EP0698143B1 - Stable railway superstructure - Google Patents

Abstract

A stable railway superstructure and a process for producing the same are disclosed. A rail-carrying sleeper lies on a solid asphalt or concrete supporting layer. The sleepers (2) are rigidly secured to at least one profile (7) parallel to the rails (3) which extends downwards away from the lower face of the sleeper sole (9) and the profile (7) is glued to the supporting layer (1). A polymer adhesive having a high affinity with the steel profile and the supporting layer materials is preferably used as glue. The profiles are preferably anchored into a groove (8) milled at a precise position in the supporting layer for sleepers provided with corresponding sole profiles.

Description

The invention relates to a stable railway superstructure with a solid carriageway and a method for producing such a superstructure.

In railway technology, a distinction is made between ballast track and slab track, which usually rests on a base made of concrete or asphalt mix.

A generic superstructure consisting of multilayer, high-strength asphalt layers and a track arranged thereon with steel sleepers for the rail mounting is shown in the German, magazine ETR (28) 5 - 1979, pp. 437-438. A Y-tie is fastened in the substructure made of asphalt base layers by anchor bolts welded onto a sheet metal, and the height of the sleepers and the rail inclination can be adjusted on the tie using appropriate fastening means for the anchor bolts. The sole of the threshold, which consists of parallel H-profiles, is connected to one another by two profile elements arranged in the area under the rail. The joint created by these profiles between the surface of the asphalt base layer and the sole of the sleeper or beyond the lower edge of the sleeper is filled with a special sealing compound. An elastic rubber plate is arranged between the rail and the top of the sleeper, while under the rail itself, which is guided in a ribbed plate, there is again an intermediate layer made of plastic. In addition to the task of leveling the sleeper or rail, the welded-on anchor bolt also has the function of stabilizing the track in the desired position through high resistance to lateral forces, transverse displacement forces and forces resulting from rail deflection and lifting the sleeper.

According to DE-OS 35 17 295, which discloses a similar superstructure, the Y sleepers can also be glued to a bearing surface on the underside of the sleepers with a thermoplastic adhesive on an asphalt base layer.

From DE-OS 37 22 627 it is known to increase the transverse displacement resistance of Y steel sleepers in the ballast bed by welding cross bars under the sleepers.

From DE-OS 28 06 128 it is known to screw steel sleepers onto U-shaped steel profiles, which in turn are cast in a substructure. This version requires precise laying of the sleepers, which is completely impossible in practice, for example, with curve radii. It is also necessary to wait for the concrete to harden before the sleepers are screwed together, because otherwise the U-profiles will be pulled out of the target position in the concrete due to the greater section modulus of the sleepers.

From DE-PS 12 75 081 it is known to store so-called two-block sleepers in trough-shaped recesses of a concrete substructure with the interposition of an elastomer material of closed-cell structure in the substructure, and the rails on the concrete sleeper itself by inserting a washer made of grooved rubber to be attached elastically to the threshold.

Finally, it is known from DE-OS 19 22 055 to also support continuous sleepers over their entire surface against the concrete substructure on a thick elastic intermediate layer such that the forces acting on the tracks are transmitted either downwards or to the sides essentially or exclusively by means of an elastic intermediate layer will. The threshold can also be used from the bottom excellent humps are formed, which rests in a recess of the concrete substructure with the interposition of the elastic intermediate layer. This layer should consist of plastic foam or a mixture of bituminous binders, minerals and rubber scrap and / or rubber latex. Optionally it is stated that the sleepers can also consist of steel or wood or plastic and the substructure can also consist of concrete or steel or plastic. Furthermore, it is optionally indicated that the sleepers, the elastic intermediate layer and the substructure can, if necessary, be glued together. The teaching for the person skilled in the art from the invention is the arrangement of an elastic intermediate layer, according to the given representation as uniformly thick as possible, between the threshold and the substructure for damping the vibrations and noises, the corresponding lateral forces and downward forces being transmitted only via this elastic layer .

Ultimately, it is known from DE-OS 41 13 566 to lay duo-block sleepers or monoblock sleepers made of concrete on an asphalt base layer with a wide central transverse force base. The trough for the transverse force base can be milled after an exactly leveled base layer has been created. This design does not offer a solution against the lifting shaft, but only against transverse displacement of the track grate.

In contrast, the invention is based on the problem of compensating for the lifting shaft, i.e. forces resulting from the rail deflection, which want to lift the threshold, as well as an inexpensive, quick installation method for all types of sleepers, in particular for, in addition to the lateral displacement forces acting laterally on the sleepers propose light sleepers made of steel or wood or similar materials that can be used in such a superstructure.

The problems are solved according to the invention by claims 1 and 8. Advantageous further developments of the invention are specified in the subclaims.

The pumping effect, which can easily be observed in ballast beds and results from a tilting movement of the sleepers, is known from track construction. With today's desired elastic movement of a train over the track, the cause, a deflection of the rails, is inevitable. This rail deflection, resulting from the local wheel loads, results in a lifting shaft for the sleepers in front and behind. This is particularly noticeable when the track is made of concrete or asphalt mix on a solid substructure and there are light sleepers, e.g. made of wood, concrete or steel, for example in the form of trough sleepers, sleepers made of H-shaped steel profiles but also Y steel sleepers. The problem is not so serious with concrete sleepers if they are so heavy that the weight forces are higher than the lifting forces. The lifting forces can be, for example, approximately 5 kN when using a UIC 60 rail and a track grate with Y sleepers. However, this lifting force and the pumping effect largely depend on the type of rail, better its moment of inertia relative to the vertical load, the threshold distance and the threshold weight, the size of the rail on the threshold, the rollover speed of the threshold and the elasticity of the base layer. This means that different types of superstructure would have to be provided for the varying circumstances.

In practice, it has also been proposed to weigh down such light sleepers by applying weights or, as in the prior art, to hold them down by means of special anchor bolts.

The present invention now proposes another universally applicable fastening system for the sleepers on a solid base layer, in which profiles are arranged under the sole of the sleepers, which extend into the base layer and are glued to it.

For this purpose, it is proposed, inter alia, to provide the previously finished base layer or during the production thereof with one or more grooves, preferably in the area below the rails, where the greatest lifting forces act on the threshold, and to insert profiles into these grooves, which then within the grooves are glued to the base layer on both sides.

The base layer is preferably coated with a tool e.g. a cutter is grooved at the points where the profiles will later lie. The joint is cut larger than the cross-section of the profiles, for example by at least 20 mm wider, in order to obtain a sufficiently large recess for later grouting of the joint. The grooves are preferably milled into asphalt base layers because the stones present in the base layer are cut and these cut surfaces are intended to serve as adhesive surfaces for the adhesive to be applied. In the case of concrete base layers, an adhesive surface formed from cement or hydraulically bound inorganic materials is usually sufficient for this, so that a concrete base layer could be produced from the outset with a shaped groove. For this purpose, these adhesive surfaces should not be organic, e.g. Vegetable substances or asphalt or bitumen residues are wetted and also as free of water as possible in order to achieve good adhesion.

In particular, a flat steel profile to be welded under the sleepers is used as the profile. However, it is also possible to use differently shaped profiles, for example T-profiles, in the groove to provide a further positive and to obtain a positive connection after closing the joint with the adhesive.

Depending on the type of threshold, these profiles can preferably be welded onto steel sleepers, but also without being screwed or riveted or glued without leaving the scope of the invention. The only important thing is the firm connection of the threshold with the profile and its sufficient protrusion from the threshold. In the case of concrete sleepers, the profiles can be cast in with appropriate holders during manufacture or using e.g. Push-through screws are firmly screwed to the threshold.

With Y-sleepers, profiles can be used that also serve as spacers for the adjacent H-profiles or double-T profiles that form a Y-threshold and are welded under the sole of the threshold. These also replace spacers which are arranged between the profiles forming the threshold.

A pourable, hardening polymer adhesive is preferably used as the adhesive between the profile and the base layer. Such an adhesive is known, for example, under the trade name ICOSIT KC from SIKA-Chemie GmbH, as a potting material, in particular for tram rails. Such a two-component adhesive based on polyurethane or epoxy resin, which is to be mixed on site and adjustable by means of appropriate curing agents, has good adhesion both with steel, for example with the profile made of flat steel, and with the rock of the base layer. When fresh, it can be foamed by water or other means. For this reason, the cut surfaces of the joints should be free of organic agents and should not be wetted with water. Adhesives that have a high affinity for concrete or bitumen or other chemical binders, e.g. those that are added to concrete, can also be used as an adhesive if they also provide sufficient adhesion to steel.

Tests have shown that such a connection between the base layer and the vertical adhesive surfaces of the profile can withstand considerably higher forces than can be expected from the lifting shaft. Experiments carried out up to the point of fracture have shown that when the profiles are torn out of the groove, the structure of the concrete or asphalt base layer is regularly torn and not the connection point between the adhesive and the profiles and / or the groove wall. The lateral forces that are transferred from the profiles to the asphalt or concrete base course are sufficient if the profiles protrude at least 30 mm into the asphalt or concrete base layer. Depending on the application, in particular with heavy sleepers and / or low resulting lifting or transverse forces, it may be sufficient not to glue each sleeper with one or two profiles, but only every second or third sleeper using a profile with the base layer.

For reasons of easy casting, the sleepers do not have a profile that covers the entire width of the sleepers, but two or more small pieces that are easier to cast around. The profiles may protrude laterally beyond the threshold. If necessary, the steel and / or the joint side surface is provided with a primer for better adhesion.

The test values presented up to the break were achieved after a very short curing time of a few hours. The result of this is that such a railway superstructure can be produced and used again within one working shift.

In contrast to the prior art, in the railway superstructure according to the invention no thick elastic underlays are attached under the sleeper, but only a thin adhesive layer or a thin foam layer, which compensates for unevenness in the concrete or asphalt base layer, because the sleepers to be laid out from mass production have a smooth surface and a thick layer can be achieved by the interposition of this thin layer. The actual elastic rail mounting takes place in the area under the rail or, when using ribbed plates, below these ribbed plates, but in any case above the threshold. This has the great advantage that the resilient masses are lower and the entire threshold system cannot be dampened against vibrations.

The superstructure according to the invention can be easily manufactured using essentially the usual techniques in the manufacture of a road, e.g. by applying a base of asphalt mix or concrete. Then high-performance milling machines, such as are used commercially in road construction, can cut grooves in the surface of the substructure, into which the prefabricated sleepers are then inserted in such a way that the profiles get their nominal position as centrally as possible in the previously cut grooves. The profiles are then cast with the adhesive prepared on site, for example the polymer adhesive described above, or commercially available prefabricated containers are used for casting the grooves. If necessary, the sleeper compartments can then be filled with crushed stone or other sound-absorbing agents; At least in the case of an asphalt superstructure, the sun's radiation must be countered by a suitable cover, which can also have a sound-absorbing effect.

The invention will be explained in more detail with the aid of the schematic sketch.

The schematic figure shows half of the track on average. The railway superstructure consists of a base layer 1 made of asphalt mix, into which grooves 8 have been cut by a milling device. A steel sleeper 2 with welded flat steel profiles 7 is placed on the asphalt base layer 1 with the interposition of a thin compensation film 4 so that the profiles 7 of e.g. 10 mm thick in the middle of the approximately 60 mm wide joint. Due to the inserted leveling foil 4, the sole 9 can lie snugly on the asphalt base layer. Then the joint is cast with polymer adhesive 11, type Sika ICOSIT KC 330-U, so that the threshold is firmly attached to the asphalt base layer 1. The rails 3 can be fastened to the sleepers 2 with commercially available fastening means 5 with the interposition of a base 6 securing the elastic train travel. Ultimately, the sleeper compartments are filled with crushed stone 10, and in order to further increase the transverse displacement resistance, crushed stone can also be arranged in front of the sleeper 2 head. However, this ballast 10 arranged in front of the head primarily serves for further sound absorption, the vibrations possibly transmitted from the rails 3 to the threshold 2 and the sun protection of the base layer.

Claims (8)

1. Stable railway superstructure with sleepers carrying rails (3) on a solid asphalt or concrete support layer (1), sleepers (2) being securely connected on the one hand to at least one profile section (7) extending parallel to the sleepers (3) beneath the sole (9) of the sleepers, and downwards away therefrom, and this profile section (7) is on the other hand glued to the support layer (1) in a groove (8).
2. Railway superstructure according to claim 1,
   characterised in that a profile section (7) is located in a groove (8) in the support layer (1) in the centre of the track, or two profile sections (7) are located in two grooves (8) in the region approximately under the sleepers (3), and the profile section (7) is glued at both sides to the support layer (1).
3. Railway superstructure according to claim 1 or 2,
   characterised in that the groove (8), made by means of a cutting tool in the support layer (1), has on its sides sections serving as adhesive surfaces, which are not wetted with organic agents and/or water.
4. Railway superstructure according to claim 1 to 3,
   characterised in that the profile section (7) is a steel profile section, preferably a flat bar.
5. Railway superstructure according to claims 1 to 4,
   characterised in that there is located between the rail (3) and the sleeper (2) a resilient, vibration-damping foundation (6), and between the sleeper (2) and the support layer (1), a levelling compensating layer (4).
6. Railway superstructure according to claims 1 to 5,
   characterised in that the profile section (7), as a spacer for two adjacent H profile sections forming a Y sleeper, is welded beneath the sole (9) of the sleeper (2).
7. Railway superstructure according to claims 1 to 6,
   characterised in that a castable hardening polymer adhesive is used as an adhesive agent (11).
8. Method of producing a stable superstructure, particularly according to one of claims 1 to 7,
   characterised by the following process steps:

   - manufacturing a load-bearing support layer (1) of concrete or asphalt mix,

   - production of two grooves (8) in the surface of the support layer (1),

   - pre-fabrication of sleepers (2) with profile sections (7) extending beneath their sole (9) in the longitudinal direction of the rails,

   - laying the sleepers (2) on the support layer (1) in such a way that the profile sections (7) project into the grooves (8),

   - filling by pouring of the free spaces remaining in the grooves (8) at least in the length of the profile sections (7) with a prepared adhesive (11),

   - if necessary, covering the superstructure (1) with sound-damping means (10).

Images