Patent Application
20110197379
The invention relates to a fixed road for rail-bound vehicles on a bridge, wherein the fixed road is composed of a bridge superstructure slab, a support slab comprising a longitudinal hump and stopper covering said slab and a ballast slab comprising clearances, on which the rails are arranged with fasteners.
On the rapid transport routes of the railway so-called fixed roads have increasingly become dominant in recent years. With these structures, the rails are not fastened to sleepers arranged on a gravel bed, but mounted on a reinforced concrete support slab. The reason for using the fixed road for high-speed routes is the better position constancy and the greater availability resulting from longer maintenance intervals.
Placing a fixed road on bridges has been a problem to date. With a fixed road with continuously welded rails every cross section practically remains almost locationally fixed undisplaceably in any temperature, while temperature changes merely cause changes in stress in the rails. Since with bridge structures changes in length materialise due to temperature changes, the combination of a fixed road with a bridge constitutes a problem that is difficult to solve.
To solve the problem, it was proposed in DE 24 43 770 to arrange the support slab longitudinally displaceable on the bridge structure so that the bridge structure can move below the fixed road. The potentially very large forces during the braking of a train are absorbed into and passed on to the support slab which has to transfer said forces to the bridge superstructure. Dimensioning of the brake force distribution over the bridge and the continuous rails is highly problematic.
In order to avoid this problem, fixed roads for rail-bound vehicles and bridges have been developed which are know as “Rheda” system. With this system, a support slab is applied to the bridge superstructure slab for protection of the surface seal, which in the region of the tracks comprises reinforcement strips of greater thickness, in which depressions longitudinally spaced from one another are arranged. Ballast slabs, which with spurs at their bottom engage in the depressions in the reinforcement strips of the support slab are located on these reinforcement strips and are thus positively connected to said support slab.
Producing this known fixed road is time-consuming and costly and requires substantial material expenditure so that the weight and the construction height with unilateral track elevation become too great.
DE 196 20 731 A1 is known, wherein a fixed road for rail-bound vehicles on bridges is described, which is composed of a bridge superstructure slab, a support slab and a ballast slab. The ballast slab comprises clearances for individual humps, each of which is arranged at the longitudinal ends of the support slab. The clearances of the ballast slab with this construction engage about the humps of the support slab.
This construction requires elaborate longitudinal reinforcement and high-precision working. This requires a lot of work and time. In addition, the reinforcement strips of the support slabs and the ballast slab each are embodied only with a short maximum length of 6 m. This requires a multiplicity of slabs on a bridge and elaborate shuttering and reinforcement work for the concrete slab and the stoppers. Through the arrangement of the stoppers each at the end of the slabs of the structure, each slab has to comprise two stoppers.
The invention is based on the object of developing a structure which makes possible simpler longitudinal reinforcement and reduced shuttering and manufacturing expenditure and the production of longer slabs.
According to the invention, this is achieved in that the support slab (1) comprising the longitudinal depression (4) comprises the stopper (5) at the height of the middle of the ballast slab (8) to be arranged above and the longitudinal depression (7) of the support slab (1) in this region is interrupted by the stopper (5) over a length of 60 to 100 cm and the ballast slab (8) comprises a longitudinal rib (4), which in its middle region is interrupted by means of a clearance (6) over a length of 65 cm to 105 cm, in which the stopper (5) of the support slab (1) positively engages.
The margins of the longitudinal rib (4) comprise strip bearings, wherein an elastomer strip as strip bearing is glued on to the margins of the longitudinal rib (4). This has a thickness of 1.0 to 1.5 cm.
Under the support slab (1) a protective concrete layer (3) is arranged. It preferentially has a minimum concrete grade of C25/35 and a thickness of 5 to 11 cm.
Between bridge superstructure slab (2) and the support slab (1) or the protective concrete layer (3) a seal (11) can be arranged. This is embodied with bitumen webs and serves to protect the bridge superstructure slab (2).
The support slab (1) at its side facing the protective concrete layer (3) comprises transverse channels (9; 10) at a mutual spacing of 300 to 800 cm, which have a width of 8 to 12 cm and are embodied over the entire width of the support slab (1).
The longitudinal rib (4) with clearance (6) can also be arranged on the support slab (1) and the longitudinal depression (7) with stopper (5) on the ballast slab (8). Because of this, the structure can be better adapted to the respective conditions of the bridge and the respective load introduced.
The length of the slabs on bridges can be increased and then amount . . . up to approximately 30 m.
Only simple and cost-effective longitudinal reinforcement is required (less cutting and bending)
The slabs altogether require less reinforcement (less reinforcement for stoppers)
The expenditure for shuttering, reinforcing and other expenditure drops by approximately 50%
The arrangement of the stoppers in the middle of the support slab merely requires one stopper per support slab and one clearance in the ballast slab
If only one stopper instead of two stoppers is arranged, of which with the conventional design, one each is arranged on each slab end, no constraints develop between ballast slab and bridge superstructure slab in the event of changes in length
“Migrating” of the ballast slab in longitudinal direction is avoided
The ballast slab can expand freely under the effect of temperature because of the middle arrangement of the stopper
The number of ballast slabs and the stoppers is substantially reduced for a bridge superstructure length (e.g. 18 m of slab length with one stopper instead of 6 m slab length with two stoppers).
In the following, the invention is explained in more detail by means of an exemplary embodiment.
Here it shows:
FIG. 1—the bridge structure of the fixed road in longitudinal section
FIG. 2—a cross section through the bridge in the end region of the slab
FIG. 3—a cross section through the bridge in the slab middle
The support slab 1 is mounted on the bridge superstructure slab 2 by way of a protective concrete layer 3. The support slab 1 has the longitudinal depression 7 and in the middle region the stopper 5, which engages in the clearance 6 of the longitudinal rib 4 of the ballast slab 8 arranged in the middle. At a spacing of 300 to 800 cm, the support slab 1 comprises transverse channels 9; 10 which are embodied in a width of approximately 10 cm. These serve for the transverse drainage of the bridge superstructure slab 2.
Between the support slab 1 and the bridge superstructrue slab 2 or the protective concrete layer 3 a seal 11 is arranged. The support slab 1 is separated from the ballast slab 8 through a separating plane 12. Because of this it is achieved that both slabs can move differently from each other under the influence of temperature, so that cracks in the structure can be avoided.
Strip bearings in form of elastomer tape (t≈10 mm) are glued on to the margins of the longitudinal rib 4.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20 2008 006 153.9 | May 2008 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2009/001547 | 3/5/2009 | WO | 00 | 11/18/2010 |
