Buildings and their construction methods

Abstract

To provide a building and its construction method that do not require excessive beam size and can simplify construction work.SOLUTION: A building 100 is of SRC construction including a part of RC construction. In at least some of beams 22a among a plurality of beams 20 installed between adjacent columns 10, a built-in steel frame 42 of the beam 22a is fixed at its end to a gusset plate 51 fixed to a built-in steel frame 31 of a column 12a using bolts, and is embedded in the beam 22a with concrete.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to buildings, and more particularly to steel-framed reinforced concrete buildings that include a portion made of reinforced concrete, and to a method for constructing such buildings. [Background technology]

[0002] Steel-reinforced concrete (SRC) buildings have the advantage of being able to reduce the number of columns and create spacious interior spaces, making them suitable for large commercial facilities, etc. In SRC buildings, the ends of the built-in steel frames of the beams (girders) that span between the columns are usually rigidly connected to the built-in steel frames of the columns.

[0003] Patent Document 1 describes the framework of an SRC building, which is a steel-framed (S-framed) building in which the built-in steel frames of some beams are pin-joined to the built-in reinforcing bars of the columns. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-37530 Summary of the Invention [Problem to be solved by the invention]

[0005] However, to achieve a rigid connection, it is usually necessary to sandwich and weld a diaphragm midway between the built-in steel frame of the column and then weld the flange portion of the built-in steel frame of the beam to the side of the diaphragm, which is a time-consuming process. Also, if the beams to be joined to the column are of different sizes, individual diaphragms must be installed, but this is not desirable because it would increase the size of the beam to match a larger beam. While it is possible to increase the size of the built-in steel frame of the beam to reduce the work required, this is not desirable because it would increase the size of the joint between the column and the beam.

[0006] In view of the above, the present invention aims to provide a building and a construction method thereof that do not require excessively large beam sizes and that can simplify construction work. [Means for solving the problem]

[0007] The building of the present invention is a steel-reinforced concrete building that includes some reinforced concrete construction, and is characterized in that, in at least some of the multiple beams erected between adjacent columns, the built-in steel frame of the beams is fixed at its ends using bolts to gusset plates fixed to the built-in steel frame of the columns, and is embedded in the beams with concrete.

[0008] In the building of the present invention, the built-in steel frames of some beams are fixed with bolts to gusset plates fixed to the built-in steel frames of columns, and are embedded in concrete in this state, making it possible to construct steel-reinforced concrete (SRC) beams with simple construction work. Note that the flanges of the built-in steel frames of the beams fixed to the built-in steel frames of the columns via gusset plates are not rigidly joined to the columns.

[0009] In addition, by assuming that the built-in steel frame of the beam, which is fixed to the built-in steel frame of the column via a gusset plate, does not bear the bending stress from the column, the size options are expanded and it is possible to make the joint between the column and the beam smaller.

[0010] In this way, in the building of the present invention, the built-in steel frame of the beam, which is fixed to the built-in steel frame of the column via the gusset plate, can be considered not to exist in the structural calculations of the building.

[0011] In addition, in the building of the present invention, it is preferable that the built-in steel frame of the beam, which is fixed to the built-in steel frame of the column via the gusset plate, has a bending strength sufficient to support the built-in steel frame of the column before the concrete hardens.

[0012] In this case, it is possible to stabilize the temporary frame consisting of steel frames built into the columns and beams before the concrete hardens.

[0013] In addition, it is preferable that the beam containing the built-in steel frame fixed to the built-in steel frame of the column via the gusset plate has a beam span shorter than that of the other beams.

[0014] In this case, the bending moment acting on the beam containing the built-in steel frame, which is fixed to the built-in steel frame of the column via a gusset plate and whose flange portion is not rigidly joined but is pin-jointed, is reduced, making it possible to reduce the cross-sectional area of ​​the beam.

[0015] The method for constructing a building of the present invention is characterized in that at least some of the beams among a plurality of beams erected between adjacent columns are formed by embedding the steel frame built into the beam in concrete with the ends fixed with bolts to a gusset plate fixed to the steel frame built into the column.

[0016] According to the method for constructing a building of the present invention, it is possible to obtain the same effects as those of the building of the present invention described above. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a schematic front view illustrating the arrangement of columns and beams of a building according to an embodiment of the present invention. [Figure 2] 1 is a schematic diagram illustrating the arrangement of columns and beams on each floor of a building according to an embodiment of the present invention. [Figure 3] Schematic XY plane cross section showing the joint between a column and a beam with built-in steel frame pin-jointed. [Figure 4] Schematic XZ plane cross section showing the joint between a column and a beam with built-in steel frame pin-jointed. DETAILED DESCRIPTION OF THE INVENTION

[0018] A building 100 according to an embodiment of the present invention will be described with reference to the drawings. Note that Figures 1 to 4 are diagrams for schematically explaining this embodiment, and the dimensions are exaggerated.

[0019] The building 100 is a steel-reinforced concrete (SRC) structure that includes some reinforced concrete (RC) construction, and all of the columns 10 and the beams (girders) 20 connecting the columns 10 are constructed with built-in steel frames embedded in concrete together with reinforcing bars. In this example, the building 100 has multiple floors and is square-shaped in plan view with a central space, but is not limited to this, and the number of floors and exterior shape are not specified.

[0020] The columns 10 consist of corner columns located at the four corners of the building 100, outer columns located between the corner columns and constituting the outer periphery of the building 100, and interior columns located between the outer columns and inside the building 100.

[0021] The beams 20 are composed of an outer perimeter beam that spans between two adjacent columns 10, i.e., between a corner column and the adjacent outer perimeter column, an inner perimeter beam that spans between the outer perimeter column and the adjacent inner perimeter column, and an inner perimeter beam that spans between the inner perimeter column and the adjacent inner perimeter column.

[0022] In some beams 21 of the beams 20 (beams other than the thinly painted beams 22 in Figures 1 and 2), the steel frames built into these beams 21 and the steel frames built into the columns 11 are rigidly connected. Columns 11 to which such beams 21 are connected in two directions (X-axis direction and Y-axis direction) incorporate a steel frame made of roughly cross-shaped steel I-shaped beams (or H-shaped beams) that intersect at right angles. Although not shown, columns to which beams are connected in only one direction (X-axis direction or Y-axis direction) incorporate a steel frame made of I-shaped beams (or H-shaped beams) with the longitudinal direction being the direction to which the beams are connected.

[0023] Then, although not shown, these columns 11 are welded to a diaphragm so that it is sandwiched midway in the vertical direction (Z-axis direction) of the built-in steel frame, and the flange of the built-in steel frame of the beam 21 formed integrally with this diaphragm is fixed by welding. This results in a rigid connection between the built-in steel frame of the column 11 and the built-in steel frame of the beam 21. After this rigid connection, reinforcing bars are arranged and concrete is poured into the installed formwork, thereby constructing the column 11 and beam 21 as an integrated SRC structure. This construction can be performed using the same construction method as in the past, and a detailed explanation will be omitted.

[0024] On the other hand, in beams 22 (thinly painted beams in Figures 1 and 2) other than beam 21 among beams 20, the built-in steel frame of beam 22 is connected to the built-in steel frame of column 12 by pin joints. Such beams 22 have a shorter beam span compared to the other beams 21. In other words, when pin joints are used, columns 12 are positioned so as to shorten the beam span.

[0025] The beam 22 connected to the column 12 with a pin in this way becomes a SRC structure rigidly connected to the column 12 by embedding its built-in steel frame in concrete. However, when performing structural calculations, the built-in steel frame is considered not to exist.

[0026] Hereinafter, with reference to Figs. 3 and 4, an example of the structure of such a joint between a column 12 and a beam 22 will be described.

[0027] Here, we will explain the case where the built-in steel frame 31 of the column 12a is rigidly connected to the built-in steel frame 41 of the beam 21a on the negative side of the Y axis, and the built-in steel frame 31 of the column 12a and the built-in steel frame 42 of the beam 22a are pin-connected in both the positive and negative directions of the X axis.

[0028] The built-in steel frame 31 of the column 12a is an I-shaped steel or H-shaped steel extending vertically (in the Z-axis direction), with its web extending in the Y-axis direction. On the other hand, the built-in steel frame 31 of the beam 21a is an I-shaped steel or H-shaped steel extending in the Y-axis direction, with its web extending in the Z-axis direction.

[0029] Two flat steel diaphragms 51 are fixed by welding to the built-in steel frame 31 of the column 12a at two locations spaced apart in the Z-axis direction. The side end faces of the built-in steel frame 41 of the beam 21a are fixed by welding to the side faces of these diaphragms 51 in the negative Y-axis direction. This results in a rigid connection between the built-in steel frame 31 of the column 12a and the built-in steel frame 41 of the beam 21a.

[0030] Meanwhile, the side of one end of a flat steel gusset plate 61 is abutted against and welded to the side surfaces on both the positive and negative sides of the X-axis of the web of the built-in steel frame 31 of the column 12a. A plurality of through holes (not shown) are formed in the other end of this gusset plate 61. A plurality of through holes (not shown) are also formed in the web of the end of the built-in steel frame 42 of the beam 22a on the column 12a side. Bolts (not shown) are inserted through the through holes formed in the gusset plate 61 and the built-in steel frame 42, respectively, and nuts (not shown) are screwed in to secure the built-in steel frame 31 of the column 12a and the built-in steel frame 42 of the beam 22a, thereby forming a pin-jointed state.

[0031] The column 12a is provided with a plurality of column main reinforcements 71 extending in the Z-axis direction to surround the built-in steel frame 31 of the column 12a, and a plurality of shear reinforcements (stirrups) 72 spaced apart in the Z-axis direction to surround these column main reinforcements 71. The beam 21a is provided with a plurality of beam main reinforcements 73 extending in the X-axis direction to the column 12a to surround the built-in steel frame 41 of the beam 21a, and a plurality of shear reinforcements 74 spaced apart in the Y-axis direction to surround these beam main reinforcements 73. The two beams 22a extending in the Y-axis direction are provided with a plurality of beam main reinforcements 75 extending continuously in the Y-axis direction through the two beams 22a via the column 12a to surround the built-in steel frame 42 of the beam 22a, and a plurality of shear reinforcements 76 spaced apart in the X-axis direction to surround these beam main reinforcements 75.

[0032] In this way, a formwork (not shown) is installed with the built-in steel frames 31, 41, 42 and reinforcing bars 71 to 76 in place, and concrete is poured into this formwork, thereby integrally forming the SRC columns 12a and beams 22a.

[0033] In this way, when rigidly connecting the built-in steel frame of a beam, a diaphragm can be installed midway through the built-in steel frame of a column and the flange of the built-in steel frame of the beam can be welded to this diaphragm.On the other hand, when connecting the built-in steel frame of a beam with a pin, a gusset plate can be installed on the built-in steel frame of the column.

[0034] Below, we will explain a method for constructing a building according to an embodiment of the present invention. This construction method involves constructing a SRC structure in which columns and beams are integrated on each floor. The following explanation applies to any floor in which an SRC structure in which columns and beams are integrated is constructed.

[0035] First, the built-in steel frame of the column is erected. Next, the built-in steel frame of the beam is temporarily assembled to the built-in steel frame of the column. At this time, the built-in steel frame 31 of the column 12a and the built-in steel frame 41 of the beam 21a are rigidly joined by welding via a diaphragm 51, and the built-in steel frame 31 of the column 12a and the built-in steel frame 42 of the beam 22a are pin-joined by bolts via a gusset plate 71. After that, the bolts are finally tightened.

[0036] Next, reinforcing bars such as column main reinforcement 71, beam main reinforcement 73, 75, shear reinforcement 72, 74, 76, etc. are arranged.

[0037] Then, although not shown, formwork for forming the columns 12a and the beams 21a and 22a is installed.

[0038] Concrete is then poured into the formwork, thereby constructing an SRC structure in which the column 12a and the beams 21a and 22a are integrated together, and the built-in steel frame 42 of the pin-jointed beam 22a is embedded within the beam 22a.

[0039] As described above, according to the embodiment of the present invention, the built-in steel frame 42 of the beam 22a can be pin-joined using bolts to the gusset plate 61 fixed by welding to the built-in steel frame 31 of the column 12a, and since this built-in steel frame 42 is embedded in concrete, it is possible to construct a SRC beam 22a with simple construction work.

[0040] In order to rigidly join the built-in steel frame of the column and the built-in steel frame of the beam, the built-in steel frame of the column must be cut in two places to match the height of the built-in steel frame of the beam, a diaphragm must be welded between the cut parts, and then the flange part of the built-in steel frame of the beam must be welded to the side of the diaphragm, which is a time-consuming process.If the built-in steel frame of the beam is at a different height, an additional diaphragm must be added, which is even more time-consuming.

[0041] Furthermore, since the built-in steel frame 42 of the pin-jointed beam 22a is not taken into account in the structural calculations, a smaller one can be used, making it possible to miniaturize the joint between the column 12a and the beam 22a. However, a frame including the pin-jointed beam 22a will be structurally reinforced concrete. Furthermore, since the bending strength of the built-in steel frame 42 of the pin-jointed beam 22a is not taken into account, it is necessary to consider the size and number of the main beam reinforcement bars 75 to be arranged in order to ensure the bending strength of the beam 22a.

[0042] Furthermore, the built-in steel frame 42 of the pin-jointed beam 22a functions as a structural member during temporary erection, thereby stabilizing the temporary frame. The built-in steel frame 42 of the pin-jointed beam 22a becomes a structural member like other reinforcing bars that act during temporary erection, and its size must be selected so that it can withstand the weight of reinforcing bars and formwork, and so that the structural member does not collapse or tilt due to the impact when pouring concrete.

[0043] Furthermore, the built-in steel frame 31 of the column 12a only needs to have a strong axis in the direction where the built-in steel frame 41 of the beam 21a is rigidly joined, and the direction where the built-in steel frame 42 of the beam 22a is pin-joined does not need to be a strong axis, so an I-shaped steel frame (or H-shaped steel frame) can be used. This eliminates the need for a cross-shaped steel frame with strong axes in two directions, making it possible to simplify the structure and reduce its weight.

[0044] The present invention is not limited to the above-described embodiment, and can be modified as appropriate. [Explanation of symbols]

[0045] 10...Column, 11...Column with built-in steel frame not pinned, 12, 12a...Column with built-in steel frame pinned, 20...Beam, 21, 21a...Beam with built-in steel frame not pinned, 22, 22a...Beam with built-in steel frame pinned, 31...Built-in steel frame of column 12a, 41...Built-in steel frame of beam 21a, 42...Built-in steel frame of beam 22a, 51...Diameter beam, 61...Gassette plate, 71...Column main reinforcement, 72, 74, 76...Shear reinforcement, 73, 75...Beam main reinforcement, 100...Building.

Claims

1. In a steel-framed reinforced concrete building that includes a portion of reinforced concrete, a joint structure is provided for joining the built-in steel frame of a beam made of I-shaped steel or H-shaped steel embedded in concrete to the built-in steel frame of a column made of I-shaped steel or H-shaped steel embedded in concrete, A flat steel gusset plate is welded to the side of the web of the built-in steel frame of the column with one end abutting against it, and a plurality of through holes are formed in the end area on the other end side of the gusset plate, A plurality of through holes are formed in the end region of the column side of the web of the built-in steel frame of the beam, A joint structure between the built-in steel frame of a beam and the built-in steel frame of a column, characterized in that a through hole formed in the end region on the other edge side of the gusset plate and a through hole formed in the end region on the column side of the web of the built-in steel frame of the beam are aligned, and these built-in steel frames are pin-joined by inserting a bolt and screwing a nut to secure them.

2. The joint structure between the built-in steel frame of a beam and the built-in steel frame of a column as described in claim 1, characterized in that the built-in steel frame of the beam erected between the built-in steel frames of two adjacent columns has a bending strength capable of supporting the built-in steel frame of the column before the concrete hardens, since both end portions are each pin-jointed via the gusset plate.

3. A joint structure between the built-in steel frame of the beam and the built-in steel frame of the column described in Claim 2, characterized in that the built-in steel frame of the column is a member that does not bear load in structural calculations of the building.

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