Bearing mounting member and bearing replacing method

Abstract

To provide a bearing mounting member and a bearing replacing method which can be manufactured simply and inexpensively, and which can minimize labor in mounting to a concrete girder and burden on the concrete girder.SOLUTION: A bearing mounting structure 2 for connecting a concrete girder B and a new bearing 1 has a bearing mounting member 3 and a filler 9 interposed between the concrete girder B and the new bearing 1. The bearing mounting member 3 is provided with a bottom plate 4 attached to the bottom surface of the concrete girder B, a pair of side plates 5, 5 attached to the side surface of the concrete girder B, a connecting member 6 connecting the bottom plate 4 and the side plate 5, and a plurality of tap bolts 7 and a plurality of dislocation prevention bolts 8 penetrating the side plate 5. The bottom plate 4 and the side plate 5 are connected via the connecting member 6 in a state where a protrusion 51 formed at the lower end of the side plate 5 is inserted into a recess 41 formed in the bottom plate 4.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a bearing mounting member that is attached to an existing concrete girder when replacing a bearing of an existing bridge, and a bearing replacement method. [Background technology]

[0002] In existing bridges, there are cases where the existing bearings are replaced with new bearings due to, for example, deterioration of the bearings, improvements in the required seismic performance, the enlargement of the superstructure, etc. In such cases, the new bearings are fixed to the superstructure and substructure via newly installed bearing mounting members.

[0003] Bearing mounting members are generally fixed via anchor bolts inserted into the superstructure or substructure. For example, Patent Document 1 discloses a bearing replacement method in which an existing upper shoe cover that covers the upper shoe of an existing bearing left on the underside of a concrete girder is fixed to the concrete girder with anchor bolts, and a new bearing is fixed to this upper shoe cover.

[0004] However, in order to fix the support mounting member so that stress can be transmitted between the support and the concrete girder, it is necessary to insert the anchor bar to a certain depth. On the other hand, if multiple anchor holes are formed in a concrete girder of a certain dimension, there is a concern that the concrete girder may have defects, which may reduce its strength. In addition, it is time-consuming to drill anchor holes upward into the concrete girder and fix the anchor bolts.

[0005] Therefore, Patent Document 2 discloses a bearing mounting member that can be installed on a concrete girder without drilling anchor holes facing upward in the concrete girder, which is made by welding a bottom plate attached to the bottom surface of the concrete girder and a pair of side plates attached to the sides of the concrete girder together. The bearing mounting member is fixed by filling the gaps between the bottom plate and the side plates and the concrete girder with a filler and hardening it, with the anchoring parts installed upright on the bottom plate and protruding inside the rebar of the concrete girder wrapped around the bearing mounting member. [Prior art documents]

Patent Document

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] In the support attachment member of Patent Document 2, since the side plate and the fixing portion are fixed to the bottom plate by welding, it takes time and cost to manufacture. Also, it takes time and cost for quality control by non - destructive inspection. Further, when strain occurs in the welded peripheral portion due to the heat during welding, it is necessary to perform a strain adjustment operation, which is time - consuming.

[0008] An object of the present invention is to propose a support attachment structure and a support replacement method that can be manufactured simply and inexpensively, and can minimize the labor and the burden on the concrete girder when attaching to the concrete girder.

Means for Solving the Problems

[0009] The support mounting structure of the present invention for solving the above problems connects a concrete girder and a support, and has a support mounting member and a filler interposed between the concrete girder and the support. The support mounting member includes a bottom plate attached to the bottom surface of the concrete girder, a pair of side plates attached to the side surface of the concrete girder, a connecting member connecting the bottom plate and the side plates, and a plurality of holding bolts and a plurality of anti-shift bolts passing through the side plates. The filler is filled between the holding bolts and the anti-shift bolts and the concrete girder, and between the concrete girder and the bottom plate. The bottom plate and the side plates are connected via the connecting member with the convex portion formed at the lower end of the side plate inserted into the concave portion formed in the bottom plate. The holding bolt passes through the side plate and the tip thereof is inserted into the side surface of the concrete girder through the filler. The anti-shift bolt passes through the side plate and the tip thereof faces the side surface of the concrete girder through the filler.

[0010] Further, the support renewal method of the present invention includes an existing support removal step of removing an existing support interposed between a concrete girder and a substructure, a mounting member installation step of attaching a used mounting member to the concrete girder using the support mounting structure, and a new support installation step of installing a new support between the support mounting member and the substructure. In the mounting member installation step, operations are performed including removing the surface of the concrete girder at the mounting location of the support mounting member until the steel bars are exposed, drilling the concrete girder to form bolt holes on the side surface of the concrete girder, disposing the support mounting member on the surface of the concrete girder, inserting the tip of the holding bolt into the bolt hole and facing the tip of the anti-shift bolt to the side surface of the concrete girder, and filling the gap between the concrete girder and the support mounting member with a filler.

[0011] According to the bearing mounting member and bearing renewal method, the bottom plate and the side plate are fixed together without welding, so the labor required for manufacturing can be minimized. In addition, there is no distortion due to welding in the plates that make up the bottom plate and the side plate during manufacturing, and the quality is highly reliable.

[0012] There is no need to form an upward anchor hole in the concrete girder, which makes it easier to install. In addition, when installing the support mounting member, the rebar of the concrete girder is exposed, so the rebar is not damaged when forming the bolt hole.

[0013] Furthermore, it is desirable to use a steel material that is L-shaped in cross section for the connecting member, with one piece bolted to the bottom plate and the other piece bolted to the side plate at the corner between the upper surface of the bottom plate and the outer surface of the side plate. Effect of the Invention

[0014] The bearing mounting structure and bearing renewal method of the present invention can be manufactured easily and inexpensively, and can minimize the effort required for mounting to a concrete girder and the burden on the concrete girder. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a front view showing the installation status of a new support according to an embodiment of the present invention. [Diagram 2] 1A and 1B are diagrams showing a support mounting member, in which (a) is a cross-sectional view and (b) is a side view. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] 1A and 1B are views showing a connecting member, in which (a) is a cross-sectional view and (b) is a side view. [Figure 6] 1A is a cross-sectional view showing the process of removing the existing support, and FIG. 1B is a cross-sectional view showing the process of installing the base. [Figure 7](a) is a cross-sectional view showing the working state of the mounting member installation process, and (b) is a cross-sectional view showing the working state of the mounting member installation process following (a).

Embodiment for Carrying Out the Invention

[0016] In this embodiment, the case of replacing an existing support with a new support in an existing bridge will be described. The new support 1 is to be installed at the location where the existing support has been removed, and as shown in FIG. 1, it is installed via a pedestal 10 installed in the lower structure K and a support mounting structure 2 formed in the upper structure J (concrete girder B).

[0017] The pedestal 10 includes a pedestal body 11 on which the new support 1 is placed, and a plurality of anchor bars 12, 12 that project downward from the pedestal body 11 and are embedded in the lower structure K.

[0018] The support mounting structure 2 has a support mounting member 3 and a filler 9 interposed between the concrete girder B and the new support 1.

[0019] As shown in FIGS. 2(a) and (b), the support mounting member 3 includes a bottom plate 4, a pair of side plates 5, 5, a plurality of connecting members 6, 6,..., pressing bolts 7, 7,..., and displacement preventing bolts 8, 8,....

[0020] The bottom plate 4 is a rectangular steel plate, and as shown in FIG. 1, it is attached to the bottom surface of the concrete girder B. As shown in FIG. 3, a plurality of recesses 41, 41,... are formed in the bottom plate 4. The recesses 41 are formed in plurality along the longitudinal direction directly below the side plates 5. The recesses 41 of this embodiment are rectangular holes. Note that the recesses 41 may be bottomed grooves. Also, the shape of the recesses 41 is not limited. Further, a plurality of bolt holes 42, 42,... for fixing the connecting members 6 are formed on the outer side (edge side) of the recesses 41 in the bottom plate 4.

[0021] As shown in FIG. 1, the pair of side plates 5, 5 are erected on the upper surface of the bottom plate 4 and attached to the side surface of the concrete girder B. That is, the bearing mounting member 3 has a concave shape in cross section due to the bottom plate 4 and the pair of side plates 5, 5. As shown in FIG. 4, a plurality of (three in this embodiment) protrusions 51, 51, 51 are formed on the lower end of the side plate 5. The protrusions 51 are formed at positions corresponding to the recesses 41 of the bottom plate 4. The protrusions 51 are rectangular parallelepiped protrusions having a planar shape equivalent to the planar shape of the recesses 41 and a height equivalent to the plate thickness of the bottom plate 4. As shown in FIG. 2, the side plates 5 are erected on the upper surface of the bottom plate 4 with the protrusions 51 inserted into the recesses 41.

[0022] As shown in Fig. 4, the side plate 5 is formed with a plurality of first through holes 52, 52, ... and a plurality of second through holes 53, 53, .... The clamping bolt 7 is inserted into the first through hole 52. In this embodiment, four first through holes 52, 52, ... are formed in the upper part of the side plate 5. The arrangement and number of the first through holes 52 are not limited and may be determined appropriately. The first through holes 52 are formed by drilling the side plate 5, and the inner diameter of the first through holes 52 is equal to or larger than the outer diameter of the clamping bolt 7.

[0023] The second through holes 53 are inserted with the anti-slip bolts 8. In this embodiment, eight second through holes 53, 53, ... are formed near the center of the side plate 5 in the height direction. The arrangement and number of the second through holes 53 are not limited and may be determined appropriately. The inner surface of the second through hole 53 is threaded, and the anti-slip bolts 8 can be screwed into it. A nut is screwed into the tip of the anti-slip bolt 8 inserted into the second through hole 53, and the tip of the anti-slip bolt 8 is expanded in diameter.

[0024] A plurality of bolt holes 54, 54, ... for fixing the connecting member 6 are formed in the lower part of the side plate 5. The arrangement and number of the bolt holes 54 are not limited, and are formed according to the connecting member 6.

[0025] As shown in FIG. 2(a), the connecting member 6 connects the bottom plate 4 and the side plate 5. As shown in FIGS. 5(a) and 5(b), the connecting member 6 is made of a steel material (so-called angle material) that is L-shaped in cross section. As shown in FIG. 2(a), one side of the connecting member 6 is bolted to the bottom plate 4 and the other side is bolted to the side plate 5 at the corner between the upper surface of the bottom plate 4 and the outer surface of the side plate 5. In this embodiment, as shown in FIG. 2(b), two connecting members 6 are provided for one side plate 5. The arrangement and shape dimensions of the connecting members 6 are not limited.

[0026] 2(a) and (b), the retaining bolt 7 passes through the first through hole 52 of the side plate 5 and has its tip inserted into the side surface of the concrete girder B. The retaining bolt 7 is screwed into the first through hole 52 and moves back and forth relative to the side plate 5 when rotated.

[0027] 2(a) and (b), the shear stop bolt 8 passes through the second through hole 53 of the side plate 5 below the restraining bolt 7, with the tip facing the side surface of the concrete girder B. The shear stop bolt 8 is screwed into the second through hole 53, and moves back and forth relative to the side plate 5 when rotated. The tip of the shear stop bolt 8 may be in contact with the side surface of the concrete girder B or separated therefrom.

[0028] The filler 9 is filled between the restraining bolts 7 and the anti-shear bolts 8 and the concrete girder B, and between the concrete girder B and the bottom plate 4. This filler 9 can be made of non-shrink mortar, epoxy resin, ultra-dense high-strength fiber-reinforced concrete, or the like.

[0029] Next, the bearing renewal method will be described. The bearing renewal method includes an existing bearing removal process S1, a base installation process S2, a mounting member installation process S3, and a new bearing installation process S4.

[0030] In the existing bearing removal process S1, as shown in Fig. 6(a), the existing bearing 1a interposed between the concrete girder B and the substructure K is removed. At this time, the existing bearing 1a is removed by cutting the anchor bolts that secure the existing bearing 1a. When removing the existing bearing 1a, the superstructure J is supported by a jack or the like.

[0031] In the pedestal installation step S2, as shown in Fig. 6(b), the pedestal is installed on the substructure K at the position where the existing support was removed. In the pedestal installation step S2, first, anchor holes AH are drilled in the substructure K. Next, anchor bars 12, 12, ... are inserted into the anchor holes AH, and the pedestal main body 11 is installed on the upper surface of the substructure K. A solidifying material is filled into the anchor holes AH into which the anchor bars 12 have been inserted, and the pedestal 10 is fixed. Note that leveling concrete or the like is also poured between the pedestal main body 11 and the upper surface of the substructure K as necessary.

[0032] In the mounting member installation step S3, the support mounting member 3 is attached to the concrete girder. In the mounting member installation step S3, first, as shown in FIG. 7(a), the surface of the concrete girder B at the mounting location of the support mounting member 3 is removed until the reinforcing bar R is exposed.

[0033] Next, the concrete girder B is drilled to form the retaining bolt holes BH on the side of the concrete girder. The retaining bolt holes BH are formed at positions corresponding to the first through holes 52. At this time, care is taken not to damage the reinforcing bars.

[0034] 7(b), the work of placing the bearing mounting member 3 on the surface of the concrete girder is performed. After the bearing mounting member 3 is placed in the specified position, the tip of the restraining bolt 7 is inserted into the restraining bolt hole BH, and the tip of the anti-slip bolt 8 is brought into contact with the side surface of the concrete girder B. Then, the work of filling the gap between the concrete girder B and the support mounting member 3 with the filling material 9 is performed.

[0035] In the new bearing installation process, the new bearing is installed between the bearing mounting member (superstructure) and the base (substructure). The new bearing is fixed to the bearing mounting member and base with bolts (see Figure 1).

[0036] The support mounting member 3 of this embodiment integrally fastens the bottom plate 4 and the side plates 5, 5 without the need for welding, minimizing the labor required for manufacturing. In addition, no distortion due to welding occurs in the plates that make up the bottom plate 4 and the side plates 5, and the quality is highly reliable.

[0037] This method is easy to install because the support mounting member 3 can be installed without forming upward anchor holes in the concrete girder B. In addition, since the reinforcing bars of the concrete girder B are exposed when the support mounting member 3 is installed, the reinforcing bars are not damaged when the bolt holes are formed.

[0038] Horizontal forces in the bridge axis direction are transmitted by the anti-slip bolts, while horizontal forces perpendicular to the bridge axis are transmitted by the restraining bolts 7, resulting in excellent earthquake resistance. Because the first through holes are formed by drilling, the anti-slip bolts screwed into the second through holes transmit the horizontal force in the bridge axis direction before the restraining bolts that pass through the first through holes. On the other hand, the horizontal force perpendicular to the bridge axis is transmitted to the superstructure by the restraining bolts being pulled at a position away from the position where the horizontal force acts (bottom plate 4).

[0039] The embodiment of the present invention has been described above. However, the present invention is not limited to the above embodiment, and each of the above components can be appropriately modified without departing from the spirit of the present invention.

[0040] In the above embodiment, the mounting member installation process S3 is performed after the base installation process S2, but the order of the base installation process S2 and the mounting member installation process S3 is not limited, and the base installation process S2 may be performed after the mounting member installation process S3, or the base installation process S2 and the mounting member installation process S3 may be performed simultaneously.

[0041] In the above embodiment, a case has been described in which the anti-slip bolt 8 is positioned below the restraining bolt 7, but the positional relationship between the restraining bolt 7 and the anti-slip bolt 8 is not limited, and the restraining bolt 7 may also be positioned below the anti-slip bolt 8. [Explanation of symbols]

[0042] 1 Newly constructed bearings 10 Pedestal 11 Base body 12 Anchor bar 2. Support mounting structure 3. Support mounting parts 4 Bottom plate 41 Recess 5 Side Panel 51 Convex 52 First through hole 53 Second through hole 54 Bolt holes 6 Connecting members 7 Retaining bolt 8 Anti-slip bolt 9 Filling material B Concrete girder J Superstructure K Substructure

Claims

1. A bearing mounting structure for connecting a concrete girder and a bearing, A bearing mounting member and a filler are interposed between the concrete girder and the bearing, The support mounting member is A bottom plate attached to the bottom surface of the concrete girder; A pair of side plates attached to the side surfaces of the concrete girder; A connecting member that connects the bottom plate and the side plate; A plurality of restraining bolts and a plurality of anti-slip bolts are provided through the side plate. The filler is filled between the restraining bolt and the concrete girder, and between the concrete girder and the bottom plate, the bottom plate and the side plate are connected via the connecting member in a state in which a convex portion formed at a lower end of the side plate is inserted into a concave portion formed in the bottom plate, The restraining bolt penetrates the side plate and has a tip portion inserted into the side surface of the concrete girder via the filler, A support mounting structure characterized in that the anti-slip bolt penetrates the side plate and has a tip facing the side of the concrete girder through the filler material.

2. The support mounting structure described in claim 1, characterized in that the connecting member is an L-shaped steel material in cross section, one piece of which is bolted to the bottom plate and the other piece is bolted to the side plate at the corner between the upper surface of the bottom plate and the outer surface of the side plate.

3. an existing support removal process for removing an existing support interposed between the concrete girder and the substructure; a mounting member installation step of installing a mounting member to be used on the concrete girder using the support mounting structure according to claim 1 or 2; A bearing replacement method comprising: a new bearing installation step of installing a new bearing between the bearing mounting member and the substructure, In the mounting member installation step, removing the surface of the concrete girder at the mounting location of the support mounting member until the reinforcing bar is exposed; An operation of drilling holes in the concrete girder to form bolt holes on a side surface of the concrete girder; an operation of disposing the bearing mounting member on a surface of the concrete girder; An operation of inserting a tip of the restraining bolt into the bolt hole and aligning the tip of the anti-slip bolt against a side surface of the concrete girder; and filling a gap between the concrete girder and the bearing mounting member with a filler.

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