Method for Lifting Materials for Repair or Reinforcement of Bridge Piers of Truss Bridges

Abstract

To provide a material lifting method for repair or reinforcement of a bridge pier of a box girder bridge that can be applied to repair or reinforcement work of the box girder bridge and can obtain a reaction force of a material lifting from an existing bridge without damaging a concrete structure of the bridge to be repaired or reinforced.SOLUTION: In a repair or reinforcement work of a bridge pier P1 of a box girder bridge B including a box girder G1, a sandwich-type overhead rail 1 including an upper limb material 2 installed along an upper surface of the box girder G1, a lower limb material 3 installed along a bottom surface of the box girder G1, and a right and left pair of connecting materials 4 connecting the upper limb material 2 and the lower limb material 3 is installed between the upper limb material 2 and the lower limb material 3 sandwiching the box girder G1 vertically, without using a post-construction anchor, and a reaction force is obtained from the box girder G1 by the sandwich-type overhead rail 1 to lift a material used in the repair or reinforce work of the bridge pier P1 of the box girder bridge B.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for hoisting materials for repairing or reinforcing the piers of a box girder bridge. More specifically, it relates to a method for hoisting materials for repairing or reinforcing the piers of a box girder bridge using a sandwich-type ceiling rail.

Background Art

[0002] When performing repair and reinforcement work on piers and their foundations, when the superstructure of the bridge is a concrete structure and there are headroom restrictions or no space (construction space) around, there is a problem that materials cannot be lifted using a hoisting machine such as a crane. In such cases, conventionally, in order to hoist materials, etc., post-construction anchors were cast into concrete structures such as the bridge girder which is the superstructure and the pier which is the substructure, and a rail made of steel for hoisting was bolted to the anchor to take the reaction force during the lifting of materials, etc. However, post-construction anchors have poor workability, there are concerns about safety, and there is also a problem of damaging the existing concrete structure.

[0003] For example, Patent Document 1 discloses a construction device for pier reinforcement work having a support member 5 installed at the top end of a pier 1 and a circle rail 6 attached to the support member 5 in a suspended state and arranged to surround the upper periphery of the pier 1, and a loading machine is attached to the circle rail 6 so as to be movable along the rail (see Claim 1 of the scope of utility model registration of Patent Document 1, paragraphs

[0011] to

[0020] of the specification, FIGS. 1, 2, etc. of the drawings).

[0004] However, the construction device for pier reinforcement work described in Patent Document 1 fixes the support member 8 with the anchor material 7, which is a post-construction anchor, on the top end of the pier 1, which is a concrete structure. For this reason, although the construction device for pier reinforcement work described in Patent Document 1 has improved safety in terms of the portion provided on the top end compared to the prior art, the problems of poor workability and damage to the concrete structure have not been solved. Further, the construction device for pier reinforcement work described in Patent Document 1 can be applied to bridges where a rail material can be installed at the top end of the pier such as a slab bridge, but cannot be applied to box girder bridges.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Therefore, the present invention has been devised in view of the above-described problems, and its object is to provide a material hoisting method for repairing or reinforcing the pier of a box girder bridge that can be applied to the repair and reinforcement work of the pier of a box girder bridge, can obtain the reaction force of material hoisting from the existing bridge without damaging the concrete structure of the bridge to be repaired or reinforced.

Means for Solving the Problems

[0007] The method for hoisting materials for repairing or reinforcing the pier of a box girder bridge according to claim 1 is a method for hoisting materials in the repair or reinforcement work of the pier of a box girder bridge provided with a box girder. A sandwich-type ceiling rail including an upper side member installed along the upper surface of the box girder, a lower side member installed along the lower surface of the box girder, and a pair of left and right connecting members connecting the upper side member and the lower side member is installed by sandwiching the box girder vertically between the upper side member and the lower side member without using a post-construction anchor, and the reaction force is obtained from the box girder by the sandwich-type ceiling rail, and the materials used for the repair or reinforcement work of the pier of the box girder bridge are hoisted.

[0008] The method for hoisting materials for repairing or reinforcing the pier of a box girder bridge according to claim 2 is the method for hoisting materials for repairing or reinforcing the pier of a box girder bridge according to claim 1, wherein the upper side member and the lower side member are connected by a pair of left and right connecting members made of threaded steel bars.

[0009] The method for hoisting materials for repairing or reinforcing the pier of a box girder bridge according to claim 3 is the method for hoisting materials for repairing or reinforcing the pier of a box girder bridge according to claim 1 or 2, wherein a buffer material is interposed between the upper side member and the upper surface of the box girder and between the lower side member and the lower surface of the box girder, respectively.

[0010] The method for hoisting materials for repairing or reinforcing the pier of a box girder bridge according to claim 4 is the method for hoisting materials for repairing or reinforcing the pier of a box girder bridge according to any one of claims 1 to 3, wherein a manual hoist attached to the sandwich-type ceiling rail is used to hoist the materials.

Advantages of the Invention

[0011] According to the invention according to claims 1 to 4, it can be applied to the repair and reinforcement of the piers of box girder bridges without space in the under-truss space, and the reaction force of material hoisting can be obtained from the bridge without damaging the concrete structure of the bridge to be reinforced, and hoisting can be carried out.

[0012] In particular, according to the invention of claim 2, since the upper side member and the lower side member are fastened with a connecting member made of a steel bar, it becomes easy to install a sandwich-type ceiling rail by sandwiching the box girder vertically between the upper side member and the lower side member, and it can be installed in a short time.

[0013] In particular, according to the invention of claim 3, since buffer materials are interposed between the upper side member and the upper surface of the box girder, and between the lower side member and the lower surface of the box girder, respectively, it is possible to prevent the upper side member and the lower side member from contacting the box girder, which is an existing concrete structure, and damaging the box girder.

[0014] In particular, according to the invention of claim 4, since a manual hoist is used to lift materials, it is possible to lift materials with inexpensive and simple equipment, and there is no need to submit an installation notice to the authorities.

Brief Description of Drawings

[0015]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0016] Hereinafter, an embodiment of a method of lifting materials for repairing or reinforcing a pier of a box girder bridge according to the present invention will be described in detail with reference to the drawings.

[0017] Using FIGS. 1 and 2, a method for lifting materials for repairing or strengthening the piers of a box girder bridge according to an embodiment of the present invention will be described. A case where a reinforcing steel plate S1 is press-fitted and installed around a pier P1 of a box girder bridge B which is an existing bridge to reinforce the pier P1 against earthquake will be exemplified and described. FIG. 1 is a schematic cross-sectional view showing a situation where a reinforcing steel plate S1 as a material is carried in by a method for lifting materials for repairing or strengthening the piers of a box girder bridge according to an embodiment of the present invention, with the box girder bridge B cut along the direction Y perpendicular to the bridge axis. Further, FIG. 2 is a side view showing a situation where a reinforcing steel plate S1 as a material is carried in by a method for lifting materials for repairing or strengthening the piers of a box girder bridge according to an embodiment of the present invention, with the vicinity of the pier P1 of the box girder bridge B viewed from the side along the direction Y perpendicular to the bridge axis. X in the figure is the bridge axis direction X, Y in the figure is the direction Y perpendicular to the bridge axis, and Z in the figure is the vertical direction Z.

[0018] First, the box girder bridge B for which the reinforcement work is to be carried out will be briefly described. As shown in FIG. 1, the box girder bridge B is an existing box girder bridge in which a box girder G1 which is a utility tunnel divided into two parts for a space for power cables and a space for telephone cables is installed on a pier P1 having a horizontally rectangular cross-section. For this reason, the width is as narrow as about 6 m and the scale is relatively small, so the headroom restriction is also severe and there is almost no space around the pier P1.

[0019] Further, as shown in FIG. 2, in this box girder bridge B, the height of the box girder G1 changes with the pier P1 as a boundary, and a step is also formed on the upper surface of the pier P1. For this reason, it is impossible to fix steel materials on the upper surface of the pier P1 and take reaction force therefrom to lift materials, as in the construction device for pier reinforcement work described in Patent Document 1 mentioned in the background art.

[0020] The reinforcement work of the box girder bridge B is to reinforce the pier P1 against earthquake by rolling up a reinforcing steel plate S1 around the side surface of the pier P1 and filling the gap with a filling material such as mortar or concrete to integrate them. Further, in this reinforcement work, as shown in FIG. 2, a plurality of press-in jacks J1 are installed on the side surface of the pier P1, and a reinforcing steel plate S1 assembled in a U-shaped cross-section according to the cross-sectional shape of the pier P1 is press-fitted and installed by the press-in jacks J1.

[0021] Note that, as shown in Fig. 1, in this reinforcement work, in order to secure a space for assembling the reinforcement steel plate S1 under the pressing jack J1, the steel sheet pile SP is pressed into the ground G for earth retention and excavation is carried out, and the ground G around the pier P1 is cut down. However, as shown in Fig. 2, since it is difficult to install the steel sheet pile SP in the part under the box girder G1, earth retention is carried out with large sandbags SB as an inclined surface. Note that C1 in Fig. 2 indicates the disposable concrete C1 for locating (marking) the installation position of the reinforcement steel plate S1.

[0022] In the material hoisting method for repairing or reinforcing the pier of the box girder bridge according to this embodiment, as shown in Fig. 1, the reinforcement steel plate S1 is lifted and transported by a small crawler crane CL which is a mobile hoisting machine, and carried into the working space in the steel sheet pile SP.

[0023] Then, using a small manual hoisting device such as a chain block CB attached to the sandwich-type ceiling rail 1 (for example, a hoisting device of less than 3t that does not require installation notification), the reinforcement steel plate S1 as a material is lifted and hoisted, and assembled in an inverted L-shaped cross-section. Of course, the device attached to the sandwich-type ceiling rail 1 for hoisting is not limited to a manual hoisting device, and may be an electric hoisting device such as a baby hoist (for example, a hoisting device of 3t or more that requires installation notification). Also, the assembly of the reinforcement steel plate S1 may be joined by welding or mechanically joined and assembled with bolts or the like. However, when a large reinforcement steel plate is not required, a small manual hoisting device of less than 3t that does not require installation notification to the government agency is preferable.

[0024] (Sandwich-type ceiling rail) This sandwich-type ceiling rail 1 is composed of an upper side member 2 made of a retaining member (for example, H-250 mainly composed of H-shaped steel) installed along the upper surface of the box girder G1, a lower side member 3 made of a retaining member installed along the lower surface of the box girder G1, and a connecting member 4 made of a threaded steel bar such as a pair of left and right PC steel bars or Geving bars connecting these.

[0025] This sandwich - type ceiling rail 1 tightly connects and joins the upper side member 2 and the lower side member 3 with a connecting member 4 made of threaded steel bars, and sandwiches the box girder G1 vertically in a sandwich shape between the upper side member 2 and the lower side member 3, so that it can be installed without being fixed by post - construction anchors. Therefore, the problem of damaging the existing concrete structure described in the background art can be solved. Also, due to the post - construction anchors, operations such as drilling holes and filling and repairing the drilled holes after reinforcement work are no longer required, which not only improves the workability but also improves the safety.

[0026] Also, between the upper side member 2 and the upper surface of the box girder G1, and between the lower side member 3 and the lower surface of the box girder G1, a cushioning material (not shown) such as a 12 - mm - thick panel is interposed. Therefore, it is possible to prevent the box girder G1, which is an existing concrete structure, from being damaged when the upper side member 2 and the lower side member 3, which are steel materials, come into contact with it.

[0027] In the method of hoisting materials for repairing or reinforcing the piers of the box - girder bridge according to this embodiment, a chain block CB is attached to the aforementioned sandwich - type ceiling rail 1, and using this chain block CB, a reaction force is taken from the box girder G1 to lift and hoist the reinforcing steel plate S1, which is the material.

[0028] After that, the reinforcing steel plate S1 of 1 rod (1 stage) is assembled in a horizontal cross - section L - shaped, and is pressed in with a press - in jack J1 fixed to the side surface of the pier P1 to perform the reinforcement work.

[0029] According to the method of hoisting materials for repairing or reinforcing the piers of the box - girder bridge according to the present embodiment described above, the reinforcing steel plate S1, which is the material, is hoisted using the sandwich - type ceiling rail 1 that sandwiches the box girder G1 vertically and is installed without using post - construction anchors. Therefore, it can be applied to the repair and reinforcement work of the pier P1 of the box - girder bridge B, and the concrete structure of the box - girder bridge B to be repaired and reinforced is not damaged.

[0030] Moreover, according to the material hoisting method for repairing or reinforcing the piers of the box girder bridge according to the present embodiment, operations such as drilling holes and filling and repairing the drilled holes after the reinforcement work, like post-construction anchors, are no longer necessary, improving the workability.

[0031] Furthermore, according to the material hoisting method for repairing or reinforcing the piers of the box girder bridge according to the present embodiment, the reaction force is obtained from the existing box girder G1 by using the sandwich-type ceiling rail 1 installed by sandwiching the existing box girder G1 vertically, and the material is hoisted. Therefore, there is no risk of the post-construction anchor installed on the lower surface of the concrete structure falling off, improving the safety.

[0032] In addition, according to the material hoisting method for repairing or reinforcing the piers of the box girder bridge according to the present embodiment, the upper side member 2 and the lower side member 3 are tightened and fastened with the connecting member 4 made of threaded steel bars such as PC steel bars and Gevin bars. Therefore, it becomes easy to sandwich the box girder vertically with the upper side member 2 and the lower side member 3 and install the sandwich-type ceiling rail 1, and it can be installed in a short time.

[0033] Moreover, according to the material hoisting method for repairing or reinforcing the piers of the box girder bridge according to the present embodiment, buffer materials are respectively interposed between the upper side member 2 and the upper surface of the box girder G1, and between the lower side member 3 and the lower surface of the box girder G1. Therefore, it is possible to prevent the box girder G1, which is an existing concrete structure, from being damaged due to the contact of the upper side member 2 or the lower side member 3 made of hard steel with the box girder G1.

[0034] Furthermore, according to the material hoisting method for repairing or reinforcing the piers of the box girder bridge according to the present embodiment, the reinforcing steel plate S1, which is the material, is hoisted by using the chain block CB, which is a manual hoist. Therefore, not only can the material be hoisted with inexpensive and simple equipment, but also there is no need to submit an installation notice to the government agency.

[0035] As described above, the method for lifting materials for repairing or strengthening the piers of the box girder bridge according to the embodiment of the present invention has been described in detail. However, any of the above-described or illustrated embodiments merely shows one embodiment embodied in practicing the present invention. Therefore, the technical scope of the present invention should not be construed in a limited manner by these.

[0036] In particular, as an example of the repair or reinforcement work, the case of installing a reinforcing steel plate around the pier to reinforce the pier against earthquake has been described. However, the present invention is not limited to the reinforcement work of the pier, and can be applied to the lifting of materials during the repair or reinforcement work of the piers of the box girder bridge. Further, the materials are not limited to the reinforcing steel plate, and any materials necessary for the repair or reinforcement work may be used.

[0037] Note that although the box girder bridge has been exemplified as the bridge, the present invention can also be provided for bridges such as a follow slab bridge that has no ground covering part and a flat upper surface and allows repair and reinforcement work of the pier with the passage above the pier blocked.

Explanation of Reference Numerals

[0038] 1: Sandwich-type ceiling rail 2: Upper side member 3: Lower side member 4: Connecting member (threaded steel bar) CB: Chain block (manual hoist) B: Box girder bridge (existing bridge) G1: Box girder (bridge girder) P1: Pier S1: Reinforcing steel plate (material) J1: Press-in jack CL: Crawler crane (mobile hoist) G: Ground SP: Steel sheet pile (earth retaining) SB: Large sandbag (earth retaining) C1: Discarded concrete

Claims

1. In the repair or reinforcement work of the pier of a box girder bridge having a box girder, a top member installed along the upper surface of the box girder, a bottom member installed along the lower surface of the box girder, and a pair of left and right connecting members connecting the top member and the bottom member, a sandwich-type ceiling rail is installed by sandwiching the box girder vertically between the top member and the bottom member without using after-construction anchors, obtaining a reaction force from the box girder with the sandwich-type ceiling rail and lifting materials used for the repair or reinforcement work of the pier of the box girder bridge A method for lifting materials for repairing or reinforcing the pier of a box girder bridge, characterized by the above.

2. Connecting the top member and the bottom member with a pair of left and right connecting members made of threaded steel bars A method for lifting materials for repairing or reinforcing the pier of a box girder bridge according to Claim 1, characterized by the above.

3. Interposing buffer materials between the top member and the upper surface of the box girder and between the bottom member and the lower surface of the box girder, respectively A method for lifting materials for repairing or reinforcing the pier of a box girder bridge according to Claim 1 or 2, characterized by the above.

4. Lifting materials using electric hoisting equipment attached to the sandwich-type ceiling rail A method for lifting materials for repairing or reinforcing the pier of a box girder bridge according to any one of Claims 1 to 3, characterized by the above.

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