EP1982019B1 - Method for producing a ballast bed which underwent partial foaming for a railway track superstructure - Google Patents

Description

The invention relates to a method for introducing a flowable, foamable reaction mixture into partial areas of a ballast body of a track superstructure. The invention further relates to the creation of a partially foamed track superstructure.

Ballast tracks are one of the traditional and most frequently used track systems. Optionally equipped with wood, concrete or steel sleepers. This track construction has been continuously optimized through practical use and theoretical recalculation since the beginning of rail traffic.

In order to obtain an economical track system, the service life of its main elements - rails, sleepers, ballast and substructure - must be properly coordinated. Low "life cycle costs" arise when the substructure has a longer service life than the ballast bed and the ballast bed does not have to be replaced until the sleepers have reached the end of their service life. The strong increase in stress caused by more trains, higher axle loads and speeds as well as heavy rolling stock has led to the fact that for economic reasons the track grating was first reinforced by using stiffer rail profiles and concrete sleepers. In a second phase, where necessary, the substructure was renovated as part of the superstructure renewal by installing formation protection layers and drainage. This effectively made the ballast bed the weakest main element of the road. The improvement of the ballast properties is an important measure for ensuring a sufficient service life of the ballast bed consisting of crushed ballast, which has a high pore volume when clean.

Today, speeds of up to 300 km / h are realized on these tracks (e.g. TGV) and large loads are transported.

From a theoretical point of view, the construction of the ballast track is a complicated, complex realization. Complicated because the ballast mass, which is not in a rigid, solid structure, changes under dynamic influence.

This means: In the manufacture of the track, after installing the track grate on a ballast bed that is at least 30 cm thick, the ballast is compacted using so-called tamping machines. Now the track grate rests on the ballast bed and transfers the loads from the train run over the rails to the sleepers and from there to the ballast body. The loads are then distributed in the ballast body - ideally viewed - from ballast stone to ballast stone down to the subgrade below and diverted into the ground.

The purely static removal of the introduced loads is done without any problems.

Changes in the structure of the ballast bed are triggered by the dynamic load that occurs during the train journey,

As is known, there are positive and negative load entries when crossing the train. This means that the track is loaded with vertical loads and additionally with a relieving leading and trailing shaft. In connection with the dynamic frequency from the train run the "stone on stone structure" can change. The ballast stones twist, become round in the final phase and the track position changes. If this process were carried out completely evenly, there would be no disadvantage for the track position. Due to the lines of the track - arch, straight line, bridge, various subsoils etc. - this does not happen. It has to be tamped with tamping machines at regular intervals to keep a good track position in the long term.

The railways now run in freight transport with an axle load of 22.5 t. The sleepers transfer this load on their underside to an average of approx. 330 ballast stone peaks and from there from stone to stone downwards. Only about 12% of the threshold area is used as a footprint. These values apply to both horizontal and vertical load transfers. The cavity in the ballast structure is approximately 40%, which means that there is enough space to allow the individual ballast stones to be twisted or shifted under dynamic loads.

1. 1. Es wurden und werden schotterlose Gleissysteme, sogenannte "Feste Fahrbahnen" entwickelt. Diese können einen Betonunterbau oder einen Asphaltunterbau aufweisen.
2. 2. Der Schotterkörper wird nach der Herstellung des fertig gestopften Gleises mit einem zementösen Gemisch ausgegossen und damit starr.
3. 3. Der Schotterkörper wird nach der Herstellung des fertig gestopften Gleises mit einem Flüssigkunststoff behandelt und dadurch an den Kontaktstellen Stein zu Stein punktweise verklebt.

Various techniques have been developed in the past to counteract this problem:

1. 1. Ballastless track systems, so-called "slab tracks" were and are being developed. These can have a concrete substructure or an asphalt substructure.
2. 2. The ballast body is poured with a cementitious mixture after the finished stuffed track and thus rigid.
3. 3. The ballast body is treated with a liquid plastic after the finished stuffed track and thereby glued point to stone at the contact points.

A number of previous proposals are known in which attempts are made to change the properties of technical structures in order, for example, to improve the stability by effectively "holding together" the stones.

Out DD 86 201 and DE 24 48 978 A1 For example, full or partial gluing of all ballast stones of the ballast body is known. This results in drainage problems, since surface water can no longer penetrate the ballast body horizontally or vertically, which is particularly unfavorable in the case of two or more tracks and especially in curve areas.

Also from DE 20 63 727 full bonding of all ballast stones of the ballast body is known, with an optionally foamable adhesive material. A machine with which this full adhesion can be achieved is in US-A-3,942,448 respectively. DE-U-7319950 described.

Out DE-A-23 05 536 a method for lifting tracks is known in which swelling material is introduced through the rails into the track body for the purpose of lifting it.

It is finally over EP-A-1 619 305 It is known to provide drainage mats below a ballast bed foamed only in the load transfer areas of the ballast body. The advantage of this track superstructure is given in particular on double or multi-track lines. Surface water (e.g. rainwater), which collects in the near-surface area of the ballast body between the sleepers and above the partial foaming, reaches the area between two tracks and, since there is no foaming in this area, can flow off to the subgrade to work from there to drain over the drainage mat of the adjacent track, which lies below the ballast body of the adjacent track and on its level. The foam is preferably a polyurethane, and it is further known to heat and dry the ballast before the foam is introduced.

The object of the invention is to propose a method for introducing a flowable, foamable reaction mixture from above into a ballast body with sleepers embedded in it, with which the foaming of the ballast body within the load transfer areas of the sleepers, such as in EP-A-1 619 305 shown, reliably sets.

The solution to the technical problem results from a method with the features of claim 1. Further advantageous configurations result from the subclaims.

To achieve this object, the invention proposes a method for introducing a flowable, foamable reaction mixture based on a polyurethane from above into a ballast body with sleepers embedded in it, in the method the mixture being introduced into the ballast body to the side of the sleepers, and depending on the height of the ballast body at the application point, preferably in an amount which is greater the higher the application point is in the ballast body, the mixture being set such that the foam formation process only begins when the front of the inside of the ballast body mixture flowing below has reached the underside or the area of the ballast body near the underside, so that the foam formation within the ballast body takes place from bottom to top. A conical foam structure forms in the ballast body, so that the ballast body is fixed in a load transfer cone of the foam structure from its base to the lower edge of the sleeper.

The invention therefore proposes to adjust the flowable, foamable reaction mixture in such a way that the foam formation process takes place only after a certain time after the mixture has been introduced into the ballast bed. Such delays in the foaming process are possible by choosing appropriate components and additives for the flowable, foamable reaction mixture. According to the invention, this causes foam formation within the ballast body from bottom to top, that is to say below the thresholds. Since the flowable, foamable reaction mixture is introduced to the side of the sleepers, it can be achieved that the foaming also takes place only in parts of the ballast body, namely within the load transfer areas at an angle of approximately 60 °, starting from the sleepers.

Alternatively, it is possible to first remove the ballast between the sleepers and outside the load transfer areas of the ballast body and then to introduce the flowable, foamable reaction mixture with the foaming process timing control described above. Subsequently, ballast is then brought back into the previously cleared areas, which serves to protect the foam from the area near the top.

For conditioning the ballast bed, in particular as preparation for carrying out the method according to the invention, the procedure is expediently such that warm air is introduced into the ballast body from above, which emerges at the side of the ballast body, the relative atmospheric humidity of the emerging air being determined and the process of heating the Ballast body is terminated when the average humidity is less than a predetermined threshold.

By removing moisture from the ballast bed, improved conditions are created for the subsequent foam formation. The heat input into the ballast body can be controlled as a function of the emerging air humidity by determining the air humidity of the air emerging laterally from the ballast body at several points and an average value being formed from these individual humidity values, the heating of the ballast body being stopped when the mean air humidity is lower than a predefinable threshold.

• auf dem Untergrund eine elastische Drainagematte angeordnet werden kann,
• auf der Drainagematte ein Schotterkörper aus einzelnen, zwischen sich Hohlräume aufweisenden Schottersteinen gebildet werden kann,
• in den Schotterkörper das Gleis (Schwellen mit Schienen) eingebettet werden kann, und
• zur Lagefixierung der im Wesentlichen lediglich innerhalb von Lastabtragungsbereichen des Schotterkörpers unterhalb der Schwellen befindlichen Schottersteine in die Hohlräume zwischen diesen erfindungsgemäß ein schäumbares Material eingebracht wird.

With the method according to the invention for introducing a flowable, foamable reaction mixture from above into a ballast body with sleepers embedded in it, a method for creating a track superstructure for a rail track on a surface inclined transversely to its extension can be realized, in which

• an elastic drainage mat can be placed on the surface,
• a ballast body can be formed on the drainage mat from individual ballast stones having cavities between them,
• the track (sleepers with rails) can be embedded in the ballast body, and
• In order to fix the position of the ballast stones, which are essentially only within load transfer areas of the ballast body below the sleepers, a foamable material is introduced according to the invention between the cavities.

Furthermore, as also mentioned above, sleepers are embedded in the ballast body with a sole made of an elastic material, in particular plastic material.

The step of partially foaming the ballast body, with which it is provided with foam exclusively in the load transfer areas, is advantageously preceded by the known steps of plugging and / or the formation of initial settling by vibrating the ballast body.

The main problem of the known ballast track - the twisting of the rock under dynamic load - is thus prevented according to the invention in that after the new or renewed track has been completed, it is only foamed with a foam material in the ballast body in the load transfer zones.

This means that all cavities between the ballast stones below the threshold and in the adjacent load transfer areas are closed by the foam of the ballast body to be introduced; the cavities between the sleepers and outside the load transfer areas remain free and thus serve to drain surface water. The foam can be adjusted so that it is flexible. The introduction of the foam and its formation in the ballast body does not change the morphology of the ballast body.

All of the track's ballast stones within the load transfer areas are connected to one another by the inserted foam to form a holistic ballast structure. The adhesive strength of the foam on the ballast stone and the structural density of the foam can be adjusted to the order of magnitude of the maximum load, plus a safety factor.

After the foam has hardened, all of the forces introduced by the train run can now be transmitted via this homogeneous structure, specifically via the ballast stones and not via the foam which serves to stabilize the ballast stones.

Since the foam consists of a large number of pores, the rigid cavities do not form when the cavities are closed. Rather, a structure is created with an infinite number of "shock absorbers". This also achieves noise insulation.

With the present invention, therefore, an alternative way of stabilizing the ballast body without influencing its morphology and taking into account the drainage problem is taken.

• einem Schotterkörper aus einzelnen Schottersteinen und
• in dem Schotterkörper eingebetteten Schwellen, an denen Schienen befestigbar sind, wobei der Schotterkörper unterhalb der Schwellen Lastabtragungsbereiche aufweist, die beim Befahren der Schienen über die Schwellen vertikal auf den Schotterkörper wirkende Lasten aufnehmen und in den Untergrund unterhalb des Schotterkörpers übertragen.

With the invention, a track superstructure can be proposed for a rail track on a surface inclined transversely to its extension, which is provided with

• a ballast body made of individual gravel stones and
• sleepers embedded in the ballast body, to which rails can be fastened, the ballast body below the sleepers having load transfer areas which, when the rails are driven over the sleepers, absorb loads acting vertically on the ballast body and transmit them into the ground beneath the ballast body.

In this track superstructure, essentially only the cavities between the ballast stones within the load transfer areas of the ballast body for fixing the ballast stones in these areas are filled with a PU foam material. An elastic drainage layer can also be arranged between the ballast body and the ground.

The main idea is that the ballast body is only partially provided with the foamable material, within these areas, however, the cavities between the ballast stones are essentially completely filled with this foamable material, but it is ensured that the track body morphology is ensured by the Foaming remains unchanged from the state of the ballast body before the foamable material is introduced. These areas of the ballast body are the load transfer areas below the thresholds, these load transfer areas, starting from the thresholds, extending obliquely outwards and below the thresholds. As a result of this partial foaming of the ballast body according to the invention, the cavities between the ballast stones remain free within the zones of the ballast body located between the load transfer areas, so that surface water that strikes the ballast body can flow downwards or laterally within these zones. Surface water reaching the side of the ballast can also penetrate the ballast horizontally.

Due to the partial foaming of the ballast body, the ballast stones that are most "stressed" when crossing the track remain stable. They therefore maintain their position permanently after the tamping process and after the (artificially) generated initial setting of the track superstructure, essentially over the entire operating period of the Track superstructure. Re-tamping, as is the case with track ballast bodies today, is therefore unnecessary.

A foam which can be used in the context of the invention is a rigid foam or a semi-rigid foam or an elastic foam, that is to say a foam which opposes deformation (if not insignificant) against resistance. The foam must have sufficient compressive strength. The foam can be adjusted with regard to pressure resistance, reaction times, reaction components, pot life. The foam can be closed or open-celled. Open-cell foams have the advantage that they are acoustically effective, which is an advantage when used in the track superstructure. The foam should be elastic, long-term stable, rot-proof, fire-resistant, resistant to vermin and resistant to chemicals.

In order to create a drainage option below the track superstructure, the ballast body is arranged on an elastic drainage layer. Here you can use the drainage mats known for drainage purposes, such as those offered by Rehau AG. Porous rubber mats or mats made of another elastomer material are advantageous. Particularly suitable are elastomer granules, the particles of which are connected to one another with cavities extending horizontally and vertically through the mat. For example, particles of recycled tire are suitable for producing such elastic drainage mats. The elastic elastomer drainage mat can absorb high weights and contact forces, is long-term stable and rot-proof and has the other properties mentioned above, which preferably apply to the foam.

So far, drainage mats could not be used under ballast bodies because they cannot withstand the stresses that occur over time due to several tamping processes. According to the invention, however, only a single tamping process, namely when creating the track superstructure, is required. In this respect, a merit of the invention can also be seen in the fact that it was possible to provide a drainage material under the track superstructure as a result of the prevention of subsequent replanting operations. The drainage leads to a controlled and directed drainage of water, which effectively prevents the subsurface from being rinsed out. Furthermore, the material of the drainage mat carries, as above described that this is long-term stable and thus maintains its (horizontal) porosity even under high pressure loads.

To further fix the ballast stones within the load transfer areas, it is expedient to provide the sleepers on their undersides with an elastic material, in particular made of plastic (so-called sleepers soles). Such thresholds with sole are for example in EP-A-1 298 252 to find. The gravel stones lying against the sleeper penetrate into the elastic material of the sleeper sole, which results in a fixation by a kind of "hooking".

• Der Untergrund unter dem Schotter wird durch die hohe Isolationsleistung der sich bildenden Mikro-Luftporen im PU-Schaum vor Frost geschützt.
• Der Untergrund unter dem Schotter wird vor Wasser geschützt.
• Die Gefahr einer Gleisverwerfung in horizontaler und vertikaler Richtung wird reduziert, da höhere Kräfte aufgenommen werden können.
• Der Querverschiebewiderstand eines Gleises wird erhöht.
• Die dynamische Belastung des Untergrundes und des Umfeldes wird reduziert.
• Die Berechnungsmethoden zur Lagesicherheit eines Gleises können optimiert werden.
• Der Schotterkörper wirkt schalldämpfend (Reduktion der Übertragung von Schwingungen aus dem Gleiskörper sowohl über den Boden als auch durch die Luft, wobei die Drainagematte zusätzlich zur Schallentkoppelung dient).

The inserted PU foam improves the track body several times:

• The underground beneath the ballast is protected from frost by the high insulation performance of the micro air pores that form in the PU foam.
• The subsoil under the gravel is protected from water.
• The risk of track warping in the horizontal and vertical directions is reduced because higher forces can be absorbed.
• The transverse resistance of a track is increased.
• The dynamic load on the subsurface and the environment is reduced.
• The calculation methods for the positional security of a track can be optimized.
• The ballast body has a sound-absorbing effect (reduction of the transmission of vibrations from the track body both through the ground as well as through the air, with the drainage mat also used for sound decoupling).

1. 1. gewaschener Schotter.
2. 2. Gleise gestopft und gleistechnisch abgenommen.
3. 3. Gleis-Schotterquerschnitt wärmetechnisch vorbehandelt - Temperaturvorgabe.
4. 4. Aushärtezeiten und Flexibilität des Schaums sind beeinflussbar.
5. 5. absolute Vollausschäumung der jeweiligen Lastabtragungszonen (ca. 60° Winkel) unter den Schwellen.
6. 6. Recyclingfähigkeit nach KrW-/AsfG.
7. 7. Erfüllung von Scherfestigkeiten, Abreißfestigkeiten und Federsteifigkeiten des Schaums je nach Anforderung.

The requirements of the process or ballast body are in particular as follows:

1. 1. washed gravel.
2. 2. Stuffed tracks and track technology removed.
3. 3. Track-ballast cross-section pretreated by thermal technology - temperature specification.
4. 4. The curing times and flexibility of the foam can be influenced.
5. 5. Absolute full foaming of the respective load transfer zones (approx. 60 ° angle) under the thresholds.
6. 6. Recyclability according to KrW- / AsfG.
7. 7. Fulfillment of shear strength, tear strength and spring stiffness of the foam depending on the requirement.

1. 1. Nach Fertigstellung des Unterbauplanums und vor Aufbringung des Gleisverlegeschotters wird auf den Flächen der PSS (Planumsschutzschicht) unter der Schotteraufstandsfläche eine elastische Drainagematte (z.B. Secudrän® von der Naue-Fasertechnik GmbH & Co. KG) verlegt. Hierdurch wird gewährleistet, dass bei zwei- oder mehrgleisigen Strecken die Mittenentwässerung dauerhaft gesichert ist. Bei eingleisigen Strecken kann hiervon abgesehen werden; es wird eine Entwässerung des in Folge der Neigung des Planums höher gelegenen Randbereichs erreicht (gilt auch bei mehrgleisigen Strecken).
2. 2. Die einzubauenden Schwellen aus Beton oder Stahl erhalten auf der Unterseite vorzugsweise eine Besohlung aus einem Kunststoffmaterial nach dem Stand der Technik (z.B. EP-A-1 298 252 ). Hierdurch werden die Schottersteine beim Stopfen im Gefüge des Kunststoffes verkeilt und festgehalten.
3. 3. Das gebaute und mit der Stopfmaschine gestopfte Gleis wird mit einem Gleisstabilisator bekannter Bauart zusätzlich behandelt. Dadurch werden Erstsetzungen aus der zu erwartenden Zugbelastung vorweggenommen. Der Gleisaufbau befindet sich nun in einem Zustand, in dem er gleistechnisch abnehmbar ist.
4. 4. Das Gleis wird unter den Schwellen und in den angrenzenden Bereichen des Druckabtrages im Schotterkörper verschäumt. Hierzu wird der Schotterkörper vorteilhafterweise zuvor wärmetechnisch behandelt und gereinigt (gewaschene Schottersteine).

The track structure is created as follows:

1. 1. After completion of the substructure plan and before applying the track laying ballast, an elastic drainage mat (eg Secudrene® from Naue-Fasertechnik GmbH & Co. KG) is laid on the surfaces of the PSS (formation protection layer) under the ballast contact surface. This ensures that the central drainage is permanently secured on two or more tracks. This can be waived for single-track routes; drainage of the higher edge area due to the inclination of the formation is achieved (also applies to multi-track lines).
2. 2. The sleepers to be installed made of concrete or steel preferably have a base made of a plastic material according to the prior art (eg EP-A-1 298 252 ). As a result, the ballast stones are wedged and held in place in the structure of the plastic.
3. 3. The track built and tamped with the tamping machine is additionally treated with a track stabilizer of a known type. In this way, initial settings from the expected tensile load are anticipated. The track structure is now in a state in which it is technically removable.
4. 4. The track is foamed under the sleepers and in the adjacent areas of the pressure loss in the ballast body. For this purpose, the ballast body is advantageously treated and cleaned beforehand using heat technology (washed ballast stones).

The present invention does not assume that the loads from the train operation are transferred or removed via the foam. The built-in foam stabilizes the ballast structure and prevents the ballast core from escaping from the compacted material produced by the tamping machine Gravel formations. The demonstrably stable ballast track is preserved for a very long time in its acceptance quality in its manufacturing form. The durability of the PU foam and its composition play an important role.

The technical behavior of particle-based constructions is basically not changed when using PU foam. Only the properties of technical strength and rigidity are significantly improved. In addition, PU foam also improves the dynamic characteristics, such as properties such as the degree of damping and the speed of the stress waves (e.g. compression wave, shear stress and surface wave).

When using a PU foam, it is desirable to ensure that the reinforced and stabilized base works at an acceptable level during its service life.

PU foam is preferably used in the correct spatial position and to the right depth to ensure that improvements in technical behavior are achieved. In addition, PU foam is preferably built up chemically to ensure that its desired properties are correct for the respective application, taking into account stiffness, strength, viscosity, fatigue limits, acoustic damping, the temperature range, the biochemical and hygroscopic properties, curing time and service life. There are freely available foams on the market that can withstand a temperature range of -30 ° to + 80 ° C, are steam and water resistant, do not shrink or press and are resistant to faeces (this should not be neglected, since there are still many passenger rail cars have open toilet systems and thus empty faeces on the gravel). In order to achieve the desired behavior and predictability, additional substances can be used for the PU foam in order to further expand the chemical properties. There are enough ready-mixed foams with the appropriate properties to be selected according to the given situation.

• kurzfristigen Stabilisierung von überbeanspruchten Unterbauten bis zur endgültigen Sanierung des Streckenabschnitts (z.B. Schlammförderung und "Feuchtpunkte" in einem Bahngleis),
• vertikalen Seiten- und Längsstabilisierung (in einem Bahngleis z.B. von Übergangskurven, großen Überhöhungen, um z.B. den Wartungsaufwand zu verringern),
• Stabilisierung von Tunnelgleisen,
• Verstärkung von Brückengleisen, einschließlich der Übergänge vor und nach Brücken zur Verhinderung von Lastsprüngen,
• Verringerung von Bahnkörperbeanspruchung durch erhöhte PU-Schaum-Steifigkeits- und Festigkeitseigenschaften,
• Verhinderung herbeigeführter plastischer Belastung und Zermürbung der Trennung von Teilchen (z.B. durch Splittern) durch nahezu totale Verhinderung der Bewegung der Teilchen,
• Verringerung des Auftretens von verschmutzten Teilchen,
• eine PU-Schaum-Membran (z.B. an Berührungsstellen verschiedener Unterbaumaterialien) kann eingesetzt werden, um das Eindringen von Schmutz in den Oberschotter/den Bahnschotter zu verhindern,
• in Kombination mit der vorzusehenden Drainagematte zur Unterstützung bei der Verhinderung von Spülerosion der Oberfläche und der Unterbauten,
• Ermöglichung eines Anstiegs angewandter Lasten und der Geschwindigkeit von schwingenden Lasten ohne erhebliche Zunahme bei der Wartung des Unterbaus und zur Verringerung der am Unterbau herbeigeführten Beschädigung auf Grund der angewandten Lasten,
• Verringerung der Erzeugung und Übertragung von Umgebungslärm,
• Hochleistungsreinigung (z.B. Sauger) von verstärktem Oberbau zur Aufrechterhaltung der Sauberkeit (Müll, Fäkalien, Laub, Astwerk, Zigarettenreste etc.) bei reduzierten Kosten ist - wenn gewünscht - möglich, indem die Schotterflächen zwischen den Schwellen mit einem anderen Material (UV beständig) in einem Arbeitsgang verklebt werden,
• Verbesserung der statischen und dynamischen Leistungsparameter des Ober- und Unterbaus.

The invention provides a stabilized ballast track in a railway track produced by this method. Preferably PU foam are used to increase the vertical and / or longitudinal stability of the substructure (e.g. rigidity and strength). The system must be carefully checked to ensure that the stresses and forces remain dynamic, vibrating or static within the fatigue or stress limits of the superstructure reinforced with PU foam with a predetermined safety factor taking into account the desired life cycles. The addition of a PU foam positively changes the static and dynamic behavior of the superstructure consisting of particles and thus also the overall and partial behavior of the substructure. Ballast superstructures that are strengthened and stabilized by the treatment process described above can also be used for:

• short-term stabilization of overstressed substructures until the final rehabilitation of the section of the route (eg sludge extraction and "wet spots" in a railroad track),
• vertical side and longitudinal stabilization (in a railroad track, for example, of transition curves, large cantilevers, for example to reduce the maintenance effort),
• Stabilization of tunnel tracks,
• Reinforcement of bridge tracks, including the transitions before and after bridges to prevent load jumps,
• Reduction of web body stress through increased PU foam stiffness and strength properties,
• Prevention of plastic stress and wear and tear of the separation of particles (e.g. by splintering) by almost completely preventing the movement of the particles,
• Reducing the appearance of contaminated particles,
• a PU foam membrane (e.g. at the contact points of different substructure materials) can be used to prevent dirt from penetrating into the upper ballast / railway ballast,
• in combination with the drainage mat to be provided to support the prevention of washing erosion of the surface and the substructures,
• Allowing an increase in applied loads and the speed of vibrating loads without a significant increase in the maintenance of the Substructure and to reduce the damage caused to the substructure due to the applied loads,
• Reducing the generation and transmission of environmental noise,
• High-performance cleaning (e.g. vacuum) of reinforced superstructure to maintain cleanliness (garbage, fecal matter, leaves, branches, cigarette remains, etc.) at reduced costs is possible - if desired - by using a different material (UV-resistant) in between the sleepers be glued in one operation,
• Improving the static and dynamic performance parameters of the superstructure and substructure.

The composition of the foam is selected on the basis of the stiffness and strength properties required by the composite. In particular, the tensile and shear strength properties of the foam are determined as part of the design process. In areas with poor geological formations, the foam properties (e.g. rigidity) are designed so that it must be ensured that an effective cushion-like foundation made of stabilized ballast is built over the weak area. If the rigidity is high enough, the load is distributed more evenly at the point of contact with the web body.

For turnouts with a high level of maintenance, the foam properties are selected so that the large vertical forces are distributed more effectively under the turnout, but still maintain good damping properties of the composite. Raising the threshold by introducing the foam is largely impossible.

When new tracks are built, holes can be drilled in the sleepers at various points during production so that the foaming material can be injected directly into the ballast underneath and stabilize it completely.

For height / side adjustability, rail fastenings that are available on the market and that correspond to the state of the art (known from the installation, for example, in the case of "fixed carriageways") must be provided when building new lines or to be installed in order to be able to subsequently regulate any subsidence from the subsoil.

As can be seen from the descriptions and the attached drawings, the track body consists of foamed ballast and non-foam ballast.

The foamed area is always below the threshold and in the load-bearing areas. This creates a cone-like foamed structure in the vicinity of the threshold.

By e.g. Double-track routing on straight lines or in arches with the necessary track elevations results in the selected economical foaming of the ballast areas in which the precipitation water cannot be discharged in the usual way as with a completely open ballast body.

The selected embodiment with the plastic drainage mat laid on the sub-level takes this problem into account.

In all cases, the rainwater finds its way into the plastic drainage mats in the problem areas and is arranged and discharged to the outside.

The water does not leave any traces of erosion on the sub-level due to the chosen full-surface installation under the ballast and thus helps to protect the substructure of the track.

Fig. 1

einen Vertikal-Querschnitt durch einen mittels des erfindungsgemäßen Verfahrens herstellbaren Gleisoberbau für einen eingleisigen Streckenabschnitt,

Fig. 2

eine Draufsicht auf den Gleisoberbau gemäß Fig. 1,

Fig. 3

einen Vertikal-Längsschnitt durch mittels des erfindungsgemäßen Verfahrens herstellbaren Gleisoberbau für einen eingleisigen Streckenabschnitt, und

Fig. 4

einen Vertikal-Querschnitt durch einen mittels des erfindungsgemäßen Verfahrens herstellbaren Gleisoberbau für einen Doppelgleis-Streckenabschnitt.

The invention is explained in more detail below with reference to the drawings. Show in detail:

Fig. 1

3 shows a vertical cross section through a track superstructure that can be produced by means of the method according to the invention for a single-track section of the route,

Fig. 2

a plan view of the track superstructure Fig. 1 .

Fig. 3

a vertical longitudinal section through track superstructure that can be produced by means of the method according to the invention for a single-track section, and

Fig. 4

a vertical cross section through a track superstructure that can be produced by means of the method according to the invention for a double track section.

A first superstructure of a track superstructure that can be produced by the method is shown in FIGS 1 to 3 shown. The track superstructure is located on a subsurface or sub-level 12, which is inclined as usual and can have a protective layer of asphalt or gravel. A drainage mat 14, on which a ballast body 16 composed of individual ballast stones 18 is arranged (in the 1 and 2 indicated and in Fig. 3 partially shown in detail). In the upper area of the ballast body 16 (wood, concrete or steel) sleepers 20 are embedded, to which the rails 24 are fastened via, in particular, height-adjustable fastening points (indicated at 22).

Starting from the sleepers 20, the load transfer areas 26 are defined in the ballast body 16, within which the loads occurring when the rails 24 pass over are transferred to the ground 12.

On average according to Fig. 3 these load transfer areas 26 are trapezoidal. Within the end area of the ballast body 16 facing the ground 12, the load transfer areas 26 merge into one another. In the top view, the load transfer area 26 is as in FIG Fig. 2 The areas between adjacent load transfer areas 26 are substantially V-shaped.

Before the track superstructure 10 is put into operation, the ballast body 16 is stuffed and vibrated to effect initial setting. According to the invention, the cavities between the ballast stones 18 within the load transfer areas 26 are now completely foamed, with a PU foam 28 that is set according to the requirements and loads. PU foams can be adjusted according to the respective requirements with regard to, for example, compressive strength, adhesion and foaming behavior, which is generally known and leads to an optimal foam material for the respective application. The ballast stones 18 within the load transfer areas 26 are thus fixed in position; below the thresholds 20 there are soles on the underside 30 made of an (elastic) plastic material. The foam 28 can also be arranged to the side of the lower regions of the sleepers 20, so that these are embedded in ballast body regions provided with the foam 28. As especially with the help of Fig. 3 can be seen, the areas 32 of the ballast body 16 between the load transfer areas 26 thus remain free of foam in the track superstructure 10, so that rainwater can flow off across the track superstructure 10. By inclination along the 34 in Fig. 3 indicated drain line of two adjacent load transfer areas 26, which forms the sole of a zone 32, this drainage process is additionally supported. Rainwater that strikes the ballast body 16 on the side of the track outside the load transfer areas 26 (in Fig. 1 indicated at 34) or that is laterally on the ballast body 16, flows off via the drainage mat 14 below the track superstructure 10.

The advantage of a drainage mat 14 underneath a track superstructure is particularly clear in the case of a two-track or multi-track route, as shown in FIG Fig. 4 is shown. As far as the individual components of the track superstructure 10 ' Fig. 4 identical or identical to the individual components of the track superstructure 10 of the 1 to 3 are, they are in Fig. 4 marked with the same reference numerals.

Rainwater falling within zones 34 of the in Fig. 4 right part of the ballast body 16 collects, flows to the center 38 of the ballast body 16, from where it through the in Fig. 4 left part of the drainage mat 14 below the in Fig. 4 the track shown on the left flows off.

The following device, for example, is suitable for introducing the foam into the ballast bed:
Railway tracks are traditionally laid in ballast beds on sleepers made of different materials. Since wooden sleepers can only be preserved with problematic substances, concrete or steel sleepers are mainly used. The forces from the mass of the trains and the dynamic effects from the travel of the trains are transmitted from the rail to the ballast via the sleeper. This load transfer is essential in an area with an angle of 60 °. The movement of the ballast stones is caused by the forces entered in the viscous ballast area, which leads to abrasion of the edges similar to river ballast and thus rounds off the ballast pieces.

In order to prevent these effects, the ballast body is fixed in the area of the load transfer with foam, namely polyurethane. The foam encloses the ballast pieces in a form-fitting manner and forms a permanent connection with their surface. The foam is adjusted flexibly and does not change the morphology of the ballast bed. The static structure of the ballast remains intact. In the upper area of this foamed ballast body, the concrete or steel sleeper or switch construction resting on it is permanently glued in with the foam. The effect of the transfer of horizontal forces into the ballast bed achieved by wooden grapples by clawing the ballast stones into the ballast bed is thereby considerably improved and fixed.

In addition to the fixation, a further effect is a considerable reduction in the transmission of vibrations from the track body both via the ground and through the air.

To drain off rainwater that can collect between the tracks and the pronounced foam cones, a drainage mat made of structured rubber recyclate is placed under the ballast body. The mat is made in such a way that it drains the rainwater horizontally under the ballast body. The mat is surrounded on both sides by a fleece, in particular geotextile, which in the long term prevents the mat's pore volume from becoming blocked. To simplify the installation, the geotextile is alternately protruding on the longitudinal edges so that the abutting edge to the next mat is covered, i.e. the fleece on the top on one or two edges of the mat and the fleece on the bottom on one or two of the edges opposite the aforementioned edges.

• Triebfahrzeug,
• Vorratslager für je einen Tank für die Komponenten des Schaums,
• Vorratslager für Brennstoff zur Aufheizung und Trocknung des Gleiskörpers,
• Heiz- und Trocknungseinheit, Pressluftversorgung,
• Schaumapplikator,
• Mess- und Regeleinheit mit Dokumentation.

The following device, which does not fall within the scope of the present invention, is preferably used for introducing the foam into the ballast bed:
The foam is introduced into an existing track bed (washed ballast, drainage track) which has been washed with a cleaning machine and provided with a drainage track or which has been newly produced according to the specification, using a device which is applied to a rail vehicle. This device consists of the following sections:

• Locomotive,
• Storage for one tank each for the components of the foam,
• Fuel storage for heating and drying the track,
• Heating and drying unit, compressed air supply,
• foam applicator,
• Measuring and control unit with documentation.

As a traction vehicle, a vehicle with the possibility of a step operation for travel of <1 m / sec is used, with which the system can be moved with cm accuracy.

The storage warehouses are equipped with KTCs that can be filled at the factory and put on and taken off with a crane.

The heating and drying unit consists of one or more lowerable bells, into which hot air is conveyed from a support burner in an air line by blowers. The bells are provided with a sealing bead towards the ballast body and towards the rail areas, so that as far as possible no warm air can escape upwards out of the ballast bed, but rather as far as possible from the side. This unit is set three times in succession in order to be able to set the necessary parameters for the foaming depending on the outside temperature and moisture of the ballast. With the help of built-in, fold-out elements, which are attached to the inside of the heating units, the heat can also be conducted separately to the rails in order to heat or cool them down to a certain working temperature. In this case, refrigeration units are activated in the airway and wash the rails with cold air to cool them down. The heating can be done with mineral oil products, gas or with natural vegetable oils. The exhaust gas heat and the waste heat from the locomotive can also be used. The warm, moisture-saturated air emerges from the track or ballast body to the side of the threshold area. The one used in the side area Condensation is not a problem since it does not take place in the area of load transfer, which is the aim of the foam fixation. The success of the treatment of the ballast is monitored and controlled by measuring the humidity of the air emerging.

According to the invention, the foam is applied to the heated and dried crushed stone. For this purpose, a device is preferably used, which consists of up to 8 discharge nozzles for each threshold side and several thresholds, e.g. 10, can operate at the same time. The foam lances can be lowered individually or together on the ballast body by means of a propulsion device. The necessary lowering is calculated individually for each nozzle by determining the inclination of the track body by a process computer. Inside the device, the nozzles can be moved by lateral drives and are positioned by measuring devices directly next to the sleeper body. After lowering the lances to the calculated point, the foaming process controlled by the process computer is triggered and documented. The calculated quantities of the components are pumped into the mixing head at the upper end of the nozzle by pumps for each nozzle, mixed there and pressed into the ballast body. The computer recognizes the end point of the foaming process and switches off the pumps or closes the valves on the mixing head. The lance is immediately blown free with compressed air.

The device is started up after this cycle, simultaneously with the heating bells. During the phase of moving the device, the air heating and the fans are switched off. The machine unit can then be moved to repeat the process on the subsequent segment.

The nozzles are interchangeably mounted on a part that receives the drive as a carrier for vertical insertion into the ballast body. The mixing head is attached to this. The lower edge of the nozzle is chamfered so that the nozzle cannot rest on a ballast stone and thus closes the lower opening. The tip of the nozzle body either displaces an unfavorably located stone or provides enough open space to ensure that the foam components can be carried away unhindered.

The setting of the foam with regard to the start time for the foaming reaction and the reaction time is such that it is in the ballast bed forms a conical foam structure and thus the ballast body is fixed in the load transfer cone from the sole to the lower edge of the sleeper.

The lances can be dispensed with by disposing or positioning outlet nozzles for the foamable reactive flowable mixture above the ballast bed. The nozzles can be moved either stationary or across the track body. The reactive mixture is adjusted in such a way that the foam formation process begins when the flowable mixture has reached the lowest region of the ballast body. Foam formation thus takes place in ascending order from bottom to top. Depending on the height of the ballast bed at the positive of the nozzle, the rate at which the mixture is applied to the ballast bed is changed (the higher the ballast bed, the greater the quantity dispensed per unit of time). The amount of mixture required due to the height of the ballast bed is thus introduced over the entire width of the ballast bed below the track body. The mixture is introduced on both sides (i.e. in the extension of the rails in front of and behind the sleepers directly next to them) of each sleeper, preferably simultaneously. This means that the mixture gets under the threshold from both sides according to its viscosity by spreading conically downwards in the ballast body. As a result, the foaming process that starts from below then brings the reactive mixture from below to below the thresholds, in that the progressing foam front pushes the unreacted mixture from below towards the threshold.

The foam insertion nozzles are mounted on a device carrier at a position corresponding to the insertion position. This bracket can be adjusted by hydraulic or electric actuators both at right angles, i.e. move across the track as well as up and down. This ensures that all calculated insertion positions for the reactive mixture can be operated in accordance with regulations.

• Es sollte ausschließlich gewaschener Schotter verwendet werden, ohne Staubanteile.
• Zwischen Schotter und Unterbau ist eine Drainagematte einzubringen. Die Matten sollten zweckmäßigerweise ohne Fehlstellen verlegt werden, so dass der Abfluss von Wasser aus dem Zwischenraum der Gleise komplett seitlich erfolgen kann.

A prerequisite for the system described here for a ballast bed below tracks, switches and crossings is a usually produced, removed track body made of ballast, sleeper and rails with the following deviations:

• Only washed gravel should be used, with no dust.
• A drainage mat must be installed between the ballast and the substructure. The mats should expediently be laid without any imperfections so that water can drain completely out of the space between the tracks.

After removing the track body, the ballast between the sleepers and outside the load transfer areas is removed (and e.g. stored on the side). After foaming, after a waiting time of e.g. 24 hours the ballast is reinstalled.

• Herbeiführung der optimierten Bedingungen für die Verschäumung durch Trocknung und Erwärmung des eingebauten Schotters, wobei die Taktzeit der Erwärmung in Abhängigkeit von der Schotterhöhe, d.h. des Schottervolumens, gesteuert wird. Die Konditionierung erfolgt durch Einblasen von Warmluft in den Schotter.
• Einbringen des schäumbaren fließfähigen Reaktionsgemisches, gesteuert nach Schotterhöhe, die über die gemessene Gleisneigung vom Prozessrechner errechnet wird, so dass der Lastabtragskegel unter den Schwellen ausgeschäumt und damit fixiert wird.
• Die dosierten Mengen werden für jeden Applikationspunkt errechnet, gesteuert, protokolliert und dokumentiert, so dass im Rahmen einer automatischen Qualitätssicherung Fehlstellen sofort ermittelt und damit ausgeschlossen bzw. nachgebessert werden können.
• Der Schaum wird mit automatischen Dosier- und Mischanlagen hergestellt, so dass damit eine konstante Qualität gesichert werden kann. Die Komponenten werden in den Leitungen vom Tank zum Mischer thermostatisiert.

The foam is introduced using a system that performs the following steps:

• The optimized conditions for foaming are brought about by drying and heating the built-in ballast, the cycle time of the heating being controlled as a function of the ballast height, ie the ballast volume. The conditioning is done by blowing warm air into the ballast.
• Introducing the foamable, flowable reaction mixture, controlled according to the ballast height, which is calculated by the process computer based on the measured track inclination, so that the load transfer cone under the sleepers is foamed and thus fixed.
• The dosed quantities are calculated, controlled, logged and documented for each application point, so that defects can be identified immediately as part of an automatic quality assurance and thus eliminated or corrected.
• The foam is produced with automatic dosing and mixing systems, so that constant quality can be ensured. The components are thermostatted in the lines from the tank to the mixer.

environmental

The process of installation has no environmentally relevant influences. The components of the foam are in tested and approved containers transported (GGVS / GGVE / IMO), there is no storage at the construction sites, the transport takes place just in time.

The processing plant is controlled in such a way that both components can only be conveyed and mixed out of the plant at the same time. This means that only a foam can escape that is not classified as a hazardous substance and cannot have any toxic effects. The polymerization reaction is already complete after 20 seconds. The system is not accessible during this time.

The foam contains only a very small amount of catalysts, which can be assigned to the amines and can be washed out with rainwater. These substances are biodegradable substances with an extremely short biological half-life. After a short exposure time, the tests show a significant decrease in the eluate value in the TOC, which is in line with expectations. The remaining substances in the foam are completely water-insoluble after polymerisation, which has already occurred after approx. 20 seconds. It is not possible to dissolve parts of the foam in other solvents either, so that after the elution of the catalytic amines has subsided, absolute environmental neutrality is achieved in compliance with the installation regulations.

In the event of a fire, it can be assumed that polyurethanes are self-extinguishing, which also applies to the rubber sheet used as a drainage mat, which can be classified as a building material in B2. The gases and substances that are generated during combustion and can be discharged by extinguishing water are largely considered to be non-toxic. Certainly, scenarios are conceivable in which incomplete combustion with substoichiometric oxygen supply can result in large quantities of toxic gases such as carbon monoxide. However, this would not be attributable to the input materials, but to a topographical situation, which in itself could then lead to negative effects and even lethal effects.

In order to reduce the fire load in any case, the products in tunnel sections are enriched with a highly nitrogenous substance so that they are practically non-combustible.

Dismantling - recycling

In the event that a section is dismantled, regardless of the reason for the dismantling, the foamed body can be removed and processed in a rotary kiln to clean ballast. The thermal decomposition of the polyurethane takes place at temperatures <550 ° C, so that the ballast stones are not affected morphologically, i.e. they can be reinstalled without any further treatment.

The drainage channels are recorded and recycled. The identical product is created.

Claims (10)

1. Method for introducing a polyurethane-based flowable and foamable reaction mixture (28) from above into partial regions of a ballast body of a permanent way, with sleepers (20) embedded therein, wherein in the method

   - the ballast is heated and dried,

   - the reaction mixture (28) is introduced into the heated and dried ballast body laterally with respect to the sleepers (20), the foamable reaction mixture (28) being introduced with a foaming-process time control,

   wherein the start time of the foaming reaction of the reaction mixture (28) is set such that the foam forming process only begins when the front of the reaction mixture (28) flowing down within the ballast body (16) has reached the underside, or the region near the underside, of the ballast body (16) lying on an underlying surface, so that the foam forming within the ballast body (16) takes place from the bottom upwards to below the sleepers (20) and forms a conical foam structure in the ballast body (16), so that from its base to the lower edge of the sleepers the ballast body (16) is fixed in a load transfer cone of the foam structure.
2. Method according to Claim 1, characterized in that the ballast between the sleepers (20) and outside the load transfer regions of the ballast body (16) is removed before the introduction of the reaction mixture (28) and is reapplied to the ballast body (16) between the sleepers (20) after foam formation as UV protection of the region of the foam near the upper side.
3. Method according to Claim 1 or 2, wherein a conditioning of the ballast body is carried out as preparation, in that

   - hot air is introduced into the ballast body (16) from above, leaving laterally with respect to the ballast body (16), wherein the relative humidity of the air leaving is detected and the process of heating the ballast body (16) is ended when the average humidity of the air is below a presettable threshold value.
4. Method according to Claim 3, characterized in that the humidity of the air laterally leaving the ballast body (16) is determined at a number of points and an average value is obtained from these individual air-humidity values, and in that the heating of the ballast body (16) is ended when the average humidity of the air is below a presettable threshold value.
5. Method according to one of Claims 1 to 3, characterized in that, depending on the height of the ballast body (16) at the point of application, the reaction mixture (28) is introduced in a quantity that is all the greater the further up in the ballast body (16) the application point is situated.
6. Method for creating a partially foamed permanent way for a railway track on an underlying surface that is sloping transversely in relation to its extent, in which

   - if desired, an elastic drainage mat (14) is arranged on the underlying surface,

   - a ballast body (16) is formed from individual ballast stones (18) with gaps between them, to be precise on the drainage mats (14), if they are present,

   - sleepers (20) are embedded into the ballast body (16),

   - rails (24) are fastened to the sleepers (20), and

   - for fixing the position of the ballast stones (18), which are substantially only located within load transfer regions (26) of the ballast body (16) underneath the sleepers (20), a foamable reaction mixture (28) is introduced into the gaps between them, to be precise by a method according to one of Claims 1 to 4.
7. Method for creating a permanent way according to Claim 6, characterized in that the ballast stones (18) are washed before the creation of the ballast body (16) and/or before the introduction of the reaction mixture (28) into the ballast body (16).
8. Method for creating a permanent way according to Claim 6 or 7, characterized in that the ballast body (16) is heated before the introduction of the reaction mixture (28).
9. Method for creating a permanent way according to one of Claims 6 to 8, characterized in that sleepers (20) with a footing (30) of an elastic material, in particular plastics material, are embedded into the ballast body (16).
10. Method for creating a permanent way according to one of Claims 6 to 9, characterized in that, before the introduction of the reaction mixture (28), the ballast body (16) is tamped and/or made to vibrate for initial settling.

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