JP2005188201A - Expansion structure of track slab board on bridge girder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify or omit an expansion device by reducing an opening-closing quantity of a joint by the expansion of a track slab board, in a traffic system for traveling on the track slab board by a rail track. <P>SOLUTION: This expansion structure has a uniformizing device for uniformly keeping a joint dimension between mutual respective divided slab boards 10a, 10b and 10c by dividing the track slab board 10 on a bridge girder 50 into a plurality in the bridge axis direction by a line crossing the bridge axis. The uniformizing device is formed of an unbonding PC steel material 21 having anchoring parts 22, 23 and 24 in the respective divided slab boards by communicating the inside of the respective divided slab boards. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a traffic system that travels on a rail track on a slab plate, and can reduce the amount of joint opening and closing due to expansion and contraction of the track slab plate on the bridge girder, and can simplify or omit the expansion device. It is about the expansion and contraction structure of the track slab version on the bridge girder.

  The prior art will be described with reference to FIG.

  The bridge girder 50 is mounted on the abutments 54 and 54a. One end of the bridge girder 50 is fixed to one abutment 54 so that the bridge girder can extend and contract in the direction of the bridge axis, and the other end of the bridge girder 50 slides on the abutment 54a. Supported as possible. Between the bridge girder 50 and the abutments 54 and 54a, gaps corresponding to expansion and contraction (joint clearances 51 and 52) are provided. Conventionally, the expansion joint of the track slab plate 10 is installed at the same position as the gap of the bridge girder 50, and the rails 13 and 13b laid on the track slab plate 10 straddle the expansion joint of the track slab plate 10. Installed.

  Conventionally, the bridge girder 50 and the track slab plate 10 mounted thereon are integrated, and the track slab plate 10 and the rails 13, 13a, 13b are also fixed. When the temperature is lowered and the bridge girder 50 is shortened, for example, as shown in FIG. 3, when the bridge girder 50a indicated by the dotted line is changed to the bridge girder 50 indicated by the solid line, the bridge girder 50 is disposed so as to straddle the expansion joint 52. The rail 13b is pulled by the shortening amount (= ΔLt) of the bridge girder 50. For this reason, a large tensile force acts on the rail 13b, and the load resistance of the rail decreases.

  Further, when the temperature rises and the bridge girder 50 extends, that is, when the bridge girder 50 shown by the solid line in FIG. 3 changes to the bridge girder 50a shown by the dotted line, the rail 13b tries to extend due to the temperature rise, but the rail 13b A force (compression force) that is forcibly shortened by the extension of the bridge girder 50a acts. For this reason, it becomes easy to produce distortion in the rail 13b.

  Previously, the track slab version on the bridge girder was integrated with the bridge girder, and the expansion joint joint was matched with the bridge girder. In such a track slab plate, when the temperature rises and falls and the bridge girder extends or shortens, the track slab plate on the bridge girder also expands and contracts, and is placed on the track slab plate so as to straddle the expansion joint. Tensile / compressive force is generated on the rail. An object of the present invention is to provide a technique for preventing this and distributing the extension / reduction amount of the bridge girder.

  According to the present invention, the track slab plate is a precast product, and the expansion and contraction joints of the track slab plate are dispersed without being concentrated at one place in the bridge girder play. That is, the present invention divides the track slab plate on the bridge girder into a plurality of directions in the bridge axis direction along the line intersecting the bridge axis, and each of the divided slab plate on the both abutment sides crossing the bridge girder at the foremost and rearmost ends. It is an expansion / contraction structure of a track slab plate on a bridge girder, which is equipped with an equalizing device that fixes and keeps joint dimensions between divided slab plates evenly.

  As the equalizing device, it is preferable to use an unbonded PC steel material that communicates in each divided slab plate and is disposed in the bridge axis direction and has a fixing portion in each divided slab plate.

  Conventionally, when the temperature rises and falls and the bridge girder expands and contracts, a compressive tensile force is generated on the rail arranged so as to straddle between the expansion and contraction joints of the track slab. According to the present invention, the expansion / contraction amount of the joint of the track slab can disperse the expansion / contraction amount of the bridge girder, so that the compression / tensile force generated in the rail is smaller than that of the conventional method. The expansion / contraction amount of the joint width of the traveling slab plate is small according to the number of joints with respect to the expansion / contraction amount of the bridge girder, and the opening / closing amount of each joint is substantially the same. Therefore, troubles due to joint opening were completely solved.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a longitudinal sectional view of a bridge girder 50 and divided track slab plates 10a, 10b, 10c showing an embodiment of the present invention. The structural form of the present invention will be described. One unit of track slab plate from the fixed end 11a of the abutment 54 to the adjacent abutment 54a is divided into divided track slab plates 10a, 10b, 10c. One unit slab plate composed of the divided track slab plates 10a, 10b, and 10c is fixed only at both ends thereof, and the divided joint sides of the divided track slab plates 10a, 10b, and 10c are movable supports. Movable bearings 11b, 11c, 12a and 12b are provided between the divided track slab plates 10a, 10b and 10c and the bridge girder 50, and a rubber bearing having a slide structure or a polyfluoroethylene resin fiber (trade name Teflon) plate is provided. Etc. The divided track slab plates 10a, 10b, and 10c are connected by incorporating an unbonded PC steel material 21 therein. This unbonded PC steel material 21 has fixing portions 22, 23, 24 attached to the center portions of the respective track slab plates 10a, 10b, 10c, and the track slab plate 10a divided from the PC steel material 21 by the fixing portions 22, 23, 24, 10b and 10c are fixed.

  When the bridge girder 50 is reduced, the divided track slab plates 10a, 10b, and 10c of the unit are fixed only at both ends, and the fixed ends of the divided track slab plates 10a and 10c are the abutments. 54, 54a side. For this reason, as shown in the figure, even if the bridge girder 50 is reduced and the joint clearance is widened, since the bearings at both ends are fixed, the divided track slab plates 10a and 10c on both sides do not move.

  When the divided track slab plates 10a, 10b, and 10c move to the left following the reduction of the bridge girder, the movement is caused by the frictional resistance between the bridge beam 50 and the divided track slab plates 10a, 10b, and 10c. When obstructed, the unbonded PC steel materials have different left and right lengths, which causes a difference in tension between the left and right PC steel materials. Since the slide slab plate and the bridge girder have a slide structure, the track slab plates 10a, 10b, and 10c divided by the difference in tension between the left and right PC steel members 21 return to their original positions. .

  Therefore, when the bridge girder 50 expands and contracts by ΔL, if the number of division joints obtained by dividing the divided track slab plates 10a, 10b, and 10c is n, the expansion / contraction amount of the expansion joint between the divided portions of the track slab plate is ΔL. / N. However, the joint width between the divided track slab plates and the adjacent track slab plates fixed to the bridge girder at both ends does not change.

  FIG. 2 shows an embodiment of the present invention in which the bridge girder 50 is placed on the piers 57, 57. A single unit track slab comprising the divided track slab plates 10a, 10b, 10c is shown in FIG. Both ends are fixed to the adjacent bridge girders 50b and 50c, the ends on the side of the intermediate joints 25a and 25b are movable bearings, and the unbonded steel bar 21 is fixed at the center of the divided track slab plates 10a, 10b and 10c. 22, 23, and 24 are provided and fixed.

  The Example about dispersion | distribution of the track | orbit slab joint width by connection steel materials, such as an unbonded steel bar, is demonstrated. The design conditions are as follows.

Bridge girder length Lg = 28.000m
Slab shape Width Bs = 1.450m
Thickness ts = 0.350m
Length Ls = 12,000m
Temperature change ΔT = 20 degrees Linear expansion coefficient εt = 1.00E-05
Connected PC Steel Type 1S19.3 (SWPR19)
Cross sectional area Ap = 2.437 cm ²
Young's modulus Ep = 2.00E + 06kg / cm ²
Steel length Lp = 8.0000m
When the bridge girder is shortened by ΔLt due to the temperature change, the track slab at the center on the bridge girder 50 tends to move in accordance with the shortening of the bridge girder as shown in FIG. When the central track slab plate 10b is moved, the connecting steel material 21 connecting the three track slab plates 10a, 10b, and 10c is Lp−ΔLt / 2 on one side and Lp + ΔLt / 2 on the other side, and the length on the left and right is reduced. Differently, there is a difference in tension between the left and right connecting steel members 21. As shown in FIG. 6, this tension difference becomes a pushing force 31 and a pulling force 32 that control the movement of the center track slab plate 10b, and moves the divided track slab plate 10b.

The amount of expansion and contraction of the bridge girder due to temperature change is
ΔLt = ΔT · ε · Lg
= 20 * 1.00E-05 * 28000
= 5.6mm
It is. At this time, the tension increase / decrease amount per connecting steel material is as follows.

Accordingly, the force T for controlling the movement of the track slab plate per connecting steel material is
T = 2 · ΔPp
= 2 × 1706
= 3.412tf
Orbital slab weight is
Ws = Bs · ts · Ls · γc
= 1.450 x 0.350 x 12.000 x 2.500
= 15.225tf
The required number of connecting steel materials 21 is as follows. First, the track slab is supported by a rubber bearing. The following values are used for the friction coefficient of the bearing.

μ = 0.5 (coefficient of friction between rubber and concrete)
Therefore, the required number of connecting steel materials 21 is as follows.

N> μ · Ws / T = 0.5 × 15.225 / 3.412
= 2.2 Next, when the amount of change in joint width (ΔLt / 2) is controlled to 2.0 to 0.5 mm, as shown in Table 1, the control force (T) per connected steel material is 2.437 to 0.609 tf, and the required number (N) of connecting steel materials is 3.1 to 12.5.

It is explanatory drawing of expansion and contraction of the traveling slab plate according to the present invention. It is explanatory drawing of expansion and contraction of the traveling slab plate according to the present invention. It is a conceptual diagram with respect to the behavior of the rail by a conventional system. It is explanatory drawing of an Example. It is explanatory drawing of an Example. It is explanatory drawing of an Example.

Explanation of symbols

10, 10a, 10b, 10c Orbital slab plate 11a, 12c Fixed part 11b, 11c, 12a, 12b Movable part 13, 13a, 13b Rail 21 Unbonded steel bar (connecting steel)
22, 23, 24 Fixing part 31 Pushing force 32 Tensile force 50, 50a Bridge girder 51, 52 Joint clearance 54, 54a Abutment 55 Fixed part 56 Movable part 57 Bridge pier

Claims (2)

  The track slab version on the bridge girder is divided into a plurality of directions along the axis of the bridge along the line crossing the bridge axis, and the cutting edge and the end of the divided slab version are fixed on both abutment sides across the bridge girder and divided. A telescopic structure of the track slab plate on the bridge girder, equipped with an equalizing device that keeps the joint dimensions between the slab plates uniform.   2. The equalizing device is an unbonded PC steel material that is arranged in the bridge axis direction so as to communicate with each divided slab plate and has a fixing portion in each divided slab plate. Stretch structure of the track slab version on the bridge girder.

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