JP6908542B2 - Reinforcement method around the bearing of the steel girder - Google Patents

Description

The present invention relates to a reinforcing method and a reinforcing structure around a support portion of a steel girder which is placed on a sole plate arranged on a pier, an abutment, or the like and repeatedly loaded.

As disclosed in Patent Documents 1-3 and Non-Patent Document 1, steel members such as bridge girders of bridges are subject to fatigue cracks due to repeatedly loaded loads such as train loads and automobile running loads. It has been known.

These documents describe methods for repairing cracks that occur at the ends of steel girders around the sole plate in the structure of bearings where steel girders are placed on the sole plates of the bearings provided on the upper end surface of the pier. Reinforcement methods and the like are disclosed.

Here, in the case of an existing bridge, when the sole plate is removed and the crack is repaired, it is necessary to jack up and temporarily receive the bridge under many restrictions of construction, which is easy to carry out. It's difficult. Therefore, some proposals have been made to suppress the growth of cracks.

For example, Patent Document 1 discloses a method of suppressing the growth of cracks by joining a sole plate and a lower flange of a steel girder by welding or bolting.

Further, in Patent Document 2, the splicing plate placed on the upper side of the lower flange of the steel girder is fixed to the lower flange with a tap bolt, and the splicing plate and the lower flange are bolted to each other at a position separated from the sole plate. A reinforcing structure for fixing with is disclosed.

Further, Patent Document 3 and Non-Patent Document 1 disclose a repair method using a three-sided backing plate member that applies a backing plate to the three surfaces of the abdominal plate of the steel girder, the end stiffener, and the lower flange. ing.

Japanese Unexamined Patent Publication No. 2004-346518 Japanese Unexamined Patent Publication No. 2000-288726 Japanese Unexamined Patent Publication No. 2016-1402434

Shoichiro Otani, Toshio Nishida, "Improvement of 3-sided plate construction method for fatigue cracks near bearings", Japan Society of Civil Engineers 66th Annual Academic Lecture Lecture Summary, September 2011, I-125, pp .249 --250

However, when bolts are used for the lower flange of the steel girder as in Patent Documents 1 and 2, the nut or bolt head is arranged on the lower surface side of the lower flange, so that a narrow space under the steel girder is used. You will have to work upwards in.

On the other hand, in the method using the three-sided backing plate member disclosed in Patent Document 3 and Non-Patent Document 1, the lower flange reinforcing plate is attached to the lower surface side of the lower flange, or the lower flange is bolted. Upward work must be done in a narrow space under the steel girder.

Therefore, an object of the present invention is to provide a reinforcing method and a reinforcing structure around the support portion of the steel girder, which can suppress the growth of cracks around the support portion only by working from above the steel girder.

In order to achieve the above object, the reinforcing method around the support portion of the steel girder of the present invention supplements connecting the web and the lower flange so as to form a vertical face substantially orthogonal to the side surface of the web. The place where the rigid material is provided is a method of reinforcing around the support portion of the steel girder which is placed on the sole plate and repeatedly loaded, and the back portion is opposed to the vertical surface of the rigid material. A step of arranging an L-shaped member having an L-shape in a side view so that the bottom portion faces the lower flange, and a step of inserting a pilot pin penetrating the back portion of the L-shaped member and the stiffener. And the step of providing a tap hole in the sole plate by penetrating the bottom portion of the L-shaped member and the lower flange, and by screwing a tap bolt into the tap hole, the lower surface of the lower flange is made into the sole. It is characterized by including a step of bringing it into close contact with the upper surface of the plate and a step of bolting the back portion and the stiffener.

Further, in the reinforcing structure around the support portion of the steel girder of the present invention, a stiffener is provided to connect the web and the lower flange so as to form a vertical surface substantially orthogonal to the side surface of the web. The location is a reinforcing structure around the support portion of the steel girder that is placed on the sole plate and repeatedly loaded, and the back portion faces the vertical surface of the stiffener and the bottom portion is the lower flange. A side view L-shaped L-shaped member arranged so as to face each other, a tap bolt that penetrates the bottom portion and the lower flange of the L-shaped member and is screwed into the sole plate, and the back portion and the bearing. It is characterized by having a bolted joint for joining a rigid material.

Here, the back portion of the L-shaped member may be configured to have a round hole and an elongated hole. Further, the L-shaped member may be arranged on both sides of the stiffener and on both sides of the web.

In the reinforcing method and reinforcing structure around the support portion of the steel girder of the present invention configured in this way, the L-shaped member is arranged with respect to the stiffener connecting the web and the lower flange, and the stiffener and the L-shaped member are arranged. After connecting with a pilot pin, the lower surface of the lower flange is brought into close contact with the upper surface of the sole plate by screwing a tap bolt into the bottom.

The step of arranging the L-shaped member, the step of providing a tap hole and screwing in the tap bolt, and the step of joining the bolt can all be carried out by working only from above the steel girder.

By bringing the lower surface of the lower flange into close contact with the upper surface of the sole plate, the independent amplitude of the lower flange does not occur even when a repeated load is applied, and the growth of cracks around the bearing portion can be suppressed.

Further, if the web and the lower flange are connected via the stiffener and the L-shaped member, the lower surface of the lower flange and the upper surface of the sole plate are most easily separated from each other around the web, and the lower flange and the sole are brought into close contact with each other. The plate can be reliably integrated. Further, the load acting on the steel girder is transmitted to the lower flange and the sole plate via the L-shaped member, so that a transmission path of the force is formed between the web and the lower flange where cracks are likely to occur or occur. It is possible to reduce the stress generated in the corner portion.

Further, if the hole into which the pilot pin is inserted is brought into close contact as a round hole, stress can be efficiently transmitted through the pilot pin. Further, by making the other holes elongated, even if the L-shaped member rotates and tilts around the pilot pin, bolt joining can be easily performed.

Further, by arranging the L-shaped members at four locations on both sides of the stiffener and on both sides of the web, it is possible to reliably reinforce the periphery of the bearing portion where cracks are likely to occur.

It is explanatory drawing for demonstrating the reinforcement structure around the support part of the steel girder of this embodiment. It is a perspective view explaining the schematic structure of the bridge supported by a rivet girder. It is a figure explaining the situation which can occur in the rivet girder where the crack occurred on both sides of the web, (a) is the cross-sectional view which showed the state before repair, (b) is the state when it repaired only with a tap bolt. It is sectional drawing which showed. It is a perspective view explaining the process of inserting a pilot pin into an L-shaped member. It is sectional drawing explaining the state in which the L-shaped member and the stiffener are connected by a pilot pin. It is sectional drawing explaining the reinforcement structure around the support part of the steel girder of this embodiment. It is a top view for demonstrating the reinforcement structure around the support part of the steel girder of this embodiment. It is explanatory drawing which showed the structure around the support part and the measurement position of the effect confirmation test. It is the figure which compared the displacement distribution before and after reinforcement. It is the figure which compared the principal stress distribution before and after reinforcement. It is the figure which compared the stress distribution before and after reinforcement.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining a reinforcing method and a reinforcing structure around a support portion of the steel girder of the present embodiment, and FIG. 2 is an explanatory view illustrating a schematic configuration of a bridge 1 supported by the steel girder. be.

First, an example of the configuration of the bridge 1 will be described with reference to FIG. The bridge 1 includes, for example, a rivet girder 3 which is a kind of steel girder. The rivet girder 3 is bridged between the abutment and the piers 11 or between the piers 11 and 11.

Further, a floor slab 12 constructed of prestressed concrete, reinforced concrete, or the like is laid on a plurality of rivet girders 3, ... The floor slab 12 may be made of steel.

Then, the end portion of the rivet girder 3 is placed on the support portion 2 installed on the upper end surface 111 of the pier 11.
The support portion 2 includes, for example, a flat plate-shaped seat portion 23 placed on the upper end surface 111 of the pier 11, a shoe portion 22 installed on the seat portion 23, a shoe portion 22, and a rivet girder 3. It is mainly composed of a sole plate 21 interposed between them.

Here, the seat portion 23 is formed of rubber or the like, and the shoe portion 22 and the sole plate 21 are formed of a steel material. Then, as shown in FIG. 1, the end portion of the rivet girder 3 is placed on the upper surface 211 of the flat plate-shaped sole plate 21.

As shown in FIGS. 1 and 2, the rivet girder 3 is formed by the upper flange 33 and the lower flange 31 arranged in parallel in the vertical direction and the abdominal plate 32 serving as a web connecting the upper flange 33 and the lower flange 31. , Mainly composed.

More specifically, the portions where the lower surfaces 311, 311 of the angle steel 310, 310 having a substantially L-shaped cross section attached to both sides of the abdominal plate 32 are formed become the lower flanges 31, 31 of the rivet girder 3. Since the configuration of the upper flange 33 is the same as that of the lower flange 31, detailed description thereof will be omitted.

Then, stiffeners 34, 34 are arranged on both sides of the abdominal plate 32 at the end of the rivet girder 3 arranged on the sole plate 21. The stiffener 34 is formed by superimposing the back surfaces of a pair of angle steels, for example, as shown in the plan view of FIG. That is, the stiffener 34 is formed with a vertical surface 341 substantially orthogonal to the side surface of the abdominal plate 32, and connects the lower flange 31 and the upper flange 33.

In the rivet girder 3, most of the steel materials are joined by the rivet 35. As shown in FIGS. 2 and 8, the connection between the rivet girders 3 and 3 is also performed by joining the brace material 361, the cross member 362 and the like to the gusset plate 36 with the rivet 35.

In the case of a railway bridge, for example, a bridge 1 having such a configuration is repeatedly loaded with a load due to the running of a train. Further, even on a road bridge, a load is repeatedly placed by the running of an automobile.

The force acting on the deck 12 due to the running of a train or an automobile is transmitted to a plurality of rivet girders 3, ... Arranged in parallel under the deck 12. Then, the force acting on the rivet girder 3 is transmitted from the lower flange 31 to the sole plate 21.

As a result, the lower flange 31 is repeatedly moved up and down on the sole plate 21 due to the repeated action of force and unloading. FIG. 3 is a diagram showing a state around the lower flanges 31 and 31 of the rivet girder 3 which has been repeatedly loaded over many years.

As shown in FIG. 3A, a gap S is formed between the upper surface 211 of the sole plate 21 and the lower surfaces 311, 311 of the lower flanges 31 and 31 that have been used for a long period of time due to repeated wear due to repeated load. It will be. Here, the alternate long and short dash line indicates the pre-wear shape 210 of the upper surface 211 of the sole plate 21.
In the present embodiment, it is described that only the sole plate 21 is worn, but the present invention is not limited to this, and the lower surface 311 of the lower flange 31 may be worn.

Even if the upper surface 211 of the sole plate 21 is worn, when the load due to train running or the like does not act on the rivet girder 3, as shown in FIG. 3A, the upper surface 211 and the lower flange 31 of the sole plate 21 There is a gap S between the lower surfaces of 31 and 311, 311.

Here, when the train load T (see FIG. 1) is loaded in the vertical direction with respect to the abdominal plate 32, the lower flanges 31 and 31 together with the abdominal plate 32 fluctuate downward so as to close the gap S.

Normally, the sole plate 21 just below the abdominal plate 32 is most severely worn, so that the angle steel 310 constituting the lower flange 31 is deformed so that the inner angle side becomes an acute angle, and stress concentration occurs. ..

When the stress concentration is repeated many times, cracks R are generated at the stress concentration points of the lower flange 31 and the abdominal plate 32. For example, when cracks R and R occur on both sides of the abdominal plate 32, countermeasures such as repair and reinforcement are required to suppress the growth of the cracks R and R.

Therefore, it is assumed that the rivet girder 3 is repaired by joining the lower flanges 31 and 31 and the sole plate 21 with tap bolts 4 and 4, as shown in FIG. 3 (b).

As a result of such repairs, if misalignments such as stepped portions D and D occur at the cracks R and R positions, there are cases where sufficient repair and reinforcement effects cannot be obtained.

Therefore, in the reinforcing method and the reinforcing structure around the support portion of the steel girder of the present embodiment, even if a crack R occurs in the lower flange 31 on the support portion 2 of the rivet girder 3, the crack R is effectively reinforced. The method that can suppress the progress of the rivet will be described.

In the reinforcing method and the reinforcing structure around the support portion of the steel girder of the present embodiment, the L-shaped member 5 connecting the stiffener 34 and the lower flange 31 is arranged. As shown in FIG. 4, the L-shaped member 5 is formed in an L-shape in a side view by a back portion 51 that stands upright in the vertical direction and a bottom portion 52 that extends in the horizontal direction.

The rectangular plate-shaped back portion 51 faces the vertical surface 341 of the stiffener 34. Further, the rectangular plate-shaped bottom portion 52 faces the upper surface of the lower flange 31 of the rivet girder 3. The L-shaped member 5 can be manufactured by cutting a part of the L-shaped steel or joining two steel plates so as to be substantially orthogonal to each other.

As shown in FIG. 5, for example, a plurality of holes are drilled in the back portion 51 facing the stiffener 34 in accordance with the position of the rivet hole 351 through which the rivet 35 previously attached to the stiffener 34 is inserted. Will be done. Then, one of the plurality of holes is a round hole 54 for inserting the pilot pin 7.

As shown in FIG. 4, the round hole 54 is formed to have an inner diameter substantially the same as (or slightly larger than) the outer diameter of the pilot pin 7. That is, by bringing the pilot pin 7 into close contact with the round hole 54, stress transmission between the stiffener 34 and the L-shaped member 5 is ensured. Further, since rotation around the pilot pin 7 is allowed, the L-shaped member 5 can be tilted when the bottom portion 52 and the lower flange 31 are integrated.

The holes other than the round holes 54 provided in the back portion 51 can be, for example, an elongated hole 53. In the present embodiment, a case where the lowermost hole is a round hole 54 and the elongated holes 53 and 53 are provided at two locations at intervals above the round hole 54 will be described.

The elongated hole 53 is formed in a hole having a height higher than the diameter of the shaft of the bolt 6 used for bolt joining and is long in the width direction of the back portion 51. By making the hole for bolt joining a long hole 53, even if the back portion 51 is tilted, the bolt 6 can be inserted into the rivet hole 351 of the stiffener 34.

On the other hand, the bottom portion 52 is drilled with a tip hole 521 for inserting the tap bolt 4. The tip holes 521 can be provided at, for example, two locations on the abdominal plate 32 side of the rivet girder 3 and on the outer edge side of the lower flange 31.

As shown in FIG. 6, the tap bolt 4 inserted into the tip hole 521 is screwed into the tap hole 41 formed so as to communicate the lower flange 31 and the sole plate 21. That is, a female screw is engraved on the inner circumference of the tap hole 41, and by screwing the tap bolt 4, the bottom portion 52, the lower flange 31, and the sole plate 21 can be integrated.

The L-shaped member 5 is arranged on both sides of the stiffeners 34 and 34 and on both sides of the abdominal plate 32, respectively. That is, as shown in FIG. 7, the upper portion of the rectangular sole plate 21 in a plan view is divided into four sections by the abdominal plate 32 extending in the bridge axis direction and the stiffeners 34 and 34 orthogonal to both sides thereof. Therefore, the L-shaped member 5 is arranged in each section, and the stiffener 34 and the lower flange 31 are connected to each other.

Here, in FIG. 7, since the crack R is shown in all the sections, further growth of the crack R can be suppressed by the reinforcement in which the L-shaped member 5 is arranged. Further, when the L-shaped member 5 is arranged in the section where the crack R is not generated, the growth including the generation of the crack R can be suppressed.

Explaining the reinforcing method around the support portion of the steel girder of the present embodiment in the order of the steps, first, the rivet 35 of the stiffener 34 in the range in contact with the L-shaped member 5 is removed in advance to expose the rivet hole 351. ..

Subsequently, as shown in FIG. 4, the L-shaped member 5 is arranged so that the back portion 51 faces the vertical surface 341 of the stiffener 34 and the bottom portion 52 faces the lower flange 31. The L-shaped member 5 is arranged on both sides of the stiffener 34.

Then, the pilot pin 7 is inserted so as to penetrate the back portion 51 of the L-shaped member 5 and the back portion 51 on the opposite side of the stiffener 34. FIG. 5 shows a state in which the pilot pin 7 is inserted. At this stage, since the L-shaped member 5 is not tilted, the rivet hole 351 of the stiffener 34 is arranged substantially in the center where the elongated hole 53 is projected.

On the other hand, the upper surface 211 of the sole plate 21 close to the abdominal plate 32 is worn, and a gap S is formed between the lower surfaces 311, 311 and the upper surface 211 of the lower flanges 31 and 31.

After the L-shaped member 5 is temporarily fixed by the pilot pin 7 in this way, a tap hole 41 penetrating the lower flange 31 and the sole plate 21 is provided by using the tip hole 521 of the bottom portion 52 as a guide.

Here, the lower flange 31 and the sole plate 21 are provided with female screws in succession, but the present invention is not necessarily limited to this. For example, the lower flange 31 may be a simple hole without a screw groove, and a tap hole 41 in which a female screw is engraved may be provided only on the sole plate 21.

Subsequently, as shown in FIG. 6, the tap bolt 4 is screwed from above the bottom portion 52 toward the tap hole 41 of the lower flange 31 and the sole plate 21. The tap bolt 4 is screwed in until the lower flange 31 is no longer deformed downward. If the subduction of the lower flange 31 is stopped, it can be said that the lower surface 311 of the lower flange 31 can be brought into close contact with the upper surface 211 of the sole plate 21.

After the L-shaped member 5 is fixed to the sole plate 21 by the tap bolts 4 and 4, the pilot pin 7 is pulled out from the back portion 51. A bolt 6 is inserted into the round hole 54 opened by removing the pilot pin 7.

If the outer diameter of the shaft portion of the bolt 6 is smaller than the inner diameter of the round hole 54 to some extent, the bolt 6 can be easily inserted. As shown in FIG. 7, the bolt 6 passes through the back portion 51, the stiffener 34, and the back portion 51 on the opposite side, and is fixed to the back portion 51 on the opposite side by the nut 61. For this bolt 6, for example, a high-strength bolt can be used.

Further, bolts 6 and 6 are also inserted into the elongated holes 53 and 53 above the round hole 54 to perform bolt joining. Here, even if the back portion 51 is tilted due to the screwing of the tap bolt 4, the bolt 6 can be easily inserted if the rivet hole 351 of the stiffener 34 overlaps the projection range of the elongated hole 53. Before the back portion 51 is tilted, the bolt 6 may be inserted into the elongated hole 53 in advance and temporarily tightened. By doing so, it is possible to prevent the rivet hole 351 behind from being out of the projection range of the elongated hole 53.

Then, by tightening the bolts 6 passed through the round holes 54 and the elongated holes 53, 53 of the back portion 51 together with the nuts 61 mounted on the tip side, the stiffener 34 and the L-shaped members 5 arranged on both sides thereof are tightened. , 5 are integrated by bolt joining.

Next, the reinforcing method and the operation of the reinforcing structure around the support portion of the steel girder of the present embodiment will be described together with the results of tests conducted to confirm the effects.
FIG. 8 is a diagram showing the configuration around the sole plate 21 of the rivet girder 3 used in the effect confirmation test. Here, M1-M4 indicate displacement measurement points. In the effect confirmation test, a sole plate 21 having a recess having a maximum of 2.5 mm provided on the upper surface 211 was used, and a downward load of P = 420 kN was applied to the abdominal plate 32.

FIG. 9 is a diagram comparing the displacement distributions before and after reinforcement. This figure is a diagram in which the plots of the measurement points M1-M4 are simply connected, but the connecting line (broken line) of the plots of the measurement points M1-M4 before reinforcement is the wear of the upper surface 211 of the sole plate 21. It can be said that it shows a shape close to the shape of the above.

When the lower surface 311 of the lower flange 31 was brought into close contact with the upper surface 211 of the sole plate 21 by reinforcement, the displacement was significantly reduced to about 20% or less of that before reinforcement. The effect of reducing the displacement is remarkable in the vicinity of the abdominal plate 32 where the displacement before reinforcement is large. This can also be confirmed by the displacement reduction result (displacement 2.1 mm before reinforcement, displacement 0.5 mm after reinforcement) measured by the abdominal plate 32 itself.

10 and 11 show the results of measuring the stress around the stop hole provided at the tip of the crack R. If the stress near the tip of the crack R is reduced by reinforcement, it can be said that the growth of the crack R can be suppressed.

In FIGS. 10A and 10B, the stress measured around the stop holes provided at the tips of the two cracks R and R generated on both sides of the stiffener 34 is defined as the maximum principal stress. It is shown by the minimum principal stress. It can be said that the maximum principal stress and the minimum principal stress decrease before and after reinforcement in any of the cracks R and R. In particular, the minimum principal stress was significantly reduced to less than 10% before reinforcement.

On the other hand, FIG. 11 shows the stress measured at a position away from the tip of the crack R. Even if you look at this figure, there are places where the negative stress becomes large before reinforcement, but after reinforcement, almost no stress is generated at any position (10% or less before reinforcement). I understand. In short, it can be said that stress concentration does not occur even if a repeated load is applied, and the crack R is difficult to grow.

In the reinforcing method and reinforcing structure around the support portion of the steel girder of the present embodiment configured as described above, the L-shaped member 5 is arranged with respect to the stiffener 34 connecting the abdominal plate 32 and the lower flange 31. After connecting the stiffener 34 and the L-shaped member 5 with the pilot pin 7, the lower surface 311 of the lower flange 31 is brought into close contact with the upper surface 211 of the sole plate 21 by screwing the tap bolt 4.

The step of arranging the L-shaped member 5, the step of providing the tap hole 41 and screwing in the tap bolt 4, and the step of joining the bolt can all be carried out by the work from only above the rivet girder 3. That is, it is not necessary to enter the narrow space between the upper end surface 111 of the pier 11 and the lower surface 311 of the lower flange 31 to perform upward work.

Then, by bringing the lower surface 311 of the lower flange 31 into close contact with the upper surface 211 of the sole plate 21 to eliminate the gap S, even if a repeated load such as a train load T is loaded, the independent amplitude of the lower flange 31 does not occur and fluctuates. Can be reduced, and the growth of cracks R in the lower flange 31 and the abdominal plate 32 of the rivet girder 3 around the support portion 2 can be suppressed.

Further, if the abdominal plate 32 and the lower flange 31 are connected via the stiffener 34 and the L-shaped member 5, the lower surface 311 of the lower flange 31 and the upper surface 211 of the sole plate 21 are most easily separated from each other. The periphery of 32 is brought into close contact with each other, and the lower flange 31 and the sole plate 21 can be reliably integrated.

Further, as shown by an arrow in FIG. 1, a force transmission path is formed in which the train load T acting on the rivet girder 3 is transmitted to the lower flange 31 and the sole plate 21 via the L-shaped member 5. It is possible to reduce the stress generated at the corners of the abdominal plate 32 and the lower flange 31 where cracks R are likely to occur or occur.

Further, if the hole into which the pilot pin 7 is inserted is brought into close contact with the round hole 54, stress can be efficiently transmitted through the pilot pin 7. Further, by making the other holes provided in the back portion 51 into elongated holes 53, even if the L-shaped member 5 rotates and tilts around the pilot pin 7, bolt joining can be easily performed.

Further, by arranging the L-shaped members 5, ... You will be able to.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes to the extent that the gist of the present invention is not deviated are described in the present invention. Included in the invention.

For example, in the above-described embodiment, the rivet girder 3 having a substantially I-shaped cross section has been described as a steel girder, but the present invention is not limited to this, and the steel girder to be joined by welding is also included in the present embodiment. Reinforcing methods and structures around the support of steel girders can be applied. In short, it can be applied to any form of steel girder having a lower flange.

Further, in the above-described embodiment, the case where the stiffener 34 and the back portions 51 and 51 on both sides thereof are integrated by the bolt 6 and the nut 61 has been described, but the present invention is not limited to this. For example, a female screw is carved on the inner peripheral surface of the rivet hole 351 of the stiffener 34 to form a tap hole, and a high-tensile tap bolt is screwed from the back 51 side toward the tap hole of the stiffener 34 to stiffen the stiffener 34. Each of the 341 vertical faces of the material 34 can be bolted to the back portion 51.

Further, in the above-described embodiment, the case where the rivet hole 351 provided in advance in the stiffener 34 is reused has been described, but the present invention is not limited to this, and the position where the stiffener 34 can be easily bolted is not limited to this. In addition, a new hole can be drilled.

R crack T train load (repeated load)
2 Bearing 21 Sole plate 211 Top surface 3 Rivet girder (steel girder)
31 Lower flange 311 Lower surface 32 Abdominal plate (web)
34 Stiffener 341 Vertical surface 4 Tap bolt 41 Tap hole 5 L profile 51 Back 52 Bottom 53 Long hole 54 Round hole 6 Bolt (bolt joint)
7 Pilot pin

Claims (3)

A portion provided with a stiffener that connects the web and the lower flange so as to form a vertical plane substantially orthogonal to the side surface of the web is placed on the sole plate and repeatedly loaded. It is a reinforcement method around the support part of the steel girder.
A step of arranging an L-shaped member having an L-shape in a side view so that the back portion faces the vertical surface of the stiffener and the bottom portion faces the lower flange.
A step of inserting a pilot pin penetrating the back portion of the L-shaped member and the stiffener, and
A step of providing a tap hole in the sole plate by penetrating the bottom portion of the L-shaped member and the lower flange.
A step of bringing the lower surface of the lower flange into close contact with the upper surface of the sole plate by screwing a tap bolt into the tap hole.
A method for reinforcing the periphery of a support portion of a steel girder, which comprises a step of bolting the back portion and the stiffener. The periphery of the support portion of the steel girder according to claim 1, wherein the back portion of the L-shaped member is provided with a round hole into which the pilot pin is inserted and an elongated hole into which a bolt is inserted. Reinforcement method. The method for reinforcing the vicinity of a support portion of a steel girder according to claim 1 or 2, wherein the L-shaped member is arranged on both sides of the stiffener and on both sides of the web.

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