JP5682960B2 - Steel structure reinforcement structure and reinforcement method - Google Patents

Description

  The present invention relates to a reinforcing structure and reinforcing method for a steel structure, and a reinforcing metal fitting.

Conventionally, as shown in FIGS. 17 and 18, the vertical stiffener 3 is fixed by welding across the deck plate (horizontal surface material 1) and the web plate (vertical surface material 2) in the steel deck 4 for reinforcement. Reinforcing structures for steel structures are known.
For example, a U-rib 10 having a U-shaped cross section on the lower surface side of the deck plate (horizontal plane material 1), a web plate (vertical surface material 2), and a reinforcing vertical rib (vertical stiffener) joined to the deck plate and the web plate by welding. In the steel deck 4 with 3), welding is frequently used. Such steel slabs are often used on routes with a large number of vehicles traveling, such as large bridges and highway viaducts, and the occurrence of fatigue cracks in the U-rib main body and deck plate is a problem.
The U-rib steel slab is known to cause fatigue cracks at various locations where welding is used as the cumulative number of vehicles traveling increases. Examples of representative sites where fatigue cracks occur (1) Deck plate and U-rib fillet welds, (2) U-rib butt welds, (3) U-rib and transverse rib intersection, (4) Deck plate and vertical stiffener There are meat welds, etc., all of which may lead to breakage of the main members such as deck plates and U-ribs.

  In addition, a structure in which a vertical stiffener is fixed by welding across the horizontal flange and the web in a steel material having an I-shaped or H-shaped cross section in which a vertical surface material such as a web is fixed to a horizontal surface material such as a horizontal flange by welding. It has been.

Further, a reinforcing rib in which a plate-like member is bent in a U shape or a V shape between a tubular structural member and a base plate or a substrate such as a joining flange is provided so that the bent portion side is a side far from the substrate. A reinforcement structure that is fixed by welding along the surface of the structural member is also known (see, for example, Patent Document 1).
Further, it is a reinforcing material that reinforces the joint part between adjacent columnar structural members or between the columnar structural member and another structural member, and the cross-sectional shape along the joint part side is a ring shape, on the side not joined to the structural member It is also known to use a reinforcing material having a ring-shaped opening (see, for example, Patent Document 2).

Japanese Patent No. 4062706 Japanese Patent No. 4181994

In a steel structure in which a vertical stiffener is fixed by welding across a horizontal plane and a vertical plane, a welded joint between the vertical stiffener and the horizontal plane at the position farthest from the vertical plane is Since stress concentrates when a vertical load such as a load is applied, fatigue cracks occur in the welded or horizontal plane material between the vertical stiffener and the horizontal plane material such as the deck plate or flange, reducing the durability of the steel structure. There was a problem.
However, when trying to apply the reinforcing rib or stiffener described in the above publicly known publication to a reinforcing structure in a steel structure in which a vertical stiffener is fixed by welding across a horizontal plane member and a vertical plane member, Since the reinforcing rib described in the publicly known publication is a U-shaped reinforcing rib or a ring-shaped stiffener in the longitudinal section, the U-shaped portion of the reinforcing rib or the middle portion of the ring-shaped stiffener is There is a problem that it interferes with the vertical stiffener and cannot be applied to form reinforcement with the vertical stiffener.
Therefore, the present invention provides a reinforcing structure and a reinforcing method for a steel structure that can be arranged without interfering with the vertical stiffener and can avoid stress concentration at the welded joint between the vertical stiffener and the horizontal plane member. The purpose is to do.

In order to advantageously solve the above-described problem, in the reinforcing structure of a steel structure according to the first aspect of the present invention, a vertical surface material is integrally provided on the lower surface side of the horizontal surface material by welding, and the vertical surface material or the vertical surface is provided. In a steel structure reinforcement structure in which a vertical stiffener is fixed by welding across a horizontal surface and a horizontal plane material, the vertical stiffener is spaced on both sides so that it surrounds the horizontal circumference of the upper end of the vertical stiffener. A reinforcing bracket having a U-shaped or arcuate cross-sectional curved connecting plate integrally connected to each vertical side plate and an upper end of each vertical side plate and the curved connecting plate in the reinforcing bracket. And the horizontal plane member are fixed to each other by welding, and each vertical side plate and the vertical plane member are welded or bolted.
In the reinforcing structure for a steel structure according to the second aspect of the present invention, a vertical surface material is integrally provided by welding on the lower surface side of the horizontal surface material, and is perpendicular to the vertical surface material or across the vertical surface material and the horizontal surface material. In a steel structure reinforcement structure in which a stiffener is fixed by welding, a pair of vertical plates and each vertical plate are spaced from each other on both sides of the vertical stiffener so as to surround the horizontal circumference of the upper end of the vertical stiffener. A reinforcing metal fitting having a U-shaped or arc-shaped curved connecting plate integrally connected to the side plate is arranged, and the upper end of each vertical side plate and the curved connecting plate and the horizontal plane member in the reinforcing metal plate are fixed by welding. Each vertical side plate and the vertical surface member are joined to each other through a joint metal that is bolted to the vertical side plate and welded or bolted to the vertical surface member.
In the steel structure reinforcement structure according to the third aspect of the present invention, a vertical surface member is integrally provided on the lower surface side of the horizontal surface member by welding, and the vertical surface member or the vertical surface member and the horizontal surface member are vertically compensated. In the reinforcement structure of a steel structure in which a rigid member is fixed by welding, the upper end of the vertical stiffener is separated from the horizontal plane member, and surrounds the horizontal circumference of the upper end of the vertical stiffener away from the horizontal plane member. In addition, a reinforcing bracket having a U-shaped or arc-shaped curved connecting plate that is integrally connected to the vertical plate and a pair of vertical plates spaced from each other on both sides of the vertical stiffener is disposed, The upper end of each vertical side plate and curved connecting plate and the horizontal plane member in the reinforcing metal fitting are fixed to each other by welding, and each vertical side plate and the vertical surface member are welded or bolted together.
In the steel structure reinforcing structure according to the fourth aspect of the present invention, a vertical surface member is integrally provided by welding on the lower surface side of the horizontal surface member, and the vertical surface member or the vertical surface member and the horizontal surface member are vertically compensated. In the reinforcing structure of a steel structure in which a rigid member is fixed by welding, the upper end portion of the vertical stiffener member is cut away so that the upper end portion of the vertical member member is separated from the horizontal plane member, and the vertical auxiliary member separated from the horizontal plane member is provided. A curved U-shaped or arc-shaped cross section that is integrally connected to a pair of vertical side plates and a pair of vertical side plates at intervals on both sides of the vertical stiffener so as to surround the horizontal circumference of the upper end of the rigid material Reinforcing metal fittings having connecting plates are arranged, upper ends of the vertical side plates and the curved connecting plates and the horizontal plane members in the reinforcing metal fittings are fixed by welding, and the vertical side plates and the vertical surface materials are connected to the vertical side plates and the vertical surface materials. It is connected via a bolted joint hardware. To.
In the fifth invention, in the reinforcing structure of a steel structure according to any one of the first to fourth inventions, the curved connecting plate of the reinforcing metal fitting has at least a height dimension of the curved connecting plate farthest from the vertical surface member. It is characterized by being 10 mm.
In the sixth invention, in the reinforcing structure of the steel structure according to the first to fifth inventions, the reinforcing metal fitting has a scallop for avoiding a horizontal plane member and a fillet welded portion of a vertical plane member, and a curved connecting plate or a curved connection. The lower surface side of the plate and each vertical plate connected to the plate is gradually lower surface from the tip of the curved connecting plate farthest from the vertical surface member toward the vertical plate in a side view from the direction perpendicular to each vertical plate. It has an arc-shaped notch so as to approach the vertical surface material as the level drops.
In the method for reinforcing a steel structure according to the seventh aspect of the invention, a vertical surface material is integrally provided by welding on the lower surface side of the horizontal surface material, and the vertical surface material or the vertical surface material and the horizontal surface material are vertically compensated. In a method of reinforcing a steel structure in which a rigid member is fixed by welding, a pair of vertical side plates and a vertical side plate are spaced apart on both sides of the vertical stiffener so as to surround the horizontal circumference of the upper end of the vertical stiffener. The reinforcing metal fitting having a U-shaped or arc-shaped curved connecting plate integrally connected to the horizontal plate is arranged, and then the upper end of each vertical side plate and the curved connecting plate and the horizontal plane member are fixed to each other by welding. Each vertical side plate and the vertical surface member are welded or bolted.
In the method for reinforcing a steel structure according to the eighth aspect of the invention, a vertical surface material is integrally provided by welding on the lower surface side of the horizontal surface material, and the vertical surface material or the vertical surface material and the horizontal surface material are vertically compensated. In a method of reinforcing a steel structure in which a rigid member is fixed by welding, a pair of vertical side plates and a vertical side plate are spaced apart on both sides of the vertical stiffener so as to surround the horizontal circumference of the upper end of the vertical stiffener. Reinforcing metal fittings having a U-shaped or arcuate curved connecting plate that are integrally connected to each other, and a reinforcing metal fitting in which one end side of a metal fitting is joined to a front end portion of each vertical side plate with a bolt in a temporarily tightened state. After placing and joining the other end side of the joint hardware and the vertical surface material in a temporarily tightened state with bolts and holding the reinforcing bracket in a predetermined position, the upper end of each vertical side plate and the curved connecting plate in the reinforcing bracket The horizontal surface material is fixed by welding, and then the joint hardware and the vertical member are attached. Characterized by the fastening bolt for joining the face material.
In a ninth invention, in the method for reinforcing a steel structure according to the seventh invention or the eighth invention, a vertical surface material is integrally provided on the lower surface side of the horizontal surface material by welding, and the vertical surface material or the vertical surface material is provided. In a method for reinforcing a steel structure in which a vertical stiffener is fixed by welding over a horizontal plane material, the upper end portion of the vertical stiffener is separated from the lower surface of the horizontal plane material.

According to the first invention, the vertical surface material is integrally provided by welding on the lower surface side of the horizontal surface material, and the vertical stiffener is fixed to the vertical surface material or across the vertical surface material and the horizontal surface material by welding. In a steel structure reinforcement structure, a pair of vertical side plates and each vertical side plate are integrally connected with a space on both sides of the vertical stiffener so as to surround the horizontal circumference of the upper end of the vertical stiffener. Reinforcing metal fittings having a curved connecting plate having a U-shaped or arcuate cross section are disposed, and the vertical plate and the upper end of the curved connecting plate in the reinforcing metal fitting are fixed to the horizontal plane member by welding, and each vertical plate and the vertical surface are fixed. Since the material is welded or bolted, it is possible to reduce the stress concentration in the weld at the top of the vertical stiffener using a small reinforcing bracket with a simple structure, and to prevent fatigue cracks in the weld. Can suppress the generation and contribute to the long life of the structure. Effects such as that can be obtained. Further, stress can be transmitted to the vertical surface member side through the reinforcing metal fittings, and further, the reinforcing metal fittings may be welded or bolted, so that the structure is simple and inexpensive.
According to the second invention, a vertical surface material is integrally provided on the lower surface side of the horizontal surface material by welding, and a vertical stiffener is fixed to the vertical surface material or across the vertical surface material and the horizontal surface material by welding. In a steel structure reinforcement structure, a pair of vertical side plates and each vertical side plate are integrally connected with a space on both sides of the vertical stiffener so as to surround the horizontal circumference of the upper end of the vertical stiffener. Reinforcing metal fittings having a curved connecting plate having a U-shaped or arcuate cross section are disposed, and the vertical plate and the upper end of the curved connecting plate in the reinforcing metal fitting are fixed to the horizontal plane member by welding, and each vertical plate and the vertical surface are fixed. Since the material is joined to the vertical side plate via a joint metal that is bolted to the vertical side plate and welded or bolted to the vertical side material, the joint metal is bolted to the vertical side plate between the vertical surface material and the reinforcing bracket. Interspersed between the bolt hole and the bolt shaft Utilizing, for the joining hardware so as to close contact with the vertical face material side can be arranged to adjust the position, the effect of such may be fixed to ensure that the vertical plane material of the reinforcing bracket is obtained. In addition, it is possible to reduce the stress concentration at the weld at the upper end of the vertical stiffener using a small reinforcing bracket and joint metal with a simple structure, and to suppress the occurrence of fatigue cracks at the weld, It is possible to contribute to a long life, and furthermore, stress can be transmitted to the vertical surface material side through the reinforcing metal fitting and the joint metal, and the structure is simple and inexpensive.
According to the third invention, the vertical surface material is integrally provided by welding on the lower surface side of the horizontal surface material, and the vertical stiffener is fixed to the vertical surface material or across the vertical surface material and the horizontal surface material by welding. In the steel structure reinforcement structure, the vertical stiffener is positioned so that the upper end of the vertical stiffener is separated from the horizontal plane and surrounds the horizontal circumference of the upper end of the vertical stiffener away from the horizontal plane. Reinforcing metal fittings having a U-shaped or arcuate cross-sectional curved connecting plate integrally connected to each vertical side plate and a pair of vertical side plates spaced from each other on the front and back sides are disposed, Since the upper end of the curved connecting plate and the horizontal plane member are fixed by welding and each vertical side plate and the vertical plane member are welded or bolted together, the upper end portion of the vertical plane member is separated from the horizontal plane member. To eliminate stress concentration at the weld at the top of the vertical stiffener Bets can be, also, it eliminates the occurrence of fatigue cracks of the welds, the effect of such can contribute to the long life of the structure is obtained. Further, stress can be transmitted to the vertical surface member side through the reinforcing metal fittings, and further, the reinforcing metal fittings may be welded or bolted, so that the structure is simple and inexpensive.
According to the fourth invention, the vertical surface material is integrally provided by welding on the lower surface side of the horizontal surface material, and the vertical stiffener is fixed to the vertical surface material or across the vertical surface material and the horizontal surface material by welding. In the reinforcing structure of a steel structure, the upper end portion of the vertical stiffener is cut away so that the upper end portion of the vertical face member is separated from the horizontal plane member, and the upper end portion of the vertical stiffener separated from the horizontal plane member is horizontal. Reinforcing metal fittings having a U-shaped or arc-shaped curved connecting plate that is integrally connected to a pair of vertical plates and a pair of vertical plates at intervals on both sides of the vertical stiffener so as to surround the periphery Arranged, the upper end of each vertical side plate and curved connecting plate in the reinforcing bracket and the horizontal plane member are fixed by welding, and each vertical side plate and the vertical surface member are bolted to the vertical side plate and the vertical surface member. Since it is joined via hardware, the upper end of the vertical face is horizontal. It is possible to eliminate stress concentration at the weld at the upper end of the vertical stiffener, and each vertical plate and vertical plate are bolted to the vertical plate and welded or bolted to the vertical plate. Since it is joined via the joined metal fittings, the bolts of the bolt joints between the vertical plate and the joint hardware are interposed between the vertical surface material and the reinforcing bracket, by interposing the joint metal bolted to the vertical plate. Use of the gap between the hole and the bolt shaft allows the fittings to be positioned and arranged so as to be in close contact with the vertical surface material side, so that the reinforcing bracket can be securely fixed to the vertical surface material, etc. Is obtained. In addition, it is possible to eliminate the stress concentration of the weld at the upper end of the vertical stiffener using a small reinforcing bracket and a joint metal with a simple structure, and to eliminate the occurrence of fatigue cracks in the weld. It is possible to contribute to a long life, and furthermore, stress can be transmitted to the vertical surface material side through the reinforcing metal fitting and the joint metal, and the structure is simple and inexpensive.
According to the fifth invention, since the height of the curved connecting plate farthest from the vertical surface member is at least 10 mm in the curved connecting plate of the reinforcing metal fitting, the bending side of the bending connecting plate in the reinforcing metal fitting is bent. The rigidity is not extremely lowered, and an effect such as a reinforcing metal fitting that can reliably receive a load from a horizontal surface material can be obtained.
According to the sixth invention, the reinforcing metal fitting has a scallop for avoiding a horizontal plane member and a fillet weld portion of a vertical plane member, and the lower surface side of each of the vertical connection plates connected to the curved connection plate or the curved connection plate is In a side view from the direction perpendicular to the vertical plate, the bottom surface level gradually descends from the tip of the curved connecting plate farthest from the vertical plate toward each vertical plate, and the arcuate shape approaches the vertical plate. Since the cutout portion is provided, fillet welding from the inside of the reinforcing bracket can be reliably performed on the vertical surface member and the horizontal surface member, so that the effect of ensuring the fixing of the reinforcing member can be obtained.
According to the seventh invention, the vertical surface material is integrally provided by welding on the lower surface side of the horizontal surface material, and the vertical stiffener is fixed to the vertical surface material or across the vertical surface material and the horizontal surface material by welding. In the steel structure reinforcement method, a pair of vertical side plates and each vertical side plate were integrally connected with a space on both sides of the vertical stiffener so as to surround the horizontal circumference of the upper end of the vertical stiffener. After arranging the reinforcing metal fittings having the U-shaped or arcuate curved connecting plate in cross section, the vertical plate and the upper end of the bending connecting plate and the horizontal plane member in the reinforcing metal fitting are fixed by welding, and perpendicular to each vertical plate. Since the face material is welded or bolted, the stress concentration of the welded portion at the top of the vertical stiffener can be reduced by a simple method using a small reinforcing bracket with a simple structure, and the fatigue of the welded portion can be reduced. Suppresses the generation of cracks and contributes to extending the life of structures. Can be, the effect of equal construction is easy and inexpensive to obtain.
According to the eighth invention, a vertical surface material is integrally provided by welding on the lower surface side of the horizontal surface material, and a vertical stiffener is fixed to the vertical surface material or across the vertical surface material and the horizontal surface material by welding. In the steel structure reinforcement method, a pair of vertical side plates and each vertical side plate were integrally connected with a space on both sides of the vertical stiffener so as to surround the horizontal circumference of the upper end of the vertical stiffener. Reinforcing metal fittings having a U-shaped or arc-shaped curved connecting plate in cross-section, a reinforcing metal fitting in which one end side of a joint metal piece is joined in a temporarily tightened state with a bolt at the front end portion of each vertical side plate, After joining the other end side and the vertical surface material in a temporarily tightened state with a bolt and holding the reinforcing bracket in place, the upper end of each vertical side plate and the curved connecting plate in the reinforcing bracket and the horizontal plane member are welded. After fixing, the bolt that joins the joint hardware and the vertical surface material Because of this, the gap between the bolt hole and the bolt shaft part of the bolt joint of the vertical side plate and the joint metal is used to bring the joint metal close to the vertical surface during the final tightening, and the joint metal and the vertical surface And the like can be brought into contact with each other.
According to the ninth invention, a vertical surface material is integrally provided on the lower surface side of the horizontal surface material by welding, and a vertical stiffener is fixed to the vertical surface material or across the vertical surface material and the horizontal surface material by welding. In the steel structure reinforcement method, since the upper end of the vertical stiffener is separated from the lower surface of the horizontal plane member, in addition to the effects of the eighth invention or the ninth invention, The effect that stress concentration can be eliminated is obtained.

1 is a partially longitudinal perspective view showing a first embodiment of a steel structure reinforcing structure according to the present invention. It is a partially vertical perspective view which shows 2nd Embodiment of the reinforcement structure of the steel structure of this invention. It is a partially vertical perspective view which shows 3rd Embodiment of the reinforcement structure of the steel structure of this invention. It is a partially vertical perspective view which shows 4th Embodiment of the reinforcement structure of the steel structure of this invention. It is a partial longitudinal cross-sectional perspective view which shows 5th Embodiment of the reinforcement structure of the steel structure of this invention. It is a partially vertical perspective view which shows 6th Embodiment of the reinforcement structure of the steel structure of this invention. It is a partially vertical perspective view which shows 7th Embodiment of the reinforcement structure of the steel structure of this invention. The flow of the stress at the time of employ | adopting the reinforcement structure of the steel structure of the steel structure of this invention is shown, Comprising: (a) is a partially longitudinal side view, (b) is a partially longitudinal front view of (a). FIG. 4C is a transverse plan view. The 8th Embodiment of the reinforcement structure of the steel structure of this invention is shown, Comprising: (a) is a cross-sectional top view, (b) is a vertical side view. It is a partially vertical perspective view which shows 9th Embodiment of the reinforcement structure of the steel structure of this invention. It is a partially vertical perspective view which shows 10th Embodiment of the reinforcement structure of the steel structure of this invention. It is a partially vertical perspective view which shows 11th Embodiment of the reinforcement structure of the steel structure of this invention. It is a figure which shows the test result in the case of this invention, and the conventional case. 1 shows a first example of a reinforcing metal fitting used in the present invention, where (a) is a front view, (b) is a left side view, (c) is a right side view, (d) is a plan view, and (e). Is a bottom view. 2 shows a second example of a reinforcing metal fitting used in the present invention, where (a) is a front view, (b) is a left side view, (c) is a right side view, (d) is a plan view, and (e). Is a bottom view. 3 shows a third example of a reinforcing metal fitting used in the present invention, where (a) is a front view, (b) is a left side view, (c) is a right side view, (d) is a plan view, and (e). Is a bottom view. It is a partial vertical perspective view which shows an example of a steel deck. It is a figure which shows the reinforcement structure by the conventional vertical stiffener. (A) (b) shows the conventional structure which carried out FEM analysis, (c) (d) is a figure which shows the structure of this invention which carried out FEM analysis.

  The following embodiments are used to reinforce (or repair against fatigue cracks that have occurred in the welded portion) in order to suppress stress concentration in the welded portion between the upper end of the vertical stiffener and the deck plate in a steel structure comprising a steel deck. Reinforcement (or fatigue generated in the welded part) to suppress stress concentration in the welded part between the upper end of the vertical stiffener of the steel structure made of plate girder and the horizontal surface made of the upper flange This shows the structure of repair and reinforcement for cracks. Hereinafter, the present invention will be described in detail based on illustrated embodiments.

(First embodiment)
FIG. 1 shows a reinforcing structure for a steel structure according to a first embodiment of the present invention, and FIG. 14 shows a reinforcing metal fitting 5. In this embodiment, a vertical surface material 2 made of a web plate that is disposed on the lower surface side of a steel horizontal surface material 1 made of a steel plate deck plate and fixed by welding W3 and supports the horizontal surface material 1 is provided. The vertical stiffener 3 in the steel structure comprising the steel floor slab 4 provided with the steel plate vertical stiffener 3 fixed to the horizontal plane member 1 and the vertical plane member 2 by the welded portions W1 and W2, respectively. In order to obtain a structure that can avoid stress concentration at the welded portion between the horizontal plane member 1 and the horizontal plane member 1, the reinforcing metal fitting 5 is used to reinforce (or reinforce as repair). The reinforcing metal fitting 5 is on the side of the welded portion W4 farthest from the vertical surface material 2 where stress is concentrated among the vertical stiffener 3, the horizontal surface material 1 and the welded portion W1. A structure that reduces the concentration of stress on the curved connecting plate 6 of the reinforcing metal fitting 5 by providing the curved connecting plate 6 curved in a bending process (semicircle, arc, or U-shape) with a curvature. It has become. The reinforcing metal fitting 5 is formed in a U shape in which the shape along the horizontal surface material 1 and the vertical surface material 2 is opened on the lower side (the same applies to the following embodiments).
The welding portion W1 between the horizontal plane member 1 and the upper end portion of the vertical stiffener 3, in particular, the welding of the tip portion at the upper end portion of the vertical stiffener 3 at a position far from the vertical plane member 2 made of a web plate. When the wheel load from the upper side of the steel floor slab 4 is transmitted from the horizontal plane member 1 to the vertical plane member 2, the portion W 4 is welded W 1 ( This is the portion where stress concentration occurs in W4 and the following. In order to prevent cracks due to fatigue of the welded portion W1 and accompanying fatigue cracks to the horizontal surface material 1 by relaxing the stress (stress concentration) of the welded portion W1 including this stress concentration, this first embodiment In the present invention, the vertical stiffener 3 is provided integrally with each of the vertical side plates 7 and the vertical side plates 7 so as to surround the horizontal periphery of the upper end portion of the vertical stiffener 3 with a gap on both sides of the front and back sides of the vertical stiffener 3. The reinforcing metal fitting 5 having the U-shaped or arc-shaped curved connecting plate 6 connecting them is disposed, and the reinforcing metal fitting 5 is fixed to the horizontal surface material 1 and the vertical surface material 2 to thereby Reinforcement is performed so as to suppress stress concentration in the welded portion W1 (or reinforcement that also serves as repair for preventing the progress of fatigue cracks), so that the fatigue performance of the steel structure can be improved.
When the reinforcing metal fitting 5 is attached to the horizontal surface material 1, it may be joined by direct welding, and the vertical surface material 2 may be joined by direct welding or via a joint metal as in the embodiment described later.
More specifically, the upper end of each vertical side plate 7 and curved connecting plate 6 in the reinforcing metal fitting 5 and the horizontal plane member 1 are fixed by welding W5, and each vertical side plate 7 and vertical surface member 2 are joined by welding W6. Has been.
The reinforcing metal fitting 5 is induced by displacement in the out-of-plane direction to the deck plate, that is, the horizontal surface material 1 by adjusting the height of the curved connecting plate 6 side (L, see FIGS. 9 and 14 to 16). The degree of stress relief that is applied can be adjusted. The height (L) on the curved connecting plate 6 side may be adjusted by using a reinforcing metal fitting 5 that has been adjusted to a predetermined height in advance, and the height (L) on the curved connecting plate 6 side according to the construction site. ) May be adjusted by cutting and removing the lower side as appropriate (the same applies to the following embodiments).
The height L is set to be at least 10 mm, so that the stress concentration at the upper end of the vertical stiffener 3 and the welded portion can be reduced. The rigidity is kept from becoming extremely low. The overall height dimension H of the reinforcing metal fitting 5 is, for example, the same height dimension as the height dimension L of the curved connecting plate 6 or a dimension higher than this (H ≧ L) and vertical. The height of the stiffener 3 may be lower than that of the stiffener 3, for example, H = 100 mm to 200 mm, and the plate thickness may be 9 mm or 6 mm to 30 mm.
The vertical side plate 7 of the reinforcing metal fitting 5 will be described with reference to FIG. 9. The width dimension a of the vertical side plate 7 is preferably larger than the width dimension of the vertical stiffener 3. If there is a predetermined length h2 parallel portion from the lower end side, the stress transmitted to the vertical surface material 2 side can be distributed and transmitted. For example, h2 ≧ L may be satisfied.

A reinforcing metal fitting 5 shown in FIG. 1 is an example of a reinforcing metal fitting used in the present invention. In this embodiment, a detailed view thereof is shown in FIG. The whole has a substantially U-shaped cross section.
A scallop 8 is formed in a corner portion of each vertical side plate 7 by being cut out in an arc shape so as to be separated from the welded portion W3 between the horizontal surface material 1 and the vertical surface material 2. In this embodiment, the reinforcing metal fitting 5 is welded by fillet welds W5 and W6 from the outside (or outside and inside) of the vertical side plate 7 and the arc-shaped curved connecting plate 6 of the reinforcing metal fitting 5, so that the reinforcing metal fitting 5 is horizontal. It is fixed to the material 1 and the vertical surface material 2.
When welding the reinforcing metal fitting 5, the vertical surface is appropriately welded manually or using a holding jig (not shown) provided with a clamp at the tip and a level-adjustable support (not shown). After welding to the material 2 or welding to the vertical surface material 2, welding is performed to the horizontal surface material 1 side.
When welding the reinforcing metal fitting 5, it may be properly welded after being temporarily attached to the vertical surface material 2 or the horizontal surface material 1, and an advantage that a cross-sectional defect to the steel structure side such as a steel deck is not generated. There is.

When the reinforcing bracket 5 is fixed to the horizontal plane member 1 and the vertical plane member 2 by welding, the distance between the vertical side plate 7 and the curved connecting plate 6 upper end surface side of the reinforcing bracket 5 and the horizontal plane member 1, the vertical side plate. A groove is appropriately provided between 7 and the vertical surface member 2, and a groove is provided on the reinforcing metal fitting 5 side for welding.
When the reinforcing metal fitting 5 is fixed to the horizontal surface material 1 or the vertical surface material 2, if there is a sufficient space between the vertical stiffener 3 and the inside of the reinforcing metal material 5, the inner surface of the reinforcing metal material 5 is connected to the horizontal surface material 1 or the vertical surface material. When fixed to the material 2 by fillet welding, the reinforcing metal fitting 5 can be reliably fixed to the horizontal surface material 1 or the vertical surface material 2.
When the external dimension from the vertical side plate 7 to the curved connecting plate 6 is set to 1 in a side view, the height of the reinforcing bracket 5 is set to a size exceeding 1, so that the vertical side plate 7 and the curved connecting plate 6 side Can be transmitted from the side end portion of the vertical plate 7 to the vertical surface member 2 side of the steel structure without causing extreme stress concentration.
The distance r from the vertical stiffener 3 to the longitudinal side plate 7 or the inner side surface of the curved connecting plate 6 in the reinforcing metal fitting 5 is, for example, the top end of the vertical stiffener 3 in the plan view shown in FIG. Stress concentration can be alleviated by setting the radius r from the center of the tip to the inside of the curved connecting plate 6 to at least 20 mm to 200 mm. Preferably, when the radius is 50 mm to 200 mm, the welding rod can be used as a reinforcing metal fitting. 5, it becomes easy to be fixed to the horizontal surface material 1 or the vertical surface material 2 by the fillet weld W5 (W6) from the inside of the reinforcing metal fitting 5.
As shown in FIG. 9B, the curved connecting plate 6 or the curved connecting plate 6 and the lower surface side of each vertical side plate 7 connected to the vertical connecting member 6 are vertical surface members 2 in a side view from the direction perpendicular to the respective vertical side plates 7. If the lower surface level gradually descends from the tip of the curved connecting plate 6 farthest to the vertical side plate 7 and has an arc-shaped cutout portion 9 so as to approach the vertical surface member, the reinforcement Fillet welding between the upper end inside the vertical side plate 7 of the metal fitting 5 and the horizontal plane member 1 or the vertical plane member 2 side, and fillet welding between the upper end inside the curved connecting plate 6 and the horizontal plane member 1 are facilitated. The arcuate notch 9 is also formed to adjust the height dimension (L) of the curved connecting plate 6 in the reinforcing metal fitting 5. Further, by forming the arc-shaped cutout portion 9, the stress is transmitted from the entire longitudinal side plate 7 and the curved connection plate 6 of the reinforcing metal fitting 5 as compared with the case where the bowl-shaped or stepped cutout portion is formed. It can be transmitted smoothly.
When the height dimension (L) of the curved connecting plate 6 in the reinforcing metal fitting 5 is adjusted, when a load (vertical load) is applied to the horizontal plane member 1, it is induced by the displacement in the out-of-plane direction to the horizontal plane member 1 such as a deck plate. The degree of stress relief that is applied can be adjusted.
Each side plate of a steel U-rib 10 having a U-shaped cross section extending in the bridge axis direction is fixed to the lower surface side of the horizontal surface member 1 made of a deck plate by welding.
The form of the reinforcing metal fitting 5 may be replaced with the form described later.

(Second Embodiment)
FIG. 2 shows a reinforcing structure for a steel structure according to the second embodiment. In this embodiment, a horizontal plane member 1 having a horizontal plane member 1 made of a steel upper flange and a vertical plane member 2 made of a steel web plate and having a cross-section I or H-shaped plate girder or girder 11, etc. 1 and the vertical surface material 2 or only the vertical surface material 2 is provided with a vertical stiffener 3 made of a steel plate and stiffened, the weld W1 at the upper end of the vertical stiffener 3 is further provided. This is a reinforcing structure for reinforcing (or repairing) by avoiding the stress concentration of the steel plate, and the horizontal plane 1 made of steel flanges and vertical stiffening due to the load acting on the steel structure from above. This can be suppressed or alleviated with respect to the stress concentration of the welded portion W1 with the material 3. Reference numeral 17 denotes a lower flange. The other parts are the same as in the above case.

(Third embodiment)
FIG. 3 shows a reinforcing structure for a steel structure according to a third embodiment of the present invention. In this embodiment, in order to completely eliminate the stress concentration between the vertical stiffener 3 and the horizontal plane member 1, the upper end portion of the vertical stiffener 3 is appropriately removed by cutting or fusing or separated from the horizontal plane member 1. And As the upper end surface 12 of an inclined cut surface (or an inclined surface, although not shown, a horizontal cut surface or a horizontal plane), the upper end portion of the vertical stiffener 3 gradually rises linearly or curvedly toward the web side. A gap G is formed between the upper end surface of the vertical stiffener 3 fixed to the face material 2 and the horizontal plane member 1, or the upper end of the vertical stiffener 3 is previously provided with a gap G from the horizontal plane member 1. In this state, when the vertical stiffener 3 is fixed to the vertical surface member 2 by welding, the weld joint between the vertical stiffener 3 and the horizontal surface member 1 is eliminated, and the stress concentration is eliminated. Stress (mainly vertical shear force) can be transmitted to the vertical surface 2 through the reinforcing metal fitting 5 that can relieve the stress concentration by applying the vertical load acting on the horizontal surface 1 at a position away from the vertical surface 2 I have to. By doing so, there is a risk that the horizontal surface material 1 tilts and swings (swings) to the left and right when there is no reinforcing metal fitting 5, but by installing the reinforcing metal fitting 5, the horizontal surface material 1 moves to the left and right. The risk of tilting (swinging) is also eliminated.
In the case where the upper end of the vertical stiffener 3 is provided with a gap G from the horizontal plane member 1, in the side view seen from the longitudinal direction (bridge axis direction) of the web plate, By arranging the reinforcing metal fitting 5 so that the lower end side of the reinforcing metal fitting 5 overlaps, the load from the horizontal surface material 1 can be transmitted from the reinforcing metal fitting to the vertical surface material 2. For example, as a preferred embodiment, the reinforcing metal fitting is such that, in the above-mentioned side view, the widest width dimension portion on the upper end side of the vertical stiffener 3 overlaps with the width dimension portion similar to the widest width dimension portion. By installing 5, the load from the horizontal surface material 1 can be reliably transmitted from the reinforcing metal fitting 5 to the vertical surface material 2. The planar positional relationship between the reinforcing metal fitting 5 and the vertical stiffener 3 is the same as in the above embodiment.

(Fourth embodiment)
FIG. 4 shows a reinforcing structure for a steel structure according to a fourth embodiment of the present invention, and FIG. 16 shows a reinforcing metal fitting 5. In the fourth embodiment, when the reinforcing metal fitting 5 is fixed to the vertical surface member 2, it is easier to fix than the above embodiments, and each of the vertical side plates 7 and the vertical surface material 2 is a vertical side plate. 7 is joined via a joint metal 13 that is bolted to 7 and bolted (or welded) to the vertical face member 2.
The metal joint 13 has a horizontal cross section and an L-shaped cross section, and is bolted to the base plate 15 and the vertical surface member 2 joined to the vertical plate 7 by bolts and nuts 14 such as high strength bolts. Or a distal end plate 16 to be welded), and the base end plate 15 and the distal end plate 16 are provided with a plurality of bolt holes 19 spaced in the vertical direction.
The angle formed between the base end plate 15 and the front end plate 16 is set to an angle (for example, a right angle or an obtuse angle) that matches the angle between the vertical surface member 2 and each vertical plate 7.
As shown in FIG. 4 or 8, when the base end plate 15 and the front end plate 16 of the metal joint 13 are respectively bolted, the bolts are spaced apart from the base end plate 15 and the front end plate 16 in the vertical direction. Bolt holes 19 are provided in the vertical surface member 2 and the vertical side plates 7 at intervals in the vertical direction, and base end plates 15 of the joint hardware 13 are provided on the vertical side plates 7 of the reinforcing metal fitting 5. Reinforcing metal fittings 5 in a state where force bolts and nuts 14 are temporarily attached are provided, and the reinforcing metal fittings 5 with the metal fittings 13 are disposed so as to surround the upper end portion of the vertical stiffener 3 so as to surround each of the metal fittings. 13 and the vertical surface member 2 are in a state where the high-strength bolts and nuts 14 are temporarily attached, and the reinforcing bracket 5 and the horizontal surface member 1 are fixed by welding, and then the high strength on the end plate 16 side of the joint hardware 13 is secured. By tightening the bolts and nuts 14, the joint hardware 13 Using the gap between the bolt hole on the base end plate 15 side and the bolt shaft portion, the position of the inner surface of the tip plate 16 of the joint metal 13 is adjusted so as to abut against the vertical surface member 2, so After the face material 2 is joined by tightening each high-strength bolt / nut 14, each base plate 15 and each vertical plate 7 are joined by fastening each high-strength bolt / nut 14. .
In this way, the joining hardware 13 is joined by adjusting the position of the joining hardware 13 using the gap between the bolt hole and the high-strength bolt shaft portion.
By adopting high-strength bolt joining, it becomes possible to absorb the gap between the reinforcing metal fitting 5 and the vertical surface material (web plate) 2 caused by welding deformation or the like. As the high-strength bolt, for example, a high-strength bolt such as F10T or F14T is used, and when managing the tightening torque, a Torcia-type high-strength bolt may be used. There are two types of high-strength bolt joints, friction joints and bearing joints, but the bolt holes provided in the vertical surface member 2 or the joint hardware 13 are in the horizontal bridge axis direction, the bridge axis perpendicular direction, or these two directions. It is better to absorb the gap due to the welding deformation of the reinforcing metal fitting 5 by using the gap between the bolt hole and the bolt shaft portion as in the above-described embodiment. Providing the bolt holes extending in the vertical direction is not desirable because the reinforcing metal fitting 5 may be shifted in the vertical direction.

(Fifth embodiment)
FIG. 5 shows a reinforcing structure according to a fifth embodiment of the present invention. This form is a modification of the form shown in FIG. 2, and is a form in which the reinforcing metal fitting 5 is installed via the joint metal fitting 13 of the above embodiment. A horizontal plane member 1 made of a steel flange, a vertical plane member 2 made of a steel web plate, and a steel structure such as a cross-section I or H-shaped plate girder or girder 11, and the like. In addition, when the vertical stiffener 3 made of a steel plate is provided only on the vertical face material 2 and is stiffened, stress concentration of the weld W1 (W4) at the upper end of the vertical stiffener 3 is avoided. Therefore, the reinforcement structure is further reinforced (or reinforced as repair).
The reinforcing metal fitting 5 is arranged on the lower surface side of the horizontal surface material 1, and, for example, the base end plate 15 of the metal fitting 13 in the metal fitting 13 with the metal fitting 13 attached to the vertical surface material 2 is temporarily attached with a high strength bolt and nut 14, for example. By fixing, the upper end side of the vertical side plate 7 and the curved connecting plate 6 is fixed by welding W5, and the front end plate 16 and the vertical surface member 2 of each metal joint 13 are joined by tightening the high strength bolts and nuts 14. After that, the high-strength bolts and nuts 14 of the vertical side plate 7 and the base end plate 15 of the joint metal 13 are finally tightened, so that the fatigue performance of the welded portion on the upper end side of the vertical stiffener 3 is the same as in the above embodiment. Reinforcement (improvement that also serves as repair) can be improved. The other parts are the same as in the above case.

(Sixth embodiment)
FIG. 6 shows a reinforcing structure according to a sixth embodiment of the present invention. This form is a modification of the form shown in FIG. 3, in which the top end of the vertical stiffener 3 is separated from the lower surface of the horizontal plane member 1 and a gap is provided. In a form surrounded by the attached reinforcing metal fitting 5 to relieve stress concentration at the welded joint between the upper end of the vertical stiffener 3 and the horizontal surface member 1 and improve fatigue performance (reinforcement that also serves as repair) is there. Since the form of the joint hardware 13 and the like is the same as that of the above-described embodiment, the same reference numerals are given to the same elements.

(Seventh embodiment)
The form shown in FIG. 7 uses a reinforcing metal fitting 5 of another form as shown in FIG. 15 to relieve the stress concentration at the welded portion between the upper end of the vertical stiffener 3 and the horizontal plane member 1 and reinforce (or This is a seventh embodiment in which repair and reinforcement are performed against cracks and the like of the welded portion. In the reinforcing metal fitting 5 of this embodiment, the curved connection plate 6 or the curved connection plate 6 and the lower surface side of each vertical side plate 7 connected thereto are most distant from the vertical surface material 2 in a side view from the direction perpendicular to each vertical side plate 7. In this configuration, the lower surface level gradually descends from the distal end portion of the curved connecting plate 6 at a distant position toward each longitudinal side plate 7 and has an arc-shaped cutout portion 9 so as to approach the vertical surface material. Since the arc-shaped cutout portion 9 is provided, the fillet welding from the inside of the reinforcing bracket can be reliably performed on the vertical surface member 1 and the horizontal surface member 2, so that the fixing of the reinforcing member is ensured. In addition, the vertical side plate 7 and the vertical surface member 2 in the reinforcing metal fitting 5 are joined through the joint hardware 13, and the same reference numerals are given to the same parts as those described above.
The height dimension L in the vertical direction of the curved connecting plate 6 in such a form is at least 10 mm.

  In FIG. 8, the stress transmission path from the horizontal surface member 1 through the reinforcing metal fitting 5 in the case of the reinforcing structure of the structure of the present invention using the reinforcing metal fitting 5 is indicated by an arrow. Stress concentration at the weld joint W4 farthest from the vertical surface material 2 at the upper end of the vertical stiffener 3 is suppressed, and the horizontal surface material 1 passes through the curved connection plate 6 and the vertical side plate 7 of the reinforcing bracket 5. Thus, it is transmitted to the vertical surface member 2 of the web plate, and a part is transmitted from the vertical surface member 2 to the vertical stiffener 3. In the case of using the metal joint 13, it is transmitted from the reinforcing metal fitting 5 to the vertical surface material 2 via the metal joint 13, and a part is transmitted from the vertical surface material 2 to the vertical stiffener 3.

(Ninth embodiment)
FIG. 10 shows a steel structure reinforcement structure according to a ninth embodiment of the present invention. In this embodiment, the cross section I or H-shaped plate girder or the horizontal stiffener 3 of the vertical stiffener 3 of the steel structure such as the girder 11 and the like in an arc shape in a side view from the direction perpendicular to each longitudinal side plate 7. The reinforcing metal fitting 5 having the notch 9 is disposed and fixed to the vertical surface member 2 with a high-strength bolt and nut 14 through a metal joint 13, and the other configurations are the same as in the above-described embodiment. .

(10th Embodiment)
FIG. 11 shows a steel structure reinforcement structure according to a tenth embodiment of the present invention. This form is a modification of the form shown in FIG. 3, in which each vertical side plate 7 in the vertical face member 2 and the reinforcing metal fitting 5 is joined by a high-strength bolt / nut 14 via a joint metal 13, and vertical stiffening is performed. A gap G is formed at the upper end of the material 3. Other configurations are the same as those of the above embodiment.

(Eleventh embodiment)
FIG. 12 shows a steel structure reinforcement structure according to an eleventh embodiment of the present invention. This form is the figure which showed the form which may weld the front end plate 16 of the metal joint 13 to the vertical surface material 2 by welding W7. In this case, the length and width of the front end plate 16 of the metal joint 13 and the reinforcement The shape and width of the lower part of the metal fitting 5 are adjusted in consideration of weldability. In this embodiment, it is not necessary to provide the bolt hole 19 in the distal end plate 16, and only the base end plate 15 may be provided with the bolt hole. In order to secure the welding length of the tip plate 16, the shape, width and length of the metal joint 13 and the height of the reinforcing metal fitting 5 are adjusted in consideration of welding workability. Other configurations in this case are the same as those in the above embodiment.

Next, in the case of the conventional structure shown in FIGS. 19 (a) and 19 (b) (when the reinforcing bracket in the present invention is not used), two examples of the reinforcing structure of the present invention shown in FIG. 19 (c), and FIG. Since FEM analysis (numerical analysis) was performed on the following four examples in combination with one example of the reinforcing structure of the present invention shown in d), this will be described.
Case 1: Conventional structure. No reinforcing bracket 5 is provided. (See FIGS. 19 (a) and 19 (b))
Case 2 (Invention Example 1): Reinforcing metal fitting 5 is present. Height L = 100 mm. (See FIG. 19 (c))
Case 3 (Invention Example 2): Reinforcing metal fitting 5 is present. Height L = 200 mm. (See FIG. 19 (c))
Case 4 (Invention Example 3): There is a reinforcing metal fitting 5 with a notch 9. Height L = 200 mm. (See FIG. 19 (d))
In FIG. 19B, reference numeral 18 in the conventional structure of the Case 1 is a suspended scaffolding support bracket 18 for inspection that is fixed to the vertical surface member 2 by fillet welding. This bracket 18 is a vertical stiffener. 3 is installed on the vertical surface material 2 on the opposite side of the vertical surface material 2 in the same plane as 3, and is often not welded to the horizontal surface material 2.
As described above, when the conventional structure shown on one side is shown in FIGS. 18 and 19A (Case 1), the reinforcing metal fitting 5 shown in FIG. 19B is used as a representative form of each embodiment of the present invention. About each reinforcement structure of this invention example 3 (Case4) shown in FIG.19 (d) using this invention example 1 and 2 (Case2 and 3) and the reinforcement metal fitting 5 which provided the notch part 9 is a vertical stiffener 3 The tip of the upper end was set as a point of interest A, and the difference in stress acting on this portion was numerically analyzed.
In both the conventional structure and the present invention, the horizontal surface material 1 made of a deck plate is a steel plate having a thickness of 12 to 30 mm, the vertical surface material 2 is a steel plate having a thickness of 9 to 30 mm, and the vertical stiffener 3 is a thickness. It is a steel plate having a plate width of 9 to 30 mm and 50 to 300 mm.
The common points of the reinforcing metal fittings 5 used in the test specimens of the present invention are as follows. As shown in FIGS. 19C and 19D, the steel plate thickness of the reinforcing metal fittings 5 is 9 mm and passes through the center of the vertical stiffener 3. In the present invention example 1 of Case 2, the height of each vertical side plate 7 and the curved connecting plate 6 is a reinforcing bracket in which the outer radius R of the curved connecting plate 6 is centered at a position 150 mm vertically away from the vertical surface material 2. When the dimension L is 100 mm, in the present invention example 2 of Case 3, when the height dimension L of each vertical side plate 7 and the curved connecting plate 6 is 200 mm (see FIG. 19C), in the present invention example 3 of Case 4 The height dimension of the curved connecting plate 6 is obtained when a notch 9 having a radius of 100 mm is provided in a side view in a range where the height dimension of each vertical side plate 7 is 200 mm and the stress generated on the lower side of the curved connecting plate 6 is low. Is 50 mm.
It is assumed that the load F is one of the rear wheels of the truck and 95.4 kN acts from above the horizontal plane member 1 at a position away from the vertical stiffener 3.
The analysis results of a total of four examples including the conventional structure of Case 1 and Examples 1 to 3 of the present invention Examples 1 to 3 are shown as a graph in FIG. From the graph of FIG. 13, the stress at the point of interest A at the tip of the vertical stiffener 3 in the order of the present invention example 1, 3, 2 (Case 2, 4, 3) from the case of the conventional structure (Case 1) located on the upper side. It can be seen that the concentration is improved by relaxation by 20% to 35% at the maximum value in the stress range.

  As shown in the above embodiment, reinforcement (or occurred in the welded portion) to suppress stress concentration at the welded portion between the upper end of the vertical stiffener 3 and the deck plate in the steel structure composed of the steel deck 4 Reinforcement that also serves as repair for fatigue cracks), or to suppress stress concentration in the welded portion W1 between the upper end portion of the vertical stiffener of the steel structure made of plate girder and the horizontal surface member 1 made of the upper flange Reinforcement (or reinforcement that also serves as a repair for fatigue cracks generated in the welded portion) is performed by suppressing (reducing) or eliminating stress concentration in each welded portion W1 using a simple reinforcing metal fitting 5. In addition, it is possible to provide a simple and reliable reinforcing structure for reinforcing the fatigue crack generated in the welded portion.

  In carrying out the present invention, although not shown in the drawings, each of the flanges is made of a vertical surface material 2 by using a reinforcing metal fitting having a flanged vertical plate 7 integrally provided with the vertical plate 7 of the reinforcing metal fitting 5. You may make it fix with a volt | bolt directly.

DESCRIPTION OF SYMBOLS 1 Horizontal surface material 2 Vertical surface material 3 Vertical stiffener 4 Steel floor slab 5 Reinforcement metal fitting 6 Curved connection plate 7 Vertical side plate 8 Scallop 9 Notch 10 Steel U rib 11 Plate girder or girder 12 Upper end surface 13 Joint metal 14 Bolt / Nut 15 Base plate 16 End plate 17 Lower flange 18 Suspended scaffolding support bracket 19 Bolt hole

Claims (9)

  A reinforcing structure of a steel structure in which a vertical surface material is integrally provided by welding on the lower surface side of a horizontal surface material, and a vertical stiffener is fixed to the vertical surface material or across the vertical surface material and the horizontal surface material by welding. In order to surround the horizontal portion of the upper end of the vertical stiffener, a pair of vertical plates and a U-shaped cross section integrally connected to each vertical plate at intervals on both sides of the vertical stiffener or Reinforcing metal fittings having an arcuate curved connecting plate are arranged, and each vertical side plate and the upper end of the curved connecting plate in the reinforcing metal fitting and the horizontal surface material are fixed by welding, and each vertical side plate and the vertical surface material are welded or joined. A steel structure reinforcement structure characterized by being bolted.   A reinforcing structure of a steel structure in which a vertical surface material is integrally provided by welding on the lower surface side of a horizontal surface material, and a vertical stiffener is fixed to the vertical surface material or across the vertical surface material and the horizontal surface material by welding. In order to surround the horizontal portion of the upper end of the vertical stiffener, a pair of vertical plates and a U-shaped cross section integrally connected to each vertical plate at intervals on both sides of the vertical stiffener or Reinforcing metal fittings having an arcuate curved connecting plate are disposed, and each vertical side plate and the upper end of the curved connecting plate in the reinforcing metal fitting and the horizontal surface material are fixed by welding, and each vertical side plate and the vertical surface material are connected to the vertical side plate. A steel structure reinforcing structure characterized in that the steel structure is joined to a vertical surface member through a joint metal that is bolted to the vertical surface member. A reinforcing structure of a steel structure in which a vertical surface material is integrally provided by welding on the lower surface side of a horizontal surface material, and a vertical stiffener is fixed to the vertical surface material or across the vertical surface material and the horizontal surface material by welding. The vertical stiffener has an upper end that is separated from the horizontal plane member, and the vertical stiffener is spaced from the front and back sides of the vertical stiffener so as to surround the horizontal circumference of the upper end of the vertical stiffener that is separated from the horizontal plane member. A reinforcing bracket having a U-shaped or arc-shaped curved connecting plate that is integrally connected to each vertical side plate, and an upper end of each vertical side plate and the curved connecting plate in the reinforcing bracket; A reinforcing structure of a steel structure, wherein the horizontal plane member is fixed by welding, and each vertical side plate and a vertical plane member are welded or bolted together.   A reinforcing structure of a steel structure in which a vertical surface material is integrally provided by welding on the lower surface side of a horizontal surface material, and a vertical stiffener is fixed to the vertical surface material or across the vertical surface material and the horizontal surface material by welding. The vertical stiffener is cut off at the upper end so that the upper end of the vertical face is separated from the horizontal plane, and surrounds the horizontal circumference of the upper end of the vertical stiffener away from the horizontal plane. Reinforcing metal fittings having a U-shaped or arcuate cross-section curved connecting plate that are integrally connected to a pair of vertical plates and spaced apart from each other on both sides of the vertical stiffener are arranged. The upper end of each vertical side plate and the curved connecting plate and the horizontal plane member are fixed by welding, and each vertical side plate and the vertical surface member are joined to each other via a joint metal fitting bolted to the vertical side plate and the vertical surface member. Reinforced structure of steel structure characterized by   The steel structure according to any one of claims 1 to 4, wherein the curved connecting plate of the reinforcing metal fitting has a height dimension of the curved connecting plate farthest from the vertical surface member of at least 10 mm. Reinforcement structure.   The reinforcing bracket has a scallop for avoiding a horizontal plane member and a fillet welded portion of a vertical plane member, and the lower surface side of the curved connecting plate or the curved connecting plate and each vertical side plate connected thereto is perpendicular to each vertical side plate. As seen from the side, the lower surface level gradually descends from the tip of the curved connecting plate farthest from the vertical surface member to each vertical side plate, and has an arc-shaped notch so as to approach the vertical surface material. The steel structure reinforcing structure according to claim 1, wherein the steel structure is reinforced.   A method of reinforcing a steel structure in which a vertical surface material is integrally provided by welding on a lower surface side of a horizontal surface material, and a vertical stiffener is fixed to the vertical surface material or across the vertical surface material and the horizontal surface material by welding. In order to surround the horizontal portion of the upper end of the vertical stiffener, a pair of vertical plates and a U-shaped cross section integrally connected to each vertical plate at intervals on both sides of the vertical stiffener or After arranging the reinforcing metal fittings having the arc-shaped curved connecting plates, the vertical side plates and the upper ends of the curved connecting plates and the horizontal plane members of the reinforcing metal fittings are fixed by welding, and the vertical side plates and the vertical surface materials are welded and joined. Or the method of reinforcing a steel structure characterized by bolting.   A method of reinforcing a steel structure in which a vertical surface material is integrally provided by welding on a lower surface side of a horizontal surface material, and a vertical stiffener is fixed to the vertical surface material or across the vertical surface material and the horizontal surface material by welding. In order to surround the horizontal portion of the upper end of the vertical stiffener, a pair of vertical plates and a U-shaped cross section integrally connected to each vertical plate at intervals on both sides of the vertical stiffener or A reinforcing metal fitting having an arc-shaped curved connecting plate, and a reinforcing metal fitting in which one end side of a joint metal piece is joined to a front end portion of each vertical side plate with a bolt in a temporarily tightened state, and is perpendicular to the other end side of the joint metal piece The material is joined in a temporarily tightened state with a bolt, and the reinforcing bracket is held in a predetermined position, and then the upper end of each vertical side plate and the curved connecting plate in the reinforcing bracket and the horizontal plane material are fixed by welding, and then joined. Tighten the bolt that joins the hardware to the vertical surface. Steel structures method of reinforcement which is characterized.   A method of reinforcing a steel structure in which a vertical surface material is integrally provided by welding on a lower surface side of a horizontal surface material, and a vertical stiffener is fixed to the vertical surface material or across the vertical surface material and the horizontal surface material by welding. 9. The method for reinforcing a steel structure according to claim 7, wherein an upper end portion of the vertical stiffener is separated from a lower surface of the horizontal plane member.