REINFORCED STRUCTURE FOR COLUMN AND BEAM FRAME

Abstract

A fracture caused by fatigue of a connecting portion positioned at a corner of a reinforcing frame directly secured to a frame is avoided regardless of a relative displacement that occurs in the frame upon disposing the reinforcing frame made of steel, which has an elevational shape surrounding the frame along an inner circumferential surface of the frame and a cross-sectional shape with a flange on a side of the frame, in a structure plane of the frame of a column and a beam of reinforced concrete structure, and joining the reinforcing frame to the inner circumferential surface of the frame. A reinforcing frame is constituted of a column portion along a column of a frame, a beam portion along a beam, and a connecting portion that is joined to the column portion and the beam portion, and connects the column portion to the beam portion. The connecting portion has a flange with a part close to the column portion and the beam portion formed to be shaped along an inner circumferential surface of the frame, and a part of the flange facing a corner of the frame formed into a shape in which a void is formed between the part and the corner of the frame.

Claims

1. A reinforced structure for a column and beam frame comprising a reinforcing frame made of steel disposed in a structure plane of a frame of a column and a beam of reinforced concrete structure, the reinforcing frame being joined to an inner circumferential surface of the frame, the reinforcing frame having an elevational shape surrounding the frame along the inner circumferential surface of the frame, the reinforcing frame having a cross-sectional shape with a flange on a side of the frame, wherein the reinforcing frame includes: a column portion along the column; a beam portion along the beam; and a connecting portion joined to the column portion and the beam portion, the connecting portion connecting the column portion to the beam portion, and the connecting portion has a flange having a part close to the column portion and the beam portion shaped along the inner circumferential surface of the frame and has a part of the flange facing a corner of the frame in a shape in which a void is formed between the part and the corner of the frame.

2. The reinforced structure for the column and beam frame according to claim 1, wherein the part of the flange of the connecting portion facing the corner of the frame is curved.

3. The reinforced structure for the column and beam frame according to claim 1, wherein the flange of the connecting portion is joined to the column and the beam of the frame.

4. The reinforced structure for the column and beam frame according to claim 1, wherein to each flange of the column portion and the beam portion, and the connecting portion of the reinforcing frame, an anchor that passes through the flange and is buried in the frame is fixed, and the anchor has a shaft portion inserted into a bore hole formed in the frame and a head portion connected to the shaft portion, and has an inserted portion inserted into the bore hole and in a shape continuing in a circumferential direction of the head portion formed in the head portion on a side of the frame.

5. The reinforced structure for the column and beam frame according to claim 4, wherein the bore hole has a fitting hole continuously formed closed to an inner circumferential surface of the frame, the fitting hole being contactable with an outer circumferential surface of the inserted portion, the fitting hole having an inner circumferential surface with a plane area perpendicular to an axial direction larger than a plane area perpendicular to an axial direction of an inner circumferential surface of the bore hole.

6. The reinforced structure for the column and beam frame according to claim 5, wherein the inserted portion has an inner circumferential surface with a plane area perpendicular to an axial direction when the inserted portion is inserted into the fitting hole is equal to or larger than the plane area perpendicular to the axial direction of the inner circumferential surface of the bore hole.

7. The reinforced structure for the column and beam frame according to claim 2, wherein to each flange of the column portion and the beam portion, and the connecting portion of the reinforcing frame, an anchor that passes through the flange and is buried in the frame is fixed, and the anchor has a shaft portion inserted into a bore hole formed in the frame and a head portion connected to the shaft portion, and has an inserted portion inserted into the bore hole and in a shape continuing in a circumferential direction of the head portion formed in the head portion on a side of the frame.

8. The reinforced structure for the column and beam frame according to claim 2, wherein the flange of the connecting portion is joined to the column and the beam of the frame.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] FIG. 1 is an elevational view illustrating a state where a reinforcing frame is joined while being in contact with an inner circumferential surface of a frame of a column and a beam.

[0046] FIG. 2A is a cross-sectional view taken along the line x-x in FIG. 1.

[0047] FIG. 2B is a partially enlarged view of FIG. 2A.

[0048] FIG. 2C is a vertical cross-sectional view illustrating a relationship between a cross-sectional area of a shaft portion and a plane area of a bore hole, and a plane area of a fitting hole when a plane area of an inserted portion is equal to or more than the plane area of the bore hole (A3>A1).

[0049] FIG. 2D is a horizontal cross-sectional view at the inserted portion in FIG. 2C.

[0050] FIG. 3 is a vertical cross-sectional view illustrating a detailed example of an anchor.

[0051] FIG. 4 is a perspective view of FIG. 1.

[0052] FIG. 5 is an elevational view illustrating a state where the reinforcing frame is disposed in one layer of the frame.

[0053] FIG. 6 is an elevational view illustrating a state where braces are installed in the reinforcing frame illustrated in FIG. 5.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0054] FIG. 1 illustrates a specific example of a reinforced structure for a column and beam frame in which a reinforcing frame 4 made of steel is disposed in a structure plane of a frame 1 formed of a column 2 and a beam 3 of reinforced concrete structure, and is joined to an inner circumferential surface of the frame 1. The reinforcing frame 4 has an elevational shape that surrounds the frame 1 along an inner circumferential surface of the frame and a cross-sectional shape with a flange on a side of the frame 1. The reinforcing frame 4 is formed of a column portion 5 disposed along an inner circumferential surface of the column 2, a beam portion 6 disposed along an inner circumferential surface of the beam 3, and a connecting portion 7 joined to both an end surface in an axial direction of the column portion 5 and an end surface in an axial direction of the beam portion 6 by welding, bolt, or the like to connect the column portion 5 to the beam portion 6. The terms “the inner circumferential surface of the column 2” and “the inner circumferential surface of the beam 3” indicate surfaces of the column 2 and the beam 3, respectively, on sides of openings surrounded by the frame 1 (the inner circumferential surface of the frame 1).

[0055] The term “disposed along the inner circumferential surface of the frame 1” refers to a flange 51 of the column portion 5 and a part of a flange 71 of the connecting portion 7 overlapping the inner circumferential surface of the column 2, and a flange 61 of the beam portion 6 and the part of the flange 71 of the connecting portion 7 overlapping the inner circumferential surface of the beam 3, which are disposed to be in contact with each other directly or indirectly on the surfaces. The term “the part of the flange 71” indicates a corner 71a of the flange 71 that ensures a void between the corner 71a and a corner 1A of the frame 1.

[0056] The word “directly” refers to the surfaces of the flanges 51, 61, and 71 on the frame 1 sides being directly in contact with the frame 1 or a slight void separating the surfaces on the frame 1 sides and the inner circumferential surface of the frame 1 as illustrated in FIGS. 2A and 2B. The word “indirectly” refers to any thin-walled buffer being interposed between the flanges 51, 61, and 71 and the frame 1. Alternatively, it refers to a filler 9, such as mortar, leaked from an inside of a bore hole 1a while being filled into the bore hole 1a formed in concrete of the frame 1, and gotten into the back of the flanges 51, 61, and 71 of the reinforcing frame 4 being interpose.

[0057] FIGS. 2A and 2B illustrate an example in the case where a backing metal 11 is disposed on back surface sides (the frame 1 sides) of the flanges 51, 61, and 71 when the flanges 51, 61, and 71 are welded to head portions 82 of anchors 8, described below, for joining (securing) the flanges 51, 61, and 71 to the frame 1. While in this example, voids of a wall thickness of the backing metal 11 are formed between the back surfaces of the flanges 51, 61, and 71 and the frame 1 in the case where the back surfaces of the flanges 51, 61, and 71 are flat surfaces, the voids are not formed in the case where grooves in which the backing metals 11 fit are formed on the back surfaces of the flanges 51, 61, and 71. In FIGS. 2A and 2B, the reference numeral 12 denotes a weld metal.

[0058] The reinforcing frame 4 is joined (secured) to the frame 1 by burying and fixing shaft portions 81 of the anchors 8, such as anchor bolts and post-installed anchors, which pass through at least the flange 51 of the column portion 5 and the flange 61 of the beam portion 6, in the concrete of the frame 1. While in the drawing, the reinforcing frame 4 is joined to the frame 1 even in the flange 71 of the connecting portion 7 for the purpose of ensuring integrity with the frame 1 in the connecting portion 7, the flange 71 of the connecting portion 7 is not necessarily joined to the frame 1.

[0059] The column portion 5 and the beam portion 6, and the connecting portion 7 that constitute the reinforcing frame 4 each overlap the inner circumferential surface of the frame 1, and have the flanges 51, 61, and 71 joined (fixed) to the frame 1 and webs 52, 62, and 72 that form surfaces perpendicular to the flanges 51, 61, and 71 to bear shear force when an in-plane deformation occurs in the frame 1. When respective configuration portions (the column portion 5 and beam portion 6, and the connecting portion 7) of the reinforcing frame 4 are formed of the flanges 51, 61, and 71 and the webs 52, 62, and 72, the reinforcing frame 4 is formed into a T-shaped cross-sectional shape on a cross-sectional surface perpendicular to the column portion 5 and the beam portion 6.

[0060] As illustrated in FIG. 1, when flanges 53 and 63 that pair up with the flanges 51 and 61 are integrated with the webs 52 and 62 of the column portion 5 and the beam portion 6, the reinforcing frame 4 is formed into an H-shaped cross-sectional shape. When the frame 1 deforms, the flanges 51 and 61 of the column portion 5 and the beam portion 6 serve as resistance elements against a bending moment, and thus, it is rational that the flanges 53 and 63 that pair up with the flanges 51 and 61 are formed.

[0061] The connecting portion 7 that is provided between the column portion 5 and the beam portion 6 basically plays a role of continuing the column portion 5 and the beam portion 6 in a circumferential direction of the reinforcing frame 4, and does not play a role of reinforcing the frame 1 as much as the column portion 5 and the beam portion 6 do. The connecting portion 7 is only necessary to provide a function of mainly maintaining the state where the column portion 5 and the beam portion 6 are joined to the frame 1 while flexibly following a generated interlayer deformation angle of the corner 1A of the frame 1 when the in-plane deformation occurs in the frame 1. In relation to this, the web 72 of the connecting portion 7 does not have a flange that pairs up with the flange 71 in FIG. 1. The flange that pairs up with the flange 71 may be formed.

[0062] In the illustrated example, not forming the flange that pairs up with the flange 71 relatively lowers flexural rigidity in an in-plane direction of the web 72 with respect to the column portion 5 and the beam portion 6 in the entire connecting portion 7, and therefore, an elastic deformation or a plastic deformation easily occurs when the frame 1 deforms, and the connecting portion 7 easily follows the deformation of the frame 1. In FIG. 1, a hole formed in the web 72 is an insertion hole 72b for connecting an end portion of a brace installed in the reinforcing frame 4 as described later by using a metal fitting, such as a clevis.

[0063] The flange 71 of the connecting portion 7 has parts close to the column portion 5 and the beam portion 6 shaped along the inner circumferential surface of the frame 1 and a part of the flange 71 facing the corner 1A of the frame 1 (the corner 71a) having a shape in which a void is formed between the corner 71a and the corner 1A of the frame 1. The term “shaped along the inner circumferential surface of the frame 1” refers to a part of the flange 71 close to the column portion 5 being disposed along the inner circumferential surface of the column 2 and a part of the flange 71 close to the beam portion 6 being disposed along the inner circumferential surface of the beam 3. The term “the corner 1A of the frame 1” indicates a corner where the column 2 intersects with the beam 3, and has a length corresponding to the corner 71a of the flange 71 of the connecting portion 7 in the axial directions of the column 2 and the beam 3.

[0064] The term “(the corner 71a having) a shape in which a void is formed between the corner 71a and the corner 1A of the frame 1” refers to a shape that maintains a state where the corner 71a of the flange 71 facing the corner 1A of the frame 1 is in contact with neither the inner circumferential surface of the column 2 nor the inner circumferential surface of the beam 3 during a normal period when the frame 1 is not deformed. While the term “the shape that maintains the state of not contacting the inner circumferential surfaces of the column 2 or the beam 3” is not particularly defined, it specifically refers to a shape in which the corner 71a of the flange 71 of the connecting portion 7 is curved as illustrated in FIG. 1.

[0065] The corner 71a of the flange 71 illustrated in FIG. 1 may be formed into a multangular shape or a shape that forms a part of a multangular shape. When the corner 71a of the flange 71 is curved as illustrated, the flexural rigidity in the curved section is uniform, and therefore, it is less likely that any part of the flange 71 is intensively deformed when the flange 71 follows the in-plane deformation of the frame 1. As the result, the concentration of stress to the flange 71 is easily avoided, thereby providing an advantage that the fracture is less likely to occur in the flange 71.

[0066] The anchor 8 is disposed at one position on a center in a width direction or a plurality of positions spaced in the width direction of each of the flanges 51, 61, and 71 of the reinforcing frame 4 as illustrated in FIG. 1 and FIGS. 2A-2D. The latter case also includes a staggered arrangement. The anchor 8 passes through an insertion hole formed in each of the flanges 51, 61, and 71 of the reinforcing frame 4.

[0067] When the frame 1 deforms, a relative movement (slippage) can occur in the axial directions of the column 2 and the beam 3 between the frame 1 and the flanges 51, 61, and 71 of the reinforcing frame 4. In view of this, the anchor 8 is divided into the shaft portion 81 inserted into the above-described bore hole 1a and the head portion 82 connected to the shaft portion 81 for the purpose of avoiding the fracture in the part of the anchor 8 projecting toward a side of the reinforcing frame 4 from the inner circumferential surface of the frame 1 caused by this relative movement. Then, an inserted portion 83 inserted into the bore hole 1a and in a shape continuing in a circumferential direction of the head portion 82 is formed in the head portion 82 on the side of the frame 1.

[0068] The head portions 82 are connected to the shaft portions 81 on sides of the reinforcing frame 4 by screwing or the like, and are exposed to the flanges 51, 61, and 71 on the inner circumferential surface side of the frame 1. The head portions 82 have surfaces on sides of an inner circumference of the frame 1 aligned with the surfaces of the flanges 51, 61, and 71 on the inner circumference sides of the frame 1, such as obtaining flush surfaces with the surfaces of the flanges 51, 61, and 71 on the inner circumference sides of the frame 1. When viewed without the flanges 51, 61, or 71, the head portions 82 project toward the inner circumference sides from the inner circumferential surface of the frame 1.

[0069] In the respective webs 52, 62, and 72 of the reinforcing frame 4, openings 52a, 62a, and 72a are formed for an operation of inserting the shaft portions 81 of the anchors 8 into the bore holes 1a and filling the filler 9, such as mortar and an adhesive, filled into voids in the bore holes 1a after the insertion of the shaft portions 81. The openings 52a, 62a, and 72a also serve to lower flexural rigidity of the webs 52, 62, and 72 and to make the webs 52, 62, and 72 themselves easily bent and deformed in the in-plane directions.

[0070] The shaft portion 81 has a distal end portion (a hole bottom side of the bore hole 1a) at which a fixing portion 84 buried into the filler 9 and fixed within the bore hole 1a is integrally formed or is connected to be integrated. As illustrated in FIG. 2A, when the shaft portion 81 of the anchor 8 is inserted into the bore hole 1a and the bottom surface of the fixing portion 84 comes into contact with or approaches close to the hole bottom of the bore hole 1a, the inserted portion 83 of the head portion 82 has an outer circumferential surface in a state of possibly being inscribed in a part close to the reinforcing frame 4 of the bore hole 1a.

[0071] The shaft portion 81 has a part (a section) close to the reinforcing frame 4 projecting toward sides of the webs 52, 62, and 72 of the reinforcing frame 4 from the head portion 82 as illustrated in FIG. 3. By filling the filler 9 into the bore hole 1a, the inserted portion 83 is buried in the filler 9 inside the bore hole 1a. Since the inserted portion 83 is inscribed in the bore hole 1a, the inserted portion 83 is in a lockable state in a radiation direction to an inner circumferential surface of the bore hole 1a.

[0072] The part projecting from the head portion 82 of the shaft portion 81 is screwed with a nut 10 for applying axial tensile force to the shaft portion 81. The nut 10, by being screwed with the shaft portion 81, applies the axial tensile force indicated by the arrow in FIG. 3 to the shaft portion 81, in order to increase a contact pressure of the head portion 82 onto the inner circumferential surface of the frame 1, the nut 10 serves to increase friction force between the head portion 82 and the inner circumferential surface of the frame 1 and to enhance a transmission effect of shear force via the head portion 82. The head portion 82 pairs up with the fixing portion 84 when the axial tensile force is applied to the shaft portion 81, and thus, the head portion 82 restrains the filler 9 in the bore hole 1a in the axial direction and applies axial compressive force to the filler 9. Therefore, the head portion 82 also serves to enhance a shearing strength of the cured filler 9.

[0073] When the anchor 8 passes through the insertion hole formed in each of the flanges 51, 61, and 71 of the reinforcing frame 4, the head portion 82 is in the lockable state to an inner circumferential surface of the insertion hole directly in the in-plane directions of the flanges 51, 61, and 71 or via the filler 9 overflown from the inside of the bore hole 1a. On the other hand, since the inserted portion 83 is in a locked state to the inner circumferential surface of the bore hole 1a, the transmission of the shear force in any direction perpendicular to an axis of the shaft portion 81 is possible between the frame 1 and the flanges 51, 61, and 71, and the head portion 82 of the anchor 8 as indicated by the arrow in FIG. 3. Accordingly, there is provided the state where the head portion 82 can transmit the force in the in-plane direction received from the flanges 51, 61, and 71 to the concrete of the frame 1 through the inserted portion 83.

[0074] FIGS. 2A and 2B illustrate an example in the case where the bore hole 1a into which the shaft portion 81 enters from sides of the flanges 51, 61, and 71 is formed in the frame 1 (the column 2 and the beam 3) when the inserted portion 83 is continuously formed in the head portion 82, and a fitting hole 1b that can be in contact with the outer circumferential surface of the inserted portion 83 is formed in the bore hole 1a on the sides of the flanges 51, 61, and 71.

[0075] In this case, for the purpose of ensuring a constant stability of the shaft portion 81 in being pulled out from the filler 9 in the section of the inserted portion 83, a plane area A2 larger than a plane area A1 of the inner circumferential surface perpendicular to the axial direction, such as an inner diameter of the bore hole 1a, is provided to the inner circumferential surface perpendicular to the axial direction, such as an inner diameter of the fitting hole 1b in FIGS. 2A and 2B. Since the plane area A2 of the fitting hole 1b is larger than the plane area A1 of the bore hole 1a (A2>A1), a situation where the filler 9 of an approximately equal amount per unit length surrounds the shaft portion 81 over the whole length of the buried section of the shaft portion 81 into the concrete (the filler 9) is obtained regardless of the insertion of the inserted portion 83 into the fitting hole 1b, thereby ensuring the stability in the pull-out of a certain degree or more of the shaft portion 81.

[0076] FIG. 2C particularly illustrates an example where a plane area A3 having a size equal to or larger than the plane area A1 of the inner circumferential surface perpendicular to the axial direction, such as the inner diameter of the bore hole 1a, is provided to the inner circumferential surface perpendicular to the axial direction, such as an inner diameter of the inserted portion 83. In this case, since the plane area A3 perpendicular to the axial direction of the inner circumferential surface of the inserted portion 83 has the size equal to or larger than the plane area A1 perpendicular to the axial direction of the inner circumferential surface of the bore hole 1a (A3>A1), a situation where the filler 9 of the same amount or more per unit length surrounds the shaft portion 81 over the whole length of the buried section of the shaft portion 81 into the concrete can be obtained compared with the case of A3<A1, thereby further improving the stability in the pull-out.

[0077] In the case of FIG. 2C, since the plane area A3 of the inner circumferential surface of the fitting portion 52 has the size equal to or larger than the plane area A1 of the inner circumferential surface of the bore hole 1a (A3>A1), a projected area in a direction of an action of shear force of the fitting portion 52 is enlarged more than the case of A3<A1, thereby enhancing the shear force transmission effect by the amount. In this case, the plane area A2 perpendicular to the axial direction of the inner circumferential surface of the fitting hole 1b is larger than the plane area A1 perpendicular to the axial direction of the inner circumferential surface of the bore hole 1a by the wall thickness of the inserted portion 83 (A2>A1). FIG. 2D illustrates a relationship of the plane area A1 of the inner circumferential surface of the bore hole 1a, the plane area A3 of the inner circumferential surface of the fitting portion 52, and the plane area A2 of the inner circumferential surface of the fitting hole 1b in the case of FIG. 2C. Here, A1 represents the inner diameter of the bore hole 1a, A3 represents the inner diameter of the inserted portion 83, and A2 represents the inner diameter of the fitting hole 1b for convenience.

[0078] When there is no fitting hole 1b having the plane area A2 larger than the plane area A1 of the inner circumferential surface of the bore hole 1a and the plane area A1 of the bore hole 1a is constant in the axial direction, the volume of the filler 9 filled around the section close to the inserted portion 83 in the buried section of the shaft portion 81 into the frame 1 (the concrete) is decreased by the volume of the inserted portion 83 when the inserted portion 83 fits in the bore hole 1a, thereby possibly lowering the bonding strength with the filler 9 in the section. It is possible to have a situation where a part with a small bonding strength is peeled off from the filler 9 and the bonding strength of another part only resists the tensile force, unless the bonding strength with the filler 9 in the buried section into the frame 1 is constant (uniform).

[0079] In contrast to this, forming the fitting hole 1b having the plane area A2 close to the flanges 51, 61, and 71 of the bore hole 1a such that the plane area A3 perpendicular to the axial direction of the inner circumferential surface of the inserted portion 83 is equal to or larger than the plane area A1 perpendicular to the axial direction of the inner circumferential surface of the bore hole 1a, it is possible to have a situation where the filler 9 of the same amount surrounds the shaft portion 81 over the whole length of the buried section of the shaft portion 81 into the frame 1 regardless of the insertion of the inserted portion 83 into the fitting hole 1b. In view of this, a constant bonding strength is ensured over the whole length of the buried section into the frame 1, thereby providing an advantage that the bonding strength of the whole length of the buried section can resist the tensile force.

[0080] FIG. 5 illustrates all the frame 1 and the reinforcing frame 4 including column and beam joint portions in the frame 1 illustrated in FIG. 1 and FIG. 4. FIG. 6 illustrates a state where braces (damper integral-typed braces) 13 are installed between the connecting portion 7 on an upper side and the beam portion 6 on a lower side in the reinforcing frame 4 illustrated in FIG. 5. The brace 13 has an end portion at one side in an axial direction, for example, pin-joined to the insertion hole 72b of the connecting portion 7 and has an end portion at the other side, for example, pin-joined to the insertion hole formed in a gusset plate 14 joined to the flange 63 of the beam portion 6.

DESCRIPTION OF REFERENCE SIGNS

[0081] 1 . . . frame [0082] 2 . . . column [0083] 3 . . . beam [0084] 1a . . . bore hole [0085] 1A . . . corner [0086] 4 . . . reinforcing frame [0087] 5 . . . column portion [0088] 51 . . . flange [0089] 52 . . . web [0090] 52a . . . opening [0091] 53 . . . flange [0092] 6 . . . beam portion [0093] 61 . . . flange [0094] 62 . . . web [0095] 62a . . . opening [0096] 63 . . . flange [0097] 7 . . . connecting portion [0098] 71 . . . flange [0099] 71a . . . corner [0100] 72 . . . web [0101] 72a . . . opening [0102] 72b . . . insertion hole [0103] 8 . . . anchor [0104] 81 . . . shaft portion [0105] 82 . . . head portion [0106] 83 . . . inserted portion [0107] 84 . . . fixing portion [0108] 9 . . . filler [0109] 10 . . . nut [0110] 11 . . . backing metal [0111] 12 . . . weld metal [0112] 13 . . . brace [0113] 14 . . . gusset plate