DE202004005761U1 - Protective layer for the ballast of a track track - Google Patents

Abstract

The protective layer for the bed element (4), in particular, of a railway track consists of a watertight foil (2) covering the contact area between the bed element and an earth foundation (1), and abutting plate elements (3) capable of supporting large compressive loads and absorbing little water during their long-term contact with moisture.

Description

The invention relates to a protective layer for the Bettungskörper a track track, especially for railways, which the ballast against the upcoming earth body separates.

For several decades it is in the Track construction of the railways usual, the ballast body constructed from track ballast against the adjacent Erdplanum demarcate by means of so-called layer protection layers (PSS). Thereby should the ballast body from the partially negative soil mechanical influences of the pending end reason decoupled or the insufficient soil mechanical Characteristics of the upcoming earth ground are compensated. Usually are PSS in the form of mineral gravel-sand mixtures (KSG) with or without the addition of crushed grain or recycled, their composition and granulation in accordance with the hydrological conditions in each individual case and soil mechanical conditions must be determined. In any case, these mineral mixtures a water-draining and sustainability-enhancing effect up and protect thus the gravel bed from waterlogging, frost damage and uneven Settlements or uplifts. As a particular disadvantage is general felt that the strength of to be installed gravel sand layers not only strong depending on location vary, but that especially large amounts of earth material excavated and transported away, at the same time as large amounts of new to install Planumssanden must be delivered. Because these transport operations are usually only in the profile of the locked work track can be done they are associated with great mechanical engineering effort.

Out DE 31 47 346 It is known to apply rigid foam boards as substitute for these PSS built up from mineral mixtures onto the ballast-free subgrade and thus to achieve a comparable effect as with the "classic" PSS, but it has been proven that it was not possible to achieve sufficiently joint-free laying of the rigid foam boards and in order that the water-draining effect required by such a protective layer could not be achieved, to achieve better waterproofing DE 31 47 346 the installation of two superimposed layers of rigid foam plates, wherein the joints of these two layers are to be arranged offset from one another in such a way. In construction site practice, however, this approach has proven to be less realistic.

The invention is based on the object Protective layer for the ballast body a track track, especially for railways, which the ballast against the upcoming earth body separates, develop, which is a cost-saving replacement of mineral Trag- or planum protective layers allows. In particular, this protective layer should be suitable for existing, rehabilitated routes with a lower Logistics and machine use as previously to be trained. In addition to the derivative of water from the ballast bed in the edge drainage and the associated Protection against frost damage should at the same time the bearing behavior of the superstructure in terms of dynamic and static loads from train services. The Protective layer is to be used in a continuous remodeling process high propulsive power be installed. It is desirable that No new, capital-intensive construction machinery required but all necessary services as far as possible should be available to the existing machinery. The installation This new protective layer should also be more weather - independent than be in the support layers of gravel-sand mixtures.

This task will be in connection according to the preamble of claim 1 according to the invention thereby solved, that the protective layer of a nonwoven layer, which is the contact area of the upcoming earth body with the ballast body covering, and resting on this fleece, abutting one another disc-shaped Elements with high compressive strength and low water absorption capacity is built up with long-term contact with moisture. Such a mass executed System can not only drain the superstructure reliably, but also the through Net weight of the superstructure and the train traffic resulting Loads reliable and record without damage. The preferred embodiment of the plate-shaped elements made of hard foam provides additional the advantages of a very low thermal conductivity, a high modulus of elasticity, better Fracture stress ratios as well a low dead weight, which also allows manual handling the plate elements is possible. A folding of the rigid foam panels ensures sufficient positive Connection of two elements.

According to an advantageous embodiment of invention Thought corresponds to the width of the protective layer in the transverse direction to the track longitudinal axis at least an amount B, where B is given by the relationship B = 2 × y + SB is determined. Here, the size y corresponds to the vertical distance between the upper edge of the protective layer and the lower edge of the on the ballast on the other hand, the size SB gives the in Transverse direction to the track longitudinal axis measured distance between both heads a track threshold. This ensures that the protective layer is independent of their vertical installation position always the relevant load propagation range covers.

According to a preferred embodiment are the plate-shaped ones Rigid foam elements, especially extruded polystyrene (e.g., X-PS-G), built up.

Furthermore, it makes sense if material, vertical thickness and base area of a single body of these plate-shaped elements depending on the soil mechanical characteristics of the upcoming earth body are dimensioned such that on the surface of the built-in protective layer deformation _moduli of E _vd ≥ 45 MN / m² or E _v2 ≥ 100 MN / m² at a _{degree of} compaction of D _pr = 100% can be achieved.

An advantageous addition to the inventive basic concept provides that the strength of the plate-shaped elements in the transition area between an invention executed Bettungskörper and a ballast body without a protective covering layer over a Length of at least 20 meters continuously decreases and the minimum strength of one Element in the final area of the transition still at least 0.04 meters. This ensures that both the load capacity of the substructure in the transition area guaranteed remains, but at the same time despite different elastic moduli between the two ballast bodies uniform driving characteristics for the Trains ensured become.

According to a preferred embodiment the nonwoven layer is made of polypropylene and has a basis weight of at least 400 g / m². It is also advantageous if the nonwoven layer in a given load of 2 kN with a minimum thickness of 3 mm. By exercises these material properties the fleece has a capillary breaking effect. This is useful so that both through the bumps between the plate-shaped Elements penetrating leachate as well as the pore water overpressure upward rising water through the fleece reliable in the edge drainage guided and water penetration of the protective layer is prevented.

The inventive idea is in the following embodiment visualized. It shows in schematic representation

1 Structure of the protective layer

Prior to the installation of the inventive protective layer must firstly by building investigations be secured that coarse-grained or mixed and fine-grained in the Endplanum ground is present, the on Vertormungsmoduli of E _vd ≥ 35 MN / m² or E _v2 ≥ 45 MN / m ^² at a Degree of compaction of D _pr = 97% can be brought or this already has.

The preparation of the inventive protective layer takes place with the aid of a commercially available ballast cleaning machine, compared to the required in gravel-sand blends planum machines significantly lower capital expenditure. The ballast cleaning machine is only to a roll-off device for the fleece and a compaction boom for Production of a level and sufficiently compacted earth added.

In the course of a bulkhead cleaning admits o.g. Ballast cleaning machine the track ballast below the track grid by means of a Schrapers or chain bar, cleans the old gravel, sieves out too small ballast components and builds the cleaned up so Track ballast below again under the track rust. The track rust is only raised during this process, but otherwise remains in his position. The in this work process of the ballast cleaning machine created ballast-free space can now also for the introduction of Fleece and plate elements are used. Within this ballastless Workspace is running Compaction Boom ahead in the direction of work and provides the required flatness, Carrying capacity and Density of Endplanums ago. From the subsequent Abrollvonrichtung the fleece is rolled out onto the final planum, whereby in case of a roll change an overlap both roller conveyors of at least 30 cm. Manual insertion the plate elements forms within the ballast-free working space the last step before the processed gravel again supplied becomes. Alternatively leaves of course a gravity-assisted mechanical feed realize the plate elements, for example in analogy to feed of track sleepers in the known track-laying machines. In radii of curvature up to 250 m, the protective layer according to the invention tolerates a deviation of which in itself desirable joint-free Aneinandenstossen the plate elements, so that this continues rectangular plate elements can be used. That has an advantageous effect on the warehouse logistics.

After incorporation of the inventive protective layer do the for Ballast cleaning measures usual Work on lifting and compaction stoppers and track stabilization.

1

earths

2

Non-woven material made of polypropylene

3

plate-shaped element

4

Ballast body ballast

5

sleeper

6

rail

Claims (7)

Protective layer for ballast of a railway track, especially for railways, which separates the ballast body against the upcoming earth, characterized in that the protective layer of a nonwoven layer, which covers the contact area of the upcoming earth body with the ballast body, and resting on this non-woven, abutting plate-shaped elements high compressive strength and low water absorption in long-term contact built up with moisture. Protective layer for Bettungskörper A railway track according to claim 1, characterized in that the width of the protective layer in the transverse direction to the track longitudinal axis corresponds to at least one amount B, where B according to the relationship B = 2 × y + SB is determined, the size y the vertical distance between the top edge of the protective layer and the lower edge of the track sleepers resting on the ballast body corresponds to SB and in the transverse direction to the track longitudinal axis measured distance between both heads indicates a track threshold. Protective layer for Bettungskörper a track track according to at least one of claims 1 to 2, characterized in that the plate-shaped elements made of hard foam, in particular extruded polystyrene. Protective layer for ballast of a track track according to at least one of claims 1 to 3, characterized in that the material, vertical thickness and base area of a single body of the plate-shaped elements depending on the soil mechanical characteristics of the upcoming earth body are dimensioned such that on the surface of the built-in protective layer deformation moduli of E _vd ≥ 45 MN / m² or E _v2 ≥ 100 MN / m² at a _{degree of} compaction of D _pr = 100%. Protective layer for Bettungskörper a track track according to at least one of claims 1 to 4, characterized in that the thickness of the plate-shaped elements in the transition area between an invention executed Bettungskörper and a ballast body without a protective covering layer over a Length of at least 20 meters continuously decreases and the minimum strength of one Element in the final area of the transition still at least 0.04 meters. Protective layer for Bettungskörper a track track according to at least one of claims 1 to 5, characterized in that the nonwoven layer of polypropylene accomplished is and a basis weight of at least 400 g / m². Protective layer for Bettungskörper a track track according to at least one of claims 1 to 6, characterized in that the nonwoven layer at a given Overload of 2 kN with a minimum thickness of 3 mm is executed.