JP2011247047A - Reinforcement method for bridge abutment in existing bridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforcement method for a bridge abutment in an existing bridge capable of ensuring the prevention of the bridge abutment from damage which has a generating mechanism as follows: in the existing bridge in which the bridge abutment and a bridge girder are connected with a rigid-framed structure, when the bridge abutment is reinforced by a reinforcement means for dispersing the deformation load of a bridge girder applying to the bridge abutment, temperature change and an earthquake or the like deform a bridge girder, and applies excessive bending tensile load to the bridge abutment through the bridge girder.SOLUTION: In the reinforcement method for the bridge abutment 1 in the existing bridge in which the bridge abutment 1 and a bridge girder 2 are connected with a rigid-framed structure, a portal column 3 is constructed on the ground around the outside of the bridge abutment 1 as a reinforcement means, and the end of the bridge girder 2 is fixed to the portal column 3, therefore the deformation load of the bridge girder 2 applied to the bridge abutment 1 is dispersed to the existing bridge abutment 1 and the portal column 3.

Description

  The present invention relates to a method for reinforcing an abutment in an existing bridge, and more particularly to a method for reinforcing an abutment in an existing bridge in which an abutment and a bridge girder are connected by a ramen structure.

  As a countermeasure when the bridge used as a business line has become obsolete and difficult to use, it is conceivable to construct a new bridge. It is necessary to go through a number of processes, such as removing the old existing bridge, constructing a new bridge, laying the track on the new bridge, and then removing the temporary line. Therefore, there is a problem that it cannot be easily implemented.

  Therefore, a method for solving the above problem is disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2009-256938) as a method for rebuilding an existing bridge. Hereinafter, this remodeling method is called a conventional remodeling method and will be described with reference to the drawings.

  4 is a schematic cross-sectional view showing an existing bridge, and FIG. 5 is a schematic cross-sectional view showing an existing bridge reinforced by a conventional reconstruction method.

  As shown in FIG. 4, the existing bridge is composed of a pair of abutments 8 constructed on the foundation 7 and a bridge girder 11 passed between the abutments 8 via a support 10 installed on a girder 9 of the abutment 8. The abutment 11 supports the earth pressure of the back embankment 12 as a cantilever beam, and the bridge girder 11 has a structure that supports a load such as a train as a simple beam supported by the support 10.

  The conventional remodeling method is a method of reinforcing a bridge when such an existing bridge is aged. As shown in FIG. 5, as shown in FIG. After removing the old paint film and rust and exposing the iron surface), the corner (connecting portion) between the abutment 8 and the bridge girder 11 is reinforced with the cheek cane reinforcement 13 to form a ramen structure. The abutment 8 and the bridge girder 11 are integrated.

  In addition, although not shown in Patent Document 1, not only the corners of the abutment 8 and the bridge girder 11, but also by installing a formwork around the corners and placing concrete in the formwork, It is disclosed that the corners of the abutment 8 and the bridge girder 11 and the periphery thereof are integrated through concrete.

  Furthermore, in Patent Document 1, as shown in FIG. 5, it is disclosed that a ground pile reinforcing material 14 is driven into the back embankment 12 to reinforce the back embankment 12 and the ground soil reinforcing material 14 and the abutment 8 are connected. Has been.

  FIG. 6 shows changes in the bending moment acting on the abutment and the bridge girder. FIG. 6 (a) is a diagram showing a bending moment acting on the abutment and the bridge girder in the case where the corner portion between the abutment and the bridge girder is not reinforced and the back embankment is not reinforced with the natural ground reinforcing material. Fig. 6 (b) shows the bending moment acting on the abutment and bridge girder at normal times when the corner of the abutment and the bridge girder are reinforced by the conventional reconstruction method and the back embankment is reinforced by the ground reinforcement. FIG. 6 (c) shows a case where the corners of the abutment and the bridge girder are not reinforced and the back embankment is not reinforced by the natural ground reinforcing material, and acts on the abutment and the bridge girder at the time of the earthquake. FIG. 6 (d) is a diagram showing a bending moment. FIG. 6 (d) shows a case where an abutment at the time of an earthquake is obtained by reinforcing a corner portion between an abutment and a bridge girder and reinforcing a back embankment with a natural ground reinforcing material by a conventional reconstruction method. It is a figure which shows the bending moment which acts on a bridge girder.

  The following is clear from FIG.

  As shown in FIG. 6 (a), when the reinforcement of the corner portion between the abutment 8 and the bridge girder 11 and the backfill 12 by the natural ground reinforcing material 14 are not performed at all times, the center portion of the bridge girder 11 is used. The maximum bending moment acts on the back, but as shown in FIG. 6 (b), the conventional remodeling method is used to reinforce the corners of the abutment 8 and the bridge girder 11 with the cheek cane reinforcement 13 and the back of the natural ground reinforcement 14 When the embankment 12 is reinforced, the bending moment acting on the bridge girder 11 decreases as a result of the upper tensile moment acting on the end of the bridge girder 11.

  As shown in FIG. 6 (c), in the event of an earthquake, when the corners of the abutment 8 and the bridge girder 11 are not reinforced and the back embankment 12 is not reinforced by the natural ground reinforcing material 14, the center of the bridge girder 11 is used. The maximum bending moment acting on the part is greatly increased by the inertial force, but as shown in FIG. 6 (d), the corner part is reinforced by the cheek cane reinforcing material 13 between the abutment 8 and the bridge girder 11 as shown in FIG. 6 (d). When the back embankment 12 is reinforced with the natural ground reinforcing material 14, the bending moment acting on the bridge girder 11 decreases as a result of the upper tensile moment acting on the end of the bridge girder 11.

  However, as is apparent from FIG. 6 (d), during an earthquake, a bending moment acting on the abutment 8 acts on the abutment 8 due to the inertial force, so it is desired to reduce this bending moment.

JP 2009-256938 A

  As described above, according to the conventional remodeling method, by integrating the abutment 8 and the bridge girder 11 with the ramen structure, it is possible to firmly reinforce the old bridge, so that the bridge is rebuilt from the beginning. Compared with, the time and cost required for building the bridge can be significantly reduced.

  However, when a bending tensile load exceeding the reinforcing strength is applied to the abutment 8 through the bridge girder 11 due to deformation of the bridge girder 11 due to temperature change or earthquake, the abutment 8 may be damaged.

  In addition, as described above, Patent Document 1 discloses that the ground embankment reinforcement 14 is driven into the back embankment 12 to reinforce the back embankment 12 and connect the ground embankment reinforcement 14 and the abutment 8. However, even if the abutment 8 is reinforced in this way, when a bending tensile load exceeding the reinforcement strength acts on the abutment 8 via the bridge girder 11 due to deformation of the bridge girder 11 due to temperature change or earthquake, etc., The abutment 8 could be damaged.

  Accordingly, an object of the present invention is to provide an abutment in which an abutment and a bridge girder are connected by a ramen structure, and the abutment is reinforced by a reinforcing means that disperses the deformation load of the bridge girder acting on the abutment. The purpose of the present invention is to provide a method for reinforcing an abutment in an existing bridge, which can reliably prevent an abutment from being damaged by an excessive bending tensile load acting on the abutment via the bridge girder due to the deformation of the bridge girder. .

  The present invention has been made on the basis of the above findings, and is characterized by the following.

  The invention according to claim 1 is a method of reinforcing an abutment in an existing bridge in which the abutment and the bridge girder are connected by a ramen structure, and the abutment is provided by a reinforcing means that distributes the deformation load of the abutment that acts on the abutment. It is characterized by reinforcement.

  The invention according to claim 2 is the method of reinforcing an abutment in an existing bridge according to claim 1, wherein the reinforcing means includes a gate-shaped column installed on the ground outside the abutment, and the gate shape It is characterized in that the end of the bridge girder is fixed on a column.

  The invention according to claim 3 is characterized in that, in the method for reinforcing an abutment in an existing bridge according to claim 1 or 2, a back embankment is provided on the back side of the abutment.

  The invention according to claim 4 is the method for reinforcing an abutment in an existing bridge according to any one of claims 1 to 3, wherein a natural ground reinforcing material is driven into the back embankment, and the natural ground reinforcing material is provided. And the abutment are connected to each other.

  According to the present invention, in an existing bridge in which the abutment and the bridge girder are connected by a ramen structure, the abutment is reinforced by the reinforcing means that disperses the deformation load of the bridge girder acting on the abutment, which is caused by a temperature change, an earthquake, or the like. Due to the deformation of the bridge girder, it is possible to reliably prevent the abutment from being damaged by an excessive bending tensile load acting on the abutment via the bridge girder.

It is a schematic perspective view which shows a part of abutment and bridge girder reinforced by the reinforcement method of the abutment in the existing bridge of this invention. It is a schematic top view which shows a part of abutment and bridge girder reinforced by the reinforcement method of the abutment in the existing bridge of this invention. It is a schematic side view which shows the abutment and the bridge girder part which were reinforced with the reinforcement method of the abutment in the existing bridge of this invention. It is a schematic sectional drawing which shows the existing bridge. It is a schematic sectional drawing which shows the existing bridge reinforced by the conventional reconstruction method. It is a figure which shows the change of the bending moment which acts on an abutment and a bridge girder.

  An embodiment of the abutment reinforcing method of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic perspective view showing a part of an abutment and a bridge girder reinforced by an abutment reinforcement method for an existing bridge according to the present invention, and FIG. 2 is reinforced by an abutment reinforcement method for an existing bridge according to the present invention. FIG. 3 is a schematic side view showing a part of the abutment and the bridge girder reinforced by the method of reinforcing the abutment in the existing bridge according to the present invention.

  1 to 3, reference numeral 1 denotes an abutment of an existing bridge, 2 denotes a bridge girder fixed on the abutment 1, and one end of the abutment 1 and the bridge girder 2 is, as shown in FIG. It is reinforced by 13 etc. so that it may become a ramen structure. In addition, as shown in FIG. 5, the back embankment 12 is piled up in the back side of the abutment 2, the natural ground reinforcement 14 is driven in in this back embankment, and the natural ground reinforcement and the existing abutment 1 are connected. Also good.

  3 is a gate-shaped column as a reinforcing means constructed on the ground outside the abutment 1, and is constructed retrofitted with a steel box-shaped pile vent or the like. The abutment 1 and the gate column 3 may be integrated. The end portion of the bridge girder 2 is fixed to the abutment 1 as described above, but is also fixed to the upper portion of the portal column 3 by the rigid linking jig 4. The rigid linking jig 4 is composed of a bar 6 that is stretched over a beam 5 fixed to the upper part of the portal column 3 and penetrates one end of the bridge girder 2. In addition, if the portal column 3 is unitized and manufactured in advance, the on-site construction is simplified.

  In this way, the end of the bridge girder 2 is fixed to the portal column 3 via the rigid jig 4, so that when the bridge girder 2 expands and contracts due to a temperature change or the like, its deformation load is It acts in a distributed manner with the portal column 3. As a result, since the bending tensile load acting on the abutment 1 is reduced, the abutment 2 can be reliably prevented from being damaged. The deformation load acting on the abutment 1 includes a bending tensile load acting on the upper part on the front side of the abutment 1 and a bending tensile load acting on the lower part on the back side of the abutment 1.

  The portal column 1 as the reinforcing means may have another structure as long as it can support the deformation stress of the bridge girder 2. The rigid linking jig 4 may have another structure as long as it can fix the portal column 1 and the end of the bridge girder 2.

  As described above, according to the present invention, in the existing bridge in which the abutment 1 and the bridge girder 2 are connected by the ramen structure, the reinforcement of the columnar column 3 and the like that distributes the deformation load of the bridge girder 2 acting on the abutment 1 is provided. By reinforcing the abutment 1 by means, it is ensured that an excessive bending tensile load acts on the abutment 1 via the bridge girder 2 due to deformation of the bridge girder 2 caused by temperature change, earthquake, etc. Can be prevented.

1: Abutment 2: Bridge girder 3: Portal column 4: Rigid jig 5: Beam material 6: Bar material 7: Foundation 8: Abutment 9: Girder seat 10: Support 11: Bridge girder 12: Back embankment 13: Cheek cane reinforcement 14: Natural mountain reinforcement

Claims (4)

In the reinforcement method of the existing abutment where the abutment and the bridge girder are connected by a ramen structure,
A reinforcing method for an existing abutment, wherein the abutment is reinforced by a reinforcing means for dispersing a deformation load of the bridge girder acting on the abutment.   The said reinforcing means is provided with the portal column installed on the ground outside the said abutment, The edge part of the said bridge girder is being fixed on the said portal column, The Claim 1 characterized by the above-mentioned. The reinforcement method of the abutment in the existing bridge.   The method for reinforcing an abutment in an existing bridge according to claim 1, wherein a backfill is piled on the back side of the abutment.   The abutment in the existing bridge according to any one of claims 1 to 3, wherein a natural ground reinforcing material is driven into the back embankment, and the natural ground reinforcing material and the abutment are connected to each other. Reinforcement method.

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