C·S joint structure

Abstract

To enable easy and simple joining of concrete and steel frame members. [Solution] A C·S joint structure is provided for joining a concrete C member (8) and a steel S member (10) that constitute a part of at least one of a column 6 and a beam 7, respectively. The S member comprises a steel frame body 11 extending in the direction of the material axis and a joint plate 12 integrally attached to the end of the steel frame body 11 in the direction of the material axis. The C member is provided with a plurality of through holes (21) extending in the direction of the material axis of the S member, and the S member is pressure-joined to the C member by a plurality of tension members 15 that are arranged to pass through the joint plate 12 and the through holes of the C member and have one end fixed to the joint plate 12.

Description

Technical Field

[0001] The present invention relates to a C·S joint structure for joining a C member made of concrete structure (hereinafter referred to as C structure) and an S member made of steel structure (hereinafter referred to as S structure), which respectively constitute at least a part of one of columns and beams.

Background Art

[0002] A column RC beam S hybrid structure in which the column is made of reinforced concrete structure (hereinafter referred to as RC structure) and the beam is made of S structure is known. Also, various column-beam joint structures for joining a steel beam to a column made of RC structure are known. For example, there is a structure in which steel bars are arranged around the end of the beam and concrete is placed, and a connection part made of steel bar reinforced concrete structure is provided at the end of the beam. In this case, it is conceivable to manufacture at a factory the connection part at the end of the beam and the column as an integral precast concrete, or to manufacture the column as precast concrete and construct the connection part at the end of the beam with in-situ concrete.

[0003] Hybrid structures such as columns of S structure and RC structure are also known. Patent Document 1 discloses a joint structure between a steel column member and an RC column member, in which both members are joined using steel bars and mechanical joints. A mechanical joint is fixed to the outer peripheral surface of the steel column member by welding, and column main steel bars for connection are fixed to this mechanical joint. A mechanical joint is embedded in the end of the RC column member on the side of the steel column member, and a plurality of column main steel bars fixed to the upper part of this mechanical joint are incorporated in the RC column member. The RC column member is joined to the steel column member via the column main steel bars by inserting and fixing the column main steel bars of the steel column member under the mechanical joint embedded in the RC column member.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] In structures where a connection is provided at the end of a beam, the length of the beam embedded in the connection must be long to prevent the beam from coming loose. Therefore, if the end of the beam with the connection and the column are manufactured as a single precast concrete (PCa) member in a factory, the connection becomes large and the PCa member becomes bulky, resulting in poor transportation efficiency. On the other hand, if the connection is constructed by pouring concrete on-site, it is necessary to pour the concrete in a way that embeds the beam, making it difficult to create dense concrete. Consequently, quality control becomes complicated and the work is time-consuming.

[0006] When RC members and steel members are joined by inserting main reinforcement bars into mechanical joints, as in Patent Document 1, the direction in which the main reinforcement bars are inserted is fixed, and the construction sequence is restricted, thus reducing the degree of freedom in construction. In addition, many mechanical joints are required to fix the reinforcement bars to the steel members, which makes the structure complex and the joining work time-consuming.

[0007] In view of the above background, the present invention aims to enable concrete members and steel frame members to be joined together with a simple structure and easily. [Means for solving the problem]

[0008] To solve the above problems, one aspect of the present invention provides a C·S joint structure for joining concrete C members (8, 33, 43, 53, 88) and steel S members (10, 34, 45, 65, 90) that constitute a part of at least one of a column (6) and a beam (7), wherein the S member comprises a steel frame body (11) extending in the direction of the material axis and a joint plate (12) integrally attached to the end of the steel frame body in the direction of the material axis, the C member is provided with a plurality of through holes (21) extending in the direction of the material axis of the S member, and the S member is pressure-bonded to the C member by a plurality of tension members (15) that are arranged to penetrate the joint plate and the through holes of the C member and have one end fixed to the joint plate.

[0009] Here, member C may be any structure containing concrete, and may be reinforced concrete reinforced with reinforcing materials such as steel bars or fiber reinforcement, pre-stressed concrete with pre-stressing introduced by pre-stressing tensioners, or unreinforced concrete. Member C may preferably be reinforced concrete or reinforced concrete in a broad sense that includes pre-stressed concrete or pre-stressed concrete.

[0010] In this embodiment, one end of multiple tensioning members is fixed to a joining plate, and the tensioning force of the tensioning members causes the S member to be compressed and joined to the C member. There is no need to make the C member complex in order to join the S member to the C member, nor is there a need to use cast-in-place concrete. Therefore, the C member and the S member can be joined easily with a simple structure.

[0011] In the above embodiment, it is preferable that one end of the tensioning member has a male thread and is fixed to the joining plate by a nut (23) that is screwed onto the male thread.

[0012] According to this embodiment, the nut can be easily fixed to the joining plate by rotating it until it contacts the joining plate while the tensioning member is under tension.

[0013] In the above embodiment, the tensioning member is preferably an unbonded tensioning member that is not fixed to the C member.

[0014] In this embodiment, during an earthquake, the C member and the S member can displace relative to each other in such a way that the joint at the connection point becomes larger, allowing the connection point of both members to function as a hinge. Therefore, damage to the C member and yielding of the S member due to an earthquake are suppressed. In addition, the tensioning members can be replaced, and the C member and S member can be dismantled and reused.

[0015] In the above embodiment, it is preferable that the C member is a joint member (8) that constitutes the joint portion of the column, and the S member is a beam member (10).

[0016] According to this embodiment, by fixing one end of a plurality of tensioning members to the joint plate of the beam member, the beam member can be pressed and joined to the joint member by the tensioning force of the tensioning members.

[0017] In the above embodiment, the connecting plate may have a width greater than the width of the steel frame body, and at least a portion of the tensioning member may be positioned on the outside of the connecting plate in the width direction of the steel frame body.

[0018] According to this embodiment, tensioning of at least some of the tensioning members and anchoring to the joint plate can be performed on the side of the steel frame body of the beam member. Therefore, the joining of the beam member to the joint member is facilitated.

[0019] In the above embodiment, the C member is a joint member (33) that constitutes the joint portion of the column, and the S member is a column body member (34) that is positioned above or below the joint member.

[0020] According to this embodiment, by fixing one end of a plurality of tensioning members to the joining plate of the column body member, the column body member can be pressed and joined to the joint member by the tensioning force of the tensioning members.

[0021] In the above aspect, the joint plate has a cross-section larger than that of the steel frame body, the joint member has a cross-section larger than that of the joint plate, and at least a part of the tension member is arranged outside the steel frame body in the joint plate.

[0022] According to this aspect, the tensioning of at least a part of the tension member and the fixing operation to the joint plate can be performed outside the steel frame body of the column main body member. Therefore, the joining action to the joint member of the column main body member is easy.

[0023] In the above aspect, the C member is a joint beam member (43) that constitutes the joint portion of the column and the end portion of the beam integrally joined to the joint portion, and the S member is a beam main body member (45) that constitutes the middle portion in the extending direction of the beam.

[0024] According to this aspect, by fixing one end of a plurality of tension members to the joint plate of the beam main body member, the beam main body member can be pressure-bonded to the joint beam member by the tension force of the tension members.

[0025] In addition, in order to solve the above problems, another aspect of the present invention is that the C member is a beam end member (53) that constitutes the end portion of the beam, and the S member is a beam main body member (45) that constitutes the middle portion in the extending direction of the beam.

[0026] According to this aspect, by fixing one end of a plurality of tension members to the joint plate of the beam main body member, the beam main body member can be pressure-bonded to the beam end member by the tension force of the tension members.

[0027] In addition, in order to solve the above problems, another aspect of the present invention is that the C member is a joint member (8) that constitutes the joint portion of the column, the S member is a beam main body member (45) that constitutes the middle portion in the extending direction of the beam, and the beam main body member is pressure-bonded to the joint member via beam end members (53, 65) that constitute the end portions of the beam.

[0028] According to this embodiment, by fixing one end of a plurality of tensioning members to the joining plate of the beam body member, the beam body member can be pressed and joined to the joint member by the tensioning force of the tensioning members via the beam end member.

[0029] Furthermore, in order to solve the above problems, another aspect of the present invention provides that the beam end member is equipped with a jaw portion (72) that supports the end of the beam body member from below.

[0030] In this embodiment, with the beam end member temporarily fixed to the joint member, the end of the beam body member can be placed on the jaw portion of the beam end member. Therefore, the process of crimping and joining the beam body member to the joint member via the beam end member is facilitated.

[0031] Furthermore, in order to solve the above problems, another aspect of the present invention is that the C member is a column-beam joint (88) joined to the side surface of an existing column (86) of an existing concrete column-beam structure (85).

[0032] According to this embodiment, a column or beam made of an S member, which is pressure-bonded to a column-beam joint, can be joined to an existing column-beam structure via a concrete column-beam joint to reinforce the column-beam structure. [Effects of the Invention]

[0033] According to the above embodiment, the C member and the S member can be joined together with a simple structure and easily. [Brief explanation of the drawing]

[0034] [Figure 1] Perspective view showing the foundation and frame of a building according to the first embodiment. [Figure 2] Side cross-sectional view of the column-beam joint of the frame shown in Figure 1. [Figure 3] Plan view of the column-beam joint shown along line III-III in Figure 2. [Figure 4] Enlarged perspective view showing part IV in Figure 1 with partial perspective. [Figure 5] Plan view of the column-beam joint according to the second embodiment. [Figure 6] Side cross-sectional view of the main part of the frame according to the third embodiment [Figure 7] Longitudinal section of the main part of the column shown along line VII-VII in Figure 6. [Figure 8] Side cross-sectional view of the column-beam joint of the frame according to the fourth embodiment. [Figure 9] Plan view of the column-beam joint shown along line IX-IX in Figure 8. [Figure 10] Side cross-sectional view of the column-beam joint of the frame according to the fifth embodiment. [Figure 11] Plan view of the column-beam joint shown along line XI-XI in Figure 10. [Figure 12] Plan view of the column-beam joint according to the sixth embodiment. [Figure 13] Side cross-sectional view of the column-beam joint of the frame according to the seventh embodiment. [Figure 14] Plan view of the column-beam joint shown along line XIV-XIV in Figure 13. [Figure 15] Perspective view showing the reinforcing structure of the frame according to the 8th embodiment. [Figure 16] Plan view of the reinforcing structure shown in Figure 15. [Modes for carrying out the invention]

[0035] Several embodiments of the present invention will be described in detail below with reference to the drawings. ≪First Embodiment≫

[0036] First, a first embodiment of the present invention will be described with reference to Figures 1 to 4. Figure 1 is a perspective view showing the foundation and frame of building 1 to which a C·S joint structure is applied. As shown in Figure 1, building 1 is equipped with a pile foundation 2. The pile foundation 2 is equipped with a plurality of piles 3 arranged in the X direction (length direction) and Y direction (span direction) perpendicular to each other on the horizontal plane. Building 1 is also equipped with a superstructure 5 that is constructed on top of the pile foundation 2 and supported by the pile foundation 2. The superstructure 5 is equipped with a plurality of columns 6 provided at positions corresponding to the piles 3, and a plurality of beams 7 that connect pairs of columns 6 adjacent to each other in the X direction or Y direction. Although building 1 is a multi-story building in which the superstructure 5 is multi-story, only the lowest layer is shown in Figure 1.

[0037] Each column 6 is composed of multiple column members made of precast concrete (PCa) in a concrete structure. Each column member on the first floor has a joint member 8 that forms the joint to which the beam 7 is joined, and a column body member 9 that forms the part of the column 6 other than the joint. The column body members 9 and joint members 8 are arranged alternately on the pile foundation 2. Except for the top floor, the column body members 9 are positioned above and below the joint members 8.

[0038] In this embodiment, the joint portion and the column body portion of the column 6 are formed by separate members, and one floor portion of the column 6 is formed by two or more precast concrete (PCa) members. In other embodiments, one floor portion of the column 6 may be formed by one cantilevered column member. Alternatively, one floor portion of the column 6 may be formed by three or more cantilevered column members.

[0039] Each beam 7 is composed of a steel beam member 10 and extends in the X or Y direction. The length of the beam member 10 is the same as or slightly shorter than the distance between a corresponding pair of columns 6. The beam member 10 is positioned between a corresponding pair of columns 6 and connects a pair of joint members 8. The beam member 10 comprises a steel frame body 11 extending in the material axis direction (X or Y direction) of the beam 7, and a connecting plate 12 integrally attached to the end of the steel frame body 11 in the material axis direction. The connecting plate 12 is welded to both ends of the steel frame body 11 in the material axis direction and is joined to the corresponding joint member 8.

[0040] Figure 2 is a side cross-sectional view of the column-beam joint of the frame shown in Figure 1. Figure 3 is a plan cross-sectional view of the column-beam joint along line III-III in Figure 2. Figure 4 is an enlarged perspective view showing part IV in Figure 1 with partial transparency. As shown in Figures 2 to 4, the steel frame body 11 is an I-beam or H-beam with a pair of flanges 13 spaced apart and facing each other, and a web 14 connecting both flanges 13. The connecting plate 12 is made of a steel plate and is joined to the steel frame body 11 perpendicular to the direction of the material axis. The width of the connecting plate 12 is greater than the width of the steel frame body 11, and the height of the connecting plate 12 is the same as the height (beam depth) of the steel frame body 11. In other embodiments, the height of the connecting plate 12 may be greater than the height of the steel frame body 11.

[0041] The steel frame body 11 is not limited to I-beams or H-beams, but may also be structural steel made of channel steel or square steel pipes, for example, or box-shaped steel formed by welding multiple steel plates together.

[0042] Next, we will explain the C·S joint structure between the joint member 8 with the above configuration and two beam members 10. Note that the joint member 8 can be a corner column (where two beam members 10 are joined), an outer column (other than a corner column) (where three beam members 10 are joined), or an inner column (where four beam members 10 are joined). Here, we will explain using as an example the joint structure of two beam members 10 positioned on both sides of a joint member 8, which is joined to a joint member 8 where three or more beam members 10 are joined, as shown in Figure 4.

[0043] The joint member 8 has a plurality of first through-holes 21, each forming part of a tension member insertion hole 20 for inserting a tension member 15. Specifically, when viewed from the beam member 10 side, a plurality of first through-holes 21 (four in the illustrated example) are formed in a vertical line at the right end and left end of the joint member 8. Also, when viewed from the beam member 10 side, a plurality of first through-holes 21 (four in the illustrated example) are formed in a vertical line at the right central part and left central part of the joint member 8 (corresponding to the parts between the left and right sides of the web 14 and the upper and lower flanges 13). The first through-holes 21 extend parallel to each other along the material axis direction of the beam 7 joined to the joint member 8. The first through-holes 21 may be defined by a sheath embedded in the joint member 8. Alternatively, the first through-holes 21 may be formed as a concrete defect formed by the sheath removed after concrete pouring of the joint member 8.

[0044] Multiple second through-holes 22 are formed in the joining plate 12 at positions that align with the first through-hole 21 of the joint member 8. Each second through-hole 22 extends parallel to each other along the material axis direction of the beam 7.

[0045] The two beam members 10 are positioned on both sides of the joint member 8, i.e., sandwiching the joint member 8, such that the second through holes 22 of each connecting plate 12 align with the first through holes 21 of the joint member 8. As a result, each first through hole 21 of the joint member 8, each second through hole 22 of the beam member 10 positioned on one side of the joint member 8, and each second through hole 22 of the beam member 10 positioned on the other side of the joint member 8 are continuous with each other. The one first through hole 21 and the two second through holes 22 that are continuous with each other form a tension member insertion hole 20 that extends in the direction of the beam 7's material axis across the joint member 8 and the two beam members 10.

[0046] A tension member 15 is positioned in each tension member insertion hole 20 so as to penetrate the tension member insertion hole 20. In this embodiment, the tension member 15 is made of PC steel bar and has male threads at both ends. On the side of the joining plate 12 opposite to the end face that is joined to the joint member 8 (hereinafter referred to as the side end face), a nut 23 is positioned so as to screw onto the male thread of each tension member 15. The nut 23 is rotated until each tension member 15 contacts the side end face while under tension. As a result, the end of the tension member 15 is fixed to the joining plate 12 via the nut 23. In other words, the nut 23 is a fixing device that fixes the end of the tension member 15 to the joining plate 12.

[0047] In this way, the beam member 10 is press-fitted to the joint member 8 by the tension of the tensioning member 15. That is, by fixing one end of multiple tensioning members 15 to the joint plate 12 of the beam member 10, the beam member 10 can be press-fitted to the joint member 8 by the tension of the tensioning member 15. Therefore, in order to press-fit a steel beam member 10 to a concrete joint member 8, the joint member 8 and the beam member 10 can be joined with a simple structure and easily, without making the joint member 8 a complex structure or using cast-in-place concrete.

[0048] Furthermore, one end of the tensioning member 15 has a male thread, and it is joined to the joining plate 12 by a nut 23 that screws onto this male thread. Therefore, by rotating the nut 23 until it contacts the joining plate 12 while the tensioning member 15 is under tension, the nut 23 can be easily fixed to the joining plate 12. As a method of tensioning the tensioning member 15, tensioning force can be applied by attaching a jack to one end and pulling the tensioning member 15.

[0049] Furthermore, the tensioning members 15 are positioned on the outside in the width direction of the steel frame body 11 on the joining plate 12. That is, the tensioning member insertion holes 20 are formed on the outside in the width direction of the steel frame body 11 on the joining plate 12. This allows the tensioning of the tensioning members 15 and their anchoring to the joining plate 12 to be performed on the side of the steel frame body 11 of the beam member 10, making it easier to join the beam member 10 to the joint member 8. In this embodiment, all of the tensioning members 15 are positioned on the outside in the width direction of the steel frame body 11, but in other embodiments, only a portion of the tensioning members 15 may be positioned on the outside in the width direction of the steel frame body 11. In that case, the anchoring of the tensioning members 15 positioned on the outside becomes easier.

[0050] In this embodiment, the tensioning member 15 had male threads at both ends, but in other embodiments, the tensioning member 15 may have male threads at only one end. For example, one end of the tensioning member 15 may be male threaded, and the other end may be provided with a widened portion that widens to engage with the joining plate 12. Furthermore, the fixing device is not limited to a nut 23, but can be any device that can fix the tensioning member 15 in a tensioned state, such as an anchor head including a wedge.

[0051] Furthermore, grout is not filled into each tension member insertion hole 20 and into the connection (joint) between each joint plate 12 and the joint member 8. In other words, the tension member 15 is an unbonded tension member that is not fixed to the joint member 8. As a result, during an earthquake, the joint member 8 and the beam member 10 can displace relative to each other in a way that enlarges the joint at the joint, allowing the joint of both members to function as a hinge. Therefore, damage to the joint member 8, which is a C member, and yielding of the beam member 10, which is an S member, due to an earthquake are suppressed. In addition, the tension member 15 can be replaced, and the C member and S member can be dismantled and reused.

[0052] In other embodiments, in addition to the joint between the joint member 8 and the beam member 10 functioning as a hinge, or alternatively, the beam member 10 itself may yield. For example, the flange 13 of the beam member 10 may yield. ≪Second Embodiment≫

[0053] A second embodiment of the present invention will be described with reference to Figure 5. Elements identical or similar to those in the first embodiment are denoted by the same reference numerals, and redundant descriptions are omitted. The same applies to subsequent embodiments unless otherwise specified.

[0054] Figure 5 is a plan cross-sectional view of a column-beam joint according to the second embodiment. As shown in Figure 5, in this embodiment, filler material 27 is filled in each tension member insertion hole 20 and in the joint portion 25 between each joint plate 12 and the joint member 8. That is, the length of the beam member 10 is shorter than the distance between the corresponding pair of columns 6. Therefore, even if the joint members 8 of both columns 6 are placed first, the beam member 10 can be easily placed in the predetermined position by lowering it with a crane. Furthermore, even if the tension member 15 breaks inside the tension member insertion hole 20 during an earthquake, the filler material 27 prevents the fragments of the broken tension member 15 from scattering from the opening of the tension member insertion hole 20.

[0055] The filler 27 is a fluid material that hardens over time, and may be, for example, a non-shrinking mortar or cement grout. Alternatively, the filler 27 may be a thermosetting resin that hardens with temperature changes, or a thermoplastic resin. Furthermore, the tensioning member 15 and the joint member 8 can be integrally fixed using a fire-resistant coating material such as sprayed rock wool. ≪Third Embodiment≫

[0056] A third embodiment of the present invention will be described with reference to Figures 6 and 7. Figure 6 is a side cross-sectional view of the main part of the frame according to the third embodiment, and Figure 7 is a longitudinal cross-sectional view of the main part of column 6 shown along line VII-VII in Figure 6. This embodiment differs from the first embodiment in that column 6 has C members and S members.

[0057] Each column 6 has a C-frame joint member 33 and a S-frame column body member 34 in the first floor section. The joint member 33 is placed at the joint of the column 6, and the column body member 34 is placed above and below the joint member 33, except for the top floor.

[0058] As shown in Figures 6 and 7, the joint member 33 has a plurality of first through holes 21 for inserting the tensioning member 15. Each first through hole 21 extends parallel to each other in the vertical direction, which is the material axis direction of the column body member 34 that is joined to the joint member 33.

[0059] The column body member 34 comprises a steel frame body 11 that connects adjacent joint members 33 (only one is shown in the figure) that constitute the column 6, and two connecting plates 12 integrally attached to both vertical ends of the steel frame body 11. Multiple second through holes 22 are formed in each connecting plate 12 at positions that align with the first through holes 21. Each second through hole 22 extends parallel to each other along the material axis direction of the column 6.

[0060] Each beam 7 is composed of a beam member 35 made of precast concrete (PCa). Each beam 7 is formed by a single beam member 35. The beam member 35 connects to the joint members 33 of a pair of columns 6 adjacent to each other in the X or Y direction, and is joined to the joint members 33. In this embodiment, the beam 7 is formed by a single beam member 35, but in other embodiments, the beam 7 may be formed by two or more beam members 35. Also, the beam member 35 may be formed integrally with the joint member 33.

[0061] Next, the C·S joint structure of the joint member 33 and the two column body members 34 having the above configuration will be described. The joint member 33 and the two column body members 34 are positioned so that the first through hole 21 of the joint member 33 and the second through holes 22 of the upper and lower joining plates 12 are aligned. As a result, the first through holes 21 of the joint member 33, the second through holes 22 of the column body member 34 located below the joint member 33, and the second through holes 22 of the column body member 34 located above the joint member 33 are continuous with each other. This creates a plurality of parallel tension member insertion holes 20 that extend in the direction of the material axis of the column 6 across the joint member 33 and the two column body members 34.

[0062] In each tensioning member insertion hole 20, a tensioning member 15 is placed in a tensioned state, similar to the first embodiment, and both ends of the tensioning member 15 are fixed to the joining plates 12 of the upper and lower column body members 34 via nuts 23. By fixing one end of multiple tensioning members 15 to the corresponding joining plates 12 of the column body members 34, the column body members 34 can be crimped and joined to the joint member 33 by the tensioning force of the tensioning members 15.

[0063] Furthermore, the connecting plate 12 has a larger cross-section than the steel frame body 11, and the end face of the joint member 33 to which the connecting plate 12 is joined has a cross-section of the same size as the connecting plate 12. This allows at least a portion of the tensioning member 15 to be positioned outside the steel frame body 11 on the connecting plate 12. Therefore, at least a portion of the tensioning member 15 and its anchoring to the connecting plate 12 can be performed on the outside of the steel frame body 11 of the column body member 34, making it easier to join the column body member 34 to the joint member 33. The end face of the joint member 33 to which the connecting plate 12 is joined may have a cross-section larger than or equal to that of the connecting plate 12, thereby enabling the above-mentioned arrangement of the tensioning member 15 and achieving the above-mentioned effect. ≪Fourth Embodiment≫

[0064] A fourth embodiment of the present invention will be described with reference to Figures 8 and 9. Figure 8 is a side cross-sectional view of the frame according to the fourth embodiment, and Figure 9 is a plan cross-sectional view of the column-beam joint shown along the line IX-IX in Figure 8. This embodiment differs from the first embodiment in that the end of the beam 7 is integrally formed with the joint member 33 of the column 6.

[0065] As shown in Figures 8 and 9, the beam 7 is composed of a portion (beam end 44) ​​of the joint beam members 43 made of concrete (C) arranged at both ends, and a main beam member 45 made of steel (S) arranged in the middle of the beam 7 in the direction of extension. The main beam member 45 comprises a steel frame body 11 that spans a pair of joint beam members 43, and a pair of connecting plates 12 integrally attached to both ends of the steel frame body 11 in the direction of the material axis. The length of the main beam member 45 is shorter than the distance between a pair of columns 6. The joint beam member 43 is formed by integrally forming the joint portion of the C column 6 and the end of at least one beam 7 connected to the joint portion.

[0066] The bending rigidity of the beam end 44 of the joint beam member 43 is higher than that of the beam body member 45. Therefore, the hinge position of the beam 7 is formed not at the end of the beam 7, but at the end of the column body member 9 (more precisely, at the end of the steel frame body 11) (hinge relocation). This moves the position where plastic deformation occurs in the beam 7 from the end of the beam 7 towards the center of the beam, thereby improving the bending performance (bending strength) of the beam 7. Furthermore, by using the joint beam member 43 and changing the length of its beam end 44, the length of the beam 7 in the material axis direction can be changed, so the present invention can be applied to buildings 1 with various spans (distance between columns) without changing the length of the beam body member 45.

[0067] The first through-hole 21 formed in the joint beam member 43 is formed to penetrate not only the joint portion of the column 6 but also the beam end portion 44. As a result, each tension member insertion hole 20 is formed to extend across the joint beam member 43 and the two beam body members 45.

[0068] Similar to the first embodiment, each tension member 15 is positioned in tension in each tension member insertion hole 20, and both ends of the tension member 15 are fixed to the corresponding joining plate 12 via nuts 23. By fixing multiple tension members 15 to the joining plate 12 of the beam body member 45, the beam body member 45 can be pressed and joined to the joint beam member 43 by the tension force of the tension members 15. ≪Fifth Embodiment≫

[0069] A fifth embodiment of the present invention will be described with reference to Figures 10 and 11. Figure 10 is a side cross-sectional view of the column-beam joint of the frame according to the fifth embodiment, and Figure 11 is a plan cross-sectional view of the column-beam joint shown along line XI-XI in Figure 10. This embodiment differs from the fourth embodiment in that the end of the beam 7 is formed as a separate member from the joint of the column 6.

[0070] As shown in Figures 10 and 11, the beam 7 has a steel beam body member 45 positioned in the middle and two canonical beam end members 53 that form the ends, with the beam body member 45 positioned in the middle and the beam end members 53 positioned at the ends. Multiple third through holes 55 are formed in the beam end members 53 so as to align with the first through hole 21 of the joint member 8 and the corresponding second through hole 22 of the connecting plate 12.

[0071] Next, the C-S joint structure of the C-structure beam end member 53 and the S-structure beam body member 45, as described above, will be explained. The joint member 8, beam end member 53, and beam body member 45 are arranged so that the first through holes 21 of the joint member 8, the third through holes 55 of the two beam end members 53, and the second through holes 22 of the joining plates 12 of the two beam body members 45 are aligned. This creates tension member insertion holes 20 that extend across the joint member 8, beam body member 45, and beam end member 53.

[0072] Similar to the first embodiment, tension members 15 are placed in each tension member insertion hole 20 in a tensioned state, and the tension members 15 are fixed to the joining plate 12 via nuts 23. By fixing multiple tension members 15 to the joining plate 12 of the beam body member 45, the beam body member 45 can be press-fitted to the beam end member 53 by the tension force of the tension members 15. In addition, the beam body member 45 can be press-fitted to the joint member 8 via the beam end member 53 by the tension force of the tension members 15.

[0073] Since the joint member 8 and the beam end member 53 are not formed as a single unit, the size of each member is smaller than when they are formed as a single unit, making them easier to transport. Also, because the joint member 8, the beam end member 53, and the beam body member 45 are separate from each other, if a part is damaged, only the damaged part can be replaced.

[0074] Furthermore, the beam end members 53 do not need to be provided one at each end of the beam body member 45; they may be placed at only one end. Also, multiple beam end members 53 may be placed at the ends (both ends or one end) of the beam body member 45. ≪Sixth Embodiment≫

[0075] A sixth embodiment of the present invention will be described with reference to Figure 12. Figure 12 is a plan cross-sectional view of a column-beam joint according to the sixth embodiment. This embodiment differs from the fifth embodiment in that the beam end member 65 is not a C member.

[0076] The beam end member 65 has a pair of steel end plates 66 and a plurality of steel connecting members 67 arranged to connect the end plates 66. The end plates 66 and the connecting members 67 are integrally formed with each other by welding. The connecting members 67 may be steel plates or steel rods, or they may be shaped steel having a predetermined cross-sectional shape such as an L. In addition, the end plates 66 have a plurality of third through holes 55 formed therein so as to align with the first through hole 21 of the joint member 8 and the corresponding second through holes 22 of the joining plate 12. The beam body member 45 is crimped and joined to the joint member 8 via the beam end member 65.

[0077] Because the beam end member 65 is made of steel (S) rather than concrete (C), the beam end member 65 can be made lighter. Therefore, transportation to the site and assembly on site are easier.

[0078] In this embodiment, as shown in Figure 12, the beam end member 65 has an opening that penetrates vertically between the end plates 66. However, the beam end member 65 may also be configured so that the opening penetrates in the beam width direction. By configuring the beam end member 65 in this way, these openings can be used as equipment openings to allow ducts and the like to pass through. By using them in this way, it becomes unnecessary to provide an opening in the web 14 of the beam body member 45 to allow equipment to pass through.

[0079] Furthermore, as described in the fifth embodiment, the arrangement and number of beam end members 65 are not limited thereto. ≪Seventh Embodiment≫

[0080] A seventh embodiment of the present invention will be described with reference to Figures 13-14. Figure 13 is a side cross-sectional view of the column-beam joint of the frame according to the seventh embodiment, and Figure 14 is a plan cross-sectional view of the column-beam joint shown along the line XIV-XIV in Figure 13. This embodiment differs from the fifth embodiment in that the beam end member 53 is configured to support the end of the beam body member 45.

[0081] The beam end member 53 has a beam end main body portion 71 and a jaw portion 72 that protrudes horizontally from the lower end of the beam end main body portion 71. The beam end main body portion 71 is a precast concrete (PCa) member, and the jaw portion 72 extends from the beam end main body portion 71 in the direction of the beam 7's axis and is formed to support the end of the beam main body member 45 from below. This allows the end of the beam main body member 45 to be placed on the jaw portion 72 of the beam end member 53 while the beam end member 53 is temporarily fixed to the joint member 8. Furthermore, the beam main body member 45 can be easily crimped and joined to the joint member 8 via the beam end member 53.

[0082] In this embodiment, the beam end member 53 is made of concrete, but the beam end member 53 may be made of steel as in the sixth embodiment. ≪Eighth Embodiment≫

[0083] An eighth embodiment of the present invention will be described with reference to Figures 15-16. Figure 15 is a perspective view showing a reinforcing structure of a frame according to the eighth embodiment, and Figure 16 is a plan cross-sectional view of the reinforcing structure shown in Figure 15.

[0084] In this embodiment, the C·S joint structure according to the invention is applied to the seismic reinforcement structure 80. The seismic reinforcement structure 80 is a structure that is additionally constructed for seismic reinforcement to an existing column-beam structure 85 of a reinforced concrete frame structure. The existing column-beam structure 85 has a plurality of existing columns 86 (only one is shown in the figure) that are adjacent to each other in the X and Y directions, and a plurality of existing beams 87 that connect a pair of existing columns 86 that are adjacent to each other in the X or Y direction.

[0085] The seismic reinforcement structure 80 comprises C-joint members 88, which are block-shaped C members joined to the side surfaces of the joint portions of each existing column 86, and steel beam members 90 that connect a pair of adjacent C-joint members 88 in the X and Y directions (only one is shown in the figure). The C-joint members 88 are column-beam joints for connecting the existing columns 86 of the existing building to the two beam members 90.

[0086] Multiple fourth through-holes 91 are formed in the joint portion of the existing column 86 for inserting the tensioning member 15. Each of the fourth through-holes 91 extends parallel to each other in a direction perpendicular to the member axis of the existing beam 87 joined to the existing column 86.

[0087] The C-joint member 88 has a plurality of fifth through-holes 92 and a plurality of first through-holes 21 formed therein for inserting the tensioning member 15. Each fifth through-hole 92 is formed to extend from each fourth through-hole 91, at a position that aligns with each fourth through-hole 91 of the existing column 86 to which the C-joint member 88 is joined. Each first through-hole 21 extends parallel to each other in a direction perpendicular to the fifth through-hole 92. Furthermore, each fifth through-hole 92 and each first through-hole 21 are arranged so as not to intersect with each other. The beam member 90 has the same configuration as the beam member 10 of the first embodiment.

[0088] Next, we will describe the seismic reinforcement structure 80 for the existing columns 86, C-connection members 88, and two beam members 90 of the existing building having the above configuration. The C-connection members 88 are positioned on the existing columns 86 so that each of the fourth through-holes 91 of the existing columns 86 and each of the fifth through-holes 92 of the C-connection members 88 are aligned. As a result, each of the fourth through-holes 91 and each of the fifth through-holes 92 are continuous, and a plurality of parallel tension member insertion holes 20 extending perpendicularly to the material axis of the existing beam 87 are formed across the existing columns 86 and the C-connection members 88. In addition, the beam members 90 are positioned on the C-connection members 88 so that each of the second through-holes 22 of the beam members 90 and each of the first through-holes 21 of the C-connection members 88 are aligned. As a result, each second through-hole 22 and each first through-hole 21 are continuous, and a plurality of parallel tension member insertion holes 20 are formed that extend in the direction of the material axis of the beam member 90 across the C joint member 88 and the beam member 90. The C joint member 88 and the two beam members 90 are joined by the C·S joint structure described in the fifth embodiment.

[0089] The existing column 86 and the C-joint member 88 are joined by a method similar to that of the C-S joint structure of the first embodiment. Specifically, tension members 15, each having male threads at both ends, are positioned to pass through each tension member insertion hole 20. Nuts 23 are also positioned on two surfaces (hereinafter referred to as outer surfaces) of the existing column 86 and the C-joint member 88 that are opposite to each other's joining surfaces, so as to screw onto the male threads of each tension member 15. One nut 23 is positioned in advance, and the other nut 23 is rotated until it contacts the corresponding outer surface of the existing column 86 or C-joint member 88 while the tension member 15 is tensioned. The existing column 86 and the C-joint member 88 are compressed and joined to each other by fixing both ends of the tension member 15 to the outer surfaces of both members via the nuts 23. That is, the steel beam member 90, compressed and joined to the C-joint member 88, is joined to the existing column 86 via the C-joint member 88. This allows for reinforcement of the existing column-beam structure 85.

[0090] In this case, the tensioning force of the tensioning member 15 acts on the outer surfaces of the existing column 86 and the C-joint member 88 via the nut 23, which may cause damage to the concrete in the area where the nut 23 contacts the tensioning member insertion hole 20. Therefore, a bearing plate 94 is placed between each outer surface and the nut 23. The tensioning member 15 compresses and joins the existing column 86 and the C-joint member 88 to each other via the nut 23 and the bearing plate 94, distributing the compressive force acting from the nut 23 on the existing column 86 and the C-joint member 88 due to the tensioning force of the tensioning member 15. This prevents damage to the concrete in the area where the nut 23 contacts each outer surface. In this embodiment, one bearing plate 94 was placed on each outer surface of the existing column 86 and the C-joint member 88, but in other embodiments, multiple bearing plates 94 may be placed for each tensioning member 15 and nut 23.

[0091] This concludes the description of specific embodiments. However, the present invention is not limited to the above embodiments or modifications and can be broadly modified and implemented. For example, in the seismic reinforcement structure 80, the placement of member C is not limited to the joint portion of the existing column 86, but may be placed in a portion other than the joint portion of the existing column 86. In the above embodiment, PC steel bars are used for the tensioning member 15, but the tensioning member 15 is not limited to this, and may be, for example, PC steel strands, high-strength reinforcing bars, or rods or cables made of fiber-reinforced plastic such as aramid fiber, carbon fiber, or glass fiber. Furthermore, the tensioning member 15 is not limited to the unbonded type, but may be a bonded type (a type in which grout is filled into the through-hole). The specific configuration, arrangement, quantity, and material of each member and part can be changed as appropriate, as long as it does not depart from the spirit of the present invention. Also, some of the configurations of the above embodiments may be combined with other embodiments. Furthermore, not all of the components shown in the above embodiments are essential and can be selected as appropriate. [Explanation of Symbols]

[0092] 1: Building 5:Superstructure 6: Pillar 7: Beam 8: Joint member (C member) 10: Beam member (S member) 11: Steel frame main body 12: Connecting plate 15: Tensile material 20: Tensioning material insertion hole 21: First through hole 23: Nut 33: Joint member (C member) 34: Column main body member (S member) 43: Joint beam member (C member) 44: Beam end 45: Beam main body member (S member) 53: Beam end member (C member) 65: Beam end member (S member) 72: Jaw 80: Seismic reinforcement structure 85: Column beam structure 86: Existing column 88: C-type joint member (C-type member, column-beam joint) 90: Beam member (S member) 94: Bearing plate

Claims

1. A C-S joint structure for joining a concrete C member and a steel S member, which each constitute a part of at least one of a column and a beam, The S member comprises a steel frame body having a material axis and a connecting plate integrally attached to the end of the steel frame body in the material axis direction, The C member is provided with a plurality of through holes extending in the axial direction of the S member, The C-S joint structure is characterized in that the S member is crimped and joined to the C member by a plurality of tensioning members, each having one end fixed to the joining plate and positioned to penetrate the through-holes of the joining plate and the C member.

2. The C-S joint structure according to claim 1, wherein one end of the tensioning member has a male thread and is fixed to the joint plate by a nut that is screwed onto the male thread.

3. The C-S joint structure according to claim 1, wherein the tensioning material is an unbonded tensioning material that is not fixed to the C member.

4. The C-S joint structure according to claim 1, wherein the C member is a joint member that constitutes the joint portion of the column, and the S member is a beam member.

5. The C-S joint structure according to claim 4, wherein the joint plate has a width greater than the width of the steel frame body, and at least a portion of the tensioning member is arranged on the outside of the joint plate in the width direction of the steel frame body.

6. The C-S joint structure according to claim 1, wherein the C member is a joint member that constitutes the joint portion of the column, and the S member is a column body member that is positioned above or below the joint member.

7. The C-S joint structure according to claim 6, wherein the joining plate has a cross-section larger than the cross-section of the steel frame body, the joint member has a cross-section larger than or equal to the joining plate, and at least a portion of the tensioning member is arranged on the outside of the steel frame body on the joining plate.

8. The C-S joint structure according to claim 1, wherein the C member is a joint beam member that constitutes the joint portion of the column and the end portion of the beam integrally joined to the joint portion, and the S member is a beam body member that constitutes the intermediate portion in the extending direction of the beam.

9. The C-S joint structure according to claim 1, wherein the C member is a beam end member that constitutes the end of the beam, and the S member is a beam body member that constitutes the intermediate part of the beam in the extending direction.

10. The C-S joint structure according to claim 1, wherein the C member is a joint member that constitutes the joint portion of the column, the S member is a beam body member that constitutes the intermediate portion in the extending direction of the beam, and the beam body member is crimp-jointed to the joint member via a beam end member that constitutes the end of the beam.

11. The C-S joint structure according to claim 9 or 10, wherein the beam end member is provided with a jaw portion that supports the end of the beam body member from below.

12. The C-S joint structure according to claim 1, wherein the C member is a column-beam joint that is joined to the side surface of an existing column of an existing concrete column-beam structure.

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