AU2018200225B2

AU2018200225B2 - A railway for an urban railway vehicle, with an improved bearing capacity

Info

Publication number: AU2018200225B2
Application number: AU2018200225A
Authority: AU
Inventors: Marcel Girardi; Caroline MASSON; Patricia VAZQUEZ-SOBRADO
Original assignee: Alstom Holdings SA
Current assignee: Alstom Holdings SA
Priority date: 2017-01-20
Filing date: 2018-01-11
Publication date: 2023-06-29
Anticipated expiration: 2038-01-11
Also published as: AU2018200225A1; FR3062140B1; FR3062140A1; EP3351683A1

Abstract

A railway for an urban railway vehicle, with an improved bearing capacity The railway (1) includes: - a layer of material (2) resting on a ground (4), the layer of material (2) having a support surface (11), and - a single-piece concrete slab (5), having no reinforcements, covering the support surface (11) of the layer of material (2). Figure 1 S31 cnI ..... . W )t >

Description

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A railway for an urban railway vehicle, with an improved bearing capacity

The present invention relates to a railway for an urban railway vehicle. Such a railway is in particular known according to US 2003/0102586 Al. This document describes a railway having two concrete side walls laterally delimiting a central concrete slab. These side walls are manufactured before the central concrete slab and serve as a mold for manufacturing the central concrete slab. The side walls also serve as a suitable path for a machine making it possible to flatten the concrete during the formation ofthe central concrete slab. Such a railway is not fully satisfactory. Indeed, after manufacturing the two side walls, it is essential to wait many days for the concrete making up these two side walls to dry. It is only possible to form the central concrete slab after the two side walls have completely solidified. Thus, this railway requires a particularly long manufacturing time, due to the drying time of the concrete. In this context, there is a need to produce a railway with a shorter manufacturing time, and that is easier to manufacture. According to an aspect of the present invention, there is provided a railway for an urban railway vehicle, wherein it includes: a ground, a layer of material resting on the ground, the layer of material having a support surface, and a single-piece concrete slab, with no reinforcements, covering the support surface of the layer of material, in direct contact with the support surface, and wherein the ground has a load-bearing capacity greater than 50 MPa. Such a railway has multiple advantages, which are summarized non-exhaustively below. The manufacturing time of the railway is reduced in particular due to the fact that the single-piece concrete slab can be placed on the planar layer of material. The inventors have in particular noted that, surprisingly, such a concrete slab is sufficient to withstand the stresses related to the exploitation of a railway for trams. A railway according to embodiments of the invention may further include one or more of the following features, considered alone or according to any technically possible combinations: the layer of material is a hydraulically bound layer of materials; the concrete slab has an upper surface bearing at least first and second tie plates fastened by fastening means to the concrete slab, each first tie plate being intended to bear a first rail and each second tie plate being intended to bear a second rail substantially parallel to the first rail, the concrete slab extending continuously substantially parallel to the rails; the concrete slab has a maximum thickness, measured along a vertical direction perpendicular to the ground, comprised between 17 cm and 19 cm, for example substantially equal to 18 cm; the concrete slab has no recesses between its upper surface and the support surface of the layer of material; and/or the layer of material has a maximum thickness, measured along a vertical direction perpendicular to the ground, comprised between 12 cm and 15 cm, for example substantially equal to 15 cm. According to another aspect of the present invention, there is provided a method for manufacturing a railway as previously defined, wherein it comprises the following steps: - pouring a layer of material having a support surface, on a ground, and - pouring a single-piece concrete slab, with no reinforcements, on the support surface of the layer of material, and wherein the step for pouring the layer of material is preceded by a step for measuring the load-bearing capacity of a ground, in order to verify whether the ground has a load-bearing capacity greater than 50 MPa and, if the ground does not have a load bearing capacity greater than 50 MPa, the method comprises a step of adapting the ground to increase its load bearing capacity beyond 50 MPa. A manufacturing method according to the invention may further include one or more of the following features, considered alone or according to any technically possible combinations: placing at least two tie plates equipped with fastening means on the upper surface of the freshly placed concrete slab; and/or the step for pouring the layer of material is configured to form a layer of material having a thickness measured in a direction perpendicular to the ground comprised between 12 cm and 15 cm, in particular 12 cm. According to another aspect, the present invention provides the use of a railway as previously defined, for consolidating the ground to a predefined load-bearing capacity greater than 50 MPa, and/or for protecting the ground from unfavorable environmental conditions.

The invention will be better understood using the following description, provided solely as an example and done in reference to the sole appended figure, showing a cross sectional schematic view of a railway according to one example embodiment of the invention. The figure shows a railway 1 according to one example embodiment of the invention, intended to be used by a railway vehicle, for example an urban railway vehicle such as a tram. The figure shows an orthogonal coordinate system defining, by a longitudinal axis X, a longitudinal direction that is locally parallel to a driving direction of a railway vehicle on the railway 1. The orthogonal coordinate system includes a transverse axis Y, perpendicular to the longitudinal axis X, defining a transverse direction that is locally transverse to the driving direction of a railway vehicle. The orthogonal coordinate system includes a vertical axis Z, perpendicular to the longitudinal axis X and the transverse axis Y, defining a vertical direction. The railway 1 shown in figure 1 comprises a layer of material 2 that rests on a ground 4. The layer of material 2 is covered by a concrete slab 5 superimposed on the layer of material 2. The concrete slab 5 bears a first tie plate 6 and a second tie plate 6'fastened by fastening means 8, 8' to this concrete slab. The tie plates 6, 6' bear rails 10, 10'. The tie plates 6, 6', the fastening means 8, 8' and the rails 10, 10' will be described later in the present description. In the present description, the term "ground" is used to designate a ground surface. The ground 4 preferably has a load-bearing capacity greater than 50 MPa. The ground can for example be obtained by digging and/or mounding and/or compacting and/or construction. In some cases, the ground 4 has a surface irregularity, measured in the vertical direction Z, comprised between 0 and 20 mm. The layer of material 2 is dimensioned based on real elements related to the travel of the trams and the environment, for example, the rainfall, temperature or geology. These real elements for example include the number of real travel cycles of the trams, the real travel loads of the trams and the real dynamic effect of the travel speed of the trams. The layer of material 2 includes a contact surface that is in direct contact with the ground 4, and includes a support surface 11 opposite the contact surface. The contact surface is shaped to compensate for any irregularities of the ground 4. Furthermore, the support surface 11 of the layer of material 2 extends substantially parallel to the ground 4, while eliminating the surface irregularities to have a substantially flat shape.

The layer of material 2 has a width L, measured parallel to the transverse direction Y, for example comprised between 240 cm and 250 cm. The layer of material 2 extends continuously along an outline of the railway. The layer of material 2 has a thickness EB, measured parallel to the vertical direction Z, for example comprised between 12 cm and 15 cm, preferably substantially equal to 12 cm. The maximum thickness EB of the layer of material 2, i.e., the thickness of the layer of material 2 where it is thickest, is substantially equal to 15. The layer of material 2 is preferably a hydraulically bound layer (HBL). The layer of material 2 in particular protects the ground, more particularly from environmental conditions such as rainfall and/or temperature. The layer of material 2 further makes it possible to have a greater load-bearing capacity of the ground. The concrete slab 5 is also dimensioned based on real elements related to the travel of the trams and the environment. These real elements are for example the number of real travel cycles of the trams, the real travel loads of the trams and the real dynamic effect of the travel speed of the trams. The concrete slab 5 includes a lower surface in direct contact with the layer of material 2, in particular in direct contact with the support surface 11 of the layer of material 2, and includes an upper surface 12 opposite the lower surface. The concrete slab 5 is in a single piece, or in other words, is monolithic. More particularly, the concrete slab 5 is formed by a single layer of concrete, in one piece. The concrete slab 5 for example has a width identical to the width L of the layer of material 2, measured parallel to the transverse direction Y, in particular comprised between 240 cm and 250 cm. In one embodiment that is not shown, the width of the layer of material 2 is greater than the width L of the concrete slab 5. The concrete slab 5 extends continuously along an outline of the railway. The concrete slab 5 has a thickness E, measured parallel to the vertical direction Z, for example comprised between 17 cm and 19 cm, preferably substantially equal to 18 cm. The concrete slab 5 has no recesses between its upper surface 12 and the ground 4. In other words, the concrete slab 5 is free of hollow spaces. The concrete slab 5 is formed by class C32 concrete according to standard EN 12390. The concrete slab 5 has no reinforcements. In particular, the concrete slab 5 is free of depressions, for example metal grids intended to stabilize the concrete slab, as is known in existing railways.

The concrete slab 5 bears at least a first tie plate 6 suitable for supporting a first rail 10. More particularly, the concrete slab 5 bears a plurality of first tie plates 6 aligned discreetly along the first rail 10, i.e., spaced apart from one another along this first rail 10. Each first tie plate 6 is provided with securing means (not shown) making it possible to secure the rail 10 with this first tie plate 6. These securing means are for example metal clips. The first tie plate 6 has a substantially parallelepiped shape. The first tie plate 6 has a width LS, considered in the transverse direction Y, for example comprised between 30 cm and 40 cm. The first tie plate 6 has a thickness ES, considered in the vertical direction Z, for example comprised between 3 cm and 10 cm. The first tie plate 6 has a length (not shown), considered in the longitudinal direction X, for example comprised between 20 cm and 25 cm. The fastening means 8 allow the first tie plate 6 to be fastened securely with the concrete slab 5. The fastening means here form anchoring sheaths. The fastening means 8 have a length LF, considered in the vertical direction Z, that is smaller than the sum of the thickness E of the concrete slab 5 and the thickness ES of the tie plate 6, 6'; for example, the length LF is 15 cm. The fastening means 8 for example include at least one stud. It should be noted that the thickness E is greater than a minimum value that is generally imposed by the length LF of the fastening means 8. The railway includes two rails, such that some elements connected to a second rail 10' are identical to those previously described, connected to the first rail 10. The elements identical to those previously described are not described again hereinafter, and are identified by a reference bearing an apostrophe. These elements are identical in both form and function. At least a second tie plate 6' is supported by the concrete slab 5 and is fastened by second fastening means 8' to the concrete slab 5. Each second tie plate 6' is suitable for supporting the second rail 10'. The first and second tie plates 6, 6' are in contact with the upper surface 12 of the concrete slab 5 and are positioned on this surface discreetly. Thus, a plurality of first and second tie plates is distributed along the concrete slab. The tie plates 6, 6' are for example spaced apart by a distance comprised between 60 cm and 75 cm along the concrete slab. The first and second rail 10, 10' form a pair of rails allowing a railway vehicle (not shown) to roll on the railway 1.

The concrete slab 5 extends continuously substantially parallel to the rails 10, 10'. Alternatively, several concrete slabs 5 can be arranged so as to be adjacent to one another. Each concrete slab 5 is supported by a shared layer of material 2, or alternatively by a respective layer of material 2. A method for manufacturing the railway 1 according to an embodiment of the invention will now be described. Initially, the ground 4 is selected subject to the criterion of having a load-bearing capacity greater than a threshold load-bearing capacity, for example a threshold load bearing capacity equal to 50 MPa. The selection of the ground 4 is done using standardized measurements, for example, according to standard NF P 94-117-1. It is possible for the ground 4 to be adapted, for example if the ground 4 has a load bearing capacity below said load-bearing capacity threshold, in order to increase its load bearing capacity beyond said threshold load-bearing capacity. Next, the layer of material 2 is poured directly on the ground 4. The support surface 11 of the layer of material 2 can be flattened and/or compacted. After the layer of material 2 has solidified, after about 24 hours, the concrete slab 5 is poured on the support surface 11 of the layer of material 2. The concrete slab 5 is poured so as to obtain a single-piece concrete slab, i.e., in one piece. More specifically, the concrete is poured on the ground 4 to form the concrete slab 5. It should be noted that no reinforcement intended to solidify the concrete slab, such as a metal grate, is coated during the pouring of the concrete slab 5, or inserted into the freshly placed concrete slab 5. The pouring step is configured to form a concrete slab 5 having a thickness E measured in a direction perpendicular to the ground comprised between 17 cm and 19 cm, in particular 18 cm. Directly after pouring the concrete slab 5, first tie plates 6 and second tie plates 6' equipped with fastening means 8, 8' are placed, spaced apart from one another, on the upper surface 12 of the freshly placed concrete slab 5. The tie plates 6, 6'equipped with fastening means 8, 8'are inserted via an automatic machine into the freshly poured concrete slab 5 such that the tie plates rest entirely on the upper surface 12 of the slab. Through the hardening and/or drying of the concrete slab 5, the fastening means 8, 8' are solidly anchored in the concrete slab 5. The anchoring of the fastening means 8, 8' allows the tie rods 6, 6' to be solidly maintained on the upper surface 12 of the concrete slab 5. After the hardening and/or drying of the concrete slab 5, the rails 10, 10' are installed on the tie plates 6, 6' and fastened on the latter by the securing means.

Lastly, owing to the solid maintenance of the rails 10, 10', an urban railway vehicle, for example a tram, can travel on the railway 1. The absence of reinforcements in the concrete slab 5 makes it possible to produce an inexpensive railway 1. Owing to the small thickness E of the concrete slab 5 and the small thickness EB of the layer of material 2, the digging of the ground 4 can be done quickly, and the cost for such a railway is reduced. The concrete slab 5 according to embodiments of the invention is not as thick as a known concrete slab. Thus, less concrete is used to manufacture the concrete slab 5 according to embodiments of the invention. The layer of material 2 makes it possible to improve the load-bearing capacity of the surface on which the concrete slab 5 is placed. The layer of material 2 then constitutes an effective foundation, and with a fast solidification time, for the concrete slab 5. The layer of material 2 also makes it possible to protect the ground 4 from water. The railway 1 is easier to manufacture than known railways, since it does not require asphalt side walls like the known railways. Thus, the railway according to embodiments of the invention is less expensive and easier to manufacture than the known railways. The inventors have in particular noted that, surprisingly, such a concrete slab 5 is sufficient to withstand the stresses related to the exploitation of a railway 1 for trams and environmental conditions. Indeed, such a conclusion was possible owing to the consideration of the real elements related to tram traffic, i.e., the number of real travel cycles of the trams, the real travel loads of the trams and the real dynamic effect of the travel speed of the trams and environmental conditions. It should be noted that such a railway 1, including a layer of material 2, is advantageously used to consolidate the surface supporting the railway up to a predefined load-bearing capacity exceeding 50 MPa, when such a predefined load-bearing capacity exceeding 50 MPa is desired, and/or used to protect the ground against unfavorable environmental conditions, in particular in case of significant rainfall and/or temperature. It will be noted that the invention is not limited to the embodiments previously described, but could take the form of various additional alternatives. Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as, an acknowledgement or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Claims

1. A railway for an urban railway vehicle, wherein it includes: a ground, a layer of material resting on the ground, the layer of material having a support surface, and a single-piece concrete slab, with no reinforcements, covering the support surface of the layer of material, in direct contact with the support surface, and wherein the ground has a load-bearing capacity greater than 50 MPa.

2. The railway according to claim 1, wherein the layer of material is a hydraulically bound layer of materials.

3. The railway according to claim 1 or 2, wherein the concrete slab has an upper surface bearing at least first and second tie plates fastened by fastening means to the concrete slab, each first tie plate being intended to bear a first rail and each second tie plate being intended to bear a second rail substantially parallel to the first rail, the concrete slab extending continuously substantially parallel to the rails.

4. The railway according to any one of the preceding claims, wherein the concrete slab has a maximum thickness, measured along a vertical direction perpendicular to the ground, comprised between 17 cm and 19 cm.

5. The railway according to any one of the preceding claims, wherein the concrete slab has no recesses between its upper surface and the support surface of the layer of material.

6. The railway according to any one of the preceding claims, wherein the layer of material has a maximum thickness, measured along a vertical direction perpendicular to the ground, comprised between 12 cm and 15 cm.

7. A method for manufacturing a railway for an urban railway vehicle according to one of claims 1 to 6, wherein it comprises the following steps: pouring a layer of material resting on a support surface, on a ground, and pouring a single-piece concrete slab, with no reinforcements, on the support surface of the layer of material, in direct contact with the support surface, and wherein the step for pouring the layer of material is preceded by a step for measuring the load-bearing capacity of a ground, in order to verify whether the ground has a load-bearing capacity greater than 50 MPa and, if the ground does not have a load bearing capacity greater than 50 MPa, the method comprises a step of adapting the ground to increase its load bearing capacity beyond 50 MPa.

8. The method for manufacturing a railway according to claim 7, comprising placing at least two tie plates equipped with fastening means on the upper surface of the freshly placed concrete slab.

9. The method for manufacturing a railway according to claim 7 or 8, wherein the step for pouring the layer of material is configured to form a layer of material having a thickness measured in a direction perpendicular to the ground comprised between 12 cm and 15 cm.

10. A use of a railway according to any one of claims 1 to 6, for consolidating the ground to a predefined load-bearing capacity greater than 50 MPa, and/or for protecting the ground from unfavorable environmental conditions.

L LS 12 8' 10 6 6' 10' ES 1/1

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