Repair method for the support section

Abstract

This invention provides a method for repairing a support structure that can improve the strength of the support structure by sealing the gaps that occur in the support structure with a simple structure. [Solution] The method for repairing the support portion 2 includes: an edge-cutting step that makes the sole plate 21 separable from the lower flange 31; a screw hole 61 forming step that forms multiple screw holes 61 penetrating in the thickness direction in the lower flange 31; a gap-forming step that moves the sole plate 21 toward the shoe portion 22 using a pressing bolt 52 screwed into the screw holes 61 to form a gap S between the sole plate 21 and the lower flange 31; and a filling step that fills the gap S formed between the sole plate 21 and the lower flange 31 with a resin 100 that hardens at room temperature.

Description

Technical Field

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[0001] The present invention relates to a method for repairing a support portion.

Background Art

[0002] It is known that steel structures such as bridges are subject to fatigue cracks due to repeated loads caused by, for example, vehicles traveling thereon. In particular, when a vehicle or the like passes over a bridge girder, a vertical load is transmitted to the support portion, so that if a repeated load acts on the support portion, the support portion is likely to be damaged. If a vertical gap occurs due to damage to the support portion, the contact area between the bridge girder and the support portion decreases, and the possibility of fatigue cracks occurring in the support portion increases. Therefore, various methods have been proposed to address fatigue cracks.

[0003] Patent Document 1 discloses a method for reinforcing a support structure. The support structure includes a bridge girder having a sole plate and a support. By making the sum of the fixing compressive force by a connection mechanism constituted by a screw hole formed in the support and a bottom plate attachment bolt screwed into the screw hole and the repeated compressive force for compressing the column larger than the boundary compressive force, the amplitude of the compressive stress acting on the lower end portion of the column can be further reduced.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in the above patent document, even when the bridge girder and the support are connected by a connection mechanism, a state in which a gap is formed between the support and the bridge girder is maintained. Therefore, there is room for further improvement with regard to the reinforcement of the support portion.

[0006] Therefore, the present invention aims to provide a method for repairing a support structure that can improve the strength of the support structure by sealing the gaps that occur in the support structure with a simple configuration. [Means for solving the problem]

[0007] To address the above-mentioned problems, the present invention provides a method for repairing a support portion, which supports a bridge girder via a support portion having an upper shoe portion and a lower shoe portion positioned below the upper shoe portion, comprising: a separation step of releasing the fastening of the upper shoe portion to the lower flange of the bridge girder by fastening members, thereby making the upper shoe portion separable from the lower flange; a screw hole forming step of forming a plurality of screw holes in the lower flange that penetrate in the thickness direction at intervals along the longitudinal and width directions of the bridge girder; a gap forming step of moving the upper shoe portion toward the lower shoe portion by bolts screwed into the screw holes to form a gap between the upper shoe portion and the lower flange; and a filling step of filling the gap formed between the upper shoe portion and the lower flange with a resin that hardens at room temperature.

[0008] Here, it is desirable that the screw holes are formed in multiple locations along the longitudinal direction of the lower flange, on either side of the web of the bridge girder.

[0009] Furthermore, in the filling step, it is desirable to inject the resin into the gap through an injection port drilled in the lower flange.

[0010] Furthermore, it is desirable to further include a sealing step before the filling step, in which the gap is sealed along the periphery of the upper shoe portion.

[0011] Furthermore, it is desirable to further include a replenishment step in which, after the resin has hardened, the bolt inserted into the screw hole in the gap-forming step is removed, and the resin is replenished in the gap left by the removal of the bolt. [Effects of the Invention]

[0012] The present invention provides a method for repairing a support portion, comprising: a separation step that makes the upper shoe portion separable from the lower flange; a screw hole forming step that forms multiple screw holes in the lower flange that penetrate in the thickness direction at intervals along the longitudinal and width directions of the bridge girder; a gap forming step that moves the upper shoe portion toward the lower shoe portion using bolts screwed into the screw holes to form a gap between the upper shoe portion and the lower flange; and a filling step that fills the gap formed between the upper shoe portion and the lower flange with a resin that hardens at room temperature.

[0013] As a result, even if a gap forms between the upper shoe and the lower flange, that gap will be sealed by the hardened resin. Therefore, the strength of the support can be improved by sealing the gap that occurs in the support with a simple structure.

[0014] Here, multiple threaded holes are formed along the longitudinal direction of the lower flange, on either side of the web of the bridge girder. This allows the bolts screwed into the threaded holes to apply even pressure to the upper shoe. Consequently, it becomes easier to bring the upper shoe into close contact with the lower shoe.

[0015] Furthermore, in the filling step, resin is injected into the gap through an injection port drilled in the lower flange. This allows the resin to be injected from the upper side of the lower flange, making it easier to fill the gap even if it is narrow in the vertical direction.

[0016] Furthermore, prior to the filling step, a sealing step is provided in which the gap is sealed along the perimeter of the upper shoe. This prevents foreign matter from entering the gap and prevents the resin filled in the gap from leaking out.

[0017] Furthermore, after the resin has hardened, the device includes a replenishment step in which the bolt inserted into the screw hole in the gap-forming step is removed, and the resin is replenished in the gap left by the removal of the bolt. This makes it less likely for rainwater or other liquids to accumulate in the gap, thus preventing deterioration of the support part.

Brief Description of the Drawings

[0018] [Figure 1] It is a diagram illustrating a schematic configuration of a bridge to which the repair method of the support portion according to an embodiment of the present invention is applied. [Figure 2] It is a plan view showing the support portion enlarged. [Figure 3] It is a diagram showing the support portion in a state where a gap has occurred. [Figure 4] It is a diagram showing a cut-off step. [Figure 5] It is a diagram showing a screw hole forming step. [Figure 6] It is a diagram showing a gap forming step. [Figure 7] It is a diagram showing a partial enlargement of the gap forming step. [Figure 8] It is a diagram showing a filling step and a sealing step. [Figure 9] It is a diagram showing a replenishment step.

Embodiments for Carrying Out the Invention

[0019] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a schematic configuration of a bridge to which the repair method of the support portion according to an embodiment of the present invention is applied, FIG. 2 is a plan view showing the support portion enlarged, and FIG. 3 is a diagram showing the support portion in a state where a gap has occurred.

[0020] As shown in FIG. 1, the bridge 1 includes bridge piers 11, a plurality of bridge girders 3 spanning between the bridge piers 11 and extending in the bridge axis direction, and support portions 2 disposed on the bridge piers 11 and supporting each bridge girder 3. On the plurality of bridge girders 3 spanned in parallel, a floor slab 12 constructed of prestressed concrete, reinforced concrete, or the like is laid. Note that the floor slab 12 may be made of steel or a track.

[0021] The end of the bridge girder 3 rests on a support section 2 installed on the upper end surface 111 of the bridge pier 11. This support section 2 mainly consists of, for example, a flat plate-shaped seat 23 placed on the upper end surface 111 of the bridge pier 11, a shoe section (lower shoe section) 22 installed on the seat 23, and a sole plate (upper shoe section) 21 interposed between the shoe section 22 and the bridge girder 3.

[0022] Here, the seat portion 23 is formed from mortar or the like, and the shoe portion 22 and sole plate 21 are made of steel. The end of the bridge girder 3 is then placed on the flat sole plate 21.

[0023] The bridge girder 3 is mainly composed of an upper flange 33 and a lower flange 31 arranged parallel to each other vertically, and a web plate 32 that connects the upper flange 33 and the lower flange 31.

[0024] Furthermore, stiffeners 34 are positioned on both sides of the web plate 32 of the bridge girder 3, which is placed on the sole plate 21. The stiffeners 34 have vertical surfaces formed that are approximately perpendicular to the side surface of the web plate 32, connecting the lower flange 31 and the upper flange 33. A gusset plate 40 is provided on one side of the stiffener 34.

[0025] As shown in Figures 2 and 3, the sole plate 21 is fixed to the lower flange 31 from below by fastening members 51. Multiple fastening members 51 are provided around the intersection P of the web plate 32 and the stiffener 34. Specifically, eight fastening members 51 are provided at equal intervals along the circumferential direction in the XY plane, with four provided along the X direction or four along the Y direction, flanking either the web plate 32 or the stiffener 34.

[0026] The fastening member 51 consists of a fastening bolt 51a that penetrates the lower flange 31 and a nut 51b. The number of fastening members 51 and the positions in which the fastening members 51 are provided are not particularly limited.

[0027] In a bridge 1 with this configuration, for example, if it is a railway bridge, repeated loads are applied by the passage of trains. Similarly, even if it is a road bridge, repeated loads are applied by the passage of automobiles. The force acting on the deck slab 12 due to the passage of trains or automobiles is transmitted to multiple bridge girders 3 arranged parallel to each other below the deck slab 12. The force acting on the bridge girders 3 is then transmitted from the lower flange 31 to the sole plate 21.

[0028] As a result, the lower flange 31 repeatedly moves up and down on the sole plate 21 due to the repeated application and removal of force. Figure 3 shows a support section 2 in a state where a gap has formed among the support sections 2 that support multiple bridge girders 3.

[0029] As shown in Figure 3, due to repeated loading, one end of the shoe portion 22 may move downward between the upper surface 222 of the shoe portion 22 and the lower surface 212 of the sole plate 21, creating a gap G between the shoe portion 22 and the sole plate 21. If this gap G is left untreated, it can lead to damage to the support portion 2, so it is necessary to repair the support portion 2 by some method. The following describes a method for repairing the support portion 2 in which a gap G has formed.

[0030] (Steps to end the relationship) First, the sole plate 21, which is fastened to the lower flange 31 of the bridge girder 3 by a fastening member 51, is released from the lower flange 31, making the sole plate 21 separable from the lower flange 31 (see Figure 4).

[0031] In the edge-separation step, the lower flange 31 is in close contact with the sole plate 21 by the fastening member 51, and with the fastening bolt 51a inserted into the lower flange 31 and the sole plate 21, the nut 51b is loosened from its engagement with the fastening bolt 51a. By loosening the nut 51b, the sole plate 21 moves towards the shoe portion 22 due to its own weight.

[0032] As the sole plate 21 moves toward the shoe portion 22, a gap S begins to form between the upper surface 211 of the sole plate 21 and the lower surface 311 of the lower flange 31, while the gap G formed between the lower surface 212 of the sole plate 21 and the upper surface 222 of the shoe portion 22 decreases.

[0033] (Screw hole forming step) Next, multiple threaded holes 61 are formed in the lower flange 31 at intervals along the longitudinal and width directions of the bridge girder 3, penetrating in the thickness direction (see Figure 5). In the threaded hole formation step, for example, multiple threaded holes 61 are formed along the longitudinal direction of the lower flange 31 at positions that straddle the web plate 32 of the bridge girder 3.

[0034] Multiple screw holes 61 are formed at four points symmetrically in a plan view, centered on the intersection P between the web plate 32 and the stiffener 34. Specifically, as shown in Figure 5, the screw holes 61 are formed at four points symmetrically in the XY plane, centered on the intersection P. The four screw holes 61 are formed closer to the intersection P than the position where the fastening member 51 is located.

[0035] Furthermore, the screw holes 61 are not limited to point-symmetrical positions; a pair of screw holes 61 may be arranged symmetrically (line-symmetrically) with respect to the web plate 32 or stiffener 34. Also, the number of screw holes 61 formed in the lower flange 31 is not particularly limited; it may be three or fewer, or five or more.

[0036] (Gap formation step) Next, the pressure bolt 52 screwed into the screw hole 61 moves the sole plate 21 towards the lower shoe portion 22, creating a gap S between the sole plate 21 and the lower flange 31 (see Figure 6).

[0037] In the gap-forming step, the sole plate 21, which was moved towards the shoe portion 22 in the edge-cutting step, is brought into close contact with the shoe portion 22. The sole plate 21 is moved towards the shoe portion 22 (in the direction of the white arrow in Figure 7) by the pressing bolt 52 which is screwed into the screw hole 61, and the pressing bolt 52 is screwed in until the lower surface 212 of the sole plate 21 is in close contact with the upper surface 222 of the shoe portion 22.

[0038] In this case, if the four screw holes 61 are formed in point-symmetrical positions around the intersection P of the web plate 32 and the stiffener 34 (see Figure 5), the pressing force applied by the pressing bolts 52 that are screwed into each screw hole 61 to the sole plate 21 can be evenly distributed. Therefore, the sole plate 21 can be made to fit more closely to the shoe portion 22.

[0039] Once the gap formation step is complete, only a gap S will be formed between the sole plate 21 and the lower flange 31, replacing the gap G, as shown in Figures 6 and 7. Even when a gap S is formed, the load transmitted to the support portion 2 by the pressing bolt 52 can be temporarily supported.

[0040] (Filling step) Next, a resin 100 that hardens at room temperature is filled into the gap S formed between the sole plate 21 and the lower flange 31 (see Figure 8). Specifically, the resin 100 is filled into the entire gap S formed between the sole plate 21 and the lower flange 31.

[0041] In the filling step, resin is injected into the gap S through injection ports 62 drilled in the lower flange 31. The injection ports 62 are through holes that penetrate the lower flange 31 in the thickness direction. The position and number of injection ports 62 formed are not particularly limited.

[0042] Here, the material of the resin 100 is, for example, acrylic resin, but the material is not particularly limited as long as it has the property of curing at room temperature and the desired compressive strength. By forming a layer of resin 100 in the gap S, the resin 100 can support the vertical load and ensure the strength between the sole plate 21 and the lower flange 31.

[0043] Furthermore, during the period until the resin 100 hardens, the load transmitted to the support part 2 can be temporarily supported by the pressing bolt 52 screwed into the screw hole 61.

[0044] (Sealing step) Furthermore, it is desirable to include a sealing step before the filling step in which the gap S is sealed along the perimeter of the sole plate 21. That is, as shown in Figure 8, by covering the entire perimeter of the sole plate 21 in the XY plane, or in other words, the entire perimeter of the lower flange 31 in the XY plane, with the sealing member 110 before filling the gap S with the resin 100, it is possible to prevent foreign matter such as rainwater from entering the gap S and to prevent the resin 100 from leaking out of the gap S.

[0045] (Replenishment step) Furthermore, it is desirable to further include a replenishment step in which, after the resin 100 filled in the filling step has hardened, the pressing bolt 52 inserted into the screw hole 61 in the gap forming step is removed, and the resin is replenished in the gap 61a from which the pressing bolt 52 was removed (see Figure 9).

[0046] In the replenishment step, all the pressure bolts 52 that were screwed into the four screw holes 61 in the gap formation step are removed, and the entire gap 61a from which the pressure bolts 52 were removed is replenished with the same type of resin 100 that was filled in the filling step. It is desirable that the resin 100 be filled not only in the gap 61a from which the pressure bolts 52 were removed, but also in the injection port 62.

[0047] As explained above, even if a gap G occurs in the support portion 2, the repair of the support portion 2 can be considered complete once the resin 100 filled into the gap S that is formed in place of the gap G hardens.

[0048] As described above, the repair method for the support portion 2 according to the embodiment includes: an edge-cutting step in which the fastening of the sole plate 21 to the lower flange 31 is released, thereby making the sole plate 21 separable from the lower flange 31; a screw hole 61 forming step in which a plurality of screw holes 61 are formed in the lower flange 31, respectively, that penetrate through the thickness direction at intervals along the longitudinal and width directions of the bridge girder 3; a gap-forming step in which the sole plate 21 is moved toward the shoe portion 22 side by a pressing bolt 52 screwed into the screw holes 61 to form a gap S between the sole plate 21 and the lower flange 31; and a filling step in which a resin 100 that hardens at room temperature is filled into the gap S formed between the sole plate 21 and the lower flange 31.

[0049] As a result, even if a gap S is formed between the sole plate 21 and the lower flange 31, the gap S is sealed by the hardened resin 100. Therefore, since the resin 100 can support the vertical load, the strength of the support part 2 can be improved by sealing the gap S in the support part 2 with a simple structure.

[0050] Here, multiple screw holes 61 are formed along the longitudinal direction of the lower flange 31 at positions that straddle the web plate 32 of the bridge girder 3. This allows the pressing bolts 52 screwed into the screw holes 61 to apply even pressure to the sole plate 21. Consequently, the sole plate 21 can be made to adhere closely to the shoe portion 22.

[0051] Furthermore, in the filling step, resin 100 is injected into the gap S through an injection port 62 drilled in the lower flange 31. This allows the resin 100 to be injected from the upper side of the lower flange 31, making it easier to fill the gap S even if it is narrow in the vertical direction.

[0052] Furthermore, prior to the filling step, the process includes a sealing step in which the gap S is sealed along the perimeter of the sole plate 21. This prevents foreign matter from entering the gap S and prevents the resin 100 filled in the gap S from leaking out.

[0053] Furthermore, after the resin 100 has hardened, the process includes a replenishment step in which the pressing bolt 52 inserted into the screw hole 61 in the gap-forming step is removed, and the gap 61a from which the pressing bolt 52 was removed is replenished with resin 100. This makes it less likely for rainwater or the like to accumulate in the gap 61a, and prevents deterioration of the support part 2.

[0054] Although various embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and any design modifications that do not depart from the spirit of the present invention are included in the present invention.

[0055] For example, in the above embodiment, resin was injected into the gap S through an injection port 62 drilled in the lower flange 31, but resin may also be injected directly into the gap S without forming an injection port 62.

[0056] Furthermore, in the replenishment step of the above embodiment, all the pressing bolts 52 screwed into the screw holes 61 were removed and the resin 100 was replenished in the removed gaps 61a. However, some of the pressing bolts 52 may be left in the screw holes 61 and the resin 100 may be replenished only in the removed gaps 61a.

[0057] Furthermore, in the sealing step of the above embodiment, the entire periphery of the sole plate 21 is covered with the sealing member 110 in the XY plane, but there may be areas around the sole plate 21 that are not partially covered by the sealing member 110. [Explanation of Symbols]

[0058] 2: Bearing part 3: Bridge girder 11: Bridge pier 21: Sole plate (upper shoe part) 22: Shoe part (lower shoe part) 31: Lower flange 32: Belly plate 51: Fastening member 52: Pressing bolt 61: Screw hole 62: Inlet G: Gap S: Gap

Claims

1. A method for repairing a support structure that supports a bridge girder via a support structure having an upper shoe portion and a lower shoe portion positioned below the upper shoe portion, A separation step that allows the upper shoe portion to be separated from the lower flange by releasing the fastening of the upper shoe portion to the lower flange, which is fastened to the lower flange of the bridge girder by a fastening member, A screw hole forming step involves forming multiple screw holes in the lower flange that penetrate in the thickness direction at intervals along the longitudinal and width directions of the bridge girder, A gap-forming step involves moving the upper shoe portion toward the lower shoe portion by a bolt screwed into the screw hole, thereby forming a gap between the upper shoe portion and the lower flange. A method for repairing a support portion, characterized by comprising a filling step of filling the gap formed between the upper shoe portion and the lower flange with a resin that hardens at room temperature.

2. The method for repairing a support portion according to claim 1, characterized in that a plurality of screw holes are formed along the longitudinal direction at positions on the lower flange that straddle the web of the bridge girder.

3. The method for repairing a support portion according to claim 1 or 2, characterized in that the filling step involves injecting resin into the gap through an injection port drilled in the lower flange.

4. The method for repairing a support portion according to claim 1 or 2, further comprising a sealing step of sealing the gap along the periphery of the upper shoe portion before the filling step.

5. The method for repairing a support portion according to claim 1 or 2, further comprising a replenishment step in which, after the resin has hardened, the bolt inserted into the screw hole in the gap forming step is removed, and the resin is replenished in the gap left by the removal of the bolt.

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