Overhead guided-transport track span, and viaduct formed by such spans
Description
1. Technical field ofthe invention
The invention relates to an overhead guided-transport track span, in particular a
viaduct having a U-shaped cross section, in particular in the shape of a flared U. The
invention also relates to a guided-transport viaduct comprising a plurality of spans according
to the invention.
2. Technological prior art
Guided public transport lines such as undergrounds and trains, whether lyre-based
or rail-based, often comprise works of art, such as viaducts or bridges, which allow rolling
stock to pass through regions where it is too difficult or expensive to lay an underground
track given the layout C7f-the places.
In the patent FR2882375, the applicant has already developed and described a
viaduct span having-a.I.J-shaped cross section and comprising a load-bearing slab that
supports the track, and at least one runway on which a guided-transport vehicle can travel.
' In the case of a rail vehicle, the runway is a shoe that is carried by the load-bearing slab and
to which the rails intended for guiding the rail vehicle are attached.
In practice, the operations for mounting the rails on the spans are complicated and
· require rigour and precision.
The applicant has therefore sought to develop an overhead track span, in particular a
viaduct span, that makes it possible to simplify the operations for mounting rails on the span.
The applicant has also sought to simplify the construction of a viaduct from such spans, to
reduce the weight of a span, and to improve the acoustics and the aesthetics of a span and
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of a viaduct formed from such spans.
3. Aims of the invention
The invention aims to remedy at least some of the disadvantages of the known
solution, in particular with a view to simplifying the operations for mounting rails on the spans
of a guided-transport viaduct.
In particular, the invention aims to provide an overhead guided-transport track span
having a U-shaped cross section.
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The invention also aims to provide, in at least one embodiment, a span that
contributes to reducing noise emissions from a vehicle travelling on the portion of track
formed by the span.
The invention also aims to provide, in at least one embodiment of the invention, a
span that has improved aesthetics compared with the spans of the prior art.
The invention also aims to provide a viaduct formed by a plurality of spans according
to the invention.
4. Disclosure of the invention
In order to achieve this, the invention relates to an overhead guided-transport track
span having a U-shaped cross section, the two arms of which form lateral walls of said track
and the central region of which, connecting the two arms, forms a load-bearing slab of said
track.
A span according to the invention is characterised in that said load-bearing slab
comprises at least one groove that is provided longitudinally in said slab along said span and
is designed to be able to receive a running support of a guided-transport vehicle intended to
travel-en said track, -and in that-4he-span comprises one longitudinal rib for each groove,
which rib extends under said load-bearing slab opposite to said groove and forms
longitudinal stiffening means of said load-bearing slab.
A span according to the invention thus comprises at least one groove that is provided
directly in the load-bearing slab. The load-bearing slab forms the deck of the span. This
groove (or recess) forms a pocket for receiving a running support, such as a rail, of a
transport vehicle intended to travel on the span. The invention therefore consists in
producing a pocket for receiving a running support of a vehicle, such as a rail, directly in the
deck of the span. In other words, according to the invention, the span makes it possible to
directly integrate the running supports, such as the rails, in the deck of the span. Thus,
according to the invention, the running supports, such as the rails, are provided directly in
the grooves and not on the shoes (or stringers) of the prior art that were raised with respect
to the load-bearing slab. It is therefore particularly simple to mount the rails using a span
according to the invention, the operators only needing to arrange the rails in the grooves and
no longer needing to attach said rails to the shoes.
It is likewise possible, using a span according to the invention, to provide the running
supports, such as the rails, directly in the workshop before mounting the span on the piles of
the viaduct on which it is intended to be used. In other words, using spans according to the
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invention it is possible to prepare integrated track portions that will then be assembled
together on site, which makes the on-site mounting and installation operations easier.
Moreover, since the rails are accommodated directly in the grooves, it is not
necessary to provide kerbs on either side of each rail, as is the case in the spans of the prior
art. The construction of a span according to the invention is therefore made easier.
Moreover, since the rail is accommodated in the groove, the acoustic signals
resuJ!ing from interaction between the vehicle wheels and the rails are trapped in the groove,
thus limiting the propagation of said signals to the surroundings of the span. The acoustic
signals are also blocked more than is the case in the spahs of the prior art because the
noise source is accommodated in the load-bearing slab, further away from the upper edges
of the lateral walls of the span than is the case in a span in which the rail is mounted on a
shoe which is, itself, carried by the load-bearing slab. A span according to the invention thus
makes it possible to limit the interfering noise caused by transport vehicles travelling on the
transport track.
-Furthermore, the span according to the invention COil!flrises one longitudinal rib for
each groove, which ribs extend under said load-bearing slab opposite to said groove and
form longitudinal stiffening means of said load-bearing slab.
These ribs not only stiffen the load-bearing slab, but also provide a span according to
the invention with aesthetics that are more visually pleasing than is the case in a span of the
prior art, by removing the lower planar surface which was considered harsh in appearance.
In particular, arranging ribs under the load-bearing slab forms a relief pattern that is
considered more pleasing to the eye than the planar surface of a span of the prior art. In a
variant, the lower surface of the load-bearing slab can be provided with lights in order to
illuminate the lower portion of the span and to provide additional visual comfort to a span
according to the invention.
The stiffening means make it possible to longitudinally stiffen the load-bearing slab,
which permits an improved longitudinal distribution of the loads concentrated in the region of
the axles of the vehicle intended to travel on the track. This improved load distribution rnakes
it possible to reduce transverse bending moments in the load-bearing slab and thus to
reduce the corresponding transverse reinforcement or to reduce the thickness of the
constant transverse reinforcement slab.
These stiffening means also compensate for the absence of material resultfng from
the presence of the grooves provided in the span. A person skilled in the art was strongly
deterred from forming grooves in an overhead track span, in particular because this would
weaken the grip of the span. The applicant has overcome this technical prejudice by
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compensating for the loss of material by fitting means for stiffening the span. The
combination of the grooves and the stiffening means thus makes it possible to combine
requirements that are in principle irreconcilable, specifically an integrated span that makes
operations for mounting rails easier, and improved stability and strength of the span.
Advantageously and according to the invention, each groove has dimensions that are
matched to and conjugate with the dimensions of said running support that is intended to be
accommodated in said groove such that, once it is<:~rranged in said groove, said running
support does not extend beyond the upper surface of sai.d load-bearing slab.
According to this advantageous variant, once accommodated in the groove, the
running support, such as a rail, does not extend beyond the upper surface of the loadbearing
slab. The upper surface of the slab is substantially at the same level as the rail. It is
therefore possible for a tyre-based vehicle, such as an emergency vehicle or a maintenance
vehicle, to travel on the track. The track thus produced also makes it possible to easily
evacuate passengers from a transport vehicle that breaks down on the track thus formed.
Furthermore, once the running support, sueR-as a rail, is accommodated in the
groove, the distance separating the upper portion of the support from the underside of the
deck (i.e. the underside.of.the load-bearing slab) is reduced compared with a conventional
viaduct span of a corresponding height, substantially to the height of the stringers. A viaduct
comprising spans according to the invention thus has a lesser visual impact than a viaduct
comprising conventional spans.
Advantageously, each longitudinal rib is formed by two longitudinal beams that are
arranged on either side of each groove.
Advantageously, said stiffening means comprise a trapezoidal caisson provided
under the load-bearing slab.
This trapezoidal caisson makes it possible to form a self-supporting structure that can
be of a significant length, for example 120 metres.
A track span according to the invention can form a path portion of one or more
adjacent guided-transport runways. The number of adjacent runways formed by one track
span according to the invention depends on the number of grooves formed in the loadbearing
slab and on the type of vehicle travelling on the span. A vehicle generally needs one
or two running supports, depending on the type of said vehicle. Most guided-transport
vehicles have parallel· two-wheel axles and therefore need two running supports provided in
two parallel grooves.
Advantageously, one span according to the invention comprises at least two parallel
grooves that are provided longitudinally along said span so as to be able to receive one
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running support each, said grooves being mutually spaced by a distance that corresponds to
the distance separating the wheels of a same axle of a guided-transport vehicle intended to
travel on the track.
According to this variant, each span comprises at least two grooves, each groove
being designed to receive one running support of a guided-transport vehicle, such as a rail.
The grooves are mutually spaced by a predetermined distance that corresponds to the
distance separating two wheels of a same_axle of rolling stock intended to travel on the
span.
A span according to this variant thus advantageously makes it possible to form a
portion of a track (or runway) for a single vehicle.
According to a variant, the span comprises four parallel grooves that are provided
longitudinally in pairs along said span so as to be able to each receive one running support
and so as to be able to form, together, a path portion of at least two adjacent tracks.
In order to achieve this, the grooves are mutually spaced in pairs by a distance that
corresponds to the distance separating the wheels of a same axle of a guided-transport
vehicle intended to travel on each track formed.
A span according to this variant thus advantageously makes it possible to form a
portion having two adjacent tracks (or runways).
Advantageously and according to the invention, each running support is selected
from the group comprising a railway rail for a wheeled rail vehicle, a central guide rail for a
tyre-based vehicle, and a lateral guide rail for a tyre-based vehicle.
A span according to this variant permits the travel of a rail vehicle, or a lyre-based
vehicle guided by a central guide rail, or a lyre-based vehicle guided by at least one lateral
guide rail.
Advantageously and according to the invention, each running support is a metal
profile.
Advantageously, a span according to the invention is formed in one piece.
The invention also relates to a guided-transport viaduct comprising a plurality of
spans according to the invention. Preferably, the viaduct comprises a plurality of successive
spans supported by piles. The construction of a viaduct according to the invention from
spans according to the invention is made easier by the operations for mounting rails in the
grooves of the spans, which operations can be carried out either directly at the workshop or
on-site without any specific difficulties on account of the absence of specific operations for
mounting rails on shoes and the absence of the need to construct separation kerbs on either
side of each rail.
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The invention also relates to a span and to a viaduct that are characterised in
combination by all or some of the features mentioned above or in the following.
5. List of figures
Other aims, features and advantages of the invention will become clear from reading
the following description, given purely by way of non-limiting example and with reference to
the accompanying drawings, in which:
Fig. 1 is a schematic perspective view of a span according to an embodiment of
the invention,
Fig. 2 is a schematic cross section of the span from Fig. 1 on which rails have
been mounted,
Fig. 3 is a schematic cross section of a span according to another embodiment of
the invention on which rails have been mounted,
Fig. 4 is a schematic perspective view of a viaduct according to an embodiment
of the invention that is formed by a plurality of spans according to the invention,-Fig.
5 is a schematic cross section of a span according to another embodiment of
the invention. ···
6. Detailed description of an embodiment of the invention
In the drawings, scale and proportion is not adhered to for reasons of illustration and
clarity. Throughout the following detailed description, which is given with reference to the
drawings, unless otherwise indicated each element of a span according to the invention is
described as it is arranged when the span is mounted horizontally, for example on a viaduct
pile (not shown in the drawings).
According to the embodiment in the drawings, the guided-transport track span has a
flared U-shaped cross section, the two arms of which form lateral walls 4, 5 that are slightly
inclined away from one another relative to the vertical, and the central horizontal region of
which, connecting the two arms, forms the deck (or load-bearing slab 6) of the track.
The load-bearing slab 6 further comprises two parallel grooves 10, 11 that are
provided longitudinally along the span. Each groove has a shape and dimensions that are
matched to and conjugate with the shape and the dimensions of a rail, forming a running
support for a vehicle that is intended to travel on the track formed by the span. According to
the embodiment in the drawings, the grooves have a rectangular cross section that is
conjugate with the overall size of a railway rail.
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According to the embodiment in the drawings, the grooves 10, 11 are designed to
receive rails 12, 13 that are formed by metal profiles and are intended to permit the travel of
a railway network train or underground. According to another embodiment, the grooves can
receive guide rails or runways of a tyre-based underground.
According to the embodiment in the drawings, the grooves 10, 11 are designed such
that, once the rails 12, 13 are accommodated in the grooves they do not extend beyond the
upper surface 7 of the load-bearing slab 6. In order to achieve this, the depth of each groove
is at least equal to the height of a railway rail. According ,to an advantageous embodiment
and in the case of a groove having a rectangular cross section, the width and the height of
each groove are selected so as to be are slightly larger than the nominal values in order to
take into account the civil engineering manufacturing tolerances.
The distance separating the grooves 10, 11 is selected so as to be equal to the
distance separating the two wheels on an axle of a vehicle intended to travel on the track
formed by spans according to the invention.
According to the embodiment in Fig. 1 and 2, the span further comprises jengitudinal
ribs 14, 15 that are arranged under the load-bearing slab 6 and form longitudinal stiffening
means of the load-bearing slab 6. These longitudinal ribs 14, 15 compens<:~te for the
absence of material resulting from the presence of the longitudinal grooves 10, 11 provided
in the load-bearing slab 6.
Only the rib 14 is described in detail in the following, given that the rib 15 is identical.
The longitudinal rib 14 is formed for example by two continuous longitudinal
reinforced concrete beams 20, 21 that are arranged on either side of the rail12 once said
rail is accommodated in the groove 10 opposite the rib 14.
According to another embodiment of the invention shown in Fig. 3, the span
comprises a trapezoidal caisson 25 that is provided under the load-bearing slab 6. This
caisson 25 forms the stiffening means for the load-bearing slab 6. This trapezoidal caisson
25 has an upper wall 26 in common with the load-bearing slab 6, a lower wall 29 that is
parallel to the upper wall 26, and two lateral walls 27, 28 that interconnect the upper 26 and
lower 29 walls to each other. The distance separating the two lateral walls 27, 28 is less than
or equal to the distance separating the two lateral walls 4, 5 of the span. A span according to
this variant makes it possible to form works of a significant length, for example 120 metres.
This thus makes it possible to increase the distance separating two piles of a viaduct formed
by a plurality of spans according to this variant, and thus to reduce the number of piles
required and the number of spans required to form a viaduct.
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According to an advantageous embodiment of the invention, the span is formed in
one piece from concrete.
According to other embodiments, the span may be formed by a plurality of pieces of
concrete that are assembled together using suitable assembly means.
Fig. 4 shows a viaduct according to an embodiment of the invention that is formed by
spans according to the embodiment in Fig. 1 and 2. The viaduct comprises two piers 50, 51
that are anchored in the ground and on which a span according to the invention rests.
According to another embodiment of the inventio[l, and as shown in Fig. 5, the span
comprises four parallel grooves 10, 11, 40, 41 that are provided longitudinally in pairs along
the span. Furthermore, a running support rail is arranged in each groove.
The span according to the embodiment in Fig. 5 forms two adjacent running tracks
60, 61 for railway vehicles. A span according to this embodiment thus forms the path
portions of two adjacent tracks.
Of course, according to other embodiments, a span according to the invention could
comprise more gmoves in order to form more parallel transport track portions.

Claims
1. Overhead guided-transport track span having a U-shaped cross section, the two
arms of which form lateral walls (4, 5) of said span, and the central region of which,
connecting the two arms, forms a load-bearing slab (6) of at least one track, characterised in
that said load-bearing slab (6) comprises at least one groove (10, 11) that is provided in said
slab (6)jongitudinally along said span and is designed to be able to receive a running
support (12, 13) of a guided-transport vehicle intended t9 travel on said span, and in that
said span comprises one longitudinal rib for each groove, which rib extends under said loadbearing
slab opposite to said groove (10, 11) and forms longitudinal stiffening means of said
load-bearing slab.
2. Span according to claim 1, characterised in that each groove (10, 11) has
dimensions that are matched to and conjugate with the dimensions of the running support
(12, 13)that is intended to be accommodated in said groove (1&,-11) such that, once it is
arranged in said groove (10, 11), said running support (12, 13) does not extend beyond the
upper surface (7) of said load-bearing slab (6).
3. Span according to either claim 1 or claim 2, characterised in that each longitudinal rib
(14, 15) is formed by two longitudinal beams (20, 21) that are arranged on either side of said
groove (14, 15).
4. Span according to any of claims 1 to 3, characterised in that said stiffening means
further comprise a trapezoidal caisson (25) provided under the load-bearing slab (6).
5. Span according to any of claims 1 to 4, characterised in that it comprises at least two
parallel grooves (10, 11) that are provided longitudinally along said span so as to be able to
each receive one running support (12, 13).
6. Span according to claim 5, characterised in that it comprises four parallel grooves
(1 0, 11, 40, 41) that are provided longitudinally in pairs along said span so as to be able to
each receive one running support and so as to· be able to form a path portion of at least two
adjacent tracks.
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7. · Span according to any of claims 1 to 6, characterised in that each running support
(12, 13) is selected from the group comprising a railway rail for a wheeled rail vehicle, a
central guide rail for a lyre-based vehicle, and a lateral guide ~ail for a lyre-based vehicle.
8. Span according to claim 7, characterised in that each running support (12, 13) is a
metal profile.
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9. Span according to any of claims 1 to 8, characterised in that it is formed in one piece.
10. Guided-transport viaduct comprising a plurality of spans according to any of claim 1
to 9.