JP4272180B2 - Steel structure and its reinforcement method - Google Patents

Description

  The present invention is intended for bridge piers and bridge beam structures that support elevated roads including expressways and railways, various bridges, etc., in particular, for existing piers with a steel box cross section, The present invention relates to a reinforcing method for dramatically improving the buckling / deformation strength and a steel structure strengthened by using this reinforcing method. However, the present invention can be applied not only to existing steel structures but also to new steel structures.

  Conventionally, this type of steel box pier is integrated into a square tube (box) by welding four steel plates 1 to each other in the width direction, as shown in FIGS. In addition, a plurality of vertical rib members 5 projecting toward the inner surface are reinforced in parallel on the inner surface side of each steel plate 1, and the pier with a hollow inside is mainly used as a bridge pier for an elevated road throughout the country. Implemented and used.

  The steel box piers made in this way are designed and manufactured so as to sufficiently retain at least the strength estimated to be necessary at the time of construction. However, this steel bridge pier contains an unstable element that buckles when subjected to a large compressive force, and may lose its function as a structure. Don't be.

In particular, the Hyogoken-Nanbu Earthquake has revealed this, and since then, various types of seismic reinforcement have been applied to existing steel piers. The main methods of seismic reinforcement can be divided into the following three types.
1. A method of filling concrete into existing steel piers.
2. A method of attaching a carbon fiber to an existing steel pier with a resin (adhesive) to form a composite structure.
3. A method to attach a steel reinforcing member to an existing steel pier by welding or using high-strength bolts.

3. As a technique for attaching a reinforcing member made of steel to an existing steel pier by welding or bolting, as shown in FIG. 10, along the longitudinal direction outside the four corners of the steel pier 1 having a box-shaped cross section. As shown in FIG. 11, the steel material 2 in the form of an angle is fixed by welding or bolts, or as shown in FIG. A technique for attaching the vertical direction by welding or bolting is already known in the literature.
JP-A-9-1111719 Japanese Patent Laid-Open No. 10-306408

Each of the above reinforcing methods is an effective technique for preventing buckling of a steel pier, but has the following problems.
1. In this method, since the weight of the structure is heavy, reinforcement such as so-called footing of the basic structure may be necessary. Or, there are restrictions for that.
2. In this method, since the carbon fiber is expensive, the overall business cost is increased.
3. In this method, welding work at the work site is required, and when the reinforcing member is attached to the inside of the steel pier using welding means, it becomes work to bring in equipment in a narrow existing structure, Work efficiency is very poor and measures such as an oxygen deficiency accident are also required. Moreover, when attaching a reinforcement member to the outer surface of a steel bridge pier, the fall of an external appearance is caused and it is not preferable.

  Therefore, the present invention aims to solve each problem included in such prior arts, and can prevent buckling, which is a weak point of steel structures, in steel structures, Or, by applying reinforcement that can be delayed, the toughness of steel structures can be remarkably improved, and it is possible to enhance the seismic resistance and load capacity of steel bridge piers, columns, beams, etc. It is a thing.

  The first structure of the steel structure according to the present invention taken in order to achieve the object will be described with reference to the reference numerals used in the examples. The reinforcing steel plate 2 provided with the stud gibel 3 on one side 2b is made of an adhesive a interposed between the one side 2b of the reinforcing steel plate 2 and the outer surface side 1a of the existing steel plate 1 constituting the steel structure C. With the adhesive force and the tightening force of the nut 4 screwed into the threaded portion 3a of each stud gibber 3 projecting to the inner surface 1b of the existing steel plate 1 through the stud hole h formed in the existing steel plate 1, the existing steel plate 1 is fixed to the outer surface side 1a.

  In addition, the second structure of the steel structure includes a plurality of threaded stud gibels 3 which are planted and fixed to the inner surface 1b of the existing steel sheet 1 constituting the steel structure C with a predetermined interval. , Nuts tightened by screwing into the screw portions 3a of the respective stud gibbles 3 projecting to the inner surface side 12b through stud holes h formed in the inner surface reinforcing plate 12 made of FRP plate, carbon fiber plate, concrete plate or the like. 4 and the adhesive force of the adhesive a interposed between the inner surface 1b of the existing steel plate 1 and the opposing surface 12a of the inner surface reinforcing plate 12, the reinforcing plate 12 is attached to the inner surface 1b of the existing steel plate 1. It is set as the structure fixed to the multilayer form.

  Moreover, the structure of the reinforcement method of the steel structure of the said 1st structure is the steel plate 2 for outer surface reinforcement formed in the magnitude | size which covers the outer surface side 1a of the to-be-reinforced part 1A of the existing steel plate 1 which comprises the steel structure C. On one side 2b of the steel sheet, a reinforcing steel plate 2 is formed, in which a number of threaded stud dowels 3 are planted and fixed by well-known means such as welding means, metal bonding means, screw standing means, etc. at a required interval, In the reinforced portion 1A of the existing steel plate 1, a stud hole h is drilled and formed at a location corresponding to the planting formation location of the stud gibel 3, and the stud gibel planting surface 2b of the reinforcing steel plate 2 is formed as the existing steel plate 1. The front end portion of each stud gibber 3 is projected to the inner surface side 1b of the existing steel plate 1 through each stud hole h, and the nut 4 is screwed to the threaded portion 3a of each stud diver 3 that protrudes. Let me On the other hand, an adhesive a is applied to either one of the surfaces 1a, 2b or both surfaces before the outer surface side 1a of the existing steel plate 1 and the stud-jivel planting surface 2b of the outer surface reinforcing steel plate 2 are opposed to each other. Alternatively, after the both surfaces 1a and 2b are arranged to face each other, the adhesive a is injected between the both surfaces 1a and 2b, and the outer surface of the existing steel plate 1 is obtained by the adhesive force of the adhesive a and the tightening force of the nut 4. The outer side reinforcing steel plate 2 is reinforced by adhering it to the side 1a in a multilayered manner.

  Further, the second structure of the steel structure reinforcing method is configured such that a welding means, a metal bonding means, and a screw stand are provided on the inner surface side 1b of the existing steel plate 1 constituting the steel structure C with a predetermined interval. A plurality of threaded stud gibbles 3 are planted and fixed by well-known means such as a fitting means, and between the longitudinal rib members 1c and 1c formed on the inner surface side 1b of the existing steel plate 1, or between the longitudinal rib members 1c and the corner surface A stud hole h is formed at a position corresponding to the planting formation position of each of the threaded stud gibels 3 on the inner surface reinforcing plate 12 formed of a steel plate, FRP plate, carbon fiber plate, concrete plate or the like formed in a width corresponding to The inner surface reinforcing plate 12 is applied to the inner surface side 1b of the existing steel plate 1 and protruded to the inner surface side 12b of the inner surface reinforcing plate 12 through each stud hole h. Screw 4 to tighten Or before applying the inner reinforcing plate 12 to the inner surface side 1b of the existing steel plate 1, either one of these surfaces 1b, 12a or the adhesive a is applied to both surfaces, or these both surfaces 1b, 12a are applied. After the opposing arrangement, the adhesive a is injected between both surfaces 1b and 12a, and the inner surface reinforcing plate 12 is overlapped on the inner surface 1b of the existing steel plate 1 by the adhesive force of the adhesive a and the tightening force of the nut 4. It is reinforced by attaching and fixing in layers.

As is apparent from the above description, the inventions of claims 1 and 3 according to the present invention are a steel plate for reinforcement in which a plurality of threaded stud gibels are formed on one side, and an existing steel plate of a steel structure. The tightening force by the nut tightening to the threaded portion of each stud gibber that protrudes to the inner surface side of the existing steel plate through the stud hole formed in the steel plate, and the adhesive force of the adhesive interposed between the existing steel plate and the reinforcing steel plate Since the steel plate for reinforcement is fixed, the entire outer peripheral surface of the existing steel plate for cultivating the steel structure can be reinforced as a two-layer structure. It was possible to expect a remarkable effect that a steel structure having a large buckling strength can be obtained.
At the same time, the reinforcing steel plate has a Suddjivel standing on only one side, and the other front side surface remains flat, so after the reinforcing steel plate is attached to the existing steel plate, A structure having a flat outer surface can be obtained, and the outer surface is also provided with an advantage that a beautiful pier can be obtained only by applying a rust preventive coating or a colored coating.

  In the inventions of claims 2 and 4 according to the present invention, a large number of threaded studs are planted on the inner surface of the steel plate to be reinforced, and the inner surface contact is formed with stud holes corresponding to the stud gibels that are formed. The plate material for reinforcement is applied to the inner surface of the steel plate to be reinforced through the stud hole, the tightening force by the nut tightening to the threaded portion of each stud gibber protruding from the stud hole, the inner surface of the existing steel plate and the reinforcing plate material Because the reinforcing plate is fixed by the adhesive force of the adhesive interposed between the two, the entire inner peripheral surface of the existing steel plate constituting the steel structure can be reinforced as a two-layer structure. As a result, the yield strength against vertical loads can be greatly increased, and a remarkable effect that a steel structure having a high buckling strength can be obtained can be expected. In addition, in this reinforcement work, there is no need to bring a burner welding instrument or the like in a narrow work space, and only the stud welding work is required, so that an efficient work can be performed without risk of an oxygen deficiency accident or the like. Also have. Further, in the case of this reinforcing method, there is an advantage that it is not necessary to perform any special work on the outer surface of the wall to be reinforced, and can be performed without requiring traffic regulation or the like when performing the work.

  Since the present invention is configured as described above, in the implementation thereof, not only the stat welding in forming the stud gibber, but also drilling the place where the jib is formed, tapping the hole, and providing one end of the stud. It is also possible to form a stud gibber by screwing, and it is preferable to use a detent nut or a double nut to prevent loosening due to vibration.

  Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 are diagrams showing a construction method according to the first embodiment of the present invention, in which FIG. 1 is an exploded perspective view during construction, FIG. 2 is a plan view thereof, and FIG. 3 is a construction completion state. FIG. 4 is a plan view thereof. FIG. 5 is a partially longitudinal side view showing the outline of the construction target pier.

  For convenience of explanation, a method for reinforcing a steel structure having the first structure will be described first. The steel structure C described in the embodiment is an existing pier shown in FIG. 5 as an example, and this existing pier is an elevated road formed on a main girder 21 spanned on a beam 22. This pier 1 is erected on a support frame 23 embedded in a footing 24 formed on a foundation pile 25.

  First, the outer surface reinforcing steel plate 2 is formed in a size necessary to cover the outer surface side 1a of the reinforced portion 1A of the existing steel plate 1 constituting the existing pier, and as shown in FIG. A steel plate fixing rod such as a threaded stud, a bolt, a threaded round bar or the like on the one surface 2b with a required interval, that is, avoiding the location of the reinforcing vertical rib member 1c formed inside the existing steel sheet 1. The reinforcing steel plate 2 is formed by fixing and fixing a number of threaded stud gibbles 3 at the base end of the material by well-known means such as welding means, metal bonding means, and screw standing means.

  This is transported to the installation location of the existing pier to be reinforced, and the stud hole h is formed in each location corresponding to the planting formation location of the stud gibel 3 with respect to the existing steel plate 1 of the reinforced portion 1A of the existing pier. Before or after this drilling operation, the outer surface of the reinforced portion 1A is cleaned by removing deposits such as paint and oil with keren or sandblast.

  Thereafter, an adhesive a such as an epoxy resin is applied to the entire surface 1a or 2b of the outer surface side 1a of the existing steel plate 1 and the stud-dive planting surface 2b of the outer surface reinforcing steel plate 2 or both surfaces 1a and 2b. Apply. Thereafter, as indicated by arrows in FIG. 1 and FIG. 2, the stud-dive planting surface 2b of the reinforcing steel plate 2 is opposed to the outer surface side 1a of the existing steel plate 1, and the tip end portion of each stud-jivel 3 is moved to each side. Through the stud hole h, the steel plate 1 is projected to the inner surface 1b of the existing steel plate 1, and the nut 4 is screwed into the threaded portion 3a of each protruding stud gibel 3 and tightened. In this way, the outer surface reinforcing steel plate 2 is fixed to the outer surface side 1a of the existing steel plate 1 in a double-stacked manner and reinforced by the adhesive force of the adhesive a and the tightening force of the nut 4. Moreover, it is preferable to weld and integrate the corner portions where the outer surface reinforcing steel plates 2 contact each other as necessary.

In order to further reinforce this reinforcement, a continuous sheet of carbon fiber or the like is wound around the entire outer peripheral surface using an adhesive having excellent water resistance and weather resistance to prevent peeling of the reinforcing steel plate 2.
In addition, the outer peripheral surface of the reinforcing steel plate 2 and a portion where the coating of the existing steel plate 1 is removed are painted. Furthermore, when the continuous sheet is rolled up, the outer surface is protected with a fire-resistant coating material.

  As other reinforcing means, without applying the adhesive a to the surface of the outer surface side 1a of the existing steel plate 1 and the stud-dive planting surface 2b of the outer surface reinforcing steel plate 2, these both surfaces 1a, 2b May be disposed directly opposite to each other, and after performing a nut tightening operation from the inner surface side of the existing steel plate 1, an operation means for injecting and bonding an adhesive a made of epoxy resin between both surfaces 1a and 2b may be provided. In this case, it is preferable to interpose a spacer necessary for the wraparound of the injection adhesive a between both surfaces 1a and 2b. Further, without interposing such a spacer, a bolt provided with a head having a thickness adapted to the space required for the wraparound of the injected adhesive a is welded to the reinforcing steel plate 2 in place of the threaded stud. By setting, the head of the bolt can be used as a spacer. The injection of the adhesive a can be performed from the upper end portion of the outer surface reinforcing steel plate 2. However, as another means, an adhesive injection hole is previously formed in an appropriate portion of the reinforcing steel plate 2 and this hole is used. After injecting the adhesive, the hole may be closed. Prior to the injection of the adhesive a, it is preferable to seal necessary portions. Needless to say, also in the case of such reinforcement, double reinforcement can be performed by winding a continuous sheet of carbon fiber or the like on the outer peripheral surface as necessary, as described above.

  Thus, as shown in FIGS. 3 and 4, the outer surface 1 a of the existing steel plate 1 has an outer surface due to the adhesive force by the adhesive a and the tightening force by tightening the nut 4 to the stud stud 3 with a screw. It is possible to obtain a reinforced pier, that is, a reinforced steel structure, which is reinforced by firmly reinforcing the reinforcing steel plates 2 in a double-stacked manner.

  6 to 9 are views showing a second embodiment of the present invention. In this case, the steel plate, FRP has a width corresponding to the width between the longitudinal rib members 1c, 1c in the existing steel plate 1 constituting the existing pier that needs to be reinforced in a factory or the like and the width between the longitudinal rib member 1c and the corner surface. An inner surface reinforcing plate 12 made of a plate, a carbon fiber plate, a concrete plate or the like is formed. Here, the inner surface reinforcing plate 12 is formed by using an FRP plate, and a plurality of stud holes h through which the stud dowels 3 are passed are formed in the inner surface reinforcing plate 12 at a predetermined interval as shown in FIG. Carry it to the installation point of the existing pier to be reinforced.

  In the installation location of the existing pier, after removing the coating such as rust prevention applied to the inner surface side 1b of the existing steel plate 1, the inner surface side 1b corresponds to the numerous stud holes h formed in the inner surface reinforcing plate 12. A stud gibber 3 is formed by stud welding a threaded stud at a location. Thereafter, an adhesive a such as an epoxy resin is applied to the stud welded surface, or an adhesive a is applied to one side of the inner surface reinforcing plate 12 of the FRP plate, and the inner surface reinforcing plate 12 is passed through the stud hole h to the stud gibber 3. Is applied to the inner surface 1b of the existing steel plate 1, and a nut is inserted through a washer 6 to the threaded portion 3a of each stud gibber 3 protruding to the front side of the inner reinforcing plate 12 through each stud hole h, that is, to the inner surface 12b of the existing pier. 4 is screwed and tightened, and the inner reinforcing plate 12 and the existing steel plate 1 are firmly attached so as to be integrated.

  In this way, as shown in FIGS. 8 and 9, the inner surface side 1 b of the existing steel plate 1 is internally reinforced by the adhesive force by the adhesive a and the tightening force by tightening the nut 4 to the stud stud 3 with a screw. It is possible to obtain a reinforced pier, that is, a reinforced steel structure, in which the plate 12 is firmly fixed in a double-stacked manner and reinforced.

  Even when the inner surface reinforcing plate 12 is attached to the inner surface 1b of the existing steel plate 1, the inner surface reinforcing plate 12 is fastened with the bolt 4 to the inner surface 1b of the existing steel plate 1 as described in the first embodiment. Needless to say, after fixing, an adhesive a may be injected between the inner reinforcing plate 12 and the existing steel plate 1. Besides the FRP plate, a carbon fiber plate in which the head of a threaded stud gibber is embedded, a prestressed concrete plate in which an anchor bolt is embedded, and the like can be used as the inner surface reinforcing plate 12.

  Although the embodiments considered to be representative of the present invention have been described above, the present invention is not necessarily limited to the methods and objects shown in these embodiments. For example, a threaded stud gibber or threaded reinforcing bar, The number, thickness, and arrangement of bolts, etc. can be calculated by calculation, and even for these studs, reinforcing bars, bolts, etc., only the same product, such as only studs and reinforcing bars, is unified. The present invention is not limited to use, and can be arbitrarily implemented, such as mixing studs and reinforcing bars, has the structural requirements of the present invention, achieves the object of the present invention, and has an effect. It can be implemented with appropriate modifications within the range.

  The steel structure and the reinforcing method according to the present invention can be easily and reliably constructed and are excellent in economic efficiency, so that they will be increasingly accepted and used nationwide in the future. Is.

The perspective view for explanation of the state just before construction which showed the 1st example. The cross-sectional top view of the principal part which showed the state of FIG. The perspective view for explanation of the construction completion state which showed the 1st example. The cross-sectional top view of the principal part which showed the state of FIG. The side view which showed the bridge pier of the elevated road. The perspective view for explanation of the state just before construction showing the 2nd example. The cross-sectional top view of the principal part which showed the state of FIG. The perspective view for explanation of the construction completion state which showed the 2nd example. The cross-sectional top view of the principal part which showed the state of FIG. The top view for description which showed the well-known technique. The top view for description which showed the other well-known technique.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Existing steel plate 1a Outer surface side 1b Inner surface side 1c Longitudinal rib material 1A Reinforced part 2 Reinforcing steel plate 2b One side (Static bell installation surface)
3 Stud Givel 3a Threaded Part 4 Nut 5 Vertical Rib Material 6 Washer 12 Internal Reinforcement Plate 12a Opposite Side 12b Inner Side C Steel Structure a Bonding Surface h Stud Hole

Claims (4)

A reinforcing steel plate 2 provided on one side 2b with a large number of threaded stud gibels 3 planted and fixed at a required interval is formed on one side 2b of the reinforcing steel plate 2 and the existing steel plate 1 constituting the steel structure C. The adhesive force of the adhesive a interposed between the outer surface side 1a and the threaded portion 3a of each stud dowel 3 projected to the inner surface side 1b of the existing steel plate 1 through the stud hole h formed in the existing steel plate 1 is formed. A steel structure fixed to the outer surface side 1a of the existing steel plate 1 with the tightening force of the nut 4 screwed. An inner surface made of a steel plate, an FRP plate, a carbon fiber plate, a concrete plate, and the like, with a number of threaded stud gibels 3 planted and fixed to the inner surface side 1b of the existing steel plate 1 constituting the steel structure C with a predetermined interval. The tightening force of the nut 4 screwed and tightened to the threaded portion 3a of each stud gibber 3 protruding to the inner surface side 12b through the stud hole h formed in the reinforcing plate 12, and the inner surface side 1b of the existing steel plate 1 A steel structure in which the reinforcing plate 12 is fixed to the inner surface side 1b of the existing steel plate 1 in a multilayered manner by the adhesive force of the adhesive a interposed between the opposing surface 12a of the inner surface reinforcing plate 12. A welding means, a metal bonding means, and a screw are provided on one side 2b of an outer surface reinforcing steel plate 2 formed in a size to cover the outer surface side 1a of the reinforced portion 1A of the existing steel plate 1 constituting the steel structure C with a required interval therebetween. A steel plate for reinforcement 2 in which a large number of threaded stud gibels 3 are planted and fixed is formed by a known means such as a standing-up means, and the stud gibel 3 is implanted in the reinforced portion 1A of the existing steel plate 1 A stud hole h is drilled and formed at a location corresponding to the formation location, the stud-jivel planting surface 2b of the reinforcing steel plate 2 is opposed to the outer surface side 1a of the existing steel plate 1, and the tip portion of each stud-jivel 3 is connected to each other. It protrudes to the inner surface side 1b of the existing steel plate 1 through the stud hole h, and a nut 4 is screwed into the threaded portion 3a of each protruding stud gibel 3 and tightened. On the other hand, the outer surface side 1a of the existing steel plate 1 and the outer surface side reinforcement Adhesive a is applied to either one of the surfaces 1a, 2b or both surfaces before the opposing placement of the plate 2 with the stud-jivel planting surface 2b, or both surfaces 1a, 2b are disposed opposite to each other. The adhesive a is injected between 2b, and the outer surface reinforcing steel plate 2 is fixed to the outer surface side 1a of the existing steel plate 1 in a multilayered manner by the adhesive force of the adhesive a and the tightening force of the nut 4. To reinforce steel structures. A large number of threaded stud dowels 3 are planted and fixed to the inner surface 1b of the existing steel plate 1 constituting the steel structure C by a known means such as a welding means, a metal bonding means, and a screw standing means at a required interval. Steel plate, FRP plate, carbon fiber plate formed in a width corresponding to the length between the longitudinal rib members 1c, 1c formed on the inner surface side 1b of the existing steel plate 1 or between the longitudinal rib member 1c and the corner surface , A stud hole h is formed in the inner reinforcing plate 12 made of a concrete plate or the like at a location corresponding to the planting formation location of each of the threaded stud gibbles 3, and the inner reinforcing plate 12 is formed on the inner surface side of the existing steel plate 1. The nut 4 is screwed and tightened to the threaded portion 3a of each stud gibber 3 that is applied to 1b and protrudes to the inner surface side 12b of the inner surface reinforcing plate 12 through each stud hole h, and is attached to the inner surface side 1b of the existing steel plate 1 Internal reinforcement plate 1 Apply adhesive a to either one of these surfaces 1b, 12a or both surfaces before applying the adhesive, or inject adhesive a between both surfaces 1b, 12a after placing both surfaces 1b, 12a facing each other. Then, the reinforcing method of the steel structure in which the inner surface reinforcing plate 12 is attached and fixed to the inner surface side 1b of the existing steel plate 1 in a multilayered manner by the adhesive force of the adhesive a and the tightening force of the nut 4 to reinforce. .

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