Abstract:
A guideway girder is provided for a vehicle transport system wherein a plurality of the girders are assembled in succession in a direction of travel of a vehicle to form a guideway for the vehicle. The girder is formed by a combination of concrete structural elements, and includes at least one sound isolation element disposed on a surface of at least one of the structural elements.

Description:
BACKGROUND  
         [0001]    The invention relates to a guideway girder, in particular for a magnetic levitation transport system, for the realization of a guideway by several girders following each other in the direction of travel of a vehicle. The guideway girder has at least one upper girder section, in particular a top chord, possibly with a lower girder section, in particular a bottom chord, and with at least one supporting section located below the upper girder section, in particular a web.  
           [0002]    Sounds and noise of all kind are known to affect the well-being of persons exposed to these sounds in a negative manner. Vehicle noises may represent a major problem in this regard. The blocking of noise produced by the vehicle on the guideway girders—in addition to the travel sounds produced directly by the vehicle on the guideway girders, in particular engine noises—by means of sound insulation walls installed next to the tracks in order to protect, e.g., dwellings or nature areas located behind them, is known. These sound insulation walls are however relatively expensive and space consuming in their installation. Furthermore they often do not contribute to the beautification of the rail line. Sound insulation devices are not provided as standard equipment on guideway girders having the characteristics mentioned above. The problem of high noise emission from such girders has not been recognized until now.  
         SUMMARY  
         [0003]    It is an object of the present invention to further develop a guideway girder of the type mentioned above in such a manner that an effective sound insulation is achieved under favorable space-saving conditions. Additional objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.  
           [0004]    This object is attained with the guideway girder of the type mentioned initially by means of at least one sound insulating element installed on the upper girder section and/or the lower girder section and/or the (at least one) supporting section.  
           [0005]    The invention proposes for this a tabular sound insulation element for installation on a guideway girder that may be located essentially above ground.  
           [0006]    The advantages of the invention consist in particular in the fact that the sound emitted by the vehicle on the guideway girders can be substantially reduced by installing one or several sound insulation elements on the upper girder section, on a possibly present lower girder section, and/or on the (at least one) supporting section. For this purpose, in particular tabular sound insulating elements lining the girder section(s) and/or supporting sections. Preferably, the elements may be in the form of porous or open-pore absorbers or plate resonators. In the latter case, the plates, foils, etc. are installed with clearance in front of the section involved. The resonance occurring in the cavities result in increased air oscillations and thereby to sound-absorbing friction. Cavity resonators can also be used, with a narrow access opening leading to a cavity between the girder section/supporting section and the sound insulation element. The flow resistance necessary for sound absorption can be located in the opening and/or in the cavity.  
           [0007]    Sound insulation elements can be made in single layers or in several layers or structures. All of the known configurations and materials can be considered if suitable.  
           [0008]    It is a further advantage of the sound insulating elements according to the invention that also sounds can be prevented from reaching the vehicle itself, or can be attenuated, and that the inconveniencing of travelers through noise can be avoided thereby. In the case of a magnetic levitation transport system, these noises are in particular the result of air eddies produced between the vehicle and the guideway girder. With a conventional train, engine noise as well as the rolling noises produced by the contact of wheel against rail are added to this.  
           [0009]    The guideway can also be designed as a bivalent guideway on which a magnetic levitation transport system as well as—with considerably narrower gauge—conventional trains can travel.  
           [0010]    It has been shown to be advantageous statically as well as from the point of view of manufacturing technology in certain cases, if the guideway girder—in particular when used for a magnetic levitation transport system—is given a hollow configuration in cross-section. For this, preferably two supporting sections or webs across from each other are provided and are connected to each other through the upper girder section or top chord. Towards the bottom, a lower-girder section or bottom web closes off the cavity advantageously. With this design, it is possible to achieve advantageous acoustic effects, in that, e.g., part of the noises produced are radiated off into the cavity, and are in part absorbed therein, without affecting the outside environment with noise.  
           [0011]    In case of, e.g. relatively small curve radii, it is advantageous if the guideway girder cross-section is full, so that only a supporting section under the upper girder section is present. Sound insulation elements are then installed, e.g. on one or on both sides on the supporting section.  
           [0012]    The guideway girder is preferably supported on one or several pillars imbedded in the ground. This solution also allows for a constructively advantageous machining of the girder during manufacture, as well as a relatively easy erection at the building site. In addition, the space underneath the guideway girder can be used. The sound-insulating elements installed high above ground on the guideway girder are in this case relatively protected from unauthorized access, e.g. vandalism, by third parties.  
           [0013]    The individual guideway girders are preferably successively assembled one after the other so that the distance between the supporting sections following each other is small or negligible. In an extreme case, a continuous sequence of successive girder sections results, forming a kind of wall in the direction of travel on which sound insulation elements of large surface can be installed.  
           [0014]    Preferably one or several sound insulation elements are provided outside and/or, in the case of a cavity as described above, inside on the supporting sections, depending on the efficiency of the sound absorption. The sound emitted, e.g. in the cavity, is still radiated off in part by the delimiting walls into the outside environment. It may therefore be useful to provide the cavity on the inside with sound insulating elements and/or to mount these elements on the outside of the cavity walls. These designs apply to the supporting sections as well as to the upper girder section and the lower girder section of the guideway girder.  
           [0015]    For the most effective sound absorption possible, it is good if the (at least one) sound insulation element is essentially tabular in form, since the absorption surface for sound energy can be sufficiently large in that case. The sound insulation elements are advantageously mounted on free surfaces of the guideway girder sections. The sound insulation elements are not imbedded in the girder in this case, but are mounted in tabular form on the guideway girder (or one layer on the guideway girder).  
           [0016]    Depending on the configuration of the guideway girder sections to be covered, the (at least one) sound insulation element can be provided with several surface segments forming an angle with each other. Such a design of the sound insulation elements can thus be adapted to the form of any of the sections of the guideway girder to be covered, and can be installed on especially critical locations emitting high sound energy.  
           [0017]    Since a guideway girder may have relatively large dimensions, it is advantageous for reasons of easier handling, to install several smaller sound insulation elements next to each other in the travel direction of the guideway.  
           [0018]    In addition to their original purpose, the sound insulation elements can advantageously be used for yet another purpose, e.g. by attaching advertising elements, in particular advertising posters and/or lighted advertising.  
           [0019]    Advantageous further developments of the invention are characterized by the features of the sub-claims: 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]    The invention is explained in detail in the following with reference to the drawings, in which:  
         [0021]    [0021]FIG. 1 shows a guideway with a magnetic levitation transport system  
         [0022]    [0022]FIG. 2 shows an alternative embodiment of a guideway girder in cross-section, with sound insulation elements, and  
         [0023]    [0023]FIG. 3 shows a perspective view of the guideway girder according to FIG. 2. 
     
    
     DETAILED DESCRIPTION  
       [0024]    Reference will now be made to embodiments of the invention, one or more examples of which are shown in the drawings. Each embodiment is provided by way of explanation of the invention, and not meant as a limitation of the invention. It is intended that the invention include modifications and variations to the embodiments described or illustrated herein.  
         [0025]    The invention is described by way of example using a hybrid carrier system for rail-bound vehicles. Such a carrier system is described in detail in EP 0 987 370 A1, the disclosed content of which is incorporated herein.  
         [0026]    [0026]FIG. 1 shows a guideway for a magnetic levitation transport system  100  in cross-section. Girders  2 , preferably made of prestressed concrete, are attached on pillars  5  at the construction site. Here, several girders  2  are successively assembled in the direction of the guideway wherein the faces of the girders  2  adjoin each other directly. Laterally, on every girder  2 , connecting consoles  1  preferably made of steel are installed at equal distances. Each connecting console  1  is welded or screwed together with tie rods  6  that are imbedded in the prestressed concrete of the girder  2 . Each connecting console  1  has a head plate  4  at which functional level supports  3  are attached to receive, e.g. stator packages  9 .  
         [0027]    [0027]FIGS. 2 and 3 show an alternative embodiment of a girder  2  which is provided with an upper girder section  12  in the form of a top chord  12 , two lateral sections  13  designed as supporting sections  13 ,  14  horizontally at a distance from each other, as well as a lower girder section designed as lower chord  15 . The chords  12 ,  15  and supporting sections  13 ,  14  delimit a cavity  16  with nearly rectangular cross-section. The installation of functional level supports  3  on connecting consoles  1  is essentially as shown in the embodiment of FIG. 1.  
         [0028]    According to the invention, tabular sound insulation elements  8 , which may be designed in the form of known sound absorbers (such as e.g. porous absorbers, plate resonators or cavity resonators), are installed outside on the chords  13 ,  14  to reduce the noise produced by traffic. The sound insulation elements  8  shown in FIGS. 2 and 3 on the chords  13 ,  14  are provided with two segments  8   a ,  8   b  designed so as to form an angle with each other that is adapted to the downward widening form of the chords  13 ,  14 . Several sound insulation elements  8  are installed so as to be directly connected to each other in the direction of the guideway.  
         [0029]    As can be seen in FIG. 1, the magnetic levitation transport system  100  reaches around the connecting consoles  1  and the functional level supports  3  to within close proximity of the chords  13 ,  14 . For this reason the sound insulation elements  8  are not continued up to the upper girder section  12 , but end in an upper edge below the magnetic levitation transport system  100 . Tabular sound insulation elements, possibly with a smaller diameter (thickness) because of lack of space, can of course also be installed on the chord segments directly across from the magnetic levitation transport system  100 .  
         [0030]    On the side of the upper girder section  12  facing up, sound insulation elements  7  are installed (not shown in FIG. 3) and preferably are successively assembled in the direction of travel, and may occupy nearly the entire width of the upper top chord  12 . The sound insulation elements  7  reach to such height as not to interfere with the functions and travel operations of the magnetic levitation transport system  100 .  
         [0031]    In an embodiment of the invention not shown here, the inner walls of the chords  13 ,  14  of the top chord  12  and/or of the bottom chord  15  are alternatively or additionally also lined with sound insulation elements. The advantage of such a measure depends in particular on the sound energy radiated from the cavity  16 . Especially with a lining of a cavity  16  as mentioned above, the possibility exists to use sound insulation elements with large surfaces so that they cover part of the chords  12 ,  16  as well as the webs  13 ,  14 .  
         [0032]    For the sake of clarity, no sound insulation elements  7 ,  8  are shown in FIG. 1. The preceding descriptions can however be applied without any restrictions to these embodiments of the guideway.  
         [0033]    The sound insulation elements  7 ,  8  according to the invention, in particular those located on the top of girder  2 , have the additional advantage that the girder  2  is protected from direct sun rays and that as a result uneven warming and thereby deformation of the girder is reduced.  
         [0034]    It is also possible to install sound insulation elements alternatively or additionally on the pillars  5  which are considered in that case to be supporting sections in the sense of the claims of the present invention.  
         [0035]    The external surfaces of the sound insulation elements  7 ,  8  can be used as advertising space, thus performing a double function.  
         [0036]    It should be apparent to those skilled in the art that modifications and variations can be made to the embodiments described and illustrated herein without departing from the scope and spirit of the invention as set forth in the appended claims and their equivalents.