Patent Application
20170275834
The invention relates to an anti-noise installation for a guided transport track , in particular for a viaduct having a U-shaped cross section. The invention also relates to a guided transport track, and in particular a viaduct, equipped with an installation according to the invention.
Public guided transport such as metros and trains generate high noise levels that result in particular from the interactions between the wheels of the transport vehicles and the runways such as rails on which these vehicles travel.
This problem of noise is a particular nuisance when the tracks are laid out in urban areas, in the immediate vicinity of residential zones, in particular in the context of viaducts or overhead tracks.
One of the technical solutions frequently used on this type of track is that of installing acoustic barriers two to three metres high that border the track so as to trap the noise and limit the propagation thereof beyond the immediate vicinity. These barriers make it possible to counter the propagation of noise by reflecting the acoustic waves that reach the internal face of the barrier.
This solution does however have several drawbacks, including the fact that the field of vision of the nearby residents is obstructed due to the presence of particularly imposing acoustic barriers.
Apart from the visual impact, the acoustic barriers are ineffective, or even aggravate the noise situation for nearby residents living in buildings located higher than the viaduct, because of the multiple reflections off the vehicle bodies or the screens on the opposite track.
Furthermore, this solution requires a large amount of space and has significant wind resistance, which has a not insignificant impact on the forces to which the engineering structure is subjected, and weighs down the structure on which it is used. Thus it is only possible to equip engineering structures, and in particular viaducts, that have been oversized during construction with anti-noise barriers of this kind. Only oversized viaducts can subsequently withstand new stresses and therefore be equipped with these anti-noise barriers. Other structures are condemned to be noisy and therefore to be detrimental to the nearby residents and/or to make the surrounding areas unpropitious for residential accommodation.
Finally, the solution of anti-noise barriers provided along tracks does not make it possible, once the barriers have been installed along the track, to modify the performance level, unless the anti-noise barriers are replaced by new barriers.
It is therefore necessary to provide a novel solution for limiting the noise caused by the passage of guided transport vehicles on engineering structures of the viaduct or bridge type.
It is also necessary to provide a solution that makes it possible to adapt all types of viaduct, in particular viaducts that have not been oversized during construction.
It is also necessary to provide a solution that makes it possible to provide different performance levels according to the needs expressed by the nearby residents.
The invention aims to overcome at least some of the drawbacks of the known solutions for limiting the noise heard by those living alongside engineering structures, of the bridge or viaduct type, in particular viaducts having a U-shaped cross section, in particular in the form of a splayed U.
In particular, the invention aims to provide an anti-noise installation for a viaduct that does not impact on the visual field of the nearby residents.
The invention also aims to provide, in at least one embodiment, an anti-noise installation that can be adapted to various viaduct designs without major difficulty.
The invention also aims to provide, in at least one embodiment of the invention, an anti-noise installation that is easy to maintain.
The invention also aims to provide, in at least one embodiment of the invention, an installation that makes it possible to respond to various distinct performance levels.
The invention also aims to provide, in at least one embodiment, a viaduct equipped with an anti-noise installation according to the invention.
To do this, the invention relates to an anti-noise installation for a guided transport track having a U-shaped cross section, in particular in the form of a flared U, the two branches of which form the lateral walls of the track and the central zone of which, connecting the two branches, forms at least one runway for a guided transport vehicle, characterised in that said installation comprises a plurality of acoustic panels arranged relative to one another so as to form at least one chamber for confining a source of noise resulting from the passage of a vehicle on said runway, which chamber can be provided around said noise source while extending as far as a free end of at least one branch of the U, each acoustic panel forming at least one portion of a partition of a noise-confinement chamber.
The invention therefore makes it possible to form at least one noise-confinement chamber arranged around the source of the noise, which results from the passage of the wheels of a vehicle over the runway, for example wheels of a train on the rails, and the free end of the lateral walls of the U-shaped viaduct. A noise-confinement chamber is a chamber that has partitions suitable for optimally insulating the space containing the sources of noise from the space downstream thereof and thus for attenuating the noise. The invention proposes confining the sources of noise resulting from the dynamic interaction of the wheels of a vehicle with the runway by using the space available between these sources and the lateral walls of the U-shaped viaduct. Since space is limited, the invention proposes using a plurality of acoustic panels and arranging them relative with one another so as to form various partitions of at least one noise-confinement chamber without these exceeding the outer dimensions of the viaduct, such that the visual impact of the installation is limited.
The invention uses and optimises the U-shape of the viaduct by forming a noise-confinement chamber that lies entirely within the permitted space between the source of the noise and the free end of the branches of the U. In other words, each portion of the U-shaped viaduct is used to reduce the noise emissions. The invention therefore takes advantage of the specific shape of the viaduct for reducing the noise emissions by integrating various acoustic panels therein.
Furthermore, the confinement chamber is provided around the source of the noise, extending as far as the free end of the lateral walls. In other words, the acoustic panels do not extend beyond the viaduct. In particular, no acoustic panel projects beyond the free end of the lateral walls. All the acoustic panels are therefore provided between the lateral walls of the viaduct. The visual impact of an anti-noise installation is therefore zero for the nearby residents. A viaduct that is carefully designed and that has aesthetic curves is therefore not compromised by the arrangement of an anti-noise installation according the invention, unlike the noise-reduction barriers of the prior art.
According to the invention, the confinement chamber is formed by arranging a plurality of acoustic panels, each panel forming at least one portion of a partition of a confinement chamber. It is therefore particularly easy to adapt the shape and dimensions of the noise-confinement chambers to the dimensions of the vehicles travelling on the track by moving and/or modifying the shape and dimensions of one or more acoustic panels.
It is also particularly easy to adapt the shape and dimensions of noise-confinement chambers to the required performance level. For example, an installation according to the invention makes it possible to adapt the sound attenuation produced to a specific requirement by modifying the shape of the confinement chamber produced by the arrangement of the acoustic panels. The performance may also be determined by the type of acoustic panels used. Furthermore, depending on the dimensions of the vehicle travelling on the track, only some of the acoustic panels of the plurality of acoustic panels may be used.
The confinement chamber is preferably formed by the combination of the acoustic panels, the vehicle and the U-shaped viaduct. In other words, the acoustic panels are at least arranged so as to form partitions where the vehicle and the viaduct do not form walls preventing the propagation of the noise.
Advantageously, and according to the invention, each acoustic panel is either an absorbent panel or a blocking panel. An absorbent panel is an acoustic panel comprising a material suitable for absorbing at least some of the noise that reaches it. A blocking panel is an acoustic panel formed of a material suitable for blocking the propagation of the acoustic waves that reach it.
Advantageously, an installation according to the invention comprises at least one acoustic panel, referred to as a cap, suitable for being mounted on the free end of at least one branch of the U, in parallel with said runway, extending in the direction of the branch of the U facing the branch on which it is mounted, so as to form a top partition of a noise-confinement chamber.
Each cap forms an upper partition of at least one noise-confinement chamber. Each cap is arranged at the end of a lateral wall of the track towards the lateral wall of the opposite track, in parallel with the runway. In other words, each cap delimits the upper part of the chamber while not extending beyond the viaduct. An anti-noise installation according to the invention and according to this variant therefore does not create a visual impact for nearby residents. Each cap forms, together with the lateral wall of the U-shaped viaduct on which it is arranged, a cavity that traps the acoustic waves emitted by the noise source, which substantially reduces the noise transmitted to those living near the viaduct when vehicles pass over the transport track. The cap may have dimensions so as to extend as close as possible to the vehicle travelling on the track in order to limit to the maximum possible extent the leakage surface formed by the space between the free end of the cap and the vehicle.
Advantageously, an anti-noise installation according to the invention comprises at least one acoustic panel, referred to as a skirt, suitable for being carried by said vehicle perpendicularly to said runway, and at least one acoustic panel, referred to as a bottom screen, suitable for being mounted on said runway facing said skirt, so as form a lateral partition of at least one noise-confinement chamber.
An anti-noise installation according to this variant therefore makes it possible to form, by combining a skirt carried by the vehicle and a bottom screen mounted on the runway, a lateral partition of a localised noise-confinement chamber that moves when the vehicle moves. In particular, the chamber is only formed when the train is present on the viaduct. This lateral partition is not continuous, but has a space between the skirt and the bottom screen to enable the vehicle to travel on the track. This space between the bottom screen and the skirt determines the leakage surface towards the outside of the confinement chamber to which the formed partition belongs. This surface can therefore be parameterised by adapting the dimensions of the skirt and of the bottom screen to the dimensions of the vehicles travelling on the track.
Preferably, the installation comprises two skirts carried laterally on each side of the vehicle and a bottom screen mounted on the track facing each skirt.
Advantageously, an anti-noise installation according to the invention comprises at least one acoustic panel, referred to as a lateral panel, suitable for being mounted in the vicinity of a lateral wall of the track, perpendicularly to the runway, so as to form a lateral partition of at least one noise-confinement chamber.
In a variant or in combination, the installation comprises at least one acoustic panel, referred to as a lateral mat, suitable for being attached to the lateral wall of the track, forming a branch of the U, so as to form a lateral partition of at least one noise-confinement chamber.
A lateral mat can follow the shape of the lateral wall of the U-shaped track so as to form a lateral partition of a noise-confinement chamber.
Advantageously, an anti-noise installation comprises at least one acoustic panel, referred to as a slab, suitable for being attached to the runway so as to form a bottom partition of at least one noise-confinement chamber.
Advantageously and according to the invention, said acoustic panels, in particular the absorbent panels, are suitable for being arranged in various distinct configurations so as to form at least one noise-confinement chamber that is compatible with the design of said guided transport track on which the installation is used.
An installation according to this variant makes it possible to adapt the design of the confinement chambers formed by the arrangement of the acoustic panels, in particular the absorbent panels, to various types of track and to the specific constraints and requirements of each track.
Advantageously, an installation according to the invention further comprises means for removably attaching said acoustic panels, in particular the absorbent panels, so as to allow easy installation/removal of each acoustic panel, in particular of each absorbent panel.
According to this variant, the installation and removal of an acoustic panel on the track or on the vehicle is done by means of removable attachment means, which makes it easier to maintain an anti-noise installation according to the invention and which makes it possible to easily adapt the design of the chambers formed by the acoustic panels to the dimensions of the vehicles travelling on the track. These removable attachment means comprise, for example, means of the screw-and-nut type.
Advantageously and according to the invention, said acoustic panels are arranged relative to one another so as to form at least two noise-confinement chambers that can be provided in series between the noise source and a free end of at least one branch of the U.
According to this variant, the installation forms at least two noise-confinement chambers arranged in series between the noise source and the outside of the viaduct. In particular, the first confinement chamber leads into the second confinement chamber, which leads to the outside of the viaduct, at the cap. The first chamber comprises, for example, a bottom partition formed by slabs, lateral partitions formed by skirts and bottom screens, and a top partition formed by the vehicle. The second confinement chamber comprises, for example, a bottom partition formed by slabs, lateral partitions formed respectively by a skirt and a bottom screen (this partition is common with the first chamber), and by a lateral mat, and a top partition formed by a cap. The space between the skirt and bottom screen of the common partition forms a passage from the first chamber to the second chamber. The space between the free end of the cap and the vehicle forms a leakage surface of the second chamber.
An anti-noise installation according to the invention can be used in connection with a guided transport track comprising two adjacent runways. In this case, the anti-noise installation advantageously comprises at least one acoustic panel, referred to as a central panel, suitable for being attached to the track between the two runways while extending perpendicularly to the runways so as to form a lateral partition of at least one noise-confinement chamber.
Advantageously and according to the invention, at least one absorbent acoustic panel is formed of a material chosen from the group comprising porous concrete, timber concrete, rubber concrete, rockwool, rockwool, steel, PVC, EPDM or a combination of a plurality of these materials.
Each of these materials offers good acoustic and/or structural performance and can be used to form one or more absorbent acoustic panels of an anti-noise installation according to the invention.
The invention also relates to a guided transport track having a U-shaped cross section, in particular in the form of a flared U, the two branches of which form the lateral walls of the track and the central zone of which, connecting the two branches, forms a runway for a guided transport vehicle, characterised in that it comprises an anti-noise installation according to the invention.
The invention also relates to an anti-noise installation and a track equipped with an anti-noise installation, characterised in combination by all or some of the features mentioned above or below.
Other aims, features and advantages of the invention will become apparent from reading the following description given solely by way of non-limitative example and which refers to the accompanying figures, in which:
In the figures, the scales and proportions are not strictly respected for purposes of illustration and clarity. Throughout the following detailed description given with reference to the figures, unless otherwise indicated, each element of the anti-noise installation is described as it is arranged when the installation is mounted on a guided transport track. This arrangement is in particular shown in
A guided transport track according to the invention intended to be equipped with an anti-noise installation according to the invention has a cross section in the shape of a U, the two branches of which form the lateral walls 15, 16 of the track and the central zone of which, connecting the two branches, forms runways 17, 18 for a guided transport vehicle 50. In the figures, the guided transport track is a track comprising two adjacent runways 17, 18 so that two vehicles can pass each other.
Throughout the remainder of the detailed description, only the anti-noise installation arranged in relation to the runway 18 will be described precisely, it being understood that the anti-noise installation may be symmetrical and have an identical design in relation to the runway 17.
The anti-noise installation according to the invention comprises a plurality of acoustic panels arranged relative to one another so as to form at least one chamber 20 for confining the noise resulting from the passage of a vehicle over a runway 18. This confinement chamber 20 is shown schematically by a dashed line in
According to the embodiment in the figures, the acoustic panels are all absorbent panels. This being the case, according to other embodiments, one or the other of the absorbent panels described below may be replaced by a blocking panel.
An anti-noise installation according to the embodiment in the figures therefore comprises a plurality of absorbent panels and in particular:
The invention makes it possible to form one or more noise-confinement chambers by using at least some of these various absorbent panels and arranging said panels relative to one another.
To do this, the invention aims to form at least one lateral partition for preventing noise from propagating laterally towards the end of the viaduct, and a top partition for preventing the propagation of noise outside the viaduct.
Hereinafter, various embodiments of each absorbent panel will be described in relation to
In
Whatever the material used, each cap has holes 61 extending in parallel with the runway and suitable for receiving attachment means of the screw-and-nut type. According to an advantageous embodiment, each cap has a top surface having a slight slope, for example of approximately 3%, towards the runway, for allowing rainwater to run off.
The caps extend over a distance of, for example, 10 to 20 cm from the edge of the lateral wall on which they are mounted and extend along the track over a distance of, for example, 6 m.
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The invention is not limited solely to the embodiments described. In particular, other types of material may be used to form the acoustic panels, in particular the absorbent panels.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1458462 | Sep 2014 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/FR2015/052240 | 8/20/2015 | WO | 00 |
