JP6573477B2 - Steel girder reinforcement method - Google Patents

Description

The present invention relates to a steel beam reinforcing method suitable for reinforcing a steel beam having a substantially H-shaped cross section.

When a railway runs on a viaduct, repeated loads are applied to the bridge girder. When the H-section steel is used for the bridge girder, the H-section steel may be deformed in a twisting direction due to the repeated load. For example, as shown in FIG. 6, the H-shaped steel web swings in the direction perpendicular to the bridge axis, and fatigue cracks may occur due to out-of-plane deformation accompanying the swing.
In order to suppress the out-of-plane deformation of the web and suppress the occurrence and progression of fatigue cracks, reinforcing materials may be reinforced by welding on both sides of the web, but the welded part may become a weak point due to metal fatigue. Therefore, reinforcement without welding is also being considered.

For example, a technique is known in which a reinforcing material is joined to both sides of a web with a bolt to reinforce (for example, see Patent Document 1).
Further, in order to reinforce the H-shaped steel web, a stiffener jack is known in which the dimension is adjusted between the flanges of the H-shaped steel, and the upper end and the lower end are abutted against and fixed to the upper flange and the lower flange, respectively ( For example, refer nonpatent literature 1.).

Japanese Patent No. 5116708

Hirose Giken Co., Ltd. website, [Search on March 6, 2015], Internet <URL: https://www.hirose-giken.co.jp/products/chuck_jack.html>

However, since the technique of the above-mentioned Patent Document 1 uses an infinite number of bolts to join the reinforcing material to the web, it may take time to install the reinforcing material. It may not be applicable to places where it is difficult to finish construction outside.
In addition, if the stiffener jack is fixed between the upper flange and the lower flange and then the distance between the upper flange and the lower flange may increase due to a load or vibration acting on the bridge girder, the stiffener jack may be detached.

The objective of this invention is providing the steel girder reinforcement method which can reinforce suitably the steel girder which has a substantially H-shaped cross section.

In order to achieve the above object, a steel girder reinforcing method according to the present application is as follows:
A steel girder reinforcement method for reinforcing a steel girder having a substantially H-shaped cross section formed by connecting an upper flange and a lower flange with a web,
Biasing means configured to be able to bias the first member and the second member in directions away from each other by an elastic member provided between the first member and the second member are installed on both sides of the web, respectively. In order to press the first member toward the upper flange by the elastic restoring force of the elastic member and press the second member toward the lower flange,
The urging means is installed between the upper flange and the lower flange in a state where the elastic member is contracted, and then the elastic member is extended so that the first member and the second member are respectively connected to the upper member. An urging force in a direction to separate the upper flange and the lower flange is applied by pressing the flange and the lower flange.

If urging means are installed on both sides of a steel girder web having a substantially H-shaped cross section, the first member is pressed toward the upper flange, and the second member is pressed toward the lower flange. Since the flange can be urged in the direction in which the flange is separated, the steel beam can be reinforced so as to suppress the swinging of the web in the direction perpendicular to the bridge axis.
In particular, after the biasing means including the elastic member contracted by prestress is placed between the upper flange and the lower flange, the elastic member is extended and both end portions of the biasing member ( If the first member and the second member are respectively brought into pressure contact with the upper flange and the lower flange, a biasing means is provided between the upper flange and the lower flange by utilizing the force (elastic restoring force) that the elastic member expands. Since the steel girder reinforcement structure for reinforcing the steel girder can be constructed in a short time.

In order to achieve the above object, a steel girder reinforcing method according to the present application is as follows:
A steel girder reinforcement method for reinforcing a steel girder having a substantially H-shaped cross section formed by connecting an upper flange and a lower flange with a web,
Biasing means configured to be able to bias the first member and the second member in directions away from each other by an elastic member provided between the first member and the second member are installed on both sides of the web, respectively. In order to press the first member toward the upper flange by the elastic restoring force of the elastic member and press the second member toward the lower flange,
After the urging means is installed between the upper flange and the lower flange, the first member and the elastic member are pushed up toward the upper flange, and the first member is brought into contact with the upper flange. Also, the elastic member is pushed up toward the upper flange to contract the elastic member, thereby pressing the first member and the second member against the upper flange and the lower flange, respectively. An urging force in the direction of separating the lower flange was applied.

If urging means are installed on both sides of a steel girder web having a substantially H-shaped cross section, the first member is pressed toward the upper flange, and the second member is pressed toward the lower flange. Since the flange can be urged in the direction in which the flange is separated, the steel beam can be reinforced so as to suppress the swinging of the web in the direction perpendicular to the bridge axis.
In particular, after the biasing means including the elastic member is placed between the upper flange and the lower flange, the first member and the elastic member are pushed up toward the upper flange to bring the first member into contact with the upper flange. Further, the elastic member is pushed up, post-stress is applied to the elastic member, the elastic member is contracted, and both ends (first member and second member) of the urging member are pressed against the upper flange and the lower flange, respectively. By doing so, an urging means can be installed between the upper flange and the lower flange using the force (elastic restoring force) that the elastic member expands, so a steel girder reinforcement structure that reinforces the steel girder is provided. Easy to install.

In order to achieve the above object, a steel girder reinforcing method according to the present application is as follows:
A steel girder reinforcement method for reinforcing a steel girder having a substantially H-shaped cross section formed by connecting an upper flange and a lower flange with a web,
Biasing means configured to be able to bias the first member and the second member in directions away from each other by an elastic member provided between the first member and the second member are installed on both sides of the web, respectively. In order to press the first member toward the upper flange by the elastic restoring force of the elastic member and press the second member toward the lower flange,
After the urging means is installed between the upper flange and the lower flange, the first member is pushed up toward the upper flange, and the second member and the elastic member are pushed down toward the lower flange. Even after the first member is brought into contact with the upper flange, the elastic member is contracted by pushing the elastic member downward toward the lower flange, thereby causing the first member and the second member to be respectively contracted. An urging force in a direction to separate the upper flange and the lower flange is applied by pressing the flange and the lower flange.

If urging means are installed on both sides of a steel girder web having a substantially H-shaped cross section, the first member is pressed toward the upper flange, and the second member is pressed toward the lower flange. Since the flange can be urged in the direction in which the flange is separated, the steel beam can be reinforced so as to suppress the swinging of the web in the direction perpendicular to the bridge axis.
In particular, after the biasing means including the elastic member is placed between the upper flange and the lower flange, the first member is pushed up toward the upper flange to bring the first member into contact with the upper flange, and the second The member and the elastic member are pushed down toward the lower flange, post-stress is applied to the elastic member to contract the elastic member, and both end portions (first member and second member) of the biasing member are moved upward. If the flange and the lower flange are pressed against each other, an urging means can be installed between the upper flange and the lower flange using the force (elastic restoring force) that the elastic member expands. The steel girder reinforcement structure to be reinforced can be easily constructed.

  According to the present invention, a steel girder having a substantially H-shaped cross section can be suitably reinforced.

It is a front view which shows the steel girder reinforcement structure of this embodiment. It is sectional drawing for demonstrating the steel girder reinforcement method of Embodiment 1, the state (a) which mounted the urging | biasing means between the upper flange and the lower flange, and extending | stretching the elastic member which was shrunk and attaching. A state (b) in which both ends of the biasing means are pressed against the upper flange and the lower flange is shown. It is sectional drawing for demonstrating the steel girder reinforcement method of Embodiment 2, the state (a) which mounted the urging means between the upper flange and the lower flange, and contracting an elastic member, pushing up a shaft. A state (b) in which both ends of the urging means are pressed against the upper flange and the lower flange is shown. It is sectional drawing for demonstrating the modification of Embodiment 2, and is the state (a) which mounted the urging means between the upper flange and the lower flange, and urged | biased by contracting an elastic member, pushing up a cylinder A state (b) in which both ends of the means are pressed against the upper flange and the lower flange is shown. It is sectional drawing which shows the modification of a steel girder reinforcement structure. It is explanatory drawing regarding the out-of-plane deformation | transformation of the web of H-section steel.

  Hereinafter, embodiments of a steel girder reinforcement structure and a steel girder reinforcement method according to the present invention will be described in detail with reference to the drawings. However, the embodiments described below are given various technically preferable limitations for carrying out the present invention, but the scope of the present invention is not limited to the following embodiments and illustrated examples.

(Embodiment 1)
FIG. 1 is a front view showing a steel girder reinforcement structure 100.
The steel girder reinforcing structure 100 is a structure for reinforcing a steel girder 1 having a substantially H-shaped cross section formed by connecting an upper flange 1a and a lower flange 1b with a web 1c.
The steel girder 1 is disposed on a support structure 2 such as a bridge pier or an abutment, and a floor slab 3 on which a track can be laid is laid on the steel girder 1.

  For example, as shown in FIG. 1, the steel girder reinforcing structure 100 of the present embodiment includes a cylindrical body 11, a shaft body 12 attached to the cylindrical body 11 so as to be able to project and retract, and the cylindrical body 11 and the shaft body 12. The urging means 10 provided with the elastic member 13 that can be stretched is disposed on both sides of the web 1 c of the steel girder 1.

The cylindrical body 11 has a cylindrical shape whose upper end is closed by a top surface portion, and a shaft body 12 is inserted into the cylindrical body 11 from an opening on the lower end side.
The shaft body 12 is arranged in the cylindrical body 11 so as to be able to advance and retreat in the axial direction.
The elastic member 13 is, for example, a spring member (here, a coil spring), and has one end abutted against the cylindrical body 11 and the other end abutted against the shaft body 12. The elastic member 13 biases the cylindrical body 11 and the shaft body 12 in a direction in which they are separated from each other.

The biasing means 10 presses the upper surface (top surface portion) of the cylindrical body 11 against the upper flange 1a by a repulsive force (elastic restoring force) that the elastic member 13 inserted in the cylindrical body 11 expands, and the shaft body 12 The cylinder 11 as the first member is pressed toward the upper flange 1a, and the shaft 12 as the second member is pressed toward the lower flange 1b.
That is, the urging means 10 applies the urging force in the direction in which the cylinder 11 is brought into contact with the upper flange 1a and the shaft 12 is brought into contact with the lower flange 1b so that the upper flange 1a and the lower flange 1b are separated from each other. Yes.
This urging means 10 is installed in pairs on both sides of the web 1c in such a manner as to sandwich the web 1c of the steel beam 1. In FIG. 1, a pair of urging means 10 is installed on the steel beam 1, but two or more pairs of urging means 10 may be installed.

At a portion where the upper surface of the cylinder 11 and the upper flange 1a are in pressure contact, at least one of the upper surface of the cylinder 11 and the lower surface of the upper flange 1a is subjected to a process for increasing frictional resistance. Similarly, at a portion where the lower surface of the shaft body 12 and the lower flange 1b are in pressure contact, at least one of the lower surface of the shaft body 12 and the upper surface of the lower flange 1b is subjected to a process of increasing frictional resistance.
For example, as a process to increase the frictional resistance of the pressed part, a processing process that gives fine irregularities so as to make the surface of the pressed part rough, or a sheet containing hard particles or hard particles at the interface of the pressed part There is a process to insert a material.
Such a process of increasing the frictional resistance is applied to a portion where the upper surface of the cylindrical body 11 and the upper flange 1a are in pressure contact and a portion where the lower surface of the shaft body 12 and the lower flange 1b are in pressure contact. Thus, the biasing means 10 attached between the flanges of the steel beam 1 is difficult to shift, and the posture of the biasing means 10 between the flanges is stabilized.

  As described above, the steel girder reinforcing structure 100 of the present embodiment is provided with the biasing means 10 in pairs on both sides of the web 1c of the steel girder 1, and the biasing means 10 includes the upper flange 1a. Since the lower flange 1b is biased in the direction of separating, the steel girder 1 can be reinforced so as to suppress the swinging of the web 1c in the direction perpendicular to the bridge axis, resulting from out-of-plane deformation of the web 1c. It is possible to suppress the occurrence and progress of fatigue cracks.

In particular, the urging means 10 urges the upper flange 1a and the lower flange 1b in a direction separating the upper flange 1a and the lower flange 1b by the repulsive force that the elastic member 13 expands. When an out-of-plane deformation (for example, an out-of-plane deformation as shown in FIG. 6) occurs, the elastic member 13 of the urging means 10 installed on the right side of the web 1c contracts and spring resistance (repulsive force) is generated. The elastic member 13 of the urging means 10 installed on the left side of the web 1c is extended and the spring resistance (repulsive force) is weakened.
That is, the urging force of the urging means 10 on the side where the upper flange 1a is inclined downward is strong, and the urging force of the urging means 10 on the opposite side across the web 1c is weakened. A force suitable for restoring the steel girder 1 deformed out of plane can be applied.

  Next, a procedure for installing the urging means 10 on the steel beam 1 will be described with respect to the steel beam reinforcement method of the present embodiment.

First, the elastic member 13 is inserted into the cylindrical body 11 and the shaft body 12 is further inserted into the cylindrical body 11, and the elastic member 13 is contracted between the top surface portion of the cylindrical body 11 and the shaft body 12. The cylindrical body 11 and the shaft body 12 are temporarily fastened by the engagement pin P so as to restrict the shaft body 12 from being pushed out of the cylindrical body 11 by the elastic member 13 contracted.
Then, as shown in FIG. 2A, the urging means 10 temporarily secured by the engagement pin P is installed so as to form a pair on both sides of the web 1 c of the steel girder 1.

Next, as shown in FIG. 2B, the urging means 10 presses the upper surface of the cylindrical body 11 against the upper flange 1a by removing the engagement pin P and extending the contracted elastic member 13. Thus, the cylinder body 11 is pressed toward the upper flange 1a, the lower surface of the shaft body 12 is pressed against the lower flange 1b, and the shaft body 12 is pressed toward the lower flange 1b. The elastic member 13 pressing the cylinder 11 toward the upper flange 1a and pressing the shaft body 12 toward the lower flange 1b is not fully extended, and the elastic member 13 is in a contracted state to some extent. The cylinder body 11 and the shaft body 12 are biased in the direction of separating.
Thus, the urging means 10 that urges the upper flange 1a and the lower flange 1b in the direction of separating can be easily installed between the upper flange 1a and the lower flange 1b, and the steel girder reinforcing structure 100 is configured. Can do.

  Thus, by extending the contracted elastic member 13, the biasing means 10 can be easily installed between the upper flange 1a and the lower flange 1b, and the steel girder reinforcing structure 100 can be constructed in a short time. can do.

As described above, in the steel girder reinforcement structure 100 of the present embodiment, the urging means 10 is installed between the upper flange 1a and the lower flange 1b using the force (repulsive force) that the elastic member 13 expands. Therefore, the steel girder 1 can be reinforced in a short time without welding the urging means 10 to the steel girder 1.
The biasing means 10 installed between the upper flange 1a and the lower flange 1b presses the cylindrical body 11 toward the upper flange 1a by the repulsive force of the elastic member 13, and the shaft body 12 is pressed against the lower flange 1b. Since the distance between the upper flange 1a and the lower flange 1b may slightly increase due to a load or vibration acting on the steel girder 1, the cylinder 11 is pressed against the upper flange 1a. Since the shaft body 12 can be brought into pressure contact with the lower flange 1b, it does not come off like the stiffener jack of the prior art.
Further, since the urging means 10 is not welded to the steel beam 1, it is possible to easily perform the work of exchanging the urging means 10 in which a failure has occurred or exchanging the urging means 10 having a different spring force. it can.
Thus, if the steel girder reinforcement structure 100 of this embodiment is used, the steel girder 1 having a substantially H-shaped cross section can be suitably reinforced.

In the steel girder reinforcing structure 100 described above, the urging means 10 is installed so as to press the cylindrical body 11 toward the upper flange 1a and press the shaft body 12 toward the lower flange 1b. The urging means 10 may be installed so that the cylinder body 11 is pressed toward the lower flange 1b, and the shaft body 12 is pressed toward the upper flange 1a with the top and bottom of 10 reversed.
If the urging means 10 is installed with the cylinder 11 on the upper side and the shaft body 12 on the lower side, the rainwater does not accumulate in the cylinder 11.

(Embodiment 2)
Next, Embodiment 2 of the steel girder reinforcement structure and steel girder reinforcement method according to the present invention will be described. In addition, the same code | symbol is attached | subjected to the same part as Embodiment 1, and only a different part is demonstrated.

The urging means 10 of the steel girder reinforcement structure 100 according to the second embodiment has an upper surface of the shaft body 12 by the repulsive force of the elastic member 13 inserted in the cylindrical body 11 as shown in FIG. Is pressed against the upper flange 1a, and the lower surface (bottom surface portion) of the cylindrical body 11 is pressed against the lower flange 1b, and the shaft body 12 as the first member is pressed toward the upper flange 1a to serve as the second member. The cylinder 11 is pressed toward the lower flange 1b. The urging means 10 also urges the upper flange 1a and the lower flange 1b in a direction to separate them from each other.
In addition, the process which increases frictional resistance is given to the part which the upper surface of the shaft body 12 and the upper flange 1a press-contact, and the part which the lower surface of the cylinder 11 and the lower flange 1b press-contact, The biasing means 10 attached between the flanges of the steel beam 1 is difficult to shift.

  Next, a procedure for installing the biasing means 10 on the steel beam 1 will be described with respect to the steel beam reinforcing method of the second embodiment.

First, as shown in FIG. 3A, the elastic member 13 is attached to the lower surface of the shaft body 12, the member having the movable plate 13 a attached to the lower end of the elastic member 13, and the movable plate 13 a as the lower surface side of the cylindrical body 11. It inserts in the cylinder 11 so that it may distribute. A space is provided between the movable plate 13 a inserted into the cylinder 11 and the lower surface of the cylinder 11.
The movable plate 13 a has a size that is in close contact with the inner wall of the cylindrical body 11.

Next, as shown in FIG. 3 (b), the solidification material 14 is injected into the space in the cylinder 11 from the injection port 11 a provided in the lower part of the cylinder 11, and the movable plate 13 a is moved onto the cylinder 11. The elastic member 13 and the shaft body 12 are pushed up together with the movable plate 13a, and the upper surface of the shaft body 12 is brought into contact with the upper flange 1a. Even after the upper surface of the shaft 12 is brought into contact with the upper flange 1a, the solidified material 14 is injected into the cylindrical body 11 so that the movable plate 13a and the elastic member 13 are pushed up to contract the elastic member 13. In addition, as the solidifying material 14, mortar or the like can be used.
Then, the urging means 10 is fixed to the shaft body 12 by solidifying the solidified material 14 injected into the cylindrical body 11 while the elastic member 13 is contracted to a predetermined length between the movable plate 13a and the shaft body 12. The shaft body 12 is pressed against the upper flange 1a by pressing the upper surface of the cylinder 11 toward the upper flange 1a, and the cylinder 11 is pressed toward the lower flange 1b by pressing the lower surface of the cylinder 11 against the lower flange 1b. Become.
Thus, the urging means 10 that urges the upper flange 1a and the lower flange 1b in the direction of separating can be easily installed between the upper flange 1a and the lower flange 1b, and the steel girder reinforcing structure 100 is configured. Can do.

  In this way, the upper flange 1a and the lower flange are brought into pressure contact with the upper flange 1a and the lower flange 1b by causing both ends (the cylindrical body 11 and the shaft body 12) of the biasing member 10 to contract while the elastic member 13 is contracted. The biasing means 10 can be installed between 1b, and the steel girder reinforcement structure 100 can be constructed easily.

  In addition, since the biasing means 10 of the second embodiment also presses the shaft body 12 toward the upper flange 1a and the cylinder body 11 toward the lower flange 1b by the repulsive force of the elastic member 13, the steel body 11 is pressed toward the lower flange 1b. Even if the gap between the upper flange 1a and the lower flange 1b slightly increases due to the load or vibration acting on the beam 1, the shaft body 12 is pressed against the upper flange 1a and the cylinder 11 is pressed against the lower flange 1b. Can be made.

  Even in the steel girder reinforcing structure 100 of the second embodiment, the urging means 10 is installed between the upper flange 1a and the lower flange 1b by using the force (repulsive force) that the elastic member 13 expands. The steel girder 1 having a substantially H-shaped cross section can be suitably reinforced.

  In the second embodiment described above, the cylinder body 11 is placed on the lower flange 1b (see FIG. 3A), and then the solidified material 14 is injected to push up the shaft body 12 toward the upper flange 1a. Although the case has been described, the cylinder body 11 and the shaft body 12 may be turned upside down.

  For example, as shown in FIG. 4A, the elastic member 13 is attached to the upper surface of the shaft body 12, and the member having the movable plate 13 a attached to the upper end of the elastic member 13 is attached so as to cover the cylindrical body 11. A space is provided between the movable plate 13 a inserted into the cylinder 11 and the upper surface of the cylinder 11.

Next, as shown in FIG. 4B, the solidifying material 14 is injected into the space in the cylinder 11 from the injection port 11a provided in the cylinder 11, and the cylinder 11 as the first member is moved upward. The upper surface of the cylinder 11 is brought into contact with the upper flange 1a. Further, by injecting the solidified material 14 into the cylindrical body 11, the shaft body 12 and the elastic member 13 as the second member are pushed down toward the lower flange 1b. Here, even after the upper surface of the cylindrical body 11 is brought into contact with the upper flange 1a, the solidified material 14 is injected into the cylindrical body 11 so that the movable plate 13a and the elastic member 13 are pressed down to contract the elastic member 13.
Then, the urging means 10 is configured to solidify the solidified material 14 injected into the cylindrical body 11 in a state where the elastic member 13 is contracted to a predetermined length between the movable plate 13 a and the shaft body 12. The cylinder body 11 is pressed against the upper flange 1a by pressing the upper surface of the shaft 11 against the upper flange 1a, and the shaft body 12 is pressed against the lower flange 1b by pressing the lower surface of the shaft body 12 against the lower flange 1b. Become.
Thus, the urging means 10 that urges the upper flange 1a and the lower flange 1b in the direction of separating can be easily installed between the upper flange 1a and the lower flange 1b, and the steel girder reinforcing structure 100 is configured. Can do.

The present invention is not limited to the above embodiment.
For example, as shown in FIG. 5, the upper surface of the shaft body 12 is pressed against the upper flange 1 a by the repulsive force of the elastic member 13 inserted in the cylinder body 11, and the lower surface (bottom surface portion) of the cylinder body 11 is lowered. The urging means 10 configured to be in pressure contact with the flange 1b may be provided with an absorber function.
Specifically, for example, as shown in FIG. 5, the biasing means 10 having an absorber function includes an elastic member 13 inserted into the cylindrical body 11, a movable plate 13 a attached to the upper end of the elastic member 13, and a movable member. An inner tube 12a provided on the upper surface of the plate 13a, a piston 12b provided on the lower surface of the shaft body 12 that advances and retreats in the cylindrical body 11, and is inserted into the inner tube 12a, a movable plate 13a, and the shaft body 12 An oil 15 or the like filled in the cylinder 11 is provided. The oil 15 can flow in and out of the inner tube 12a through an orifice 12c provided in the inner tube 12a.
Even the steel girder reinforcement structure 100 provided with such an urging means 10 can suitably reinforce the steel girder 1 having a substantially H-shaped cross section.

  Further, when the biasing means 10 having the above-described absorber function is installed on the steel beam 1, the cylindrical body 11 may be pressed against the upper flange 1a and the shaft body 12 may be pressed against the lower flange 1b.

  In the above embodiment, a spring member (for example, a coil spring) has been described as an example of the elastic member 13. However, the present invention is not limited to this, and for example, the elastic member 13 can be expanded and contracted. A member in which a compressed gas is sealed in a simple bag body may be used.

  In addition, it is needless to say that other specific detailed structures can be appropriately changed.

DESCRIPTION OF SYMBOLS 1 Steel girder 1a Upper flange 1b Lower flange 1c Web 2 Support structure 3 Floor slab 10 Energizing means 11 Cylindrical body 11a Inlet 12 Shaft body 13 Elastic member 13a Movable plate 100 Steel girder reinforcement structure

Claims (3)

A steel girder reinforcement method for reinforcing a steel girder having a substantially H-shaped cross section formed by connecting an upper flange and a lower flange with a web,
Biasing means configured to be able to bias the first member and the second member in directions away from each other by an elastic member provided between the first member and the second member are installed on both sides of the web, respectively. In order to press the first member toward the upper flange by the elastic restoring force of the elastic member and press the second member toward the lower flange ,
The urging means is installed between the upper flange and the lower flange in a state where the elastic member is contracted, and then the elastic member is extended so that the first member and the second member are respectively connected to the upper member. A method for reinforcing a steel girder , comprising pressing a flange and the lower flange to apply an urging force in a direction in which the upper flange and the lower flange are separated from each other . A steel girder reinforcement method for reinforcing a steel girder having a substantially H-shaped cross section formed by connecting an upper flange and a lower flange with a web,
Biasing means configured to be able to bias the first member and the second member in directions away from each other by an elastic member provided between the first member and the second member are installed on both sides of the web, respectively. In order to press the first member toward the upper flange by the elastic restoring force of the elastic member and press the second member toward the lower flange ,
After the urging means is installed between the upper flange and the lower flange, the first member and the elastic member are pushed up toward the upper flange, and the first member is brought into contact with the upper flange. Also, the elastic member is pushed up toward the upper flange to contract the elastic member, thereby pressing the first member and the second member against the upper flange and the lower flange, respectively. A method for reinforcing a steel girder characterized by applying an urging force in a direction to separate the lower flange . A steel girder reinforcement method for reinforcing a steel girder having a substantially H-shaped cross section formed by connecting an upper flange and a lower flange with a web,
Biasing means configured to be able to bias the first member and the second member in directions away from each other by an elastic member provided between the first member and the second member are installed on both sides of the web, respectively. In order to press the first member toward the upper flange by the elastic restoring force of the elastic member and press the second member toward the lower flange ,
After the urging means is installed between the upper flange and the lower flange, the first member is pushed up toward the upper flange, and the second member and the elastic member are pushed down toward the lower flange. Even after the first member is brought into contact with the upper flange, the elastic member is contracted by pushing the elastic member downward toward the lower flange, thereby causing the first member and the second member to be respectively contracted. A method for reinforcing a steel girder , comprising pressing a flange and the lower flange to apply an urging force in a direction in which the upper flange and the lower flange are separated from each other .

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