EP0767275A1 - Sound absorber for ballastless railway superstructure - Google Patents

Abstract

The absorber consists of two formed bodies with sound-absorbent characteristics, located between and next to the rails. The formed bodies (1) consist of a water-impermeable bearing concrete layer (9) and a sound-absorbent layer (10) above it. This consists of bonded macropore bulk material. A large number of vertical drainage passages (14) pass through one or both layers. The formed bodies are elastically borne on the ground plate (2). The elastic bearing can consists of strips (8) etc. of elastic synthetic material, located between formed bodies and plate, esp. of neoprene, or of felt. The sound-absorbent layer may have inclined cross channels in the top.

Description

The present invention relates to a sound absorber for a ballastless railway superstructure, consisting of moldings with sound-absorbing properties arranged between and next to the rails on the supporting plate of the superstructure.

Given the high train speeds and high train densities to be expected on the railroad tracks in the future, extremely high availability, a longer service life and a longer positional accuracy of the track body must be achieved than before. In order to meet these requirements, so-called fixed carriageways have been and are being developed, which represent a ballast-free superstructure system.

It has been shown that solid carriageways have a significantly higher level of noise radiation than train structures. The reasons for this are, due to the system, the softer coupling of the rails to the support points and the increased sound reflection on the smooth surface of the solid carriageway. Effective noise protection measures are therefore required in the area of buildings.

In this regard, DE 37 36 943 C1 proposes a sound-absorbing material, such as, for example, on a supporting plate made of reinforced concrete next to and between the rails. B. pile concrete. Due to its coarse pores, this material absorbs airborne noise and is also water-permeable, which is advantageous for the drainage of rain and surface water. However, the pores of the aggregate concrete become clogged with dirt particles over time, so that there is no long-term effective drainage of the track and the sound absorption is reduced.

Furthermore, according to the prior art (DE 94 17 008.8 U1) for solid carriageways, it is known to arrange shaped bodies made of aggregate concrete between and next to the rails. These bodies are placed directly on the support plate of the solid carriageway, if necessary on molded feet. As a result, the moldings can vibrate and develop airborne noise themselves.

Another disadvantage of this solution is the fact that the strength of the moldings leaves something to be desired due to their porosity. This lack of strength has the consequence that the shaped bodies are destroyed over time when the tracks are driven by motor vehicles, be it for repair purposes or in the event of an emergency.

The object of the present invention is to provide a further, improved sound absorber for solid carriageways.

According to the invention, this object is achieved by means of a sound absorber of the type mentioned at the outset in that the moldings consist of a water-impermeable, load-bearing concrete layer and a sound-absorbing layer of bonded aggregate arranged above it, a large number of openings being provided, both layers or only the load-bearing concrete layer in the enforce substantially vertically, and the moldings are elastically supported on the support plate.

In the case of the composite molded body according to the invention, the water-impermeable load-bearing concrete layer provides the required strength and the sound-absorbing layer the desired noise reduction, the load-bearing concrete layer being interspersed with a large number of openings in order to discharge the rain or surface water that seeps through the sound-absorbing layer.

Due to the intended elastic support of the shaped bodies on the support plate, these are somewhat spaced from the latter, so that the water can flow out under the shaped bodies. In particular, however, the elastic support, for which strips or stains made of an elastic plastic or felt are preferably provided, decouples the molded bodies from the support plate in the low-frequency range. This avoids natural vibrations of the moldings and the associated noise emission.

The distance between the shaped bodies and the supporting plate (concrete or asphalt) can be increased by elevations, as is necessary with superimposed systems, in which case the elastic intermediate layer is arranged under the elevation surfaces.

It is advantageous if the openings provided in the load-bearing concrete layer continue through the sound-absorbing layer. The through openings created thereby ensure that the suction effect of high-speed trains on the moldings is significantly weakened, since air can flow in.

Another advantage of the through openings is that at least part of the surface water flows directly through these openings, that is, not the way through the sound absorbing Layer takes through, and that the rinsing is easier when cleaning the moldings required.

The openings completely penetrating the molded bodies do not reduce the sound absorption behavior of the molded bodies; on the contrary, this is even somewhat improved by the enlarged surface of the sound absorbing layer.

Further advantageous refinements of the present invention result from the subclaims.

Fig. 1

eine Draufsicht auf eine Gleistrasse mit verlegten erfindungsgemäßen Formkörpern,

Fig. 2

einen Schnitt II-II durch die in Fig. 1 dargestellte Draufsicht,

Fig. 3

einen Querschnitt durch einen Formkörper gemäß der Darstellung in der rechten Bildhälfte von Fig. 2 mit sich nach unten konisch erweiternden Durchgangsöffnungen,

Fig. 4

eine Darstellung analog Fig. 3 mit sich konisch nach unten erweiternden Öffnungen nur in der tragenden Betonschicht, und

Fig. 5

einen Querschnitt durch einen gegenüber den Formkörpern gemäß Fig. 1 verkürzten Formkörper parallel zu den Schienen.

The invention is explained below with reference to exemplary embodiments shown in the drawing. It shows:

Fig. 1

a plan view of a track line with laid molded bodies according to the invention,

Fig. 2

2 shows a section II-II through the top view shown in FIG. 1,

Fig. 3

3 shows a cross section through a shaped body as shown in the right half of FIG. 2 with through openings that flare conically downward,

Fig. 4

a representation analogous to FIG. 3 with conically widening openings only in the load-bearing concrete layer, and

Fig. 5

a cross section through a shortened compared to the shaped body according to FIG. 1 shaped body parallel to the rails.

Fig. 2 shows a cross section through a solid roadway, which has a reinforced concrete slab 2, which is continuously reinforced and concreted on a hydraulically bound base layer 3. A frost protection layer 4 forms the lower end of the ballastless superstructure. All layers of the superstructure are covered laterally by a ballast fill 5. The rails 6 are fastened to the reinforced concrete plate 2 via individual support points 7.

The reinforced concrete slab 2 is covered with moldings 1 according to the invention, which are stretched over elastic plastic strips 8, e.g. Neoprene or rubber, with appropriate damping behavior are supported on it. Three plastic strips 8 are provided for each molded body 1 - one at the edge and one strip 8 in the middle. The plastic strips 8 are arranged transversely to the rails in order not to hinder the water drainage below the molded body 1.

The molded bodies 1 consist of a water-impermeable, load-bearing concrete layer 9, which can also be reinforced, and a sound-absorbing layer 10. This layer 10 can consist, for example, of aerated concrete, a mixture of aerated concrete and large-grain rubber granulate or other porous building materials. The moldings 1 are manufactured as finished parts.

From the figures it can be seen that the sound-absorbing layer 10 is somewhat thicker than the load-bearing concrete layer 9. When dimensioning the layer thicknesses, care must be taken to ensure that the load-bearing concrete layer 9 must have a certain minimum thickness in order to fulfill its functions, namely to ensure the necessary strength of the molded body 1 and to load the vehicle when driving on motor vehicles. With a molded body height of approx. 23 cm, the height of the load-bearing concrete layer 9 should, for example, be at least 10 cm.

From Figures 1 and 2 it can be seen that a Shaped body 1 are arranged on the outside next to the rails 6 and two shaped bodies 1 between the rails 6, so that the entire width of the solid carriageway is covered. Only the areas directly next to the rails 6, at the individual support points 7, areas for signaling and safety-related elements and fastening points for rail earth electrodes are left free.

The molded bodies 1 are all constructed identically, which simplifies storage and laying. Each molded body 1 comprises several individual support points 7, their length being adapted to their grid. Of course, shorter shaped bodies 1 can also be used.

Furthermore, the molded bodies 1 each have two mounting openings 11, into which hooks etc. can be used when laying or picking up, which makes these activities easier.

The side surfaces of the molded bodies 1 are inclined outwards, so that the area to be kept clear next to the rails 6 can be kept very small. In the area of the individual support points 7, the side faces of the molded bodies 1 facing the rails 6 are offset in order to have a not too wide gap to the rails 6 and at the same time have enough space for the base plate of the individual support points 7. This training ensures that all screws and clamps of the individual support points 7 can be viewed and replaced if necessary.

Due to the inclined side surfaces of the molded bodies 1, the longitudinal gaps 12 and transverse gaps 13 formed between them differ, as a result of which the water drainage and also the possibility of cleaning are improved. In particular, in the longitudinal and transverse gaps 12 and 13 there can be no blockages due to larger objects such as leaves etc. due to this gap shape which widens downwards.

In the embodiments shown in FIGS. 1, 2 and 3, the molded bodies 1 have a multiplicity of openings 14 with a circular cross section, which completely penetrate the molded bodies 1 as through openings. For the sake of simplicity, these openings 14 are only shown in FIG. 1 for one of the left molded bodies. From Fig. 3 it can be seen that these openings 14, as well as the longitudinal and transverse gaps 12 and 13, diverge downward, which also counteracts blockages of these openings 14. The taper of the openings 14 also facilitates the shaping of the shaped bodies 1 during manufacture, which also applies to the inclination of the side surfaces of the shaped bodies 1.

4 shows a further embodiment of a molded body 1 according to the invention. Here, openings 14 with a likewise conical cross section are provided only in the load-bearing concrete layer 9, while the sound-absorbing layer 10 is closed. Rain or surface water seeps through the layer 10 and then flows out through the openings 14 and the gap between the underside of the molded body 1 and the reinforced concrete plate 2.

FIG. 5 shows an embodiment in which channels 15 are provided in the sound-absorbing layer, which in the installed position of the shaped bodies 1 extend transversely to the rails 6. These transverse channels 15 have a slope to the longitudinal gaps 12 or to the outside. Since the transverse channels 15 are quite short, part of the water flows out via the channels 14 when it rains, since it does not have enough time to infiltrate the sound-absorbing layer 10. In this embodiment, the molded body 1 is supported on two lateral edge strips 8 made of plastic.

Claims (5)

Sound absorber for a ballast-free railway superstructure, consisting of shaped bodies with sound-absorbing properties arranged between and next to the rails on the supporting plate of the superstructure, characterized in that the shaped bodies (1) consist of a water-impermeable load-bearing concrete layer (9) and a sound-absorbing layer (10) arranged above consist of bound, coarse-pored piles, a plurality of openings (14) penetrating the layer (9) or both layers (9, 10) essentially vertically and the molded bodies (1) being elastically supported on the support plate (2). Sound absorber according to Claim 1, characterized in that the elastic support consists of strips (8) or spots made of an elastic plastic, in particular neoprene, or of felt, arranged between the shaped bodies (1) and the support plate (2). Sound absorber according to one of the preceding claims, characterized in that the side surfaces of the shaped bodies (1) are inclined outwards in such a way that the underside of the shaped bodies (1) is smaller than their top side. Sound absorber according to one of the preceding claims, characterized in that the sound-absorbing layer (10) has transverse channels (15) on its surface, and only the load-bearing concrete layer (9) is provided with openings (14). Sound absorber according to claim 4, characterized in that the transverse channels (15) have a slope.

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