the rigidity, strength, and toughness of the frame. Can do. The joint reinforcing bars are preferably arranged outside the column main bars and the beam main bars, but are not necessarily limited to this configuration.

  The joint reinforcement can also serve as a column or beam shear reinforcement. In the column beam joint portion of the frame, it is preferable that at least one of a joint reinforcing bar and a beam reinforcing bar that intersect with an imaginary shear plane connecting the column side surfaces of the upper and lower floors. In this case, the beam reinforcement may not be a closed shape, but may be a partially open shape such as a U shape or a combination of L shapes. In that case, it is preferable to reinforce the pulling out by a process such as bending the end portion of the barb.

  The present invention proposes a building having any of the above-mentioned frames on the outer periphery. However, the position of the frame according to the present invention is not limited to the outer periphery of the building. For example, the frame can be applied to any position such as a tube inside the double tube structure or a frame located on the side surface of the passage in the building.

  Moreover, the said building based on this invention may install the seismic isolation apparatus in the predetermined floor, and may be seismically isolated. By adopting a seismic isolation structure, the stress at the time of earthquake of column beams and joints is reduced, and the degree of freedom in cross-sectional design is improved. In addition, an earthquake-resistant core composed of a earthquake-resistant wall that bears a horizontal force during an earthquake may be provided to bear about half or more of the layer shear force. In particular, when the cross-sectional design of the flat cross section is substantially restricted by the seismic design conditions, it is a seismic isolation structure or a combination with a seismic core, and a frame that does not allow bending yielding at the end of the beam even at the end. Is preferred.

FIG. 1 is a conceptual diagram of an eccentric column beam joint according to the present invention. FIG. 2 is a conceptual diagram showing a concept of joint reinforcement of an eccentric column beam joint based on the present invention. FIG. 3 is a conceptual diagram showing an example of the arrangement of the joint reinforcing bars of the eccentric beam-column joint according to one embodiment of the present invention. FIG. 4 is a vertical sectional view showing the arrangement of the joint reinforcing bars of the eccentric beam-column joint portion according to one embodiment (first embodiment) of the present invention. FIG. 5 is a conceptual diagram of an eccentric beam-column joint based on another embodiment (second embodiment) of the present invention. FIG. 6 is a vertical sectional view showing the bar arrangement of the eccentric beam-column joint portion according to the second embodiment of the present invention. FIG. 7 is a vertical sectional view showing the bar arrangement of the eccentric beam-column joint portion according to the third embodiment of the present invention. FIG. 8 is a vertical sectional view showing the bar arrangement of the eccentric beam-column joint according to the fourth embodiment of the present invention. FIG. 9 is a horizontal sectional view showing the bar arrangement of the eccentric beam-column joint portion according to the fifth embodiment of the present invention. FIG. 10 is a vertical sectional view showing the bar arrangement of the eccentric beam-column joint portion according to the sixth embodiment of the present invention. FIG. 11 is a vertical sectional view showing the bar arrangement of the eccentric beam-column joint according to the seventh embodiment of the present invention. FIG. 12 is a diagram schematically illustrating a state of stress generated at the column beam joint. FIG. 13 is a diagram illustrating a failure mode of a column beam joint.

  Specific embodiments of the present invention will be described below on the basis of examples. However, the examples are only described to help the understanding of the invention, and therefore the present invention is not limited to the examples described below. Needless to say, it is not limited.

  FIG. 1 is a conceptual diagram showing an eccentric beam-column joint according to the present invention. In the present invention, the eccentric column beam joint is a column beam joint where the column 200 and the beam 100 are joined, but the column center and the beam center do not intersect with each other and the two are shifted. . FIG. 1 illustrates a case where the displacement between the column 200 and the beam 100 substantially contacts only one surface.

  FIG. 2 is a conceptual diagram (seen from the direction of arrow A in FIG. 1) schematically showing how the eccentric column beam joint is reinforced according to the present invention. In order to transmit the moment (indicated by M in the figure) between the columns and beams, and to reinforce the column beam joints against bending moment, shearing force and torsional force, in the present invention, the column main bars and beam main bars are orthogonal to each other. The reinforcing reinforcement 400 that intersects the joint surface of the column and the beam is arranged in the direction to be connected. The joint reinforcing bar 400 reinforces the rigidity and strength of the column beam joint by the same mechanism as the column beam shear reinforcement.

  FIG. 3 is a perspective view (conceptual diagram) for displaying the joining reinforcing bar 400 in an easily viewable manner. The joint reinforcing bars intersect the column and beam joint surfaces in a direction perpendicular to the column main bars and beam main bars, but a plurality of U-shaped joint reinforcing bars are connected in parallel (that is, in the vertical direction) to the column main bars. 460, or a U-shaped joint reinforcing bar 450 in which a plurality are connected in parallel (that is, in the horizontal direction) to the main bar of the beam. Further, these 450 and 460 may be connected to each other.

The amount of joint reinforcement of the present invention is not limited to this based on the proof stress required for the eccentric beam-column joint, but can be determined by the method described below if an example is shown.
FIG. 12a shows the torsional force produced at the eccentric column beam joint of the present invention. To the eccentric beam-column joints, the pillar member shaft torsional force M _TC (FIG. 12b), the torsion of the three types of beam members shaft torsional force M _TB (Fig. 12c) and Plane orthogonal axes torsional force M _TCB (Figure 12d) Force (moment) is generated. The column member axial torsional force _MTC and the beam member axial torsional force _MTB are torsional forces generated in the horizontal and vertical cross sections of the joint, respectively, and affect the shear strength of the joint. Further, M _TCB of Plane orthogonal axes are the same as nodes moment, it shows a moment transmission force at the bonding surfaces of the columns and beams.

Therefore, strength of joint, the shear strength of the horizontal cross section is calculated in consideration of the pillar member axial torsional strength T _c (corresponding to M _Tc), the beam member axial torsion strength T _b (M _Tb 3), the shear strength of the vertical section calculated in consideration of the correspondence) and the torsional strength T _cb (corresponding to M _Tcb ) of the column-beam interface.
Here, the three torsional strengths (T _c , T _b , T _cb ) are respectively determined by the column shear reinforcement, the beam shear reinforcement, and the reinforcement that crosses the interface between the column and the beam. To rise.
Therefore, the amount of reinforcement of the joint reinforcement is determined mainly from the torsional strength T _{cb of} the necessary joint between the column and the beam. In addition, when used in combination with shear reinforcement, the amount of reinforcement is determined taking into account the required torsional strength T _{c in} the axial direction of the column member and torsional strength T _{b in} the axial direction of the beam member. Is done.
As an example of the design of the reinforcing bar amount, the necessary amount is determined by calculating the proof stress share of concrete by applying the torsional strength formula of Hirosawa et al. : Architectural Institute of Japan: Great Hanshin-Awaji Earthquake and future RC structural design-Causes of characteristic damage and proposal for design-1998.10). FIG. 13 is a reference diagram showing a failure mode of a column beam joint with torsion.

  FIG. 4 is a vertical sectional view showing the arrangement of the joint reinforcing bars according to the first embodiment of the present invention. The column 200 is provided with a column main reinforcement 210, and a beam main reinforcement 110 is provided near the upper end and the lower end of the cross section of the beam 100. In this embodiment, the end part of the shear reinforcement bar 120 of the beam is extended into the inside of the column and both end parts are bent and fixed in the cross section of the column 200, thereby constituting the joint reinforcement bar 430. . In the joint portion of the column beam, all the shear reinforcement bars 120 of the beam may be used as the joint reinforcement bar 430 in this way, or only a part thereof is used as the joint reinforcement bar 430, and the others are used as usual. A shear reinforcement bar wound around the main bar may be used.

  5A and 5B are perspective views (conceptual views) showing an eccentric column beam joint portion according to a second embodiment of the present invention. FIG. 5A shows an example in which the column 200 is located outside the space defined by the beams 100 and 300, and FIG. 5B is an example in which the column 200 is located inside the space defined by the beams 100 and 300. The present invention corresponds to both of these. In this embodiment, the column 200 and the beam 100 are so-called eccentrically joined, but the beam 300 is joined to the column 200 without any eccentricity. Obviously, the beam 300 may also be eccentrically joined to the column 200.

  6A and 6B are vertical sectional views showing the bar arrangement in the second embodiment. 6A corresponds to FIG. 5A, and FIG. 6B corresponds to FIG. 5B. Taking the structure shown in FIG. 6B as an example, the main bar 410 of the beam 300 penetrates the column 200 and the beam 100, and the end 420 is fixed on the outer side of the beam 100 (the side surface opposite to the beam 300). The In this case, the main muscle 410 can be applied with tension, but it is not always necessary to apply tension. The beam 100 includes a main reinforcement 110 disposed in the vicinity of the upper end and the lower end, and a loop-shaped shear reinforcement 120 disposed in a vertical plane so as to surround the main reinforcement 110. The main reinforcement 410 of the beam 300 also functions as a joint reinforcement of the joint between the column 200 and the beam 100.

  FIG. 7 shows the structure of the joint reinforcing bar at the joint between the column 200 and the beam 100 according to the third embodiment. Also with respect to the third embodiment, it is obvious that the column 200 can be configured to be located outside the space defined by the beams 100 and 300, but the illustration is omitted here. The same applies hereinafter. The main bars of the beam 300 may be the same as those shown in FIG. 6, or may be fixed in the column 200 or the beam 100. A part 430 of the shear reinforcing bar 120 wound in a circle face so as to surround the main bar 110 of the beam 100 has a fixing part 440 whose end is extended into the column 100 and bent. Further, another joint reinforcing bar 420 is arranged in a horizontal plane so as to surround the shear reinforcing bar 120 of the beam and the main reinforcing bar 210 of the column. The joint reinforcing bar 420 may be interpreted as extending the column shear reinforcing bar 220 in the direction of the beam 100 and surrounding the beam shear reinforcing bar 120. Either the joint reinforcing bar composed of a part 430 of the shear reinforcing bar or the joint reinforcing bar 420 obtained by extending the column shear reinforcing bar 220 may be used.

  FIGS. 8A and 8B show the structure of the joint reinforcement in the fourth embodiment of the present invention. The difference from the third embodiment is that the shear reinforcement of the beam 100 is closed as usual. A loop is formed and a joint reinforcing bar 435 is provided outside the main reinforcing bar and shear reinforcing bar of the beam. In this embodiment as well, it is preferable to provide a joint reinforcing bar constituted by extending the shear reinforcing bar of the column in the direction of the beam, but this is not necessary depending on the design conditions.

  FIG. 9 is a horizontal cross-sectional view showing the state of the main bar 110 of the beam 100 according to the fifth embodiment of the present invention. FIG. 9 shows a configuration in which the column 200 is located outside the space defined by the beams 100 and 300. The main reinforcement 112 of the beam 100 on the side close to the column 200 to be joined is extended in the direction of the column 100 and the end portion 114 is fixed inside the beam. With such a configuration, the main bar 112 of the beam can function as a joint reinforcing bar. The main bars 112 of the beam 100 closer to the column 200 do not necessarily need to be fixed in the cross section of the column 200 in this way, and may extend over the entire length of the beam, like the main bar 110 far from the column 200. .

  FIG. 10 is a horizontal sectional view showing the structure of the joint reinforcing bar based on the sixth embodiment of the present invention. FIG. 10 shows a configuration in which the column 200 is positioned inside the space defined by the beams 100 and 300. A part of the column shear reinforcement 220 wound in the horizontal plane so as to surround the column main bar 210 is extended into the beam 100, and the end 230 is fixed inside the beam 100. On the other hand, a part 115 of the shear reinforcement bar 120 of the beam 100 is extended in the cross section of the column 200, and extends in the horizontal direction with the auxiliary reinforcing bar 222 extending over the shear reinforcement bar 220 of the column and the main reinforcement 110 of the beam. It is provided in a vertical plane so as to surround it.

  FIG. 11 is a horizontal sectional view showing the configuration of the joint reinforcing bar based on the seventh embodiment of the present invention. The difference from the sixth embodiment is that the column reinforcing bars are wound around the column main bars as usual to form a closed loop. Separately, the connecting reinforcing bars 235 are the column main bars. And a point provided outside the shear reinforcement bar and extending inside the beam 100. Similarly, the beam shear reinforcement is normally a closed loop that surrounds the beam reinforcement, and a joint reinforcement that extends from the outside of the beam reinforcement and the shear reinforcement to the inside of the column. Also good.

100, 300 Beam 110 Beam reinforcement 120 Beam shear reinforcement 200 Column 210 Column reinforcement 220 Column shear reinforcement 115, 235, 420, 430, 435, 460 Joint reinforcement

Claims (4)

A column beam joint consisting of column beams, in which the column center and the beam center are shifted without crossing, and one side of the column protrudes from one side of the beam in pillars main reinforcement and in the direction perpendicular to the beam main reinforcement, column Frame with joint reinforcement in combination with posts and U-shaped joint reinforcement crossing the joint surface of the beam, or L-shaped. The joint reinforcement is arranged so as to surround the pillar main reinforcement is fixed to the cross section of the beam, or,
Column Frame according to claim 1, characterized in that the fixing is arranged so as to surround the beam main reinforcement in the cross section of said post.   The column-beam frame according to claim 1 or 2, wherein the joint reinforcement also serves as a column or beam shear reinforcement. A building comprising the column beam frame according to any one of claims 1 to 3.

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