ES2684429A1 - Transition zone of a railway line located between a ballast track and a track in concrete slab (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Transition zone (1) of a railway line located between a ballast track (2) and a track in concrete plate (3), comprising: - a set of sleepers (7) of concrete longer than the sleepers (8) of the tracks in concrete plate (3) and in ballast (2), grouped in sections (9) of sleepers (7) thereof length, with increasing length from ballast track (2) to track in concrete plate (3), - a damping sheet (10) of the vibration located transverse to the track in concrete plate (3) extending at least between the ballast layer (6) of the transition zone (1) and the layer of concrete (11) of the track in concrete slab (3), - support pads (12) under rail (13) with equal or increasing rigidity from the track in concrete plate (3) to the ballast track (2), - additional internal lanes (14), and - two additional external lanes (15). (Machine-translation by Google Translate, not legally binding)

Description

Transition zone of a railway line between a ballast track and a concrete plate track

Field of the Invention

5 The application is framed in the railway sector, specifically in railway line infrastructures and especially in the transition zones between a ballast track and a concrete plate track.

State of the art

A transition zone is a structural solution used to graduate the change of a

10 track with a great difference of mechanical characteristics and resistant in vertical sense. This difference makes the exchange zones conflict points within a railway network, whether conventional or high speed. It is necessary to graduate the change that occurs both between the materials and in the geometry between the two ways so that the structural behaviors are similar and there are no sudden changes that generate

15 wear and structural malfunction.

The known solutions on transition zones have focused mainly on proposing methodologies for the design of railway infrastructure, such as transition wedges, technical blocks, driven bars, piles, gravel columns, in short, a whole compendium of geotechnical improvements.

20 The use of sleepers, for example of wood, of greater length than the sleepers of the tracks attached to the transition zone is also known. However, these longer sleepers for the transition zone give rise to ballast migration problems, increase the width of the platform and also their effectiveness is linked to the degree of uniformity of the ballast.

25 Other solutions are known where numerous pads of different stiffnesses are placed between the rails and the sleepers and also even combined with pads under the sleeper.

Solutions with additional rails, usually interiors, are also known since the dimensions of the crossbar do not allow the other types of rails to be dragged. These additional rails have problems of weakening of the cross-section of the cross-section in addition to interference with the reinforcements and generate

5 problems in signaling.

Description of the invention

The technical problem solved by the invention is to reduce the wear and deterioration of the road infrastructure in the transition zones between roads with a large difference of mechanical and resistant characteristics in the vertical direction and thus reduce the costs of

10 maintenance and conservation. Additionally, the technical problem of increasing comfort under safety conditions in railway users is also resolved by reducing vertical accelerations in the transition zone. Both technical problems are solved by the claimed invention.

The claimed transition zone comprises elements located in the track structure,

15 both in the superstructure and in the infrastructure, unlike part of the state of the art cited above that acts solely on the infrastructure.

The transition zone object of the invention comprises the following elements:

•

A ballast layer that extends over the entire length of the transition zone.

•

A set of concrete sleepers longer than the sleepers of the

20 tracks in concrete plate and ballast, the sleepers being embedded in the ballast layer and grouped in cross sections of the same length, the sections being placed progressively according to the length of their sleepers with increasing length from the track in ballast to the track in concrete plate.

25 • A vibration damping foil located transversely to the concrete plate track that extends at least between the ballast layer of the transition zone and the concrete layer of the plate path throughout the cross section of the concrete layer of the plate track. This sheet prevents

Vibration transmission in the longitudinal direction and, therefore, helps to avoid the decompaction of the ballast. Thanks to this, a layer of sub-ballast can be dispensed with in the area near the plate track and the transmission of vibrations in the first sleepers closer to the plate track area is also decreased.

•

Under-rail support pads located between the rails of the railway line and the sleepers, configured so that they are located with equal rigidity

or increasing from the plaque path to the ballast path. Preferably the support pads consist of a sheet of polymeric material that is placed under the rail. Its mission is to serve as a connecting element of the rail to the crossbar and distribute and dampen the dynamic forces that reach the crossbar as a result of the passage of the trains.

•

Two internal additional rails, fixed on the sleepers internally to the rails of the railway line and parallel to them, which are braced on part of the sleepers of the transition zone closest to the track in concrete plate and part of the sleepers of the track in concrete plate.

•

Two additional external rails, fixed on the sleepers externally to the rails of the railway line and parallel to them, which are braced on part of the sleepers of the transition zone closest to the track in concrete plate and part of the plate of concrete of the track in concrete plate.

Each of the elements of the transition zone object of the invention collaborate in the planned improvement. The lack of one of the elements, whether elements of the superstructure or infrastructure, will not achieve improvements in tensions and vertical displacements, reducing the dynamic effects in the ballast area of the track.

Therefore, the claimed invention achieves the reduction of vertical displacements and vertical stresses under sleepers, that is, on the ballast track, and under the main plate, that is, on the plate path. This results in less fatigue in the ballast of the transition zone and therefore an increase in the service life of the transition zone, reducing the

maintenance and conservation costs of this type of abundant areas in all railway lines.

The essential objective of a transition zone is to make the transition of properties and behavior of the materials of the railway superstructure and infrastructure between zones of different characteristics, for example, passing from a conventional road to a plate road, a ballast road to a structure on it, tunnel, bridge, viaduct, etc ... Therefore, the synergy of all the elements that compose it is essential for this transition to be as continuous as possible.

Especially, the ballast insulation sheet with respect to the concrete of the plate track in the longitudinal direction allows attenuating the transmission of vibratory waves to the train passage, thus preventing the ballast in the vicinity of the concrete plate from migrating and as a consequence the ballast track would lose stability in the vicinity of the concreted track when said migration occurred with the consequent mismatch of the sleepers. The damping sheet, therefore, helps to reduce the possible deconsolidation of ballast that can be produced by horizontal and vertical vibration and which is further enhanced by the use of sleepers of longer length. This decrease in vibration directly reduces maintenance work in the area of the plate track.

This not only occurs along the longitudinal direction of the track but has also been shown to have repercussions in the vertical direction since there is an unexpected effect in reducing longitudinal accelerations in that area and, as a consequence, vibration in the longitudinal direction it decreases.

Additionally, the transition zone may also comprise a mudguard wall, located next to the concrete slab track and transverse to the sleepers that extend longitudinally over a part of the transition zone. The side fender wall is also a ballast protection element when the solution is executed mostly in a single track. This element minimizes the migration of the ballast in the vicinity of the plate path, since that is where the greatest vibrations on the ballast occur because they are in the vicinity of a very rigid structure such as the plate path. The vertical damping sheet ensures the absorption of these horizontal vibrations, so the wall guard is an additional safety element. This runs at the base of the ballast platform of the section closest to the plate track.

The collaboration of each and every one of the elements of the transition zone allows the objective to be achieved, since the modifications in each of the elements are compensated by the influence of the rest of the elements, that is, to increase the length of the elements. sleepers allows to include more additional lanes and in turn increase the resistance 5 of the elements of the superstructure and achieve through the internal and external rails define a rigid frame between both types of track which in turn allows to reduce the resistant characteristics of the infrastructure. The collaboration of sleepers, pads and rails makes it possible to progressively reduce vertical stresses under sleepers and vertical shifts from ballast track values to track values in

10 plate

Description of the figures

Figure 1 represents a graph describing the percentages of improvement in the maximum and minimum relative displacements of the solution object of the invention with respect to a solution known in the state of the art.

Figure 2 represents a graph describing the percentages of improvement in the maximum and minimum shear stresses of the solution object of the invention with respect to a solution known in the state of the art.

Figure 3 represents an extension in the maximum vertical stresses corresponding to the graph in Figure 2.

20 Figure 4 represents an extension in the minimum vertical stresses corresponding to the graph in Figure 2.

Figure 5 represents a plan view of an embodiment of the transition zone object of the invention.

Figure 6 represents a longitudinal section of the transition zone corresponding to Figure 5.

Figure 7 represents a schematic longitudinal section of the transition zone near the concrete plate track.

Detailed description of the invention

Figures 1 to 4 represent graphs describing the percentages of improvement in the maximum and minimum relative displacements and in the maximum and minimum shear stresses of the solution object of the invention, obtained from the measurements on a

5 prototype according to the object of the invention and a solution known in the state of the art.

The solution of the state of the art tested as a comparison for the measurements of graphs 1 to 4 includes two internal stiffener rails in the central section of the crossbar and pads both under rail and under crossbar.

The graphs show that the results for the tensions and the relative displacements are positive for the solution object of the invention since they are reduced with respect to the solution of the state of the art. Lower vertical tensions and lower vertical displacements occur under sleepers under the same loading conditions.

In the exemplary embodiment shown in Figures 5 to 7, the transition zone (1)

15 comprises a concrete layer (4) that extends over the entire length of the transition zone (1) located on the natural terrain layer (5) in which the railway line is located and under the ballast layer (6 ).

More specifically, in the example of embodiment shown, the transition zone (1) consists of a concrete layer (4) whose quality, referring to its quality as Strength

20 compression characteristic at 28 days in N / mm² coming is designated as HAX, it is HM 25 on the layer of natural terrain (5) with a thickness of 0.6 meters and a length of 24 meters. It is advisable to make a wedge area (17) of at least 10 meters in length to ensure a smooth transition.

In the exemplary embodiment shown in Figures 5 to 7, the transition zone (1) consists of

25 of a concrete layer (4) whose resistant capacity is less than that of conventionally used concrete, which results in economic benefit.

The length and width of the concrete layer (4) must contain the entire structure of the transition, so its length and width is determined by the width of the

longer sleepers (8) and the length of the transition zone (1), in the example of embodiment shown its length would be 24 meters.

As previously mentioned, to avoid discontinuities in vertical tensions and vertical displacements at the end of the transition zone (1) at its junction with track 5 in ballast (2), a wedge (17) is recommended as a continuation of the layer concrete (4) in 10 meters already in the conventional way.

The superstructure of the transition zone (1) comprises, in the embodiment shown in the figures, a thickness of the ballast layer (6) of 0.3 meters from the bottom base of the crossbar (8) to the part top of the concrete layer (4). The ballast (6)

10 completely covers each and every one of the sleepers (8) to avoid longitudinal movements and transverse movements so that the total height of the ballast layer (6) will be 0.3 m plus the longest edge of the sleepers ( 8) 0.220 meters used, that is, 0.520 meters.

In the exemplary embodiment shown, the ballast path (2) comprises a layer of

15 sub-ballast (18), however, a sub-ballast layer (18) in the transition zone (1) is not considered necessary, since with the thickness of the ballast layer (6) of the embodiment example and the quality of The concrete layer (4) is not necessary.

In conventional tracks, the ballast height (6) is a function of the loads that the track will support. 0.3 meters are often used on high-speed lines, but with a layer

20 sub-ballast (18) which is dispensed with here.

In the exemplary embodiment shown in Figure 5, the transition zone (1) comprises forty concrete sleepers (7) of length greater than the length of the sleepers (8) of the ballast (2) and plate ( 3). These (7) are grouped into five sections (9) of eight sleepers (7) separated 0.6 meters between axes and distributed as follows:

25-eight sleepers (7) of 4 meters in length located in the area closest to the plate track (3);

-

eight sleepers (7) of 3.68 meters in length located after the section

(9) above;

-

eight sleepers (7) of 3.36 meters in length located after the previous section (9);

-

eight sleepers (7) 3.04 meters long located after the previous section (9);

5-Eight sleepers (7) of 2.72 meters in length located in the area closest to the ballast track (2).

The number of sections (9) containing eight sleepers (7), as well as the length of sleepers

(7) of each section (9) basically serves two effects:

• The transition of vertical displacements under the crossbeam (7) between the track in 10 ballast (2) and the track in plate (3).

• The transition of vertical tensions under the crossbeam (7) between one type the ballast track (2) and the plate track (3).

Excessive length of the sleeper (7) in the transition zone (1) can cause several problems:

15 -Bolding of the sleepers (7), in concrete this can mean breakage and loss of resistance.

-

Permanent deformation of the sleepers (7), which can lead to problems of track width conservation.

-

Damage of sleepers (7) during batting operations.

20 -Interference with the road that runs in parallel, since it would occupy the zone of affection of the parallel track, especially if the parallel track had a transition zone.

The increase in the length of the sleepers (7), although it also has drawbacks regarding the deconsolidation of the ballast (6) that are overcome by the invention as

discussed above, it also has the advantage that it allows the bracing of additional external rails (15), achieving a naughty frame (7) - additional rails (14, 15) that stiffens the system. The fundamental combination between sleepers (7) and additional rails (14, 15) makes it possible to reduce vertical stresses under sleepers (7) and vertical displacements, so that in the long term there is a decrease in track maintenance in those areas contributing to to alleviate the problems of sleepers (7) of greater length.

On the contrary, if the sleepers (7) are shorter than normal, they can cause problems of riding and thinning of the upper part of the ballast (6) under them.

The additional rails (14, 15) allow joining both track structures (2, 3) in the superstructure. Said additional rails (14, 15) allow the crossbars (7) to be braced to a length that allows the transition as continuous as possible without generating discontinuities along the crossbar itself (7). The additional internal rails (14) generate a progressive transition of vertical displacements and vertical tensions under sleepers (7) in the transition zone (1) when the train passes.

The additional internal rails (14) of the embodiment have a length of 22.80 meters and are fixed to nine sleepers (8) of the track in concrete plate (3) and several of the sleepers (7) comprising the area of transition (1) in its area closest to the plate path (3). This length is what allows a progressive transition in continuity in the transition of vertical displacements and vertical tensions.

The additional external rails (15) of the embodiment have a length of 18 meters and are fixed to the concrete layer (11) of the concrete slab track (3) and to twenty sleepers (7) of the transition zone ( 1) closer to the track in concrete plate (3), specifically, the first two sections (9) of sleepers of 4 meters and 3.68 meters and half of the third section of 3.36 meters. The length of the additional external rails (15) is conditioned by the width of the sleepers (7) so that in the transition zone (1), it is the sleepers (7) that fix their length, since it cannot be braced through sleepers (7) smaller. In the area of the track in concrete plate (3) the length is the minimum that ensures a bracing without causing great efforts due to the buckling of the rails.

It is not advisable to use additional lanes (14, 15) that are excessively long, since the use of rail welds must be avoided at all costs due to their cost and to avoid their breakage. It is not advisable to use additional lanes (14, 15) that are excessively short since these would generate additional discontinuity in the installation area. The length of the rails, internal (14) and

5 external (15), is calculated so that its action on the set is optimal. A smaller or greater length thereof negatively modifies the distribution of stresses transmitted to the ballast.

On the other hand, there are support pads (12) of three different rigidities, this is related to the above, that is, depending on the thickness of the ballast layer (6) and

10 of the concrete layer (4) of the infrastructure. These rigidities range from 60 KN / mm to 100 KN / mm.

The fastenings of the rails (13) to the sleepers (7) in the transition zone (1) in the exemplary embodiment comprise three stiffness values:

-

the twelve sleepers (7) closest to the track in concrete plate (3), comprise 15 support pads (12) under rail (13) of rigidity 60KN / mm;

-

the sixteen sleepers (7) closest to the ballast track (2), comprise support pads (12) under 100KN / mm stiffness rail;

-

The twelve intermediate sleepers (7) comprise support pads (12) under 80KN / mm stiffness rail.

20 With all these elements the transition is as continuous as possible. In the state of the art, several support support pads (12) under rail (13) and several under sleepers (7) are used to make the most similar transition in rigidities, it has been seen that with that arrangement of only three rigidities the magnitudes studied have a continuous transition.

The solution object of the invention therefore decreases the use of support pads.

(12) under rail (13) and dispenses with pads (12) under sleepers (7), as the assembly results in improvements in the stiffness transition without the need to introduce so many elastic elements. The support pads (12) under sleepers (7) are subject to

higher loads so that its useful life decreases, thus, being possible to dispense with this type of elastic elements under sleepers (7), savings in construction and maintenance costs occur.

The damping sheet (10) of the concrete layer (11) of the plate track (3) with

5 with respect to the ballast (6) of the ballast track (2), it comprises in the exemplary embodiment, a thickness of 0.06 meters and width and depth of the cross section of the concrete layer (11) of the track in plate (3). The damping sheet (10) of the concrete layer (11) will preferably be made of elastomeric material and, in an embodiment, will consist of two sheets of 0.03 meter thickness, with a smooth face and another

10 wavy face, placing both sheets with their smooth face in contact while the wavy face will be in contact with the ballast layer (6) and the concrete layer (11) of the concrete plate path (3).

To obtain the dimensions of the damping sheet (10), the following conditions must be taken into account:

15 • It should allow to reduce a certain frequency range, this determines its dimensions, fundamentally its thickness.

• The cross section of the plate track (2) has to be completely covered but a certain length of sheet is also recommended under the plate track (2) for constructive reasons and of good covering of the entire section.

20 • Check that placing two damping sheets (10) the transmission is lower due to a greater insulating barrier. The two sheets are placed so that the smooth faces are in contact with each other and the wavy faces are in contact with the ballast (6) and with the concrete (11) of the concrete plate path (3).

25 • The thickness is in turn conditioned by the longitudinal frequency range that is intended to be absorbed and also by the distance between the end of the plate track (2) and the first crossbar (7) since the space is reduced and contains ballast (6).

In the exemplary embodiment, the damping sheet (10) has a depth of 0.6 meters, a thickness of 0.06 meters and allows absorbing a frequency of vibration in the longitudinal direction generated by the train as it passes 40 Hz.

In the exemplary embodiment, the mudguard wall (16), preferably of wood, is located next to the slab of the concrete slab and transverse to the sleepers, and whose length is 5 meters from the slab track. .

Claims (7)

1.-Transition zone (1) of a railway line located between a ballast track (2) and a concrete plate track (3), characterized in that it comprises: • a ballast layer (6) that extends over the entire length of the transition zone (1), • a set of concrete sleepers (7) longer than the sleepers (8) of the tracks in concrete slab (3) and ballast (2), the sleepers (7) being embedded in the ballast layer (6) ) and grouped into sections (9) of sleepers (7) of the same length, the sections (9) being placed progressively 10 according to the length of its sleepers (7) with increasing length from the ballast track (2) to the concrete plate track (3), • a vibration damping sheet (10) located transversely to the concrete plate track (3) that extends at least between the ballast layer (6) of the transition zone (1) and the layer of concrete (11) of the track in 15 concrete plate (3) in the entire cross section of the concrete layer (11) of the concrete plate track (3), • support pads (12) under rail (13) located between the rails (13) of the railway line and the sleepers (7), configured so that they are located with an equal or increasing stiffness from the concrete plate track ( 3) towards 20 ballast track (2), • two additional internal rails (14), fixed on the sleepers (7, 8) internally to the rails (13) of the railway line and parallel to them (7), which are braced on part of the sleepers (7) of the transition zone (1) closest to the concrete plate path (3) and part of the 25 sleepers (8) of the track in concrete plate (3), and • two additional external rails (15), fixed on the sleepers (7) externally to the rails (13) of the railway line and parallel to them (13), which are braced on part of the sleepers (7) of the area from transition (1) closer to the track in concrete plate (3) and part of the plate of concrete (11) of the track in concrete plate (3). 2.-Transition zone (1) of a railway line located between a ballast track (2) and a concrete plate track (3) according to claim 1, characterized in that it comprises 5 a concrete layer (4) that extends over the entire length of the transition zone (1) located on the natural terrain layer (5) in which the railway line is located and under the ballast layer (6) . 3.-Transition zone (1) of a railway line located between a ballast track (2) and a concrete plate track (3), according to any one of the preceding claims, 10 characterized in that it comprises a mudguard wall (16), located next to the concrete slab track (3) and transverse to the sleepers (7) extending longitudinally over a part of the transition zone (1). 4.-Transition zone (1) of a railway line located between a ballast track (2) and a concrete plate track (3), according to any one of the preceding claims, 15 characterized in that it comprises forty concrete sleepers (7) grouped into five sections (9) of eight sleepers (7) each. 5.-Transition zone (1) of a railway line located between a ballast track (2) and a concrete plate track (3) according to claim 4, characterized in that it comprises:

-

eight sleepers (7) of 4 meters in length located in the area closest to track 20 on plate (3);

-

eight sleepers (7) of 3.68 meters in length located after the section

(9) above;

-

eight sleepers (7) of 3.36 meters in length located after the previous section (9);

-

eight sleepers (7) 3.04 meters long located after the previous section (9);

-

eight sleepers (7) of 2.72 meters in length located in the area closest to the ballast track (2).

6.-Transition zone (1) of a railway line located between a ballast track (2) and a concrete plate track (3), according to claim 4, characterized in that it comprises: 5-the twelve sleepers (7) closest to the track in concrete plate (3), include support pads (12) under rail (13) of rigidity 60KN / mm;

-

the sixteen sleepers (7) closest to the ballast track (2), comprise support pads (12) under 100KN / mm stiffness rail;

-

The twelve intermediate sleepers (7) comprise support pads (12) under 10 80KN / mm stiffness rail.

7.-Transition zone (1) of a railway line located between a ballast track (2) and a concrete plate track (3), according to any one of the preceding claims, characterized in that the external rails (15) are braced to at least nine supports of the concrete layer (11) of the concrete slab track (3) and at least the 15 double sleepers (7) in the transition zone (1).