Building structure with multiple column capitals

Abstract

To provide a building structure having a capital provided with a plurality of columns capable of suppressing torsional moment generated in a column-beam frame of an upper layer even when movement allowing means for allowing horizontal relative movement of a column of a lower layer and the column-beam frame of the upper layer is provided between a support member provided on the column side of the lower layer in place of a base isolation member to be removed and the column-beam frame of the upper layer.SOLUTION: A building structure in which a capital 2 is provided on a lower column 3 with lower parts of multiple CFT columns 4 of a column beam frame 1 of an upper layer buried through removable seismic isolation members 7, comprises: a support member 8 provided between the lower column side and the capital to which a capital side weight can be transferred from the removed seismic isolation member; movement allowance means 12 provided between the support member and the capital and permitting the relative horizontal movement of the lower column and the capital; and a torsional reinforcement 13 buried in the capital and resisting torsional moment around a horizontal axis generated in the capital by horizontal relative movement of the lower layer column and the capital.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a building structure having a capital with multiple columns that can suppress the torsional moment occurring in the column-beam structure of the upper floor, even when a movement allowing means is provided between the support member provided on the lower floor column side in place of the removed seismic isolation member and the column-beam structure of the upper floor, allowing horizontal relative movement between the column of the lower floor and the column-beam structure of the upper floor. [Background technology]

[0002] Patent Documents 1 to 3 are known as building structures in which the vertical column axial force of a column-beam frame on an upper floor is supported by seismic isolation members provided on columns on a lower floor, the number of which is fewer than the number of points on which the column axial force acts.

[0003] The "multiple-building connected building" in Patent Document 1 has the objective of providing a multiple-building connected building that is economical because it reduces the number of seismic isolation devices, while also maintaining the stability of the entire building.In a building in which multiple adjacent buildings are connected to each other, multiple columns in each building are integrated with each other at their lower ends, and seismic isolation devices are interposed between the lower ends of the integrated columns, and the support positions of the seismic isolation devices for the lower ends of the columns are arranged on the outer periphery of the building relative to the center of gravity of each building.

[0004] In the "Seismic isolation structure and construction method of the seismic isolation structure" of Patent Document 2, the seismic isolation structure does not have seismic isolation devices under the upper columns at both ends in the left-right direction in the drawing of the upper second structural face, where the fluctuating axial force during an earthquake is large, but the column axial force of the upper columns is mainly concentrated in the upper columns and is borne by the seismic isolation devices. As a result, the long-term load acting on the seismic isolation devices is made larger than the fluctuating axial force during an earthquake.

[0005] The "seismic isolated building" of Patent Document 3 is a seismically isolated building having a lower structure and an upper structure connected via a seismic isolation device, in which at least one protruding corner forming the upper structure is constructed of a wall or exterior material, and the upper column adjacent to the protruding corner is supported by a protruding corner inclined column arranged so that its lower side expands outward and is connected to the lower structure. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2001-295494 A [Patent Document 2] JP 2017-160608 A [Patent Document 3] JP 2019-082092 A Summary of the Invention [Problem to be solved by the invention]

[0007] In this type of building structure, the seismic isolation members may need to be temporarily removed to perform maintenance or to replace the seismic isolation members.

[0008] During the period in which the seismic isolation members are removed, support members that support the column-beam structure on the upper floors are installed on the column side of the lower floors in place of the seismic isolation members.

[0009] In order to ensure the seismic isolation effect even during the period when the seismic isolation members are removed, movement permitting means such as sliding bearings or rolling bearings may be provided between the support members and the column-beam structure, which provide a vibration damping effect while allowing relative horizontal movement between the columns on the lower floor and the column-beam structure.

[0010] Because there are fewer columns in the lower story than in the multiple columns of the column-beam structure on the upper story, if horizontal relative movement between the columns on the lower story and the column-beam structure is allowed, in other words, if the point of application of the vertical column axial force of each column on the upper story relative to the column on the lower story moves and the support position of the column-beam structure by the columns on the lower story changes, there is a problem that a torsional moment around the horizontal axis is generated in the column-beam structure, and measures to suppress the torsional moment are desired.

[0011] The present invention was devised in consideration of the above-mentioned problems in the conventional technology, and aims to provide a building structure with a capital provided with multiple columns that can suppress the torsional moment generated in the column-beam structure on the upper floor, even when a movement allowing means is provided between the support members provided on the lower floor columns in place of the removed seismic isolation members and the column-beam structure on the upper floor, which allows horizontal relative movement between the columns on the lower floor and the column-beam structure on the upper floor. [Means for solving the problem]

[0012] The building structure having a capital with multiple columns of the present invention is a building structure in which a capital is provided on a lower column, with the lower parts of multiple adjacent columns of an upper-level column-beam structure embedded therein via removable seismic isolation members, and is characterized in that the structure is provided with a support member provided between the lower column side and the capital, on which the weight of the capital side is transferred from the removed seismic isolation member, a movement allowing means provided between the support member and the capital, which allows horizontal relative movement between the lower column and the capital, and a torsional reinforcement bar embedded in the capital, which resists the torsional moment around the horizontal axis generated in the capital due to the horizontal relative movement between the lower column and the capital.

[0013] The torsional reinforcement is characterized in that it is arranged directly below the lower part of the column and in the surrounding area of ​​the lower part of the column in order to reinforce the area around the lower part of the column.

[0014] The torsional reinforcement bars are arranged in parallel in the arrangement direction of adjacent columns.

[0015] The torsional reinforcement is characterized in that it has an upward U-shape extending from below the lower part of the column to the upper part along the lower part of the column.

[0016] The torsional reinforcement is characterized in that it is arranged inside the structural steel bars embedded in the capital.

[0017] The support member is fixed to the lower column, and the movement allowing means allows relative horizontal movement between the upper part of the support member and the bottom surface of the capital. Effect of the Invention

[0018] In a building structure having a capital with multiple columns according to the present invention, even if a movement permitting means is provided between the support member provided on the lower level column side in place of the removed seismic isolation member and the column-beam structure on the upper level, which allows horizontal relative movement between the column of the lower level and the column-beam structure on the upper level, the torsional moment generated in the column-beam structure on the upper level can be suppressed. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is an enlarged side view of a preferred embodiment of a building structure having a capital with multiple columns according to the present invention. [Diagram 2] 2 is a view taken along line AA in FIG. [Diagram 3] 3 is a cross-sectional view taken along line BB in FIG. 2. [Figure 4] FIG. 2 is an explanatory diagram for explaining a torsional moment acting on the capital shown in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] A preferred embodiment of a building structure having a capital with multiple columns according to the present invention will be described in detail below with reference to the accompanying drawings. Fig. 1 is an enlarged side view of a main part of the building structure according to this embodiment, and Fig. 2 is a view taken along line AA in Fig. 1.

[0021] The building structure having a capital with multiple columns in this embodiment is constructed by supporting an upper-story column-beam structure 1 (hereinafter sometimes simply referred to as the column-beam structure) via a capital 2 on a lower-story reinforced concrete column 3 (hereinafter sometimes simply referred to as the lower-story column).

[0022] The column-beam structure 1 is a mixed structure in which the columns are concrete-filled steel pipe columns 4 (hereinafter referred to as CFT columns) and the beams are H-shaped steel beams 5, 6 (the first and second steel beams described below).

[0023] The columns of the column-beam structure 1 may be made of steel concrete, steel reinforced concrete, reinforced concrete, or steel, other than CFT, and the beams of the column-beam structure 1 may be made of reinforced concrete or steel reinforced concrete. The lower level columns 3 may be made of steel reinforced concrete.

[0024] A seismic isolation member 7 is placed on the lower columns 3. The seismic isolation member 7 is, for example, a laminated rubber, and exhibits a seismic isolation effect against a horizontal vibration external force H that moves the column-beam frame 1 and the lower columns 3 relatively in the horizontal direction.

[0025] A capital 2 made of reinforced concrete that constitutes the upper part of the lower column 3 is provided on top of the seismic isolation member 7 , and the capital 2 is supported by the lower column 3 via the seismic isolation member 7 .

[0026] The seismic isolation member 7 can be removed from between the lower column 3 and the capital 2 for maintenance or replacement. When the seismic isolation member 7 is removed, the weight on the capital side is transferred to the support member 8 described later.

[0027] In the capital 2, the lower parts of a plurality of adjacent CFT columns 4 of the column-beam structure 1 (hereinafter, sometimes simply referred to as the lower parts of the columns) are embedded.

[0028] In this embodiment, the column-beam structure 1 is supported by the lower column 3 below the capital 2, so that the lower part of the lowest CFT column 4 of the column-beam structure 1 and parts of the periphery of the lower part of the steel beams 5, 6 which are arranged at the bottom of the column-beam structure 1 and connected to the lower part of the column are embedded in the capital 2.

[0029] The lower part of the CFT column 4 and the steel beams 5, 6 are joined by a column-beam joint 9 having a diaphragm. Therefore, the capital 2 is provided with the lower parts of the adjacent CFT columns 4 of the column-beam structure 1, and the vertical axial force of the CFT columns 4 acts from these lower parts.

[0030] In the building structure of this embodiment, the vertical column axial force of the CFT column 4 is supported by lower columns 3 whose number is fewer than the points of application of the column axial force, i.e., the column-beam structure 1 is supported by lower columns 3 whose number is fewer than the multiple CFT columns 4 of the column-beam structure 1.

[0031] Specifically, multiple CFT columns 4 of the column-beam structure 1 are provided on the capital 2 on one lower-story column 3. The multiple CFT columns 4 have their column centers displaced from the column center 3C of one lower-story column 3 (see Figures 2 and 4) and their lower parts are embedded in the capital 2.

[0032] The illustrated example shows a case in which the lower parts of two CFT columns 4, a first steel beam 5 extending in the direction in which the two CFT columns 4 are aligned and connecting the lower parts of the two CFT columns 4, and a second steel beam 6 joined perpendicularly to the first steel beam 5 at the center position of the two CFT columns 4 are embedded in the capital 2.

[0033] The number of CFT columns 4 installed in the capital 2 is not important as long as it is two or more, and the position of the CFT columns 4 may be such that one of the CFT columns 4 is installed directly above the lower column 3.

[0034] In addition, in the illustrated example, the first and second steel beams 5, 6, which are partially embedded in the capital 2, are constructed as steel-reinforced concrete beams in which the steel beams 5, 6 and the reinforcing bars 10 surrounding the steel beams 5, 6 are embedded in concrete to form a structure continuous with the capital 2 made of reinforced concrete.

[0035] The number of CFT columns 4 and the number of first steel beams 5 to be installed in the capital 2 are not limited to the illustrated example, and the presence or absence of installation of second steel beams 6 and their number are also not limited to the illustrated example.

[0036] The reinforced concrete capital 2, which is installed on the lower column 3 via the seismic isolation member 7, is formed in a rectangular parallelepiped shape with its length aligned along the extension direction of the first steel beam 5 and its width aligned along the extension direction of the second steel beam 6, and with the lower part of the column and the beam ends of the first and second steel beams 5, 6 connected to the lower part of the column buried within its thickness from the top surface 2a to the bottom surface 2b.

[0037] As shown in Figs. 2 and 3, a reinforcing bar cage 11 having a three-dimensional mesh structure is embedded in the capital 2 as structural reinforcing bars.

[0038] This reinforcing bar cage 11 is composed of annular ribs 11a arranged along the width direction of the capital 2 and main reinforcements 11b arranged along the length direction of the capital 2.

[0039] The ribs 11a are composed of a ring-shaped reinforcing bar 11f having a bottom reinforcing bar portion 11c along the bottom surface 2b of the capital 2, an upper reinforcing bar portion 11d along the top surface 2a of the capital 2, and a pair of left and right rising reinforcing bars 11e, 11e that connect the left and right ends of the bottom reinforcing bar portion 11c and the upper reinforcing bar portion 11d at both left and right widthwise ends of the capital 2, and vertical reinforcing bars 11g that are arranged at intervals from each other and positioned closer to the inside of the ring-shaped reinforcing bar 11f than the pair of left and right rising reinforcing bars 11e, 11e, and connect the bottom reinforcing bar portion 11c and the upper reinforcing bar 11d.

[0040] The ring-shaped reinforcing bar 11f is arranged to surround the lower part of the column from the bottom surface 2b side of the capital 2 and from both the left and right width directions.

[0041] The vertical reinforcing bars 11g are arranged so as to sandwich the lower part of the column in multiple layers from both the left and right sides of the capital 2 in the width direction.

[0042] A plurality of the thus configured stirrup members 11a are arranged in parallel at intervals from each other in the longitudinal direction of the capital 2.

[0043] On the other hand, the main reinforcements 11b are formed long in the length direction of the capital 2. These main reinforcements 11b are arranged in parallel at intervals along the inner periphery of the annular reinforcements 11f constituting the ribs 11a and along the vertical height direction of the vertical reinforcements 11g.

[0044] When removing the seismic isolation member 7, a support member 8 such as a jack to support the weight of the capital side is installed next to the seismic isolation member 7, i.e., between the lower column 3 side and the capital 2.

[0045] The lower column 3 side refers not only to the lower column 3 itself, but also to the temporary body 3a temporarily installed adjacent to the lower column 3.

[0046] In the case where the support members 8 can be installed on the lower columns 3 together with the seismic isolation members 7, the support members 8 may be provided on the lower columns 3, whereas in the case where such installation is not possible, a temporary body 3a is temporarily set up and the support members 8 are provided on top of it. In the illustrated example, four support members 8 are provided around the seismic isolation members 7.

[0047] Then, the support member 8 on the lower column 3 side is abutted against the bottom surface 2b of the capital 2 and lifted up, gradually unloading the weight on the capital side acting on the seismic isolation member 7. After that, when the seismic isolation member 7 is removed, the weight on the capital side is transferred entirely to the support member 8.

[0048] Between the upper part of each support member 8 and the bottom surface 2b of the capital 2, a movement allowing means 12 is provided which allows horizontal relative movement between the lower column 3 and the capital 2 by being placed on the upper part of the support member 8 before the support member 8 is abutted against the capital 2.

[0049] Specifically, the support member 8 is fixed to the lower column 3, and the movement allowing means 12 is fixed to the support member 8 to allow relative horizontal movement between the upper part of the support member 8 and the bottom surface 2b of the capital 2.

[0050] A sliding bearing or a rolling bearing, which are well known in the seismic isolation technology, is used as the movement allowing means 12. The movement allowing means 12 may have a damping effect for damping the relative movement force.

[0051] By providing the movement allowing means 12, even when a horizontal vibration external force H acts on the lower column 3, causing the lower column 3 to move horizontally relative to the column-beam structure 1 and capital 2, when the seismic isolation member 7 is removed, the support state of the column-beam structure 1 by the lower column 3 is maintained.

[0052] Further, torsional reinforcement bars 13 are embedded in the capital 2 to bear the torsional moment around the horizontal axis generated in the capital 2 due to the horizontal relative movement between the lower columns 3 and the capital 2, and to resist the torsional moment.

[0053] As shown in FIG. 3, each of the torsional reinforcement bars 13 is bent to have an upward U-shape such that both ends in the lengthwise direction are raised upward from the central portion 13a to form raised portions 13b.

[0054] The torsional reinforcement 13 has a central portion 13a disposed below the lower portion of the column and near the bottom surface 2b of the capital 2, and the rising portions 13b on both ends are disposed along the lower portion of the column in the thickness direction from the bottom surface side of the capital 2 so as to sandwich the lower portion of the column from the sides. Each rising portion 13b is disposed close to the side surface 2d of the capital 2 in the width direction.

[0055] In order to reinforce the capital 2 around the lower part of the column, a plurality of torsional reinforcement bars 13 are arranged immediately below the lower part of the column and in the surrounding area of ​​the lower part of the column, as shown in FIG.

[0056] These multiple torsional reinforcement bars 13 are arranged in parallel in the arrangement direction of adjacent CFT columns 4. That is, these multiple torsional reinforcement bars 13 are arranged closely together in the length direction of the capital 2 (the extension direction of the first steel beam 5 in the figure) with their central parts 13a aligned along the width direction of the capital 2.

[0057] Furthermore, the torsional reinforcement 13 is arranged inside the ribs 11a, which are structural reinforcement bars, specifically the ring-shaped reinforcement bars 11f, so that the supporting action from the capital 2 acts on the rising portion 13b.

[0058] Next, the operation of the building structure having a capital with multiple columns according to this embodiment will be described.

[0059] When the seismic isolation member 7 is removed and the column-beam structure 1 is supported by the lower columns 3 via the support members 8, if a horizontal vibration external force H such as earthquake motion acts on the lower columns 3, the seismic isolation effect is maintained by the movement allowing means 12. However, as shown in FIG. 4, the position of the lower columns 3 moves back and forth horizontally relative to the capital 2, and during this relative movement, the support members 8 on the lower column 3 side support the capital 2 at an offset position depending on the amount of movement. In other words, the capital 2 is supported by the support members 8 at an offset position.

[0060] In addition to its own weight, the capital 2 is subjected to the vertical column axial forces of multiple CFT columns 4. When the lower columns 3 move relative to each other due to the external vibration force H and the support position of the support member 8 moves relative to the position where the vertical column axial force acts, a torsional moment M is generated in the capital 2.

[0061] Specifically, when horizontal relative movement of the lower column 3 occurs in the width direction of the capital 2 (the extension direction of the second steel beam 6 in the figure; the X direction in the figure), a torsional moment Mx is generated in the capital 2 around an axis in the length direction of the capital (the extension direction of the first steel beam 5 in the figure), which is perpendicular to the X direction.

[0062] In addition, when horizontal relative movement of the lower column 3 occurs in the length direction of the capital 2 (Y direction in the figure), a torsional moment My is generated in the capital 2 around the width axis of the capital 2 that is perpendicular to the Y direction.

[0063] Normally, a horizontal vibration external force H such as an earthquake motion acts in a diagonal direction between the X and Y directions (direction P in the figure), causing horizontal relative movement of the lower column 3, and a torsional moment Mp is generated in the capital 2 around an axis perpendicular to the P direction. This torsional moment Mp in the diagonal direction P is a combination of the torsional moments in the X and Y directions, and is used during structural design by decomposing it into torsional moments Mx and My from the horizontal relative movement amounts in the X and Y directions and the vertical column axial force.

[0064] In this embodiment, the capital 2 is provided with torsional reinforcement 13 that resists the torsional moment M around the horizontal axis acting on the capital 2, thereby preventing the capital 2, and by extension the column-beam structure 1 composed of CFT columns 4 with their lower parts embedded in the capital 2, from being significantly deformed and damaged by the torsional moment.

[0065] In the present embodiment, in the capital 2 in which two CFT columns 4 are arranged in parallel in the Y direction, which is the extension direction of the first steel beam 5, when the lower column 3 moves relatively in the Y direction, the support member 8 moves to the same side with respect to the application point of the two vertical column axial forces of the CFT columns 4, so a torsional moment My is generated around the axis in the width direction of the capital 2. In this direction, the first steel beam 5 connecting the two CFT columns 4 bears the torsional moment My together with the longitudinal reinforcing bars of the capital 2, so the capital 2 is less likely to be deformed or damaged. On the other hand, when the lower column 3 moves relatively in the X direction, although there is a second steel beam 6, it is a member joined to the first steel beam 5, and has a longer span length and lower rigidity than the first steel beam 5, so there is a high possibility that deformation or damage will occur due to the torsional moment M generated for the same amount of movement.

[0066] For this reason, in this embodiment, as shown in Figures 2 and 3, the arrangement of the torsional reinforcement bars 13 is such that multiple torsional reinforcement bars 13 are densely arranged in the longitudinal direction of the capital 2 with their longitudinal direction (central portions 13a) aligned along the width direction of the capital 2 so as to provide effective resistance to the torsional moment Mx that occurs when the lower column 3 moves relatively in the X direction (width direction of the capital 2).

[0067] In order to reinforce the area around the lower part of the CFT column 4 embedded in the capital 2, the torsional reinforcement bars 13 are arranged directly below the lower part of the column and in the surrounding area of ​​the lower part of the column, so that the area around the lower part of the column, which transmits the vertical column axial force to the capital 2, can be appropriately and reliably reinforced against the torsional moment M.

[0068] Since the torsional reinforcement bars 13 are arranged in parallel in the arrangement direction of adjacent CFT columns 4, the capital 2 can be reinforced with directionality, and the torsional deformation occurring in the capital 2 can be suppressed without generating unnecessary stress.

[0069] Since the torsional reinforcement bar 13 is formed in an upward U-shape that extends from below the bottom of the column to the top along the bottom of the column, when embedding the torsional reinforcement bar 13 in the concrete of the capital 2, the reinforcement work can be facilitated and the bottom surface 2a side of the capital 2 supported by the support member 8 can be formed with high strength.

[0070] Since the torsional reinforcement 13 is arranged inside the reinforcing bar cage 11 embedded in the capital 2, the torsional reinforcement 13, including the rising portion 13b of the torsional reinforcement 13, can receive supporting pressure from the reinforcing bar cage 11 and the surrounding concrete, and the capital 2 can be formed with high strength.

[0071] The torsional reinforcement 13 and its arrangement described in this embodiment are merely an example, and any configuration may be used as long as it provides resistance to the torsional moment M generated in the capital 2. [Explanation of symbols]

[0072] 1 Column beam frame 2. Capital 3 Lower pillar 4 CFT columns 7 Seismic isolation materials 8 Support member 11 Reinforced Concrete Cage 12. Means of travel allowance 13 Torsional reinforcement M, Mx, My, Mz Torsional moment

Claims

1. In a building structure in which a capital is provided on a lower-level column, the lower portions of a plurality of adjacent columns of a column-beam structure in an upper level are embedded via a removable seismic isolation member, the temporary support structure temporarily supports the capital when the seismic isolation member is temporarily removed, A support member provided between the lower column side and the capital, on which the weight of the capital side is transferred from the removed seismic isolation member; A movement permitting means is provided between the support member and the capital, and permits horizontal relative movement between the lower column and the capital; Equipped with The building structure is a temporary support structure characterized in that it is provided with a torsional reinforcement bar embedded in the capital and resists a torsional moment around a horizontal axis that occurs in the capital due to the horizontal relative movement of the lower column and the capital during removal of the seismic isolation member.

2. 2. The temporary support structure according to claim 1, characterized in that the torsional reinforcement is arranged immediately below the lower part of the column and in the surrounding area of ​​the lower part of the column in order to reinforce the area around the lower part of the column.

3. 3. The temporary support structure according to claim 1 or 2, wherein the torsional reinforcement bars are arranged in parallel in the arrangement direction of the adjacent columns.

4. The temporary support structure according to any one of claims 1 to 3, characterized in that the torsional reinforcement is in an upward U-shape extending from below the lower part of the column upward along the lower part of the column.

5. 5. The temporary support structure according to claim 1, wherein the torsional reinforcement is arranged inside the structural steel embedded in the capital.

6. A temporary support structure as described in any one of claims 1 to 5, characterized in that the support member is fixed to the lower column, and the movement allowing means allows horizontal relative movement between the upper part of the support member and the bottom surface of the capital.

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