JP2014163150A - Through girder - Google Patents

Abstract

A lower girder capable of reducing the distance between a raceway surface and a lower surface of a girder is provided.
A lower girder 1A having a U-shaped cross-section in which a floor slab 3 is rigidly connected to lower ends of main beams 2 and 2, and a floating ladder track 10 is provided on the upper surface side of the floor slab 3. The lower surface of the vertical beam 11 of the floating ladder track 10 is provided so as to be substantially coincident with the upper surface of the floor slab 3. The resistance member 7 is provided.
[Selection] Figure 1

Description

  The present invention relates to a lower girder, and more particularly to a device capable of reducing the distance between a raceway surface and a girder lower surface.

  Conventionally, when a structure such as a road exists in the underarm space and a predetermined building limit must be secured under the underarm, the cross-sectional shape shown in Patent Document 1 is a U-shape. Presented prestressed concrete (PC) underpass girders may be planned. The lower girder is configured such that a floor slab is rigidly connected to the lower end of the main beam, and a track on which the train travels is laid on the floor slab.

  When the train passes, the excitation force from the train is transmitted from the track to the floor slab, and therefore, a slab track having an asphalt mortar layer as a ballast track or a cushioning material is used to disperse the excitation force. Generally, in order to obtain a sufficient load dispersion effect, ballast or roadbed concrete having a thickness of about 100 to 300 mm is required. The cause of this excitation force includes the mass of the train, the unevenness of the rail, the presence of a so-called wheel flat, or the presence of a rail joint, where a part of the tread is worn and a flat portion is generated by sliding the wheel.

JP 2001-214402 A

  However, in the conventional lower girder, in order to obtain the load distribution effect at the time of passing the train, a ballast or roadbed concrete having a thickness of about 100 to 300 mm is required. There was a problem that the interval could not be reduced.

Further, in the conventional lower girder, since the fastening device for fixing the rail cannot be embedded in the lower girder, the distance between the raceway surface and the lower surface of the girder cannot be reduced. This is because the value of the impact coefficient of the track member on which the train travels, that is, the value obtained by subtracting the static load from the dynamic load divided by the static load must be extremely large as about "4", This is because an elastic body must be provided on the track support in order to cope with the wear of the rail.
Furthermore, the reason why the distance between the raceway surface and the underside of the girder cannot be reduced is that creep deformation is increased in a lower girder with low rigidity.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a lower girder that can reduce the distance between the raceway surface and the lower surface of the girder.

  In order to achieve the above-mentioned object, the lower girder according to the present invention is a lower girder having a U-shaped cross-section in which a floor slab is rigidly connected to the lower end portion of the main beam, on the upper surface side of the floor slab. It features a floating ladder track.

  According to the lower girder of the present invention, the floating ladder track provided on the upper surface of the floor slab can disperse the load when the train passes, and the distance between the track surface and the lower surface of the girder can be reduced.

  In the lower girder according to the present invention, it is preferable that the lower surface of the vertical beam of the floating ladder track is provided so as to substantially coincide with the upper surface of the floor slab.

  In this case, since the lower surface of the vertical beam of the floating ladder track substantially coincides with the upper surface of the floor slab, the distance between the track surface and the lower surface of the girder can be reduced.

  In the lower girder according to the present invention, the upper surface of the vertical beam of the floating ladder track is provided so as to substantially coincide with the upper surface of the floor slab.

  In this case, since the lower surface of the vertical beam of the floating ladder track substantially coincides with the upper surface of the floor slab, the distance between the track surface and the lower surface of the girder can be reduced.

  Further, the lower girder according to the present invention is characterized in that a resistance member that resists lateral pressure is provided outside or inside the longitudinal beam of the floating ladder track.

  In this case, when a lateral excitation force is applied to the floating ladder track by the train, the lateral pressure of the floating ladder track can be resisted by the resistance member.

  Further, the lower girder according to the present invention is characterized in that a support member having a sliding function is provided on the lower surface of the elastic member provided on the lower surface of the vertical beam of the floating ladder track.

  In this case, an abnormal displacement of the floating ladder track can be dealt with by providing a supporting member having a sliding function.

  According to the lower girder of the present invention, since the floating ladder track is provided on the upper surface side of the floor slab, the load distribution effect at the time of passing a train without providing a thick ballast or roadbed concrete as in the past Therefore, the distance between the raceway surface and the underside of the beam can be reduced.

It is a perspective view when the lower spar according to the embodiment of the present invention is applied to a single track. FIG. 2 is an enlarged sectional view taken along line XX shown in FIG. 1. It is a perspective view when a lower girder is applied to a double track. It is explanatory drawing which shows the example of arrangement | positioning of the resistance member for resisting lateral pressure and spreading.

  Hereinafter, embodiments of a lower girder according to the present invention will be described with reference to the drawings. The present invention is not limited to this embodiment, and constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same. .

  FIG. 1 is a perspective view when a lower girder according to an embodiment of the present invention is applied to a single track, and FIG. 2 is an enlarged sectional view taken along line XX of FIG. The lower girder 1 </ b> A includes a lower girder body 2 and a floating ladder track 10.

  As shown in FIG. 1, the lower girder 1A is manufactured at the site where the lower girder 1A is installed, in the same manner as the known PC lower girder, that is, manufactured on the spot, It has a pair of main beams 2 and 2 that extend at a predetermined distance in the direction of the traveling track and are provided at a predetermined interval.

  A floor slab 3 is rigidly connected between the lower ends of the main beams 2 and 2. Since the thickness (D0) of the floor slab 3 for single wires is 350 mm or more in the design standard [concrete structure] such as a railway structure, the thickness of the floor slab 3 is also secured. A chain line indicated by reference numeral 4 in the floor slab 3 represents a compression main reinforcing bar provided in the floor slab 3 between the main beams 2 and 2. In the illustrated example, only one compression main reinforcing bar 4 is shown. However, a large number of compression main reinforcing bars 4 are arranged at predetermined intervals in the line direction.

  At the center in the width direction on the upper surface of the floor slab 3, the longitudinal direction extends over the entire track direction, the length in the direction orthogonal to the track direction is slightly larger than the width dimension of the floating ladder track 10, and a predetermined depth. A concave groove 5 is formed. The depth of the concave groove 5 is determined so that a part of the compressed main reinforcing bar 4 arranged in the floor slab 3 appears. The concave groove 5 is formed when the floor slab 3 is formed.

  In FIG. 1, the groove groove 5 and the floor slab 3 are shown as being separated from each other, but the groove groove 5 is filled with concrete 6 by a post-coating as will be described later. Therefore, when the lower girder 1A is completed, the concrete 6 is integrated with the floor slab 3 and becomes a part of the floor slab 3.

  The floating ladder track 10 is provided with two prestressed concrete (PC) vertical beams 11 and 11 in parallel with a predetermined distance between the tracks, as in the known floating ladder track. On these vertical beams 11, 11, rails R, R are attached using a fastening device to form a track on which the train travels. Since the floating ladder track 10 has a length of one unit, a plurality of floating ladder tracks 10 are provided on the floor slab 3.

  Between these vertical beams 11, 11, steel pipe joints 12, 12,... Are provided at predetermined intervals in the longitudinal direction, and the back surfaces of both vertical beams 11, 11 are shown in FIG. As shown, a plurality of elastic members 13 made of anti-vibration rubber or the like are provided at predetermined intervals in the longitudinal direction, and a support member made of a metal plate or the like having a low friction coefficient on the lower surface of the elastic members 13 14 are provided. And these support members 14 are comprised so that it may be mounted on the concrete 6 post-placed by the groove 5.

Hereinafter, a method for manufacturing the lower girder 1A having the above configuration will be described with reference to the drawings.
First, as shown in FIG. 1, the floor slab 3 having the main beams 2 and 2 and the concave groove 5 is manufactured on site at the construction site of the lower beam 1A. Next, the floating ladder track 10 is positioned and set in the concave groove 5 so that the upper surface position of the rails R, R becomes a predetermined position. After the setting, the concrete 6 is placed in the concave groove 5. It is cast. In the illustrated example, the set of the floating ladder track 10 in the concave groove 5 is such that the lower surface positions of both vertical beams 11 and 11 substantially coincide with the upper surface position of the floor slab 3.

  At the time of this placement, on the outside of the vertical beams 11, 11 of the floating ladder track 10, lateral pressure and expansion are dealt with so that the upper surface position is substantially the same as the upper surface position of the vertical beams 11, 11. A resistance member 7 is formed by the concrete 6. When the concrete 6 is solidified, the concrete 6 and the resistance member 7 in the groove 5 are integrated with the floor slab 3.

  Since the lower girder 1A having the above-described configuration is provided with the floating ladder track 10 as a track structure, the distance between the track surface and the bottom surface of the beam can be reduced. That is, the distance from the upper surface position of the rails R, R to the lower surface position of the floor slab 3 can be reduced. This is because the floating ladder track 10 is provided with the elastic member 13 on the back side of the vertical beams 11 and 11 so that the train can pass without a thick ballast or roadbed concrete as in the prior art. This is because a load dispersion effect can be obtained.

  Moreover, the lower girder 1A having the above-described configuration can reduce the distance between the raceway surface and the lower surface of the girder, so that the height of the main beams 2 and 2, that is, the girder height can be reduced, so that the entire lower girder bridge In addition, since the raceway surface can be lowered, the construction cost of a structure such as a tunnel existing before and after the lower girder 1A can also be reduced.

  In addition, the lower girder 1A having the above-described configuration is provided with a support member 14 having a sliding support function on the back side of the elastic member 13, so that the floor slab 3 can cope with shrinkage due to drying shrinkage, temperature change, and the like. can do. Further, since the resistance member 7 that resists lateral pressure and expansion is provided integrally with the floor slab 3 on the outside of the vertical beams 11, 11, it can cope with an abnormal displacement of the floating ladder track 10. it can.

  Further, the lower beam 1A having the above-described configuration is formed in a space in which a tool such as a jack can be mounted between the vertical beams 11 of the floating ladder track 10, so that an adjustment pad is inserted. Creep deformation adjustment and smoothness can be easily performed.

  In the above example, the floating ladder track 10 in the groove 5 is set such that the lower surface positions of the vertical beams 11 and 11 substantially coincide with the upper surface position of the floor slab 3. When the floating ladder track 10 is used as the road girder 1A, it has been analytically confirmed that the local load can be reduced to about 70%, so that it can be made smaller than the conventional thickness (D0). However, even below the floating ladder track 10, the thickness (D0) of the floor slab 3 is the same as in the conventional case to ensure a sufficient load resistance. Accordingly, the single-line lower girder 1A is also configured so that the upper surface positions of the vertical beams 11 and 11 substantially coincide with the upper surface position of the floor slab 3 as in the double-line lower girder 1B described later. You can also.

Next, an example in which a lower girder according to an embodiment of the present invention is applied to a double track is described with reference to FIG.
The lower girder 1B shown in FIG. 3 is formed such that the floor slab 3 rigidly connected between the lower ends of the main beams 2 and 2 is wider than the lower girder 1A for a single wire described above. Since the thickness (D0) of the floor slab 3 is set to 500 mm or more in the design standard [concrete structure] such as a railway structure, it is configured to be thicker than the lower girder 1A for a single wire.

  On the upper surface side of the floor slab 3, a floating ladder track 10 for one direction (upward direction) and a floating ladder track 10 for the other direction (downward direction) are provided in parallel. These floating ladder tracks 10, 10 are configured in the same manner as the above-described lower beam 1 </ b> A, and are respectively provided in the groove grooves 5, 5 provided in the floor slab 3.

  Since the floating ladder tracks 10 and 10 for both directions have the same configuration, the floating ladder track 10 located on the left side of FIG. 3 will be described as an example. The floating ladder track 10 disposed in the concave groove 5 is set so that the upper surface position of the longitudinal beams 11 of the floating ladder track 10 is set to be the same as the upper surface position of the floor slab 3. The compression main reinforcing bar 4 provided in the floor slab 3 between the two is bent in the concave groove 5 to near the lower surface of the longitudinal beams 11 and 11.

Hereinafter, a method for manufacturing the lower girder 1B having the above configuration will be described.
First, the floor slab 3 having the main beams 2 and 2 and the concave groove 5 is manufactured on-site at the construction site of the lower beam 1B. Next, the floating ladder track 10 is positioned and set in the concave groove 5 so that the upper surface position of the rails R, R becomes a predetermined position. After the setting, the concrete 6 is placed in the concave groove 5. It is cast. In the illustrated example, the set of the floating ladder track 10 in the concave groove 5 is such that the upper surface positions of both vertical beams 11, 11 substantially coincide with the upper surface position of the floor slab 3.

  The concrete 6 is placed in the groove 5 so that the upper surface position of the outer side of the vertical beams 11 of the floating ladder track 10 is the same as the upper surface position of the floor slab 3. The resistance member 7 for coping with the above is formed by the concrete 6. When the concrete 6 is consolidated, the concrete 6 and the resistance member 7 in the groove 5 are integrated with the floor slab 3.

  In the example shown in the figure, the concrete 6 in the concave groove 5 is hit by the inner part between the vertical beams 11 and 11 of the floating ladder track 10. it can. However, as shown in the illustrated example, when it is placed between the two vertical beams 11, 11, the placed concrete 6 is expected to be integrated with the floor slab 3 to increase the load bearing capacity of the floor slab 3. Is done. In this way, when the concrete 6 is placed between the two vertical beams 11, 11, the opening 8 for performing the creep deformation adjustment work or the like is provided at a predetermined interval.

  When the floating ladder track 10 is used for the lower girder 1B, it has been analytically confirmed that the local load can be about 70%. Therefore, the thickness of the floor slab 3 is below the floating ladder track 10. The thickness (D1) can be 350 mm, which is smaller than the original thickness (D0) of 500 mm. The thickness of the floor slab 3 other than the portion where the floating ladder track 10 is provided is set to the same thickness (500 mm) as before.

  The other floating ladder track 10 of the lower beam 1B is also attached to the floor slab 3 in the same procedure as described above.

  The lower girder 1B having the above-described configuration is provided with the floating ladder track 10 on the upper surface side of the floor slab 3, so that the load at the time of passing the train can be obtained without providing a thick ballast or roadbed concrete as in the past. Since a dispersion effect can be obtained, the distance between the raceway surface and the underside of the beam can be reduced. In addition, many effects similar to those of the above-described lower girder 1A can be obtained.

  Note that the double girder lower girder 1B configured as described above is configured such that the upper surface positions of the vertical beams 11 and 11 substantially coincide with the upper surface position of the floor slab 3, but also in this lower girder 1B. The distance between the raceway surface and the underside of the girder is slightly higher than in the illustrated example, but the lower surface position of both vertical beams 11 and 11 is the upper surface position of the floor slab 3 in the same manner as the single-line lower girder 1A described above. It can also be configured so as to be substantially coincident.

  In the above example, the resistance member 7 is provided on the outer side of both the longitudinal beams 11 and 11 as schematically shown in FIG. 4A, and this is shown in FIG. 4B. As shown in FIG. 4C, the resistance member 7A made of concrete may be provided inside the two vertical beams 11 or 11, or the resistance member 7B made of an L-shaped bracket may be provided as shown in FIG. , 11 may be provided on the outside of each of the vertical beams 11, and further, resistance members 7C made of L-shaped metal fittings may be provided on the inside of the vertical beams 11, 11, respectively, as shown in FIG.

  The embodiment of the lower girder according to the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1A, 1B Lower girder 2 Main beam 3 Floor slab 4 Compression main reinforcement 5 Concave groove 6 Concrete 7, 7A, 7B, 7C Resistance member 8 Opening 10 Floating ladder track 11 Vertical beam 12 Joint material 13 Elastic member 14 Support member

Claims (5)

A lower girder having a U-shaped cross section with a floor slab rigidly connected to the lower end of the main beam,
A lower girder characterized in that a floating ladder track is provided on the upper surface side of the floor slab.   The lower girder according to claim 1, wherein a lower surface of the vertical beam of the floating ladder track is provided so as to substantially coincide with an upper surface of the floor slab.   The lower girder according to claim 1, wherein an upper surface of the vertical beam of the floating ladder track is provided so as to substantially coincide with an upper surface of the floor slab.   4. The lower girder according to claim 1, wherein a resistance member that resists lateral pressure is provided outside or inside a longitudinal beam of the floating ladder track. 5.   The lower surface according to any one of claims 1 to 4, wherein a support member having a sliding function is provided on a lower surface of an elastic member provided on a lower surface of a vertical beam of the floating ladder track. Road girder.

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