JP2011247064A - Reinforcement method for bridge abutment and back fill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforcement method for a bridge abutment and a back fill of the bridge abutment in a bridge abutment which has a back fill and supports a bridge girder, while maintaining the traffic state of a railroads and vehicles.SOLUTION: Rod-like reinforcement members 5 are placed to a back fill 3 from the front face of a bridge abutment 1 nearly parallel to the axial direction of a bridge girder 2. In addition, the rod-like reinforcement members 5 are placed to the direction perpendicular to the axial direction of the bridge girder 2 from the slope face of the fill.

Description

The present invention relates to a method for reinforcing an abutment and a backfill.
More specifically, the present invention relates to a method of reinforcing a railway abutment and a road abutment together with a back embankment, the back of which is constructed as a back embankment structure.

There are many railway abutments and road abutments with back embankment on the back.
Among these abutments, there are also structures that have problems with seismic resistance according to the current design standards.
Even if this is not the case, it is possible that the safety of the abutment and the bridge girder has deteriorated.
As a method for reinforcing such abutments and bridge girders, the following methods have been conventionally employed.
<1> A method of constructing a new structure by constructing a temporary line separately from the abutment to be repaired and removing the aged abutment and bridge girder in order to secure the use of railways and roads.
<2> A method of reinforcing aged abutments by constructing a temporary line separately.
<3> A method of repairing the abutment by winding a steel plate or installing a new wall on the abutment.
<4> A method of installing an approach block c between the abutment a on the support ground d and the backfill b as shown in FIG.

JP 2009-256938 A.

The above-described conventional abutment and back embankment reinforcement methods have the following problems.
<1> Regardless of the method of construction, there will be times when rail and vehicle traffic will be impossible, affecting the surrounding economic activities.
<2> Construction of a temporary line is a large-scale construction, resulting in an extra huge cost.
<3> In the case of railroads, there is a situation where it is not used at night, but even when reinforcement work is performed using that time, the work must be divided into short periods of time, which is uneconomical. is there.
<4> If the abutment is momentarily separated from the back embankment due to vibration during an earthquake, the back embankment may be pushed out into the gap and the abutment may not return to its original position. It has been reported that when this phenomenon is repeated, the back embankment on the back of the abutment has subsided nearly 1 meter.
<5> Therefore, even if only the abutment is reinforced, there is a possibility that it will lead to a major accident if the abutment and the back embankment are not integrated, as in the case where the back embankment sinks greatly.
<6> If it is a new abutment, the approach block c can be installed from the beginning as shown in FIG. 7, but the settlement of the embankment b on the back is still unavoidable. The road is re-paved.

In order to solve the problems as described above, the abutment and back embankment reinforcement method of the present invention has a back embankment on the back and supports the bridge girder. It is characterized by a method of reinforcing an abutment and a back embankment, which is performed by placing a rod-shaped reinforcing material substantially parallel to the direction.
Further, the present invention provides a method for reinforcing an abutment and a back embankment in the above-mentioned abutment by placing a rod-shaped reinforcing material in a direction orthogonal to the axial direction of the bridge girder from the slope of the embankment toward the back embankment of the abutment. It is characterized by.
Furthermore, in the abutment described above, the present invention provides the above-mentioned abutment with a rod-shaped reinforcing material placed almost in parallel with the axial direction of the bridge girder from the front of the abutment toward the back embankment, and further toward the back embankment of the abutment. It is characterized by a method of reinforcing the abutment and back embankment by placing a rod-shaped reinforcing material in a direction perpendicular to the axial direction of the bridge girder from the slope.

Since the abutment and back embankment reinforcement method of the present invention is as described above, one of the following effects can be obtained.
<1> While securing rail and road traffic, the abutment and backfill can be reinforced without installing temporary lines. It is extremely economical in comparison.
<2> Since the back embankment and the abutment are integrated via a bar-shaped reinforcement placed in the back embankment, the back embankment of the abutment behaves in an integrated manner even during an earthquake, causing subsidence of the back embankment. Hateful.

Explanatory drawing of the abutment and back embankment before reinforcement. Explanatory drawing of the state which laid the rod-shaped reinforcement from the front of the abutment. Explanatory drawing of the state which provides a head block in the front of an abutment. The top view of the Example of FIG. FIG. 3 is a side view of the embodiment of FIG. 2. The top view of the Example which drives a rod-shaped reinforcement from the side surface of back embankment. Explanatory drawing of the conventional Example which installs an approach block.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

<1> Precondition. (Figure 1)
As described above, the object of the reinforcing method of the present invention is a method for reinforcing the abutment 1 having the back embankment 3 on the back surface and the back embankment 3.
The abutment 1 is made of concrete, and bridge girder 2 such as a road and a railroad is bridged over two abutments 1 facing each other across a road.
On both sides of the abutment 1, there is a backfill 3 on the back, and the backfill 3 has a slope, and the skirt portion is surrounded by an existing fill retaining wall 4 made of stone or concrete.
In the present specification, for the convenience of explanation, regarding the abutment 1 having a substantially rectangular plan view, the back embankment 3 side is referred to as the “rear surface”, the passage side is referred to as the “front surface”, and both surfaces parallel to the bridge girder 2 are referred to as “side surfaces”. I will decide.

<2> Placing a rod-shaped reinforcing material. (Figure 2)
A plurality of bar-shaped reinforcing members 5 are driven from the front surface of the abutment 1 toward the back embankment 3 at a position below the support portion 11.
The direction in which the rod-shaped reinforcing member 5 is placed is substantially parallel to the axial direction of the bridge girder 2. A plurality of parallel placements are placed in the embankment 3 on the back of the abutment 1, and the end on the front side is integrated with the abutment 1. Turn into.
As this rod-shaped reinforcing material 4, a well-known construction method described in, for example, Japanese Patent No. 2575329 can be adopted.
This patent method is a method using an excavation stirring rod provided with an excavation blade and a stirring blade around a hollow rotating shaft.
The excavation stirring rod forms a mixture of cylindrical stirring soil and cement milk in the ground.
A central reinforcing body made of cement milk is located at the center of the mixture.
In the center of the central reinforcing column, a core material with the tail end exposed outside the hole is positioned, and this core material is used as a tension reinforcing body.
However, this construction method is an example, and various other known bar-shaped reinforcing materials 5 can be employed.
The end of the rod-shaped reinforcing member 5 on the abutment 1 side is exposed on the front surface of the abutment 1.
Therefore, the exposed end of the rod-shaped reinforcing member 5 can be formed as a head block 6 by being surrounded by a concrete block.
Since the head block 6 is formed on the front surface of the abutment 1, the integration of the abutment 1 and the rod-shaped reinforcing member 5 is further ensured.

<3> Integration of abutment and backfill.
As described above, the abutment 1 and the backfill 3 are firmly connected via the bar-shaped reinforcing material 5.
Therefore, unlike the reinforcement of only the abutment 1, the abutment 1 and the backfill 3 are integrated, so that the abutment 1 behaves integrally with the backfill 3 even during an earthquake.
Therefore, a stable structure can be provided without causing the phenomenon that the edge of the abutment 1 and the back embankment 3 is cut and the back embankment 3 sinks greatly as in the prior art.

<4> Other Embodiment 1. (Fig. 6)
In the above embodiment, the rod-shaped reinforcing member 5 is driven in parallel with the direction of the bridge beam 2.
However, the rod-shaped reinforcing material 5 can be driven from the slope of the embankment 3 in the direction orthogonal to the axial direction of the bridge girder 2 toward the back embankment 3 of the abutment 1.
Also by this method, the abutment 1 and the back embankment 3 can be integrated and reinforced through the rod-shaped reinforcing material.

<5> Other embodiment 2.
For the back embankment 1 of the abutment 1 as described above, the method of placing the rod-shaped reinforcing material 5 from the front surface of the abutment 1 almost parallel to the axial direction of the bridge girder 2, and the back embankment 1 of the abutment 1 The abutment 1 and the back embankment 3 can also be reinforced by combining the method in which the rod-shaped reinforcing material 5 is driven in the direction orthogonal to the axial direction of the bridge girder 2 from the slope of the back embankment 3.

1: Abutment 2: Bridge girder 3: Embankment 4: Existing retaining wall 5: Bar-shaped reinforcement 6: Head block

Claims (3)

In the abutment that has the back embankment on the back and supports the bridge girder,
For the back embankment, a rod-shaped reinforcing material is placed from the front of the abutment almost parallel to the axial direction of the bridge girder.
Reinforcement method of abutment and back embankment.
In the abutment,
For the back embankment of the abutment,
From the slope of the embankment, in the direction orthogonal to the axial direction of the bridge girder, perform by placing a rod-shaped reinforcing material,
The abutment and back embankment reinforcing method according to claim 1.
In the abutment,
For the back embankment of the abutment, a bar-shaped reinforcing material is placed from the front of the abutment almost parallel to the axial direction of the bridge girder,
Furthermore, toward the back embankment of the abutment, a rod-shaped reinforcing material is placed in the direction perpendicular to the axial direction of the bridge girder from the slope of the back embankment.
The abutment and back embankment reinforcing method according to claim 1.

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