GB1600961A

GB1600961A - Railways concrete plates for use in such railways and methods to lay such railways

Info

Publication number: GB1600961A
Application number: GB1196078A
Authority: GB
Original assignee: Walker Nederland Nv James
Current assignee: Walker Nederland Nv James
Priority date: 1977-03-25
Filing date: 1978-03-28
Publication date: 1981-10-21
Also published as: NL7703279A; ES468207A1; NL180688B; NL180688C

Description

(54) IMPROVEMENTS IN AND RELATING TO RAILWAYS, CONCRETE PLATES FOR USE IN SUCH RAILWAYS AND METHODS TO LAY SUCH RAILWAYS (71) We, JACOBUS ALBERTUS EIS SES, a subject of the Kingdom of the Netherlands, residing at Bilthoven, the Netherlands, and James Walker Nederland N.V., a company organized under the laws of the Netherlands, residing at Oud Beijerland, the Netherlands, do hereby declare the invention, for which we pray that a patent may be granted to us and the method by which it is to be performed to be particularly described in and by the following statement: The invention relates to railway tracks having a rail structure which is fastened on a supporting construction.

Up to now most railway tracks are supported by a support embedded in a ballast bed. A ballast bed requires much maintenance, so that a construction without using such a ballast bed offers many advantages.

Side by side with the advantage of little maintenance there is the advantage that the alignment of the track can be better maintained, so that higher traffic speeds are allowed. The protection against derailments is greater and the safety against lateral deflection of the track due to thermal stresses, when a modern jointless track is used, is completely guaranteed.

In practice the possibility of readjusting the rail structure in vertical and lateral directions with respect to a supporting construction, which may consist of concrete, asphalt or the like, has appeared to be necessary for main-line railways, to compensate for slight settlings of the subsoil. To this end rather complicated rail structures are required. In the supporting constructions used up to now, mechanical damage such as for instance cracking had to be suffered.

The invention has the object to provide a railway track which offers the advantages of a track without a ballast bed but avoids the disadvantages thereof experienced up to now.

According to the invention this is achieved by a supporting construction, the supporting construction being composed of oblong prefabricated concrete plates resistant to bending and having a length extending in the longitudinal direction of the rails and a width greater than the gauge of the track, each plate at end portions having bearing surfaces supported on levelled areas of the earth bed, these supporting areas being stabilised by means of cement, synthetic resin or equivalent stabilising material, and there being a cavity between the plate and the earth bed between the levelled areas, this cavity being filled with polyethylene foam or a material of similar elastic properties.

With this construction it becomes possible to readjust the rails and the supporting construction by making small displacements with respect to the earth bed in vertical and lateral directions, so that settlings of the subsoil, if occurring, can be compensated in a simple way without the necessity of disassembly of the rail structure.

The concrete plates may be provided with carrying members to handle the plates by means of cranes or the like. These carrying members may be used both when the plates are laid and when they have to be readjusted as described here above.

The plates may rest on the levelled stabilised areas through one or more interposed elastic layers. During readjustment operations it is then possible to provide an additional elastic layer under the plates after the latter have been lifted by means of the carrying members.

As will be further described in the following part of the description the elastic layers may also be provided by injection of a curable synthetic resin under the bearing surfaces.

The plates may have horizontally directed complementary semi-cylindrical recesses in the ends facing each other. Into these semi-cylindrical recesses a pipe or the like may be inserted, by which the plates are protected against relative vertical movement, so that the joining edges of the plates cannot be at different levels.

Furthermore, the plates may have between the bearing surfaces slightly recessed areas, so that a clear boundary of the bearing surfaces is obtained.

The invention also relates to methods for laying a railway track of the above described kind. According to the invention the method comprises levelling the earth bed; laying the concrete plates on the earth bed; stabilising the earth bed where the bearing surfaces of the concrete plates are supported; and filling the cavities extending under the concrete plates between the bearing surfaces with a layer of polyethylene foam or of a material of similar elastic properties.

The plates may be adjusted and held at the right level; each bearing surface may be surrounded by a margin of synthetic resin foam confining, together with the concrete plate, the bearing surface on all sides; and cement, synthetic resin or equivalent stabilising material may be injected through passages made in the concrete plates. In this way a particularly simple and quick way to replace the track is achieved, as the plate may be prefabricated together with the layer of synthetic resin foam.

In that case, concrete plates may be used which are each, before laying, provided on their undersides with a layer of polyethylene foam or of a material of similar elastic properties, and openings of the size of the bearing surfaces of the plates may be left in the end portions of said layer.

An elastic layer interposed between a bearing surface of the concrete plate and a supporting area of the earth bed may consist of a layer of material which is attached to the concrete plate in advance. Then an elastic support of the plate is obtained as soon as the latter has been laid down and the supporting surface has been stabilised.

Alternatively a layer of elastic material under the bearing surfaces may be injected in the state of a curable synthetic resin after the concrete plates have been adjusted at the right level. This way of applying the layer of elastic material may also be used for readjusting the level of the plates after some subsidence has occurred.

The invention will be further elucidated in the following description of an exemplary embodiment shown in the accompanying drawing. In the drawing are Figure 1 partly an elevational, partly a sectional view of a railway track according to the invention; Figure 2 an enlarged sectional view taken along line II-II shown in Figure 1; and Figure 3 a bottom view of plates used in the embodiment illustrated in Figures 1 and 2.

An earth bed, on which a railway track according to the invention is laid, is designated by 1. Parts 2 and 3 of the earth bed are levelled. A plate 4 of concrete is placed on these levelled parts. The concrete plate 4 has throughgoing passages 7 and 8 in bearing surfaces 5 and 6, which rest on the parts 2 and 3, respectively. On the underside the plate 4 is provided with a layer of polyethylene foam 9. In the places where the bearing surfaces 2 and 3 are, this layer 9 has square holes 10 and 11. Consequently, the holes 10 and 11 are bounded on all sides by the layer of polyethylene foam. This layer of polyethylene foam is applied on the plates in advance.Now, when the plate is placed onto the earth bed 1, cement, synthetic resin or equivalent stabilising material 22 is injected through the passages 7 and 8, so that the holes 10 and 11 are filled, and the parts 2 and 3 of the earth bed are stabilised and form rigid supporting surfaces for the plate 4.

The plate 4 is provided on its sides with projections 12 and 13. During the laying of the plate, it can be handled by means of these projections, and they may also be used to adjust the plate vertically and laterally.

In each end of each plate is a semicylindrical recess. A pipe 21 is inserted into each pair of facing recesses.

Provided in the upper surface of the plate 4 are grooves 14 and 15 in which the rails 16 and 17 are mounted. The rails are secured with synthetic resins or elastomers, and thereafter the grooves are completely filled.

The upper surface of the plate 4 is slightly deepened at 18 and the plate has a passage 19, so as to permit rain-water to be drained to a side.

The plates 4 rest on the stabilised parts 2 and 3 of the earth bed through interposed elastic layers 20. These elastic layers 20 may be inserted into the holes 10 and 11 in advance; however, they may also be injected in the form of a curable synthetic resin later on.

To readjust the level of the track, after it has been used for a certain time, the layer 20 may be supplemented with an additional layer, so that the rails come to lie again at the right level. It will be obvious that the vertical and the lateral adjustment are carried out by adjustment of the entire track, that means by adjusting the plates 4. Consequently, it is not necessary to detach and to readjust the rail structure itself.

WHAT WE CLAIM IS: 1. A railway track laid on an earth bed without ballast, comprising rail structure

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. complementary semi-cylindrical recesses in the ends facing each other. Into these semi-cylindrical recesses a pipe or the like may be inserted, by which the plates are protected against relative vertical movement, so that the joining edges of the plates cannot be at different levels. Furthermore, the plates may have between the bearing surfaces slightly recessed areas, so that a clear boundary of the bearing surfaces is obtained. The invention also relates to methods for laying a railway track of the above described kind. According to the invention the method comprises levelling the earth bed; laying the concrete plates on the earth bed; stabilising the earth bed where the bearing surfaces of the concrete plates are supported; and filling the cavities extending under the concrete plates between the bearing surfaces with a layer of polyethylene foam or of a material of similar elastic properties. The plates may be adjusted and held at the right level; each bearing surface may be surrounded by a margin of synthetic resin foam confining, together with the concrete plate, the bearing surface on all sides; and cement, synthetic resin or equivalent stabilising material may be injected through passages made in the concrete plates. In this way a particularly simple and quick way to replace the track is achieved, as the plate may be prefabricated together with the layer of synthetic resin foam. In that case, concrete plates may be used which are each, before laying, provided on their undersides with a layer of polyethylene foam or of a material of similar elastic properties, and openings of the size of the bearing surfaces of the plates may be left in the end portions of said layer. An elastic layer interposed between a bearing surface of the concrete plate and a supporting area of the earth bed may consist of a layer of material which is attached to the concrete plate in advance. Then an elastic support of the plate is obtained as soon as the latter has been laid down and the supporting surface has been stabilised. Alternatively a layer of elastic material under the bearing surfaces may be injected in the state of a curable synthetic resin after the concrete plates have been adjusted at the right level. This way of applying the layer of elastic material may also be used for readjusting the level of the plates after some subsidence has occurred. The invention will be further elucidated in the following description of an exemplary embodiment shown in the accompanying drawing. In the drawing are Figure 1 partly an elevational, partly a sectional view of a railway track according to the invention; Figure 2 an enlarged sectional view taken along line II-II shown in Figure 1; and Figure 3 a bottom view of plates used in the embodiment illustrated in Figures 1 and 2. An earth bed, on which a railway track according to the invention is laid, is designated by 1. Parts 2 and 3 of the earth bed are levelled. A plate 4 of concrete is placed on these levelled parts. The concrete plate 4 has throughgoing passages 7 and 8 in bearing surfaces 5 and 6, which rest on the parts 2 and 3, respectively. On the underside the plate 4 is provided with a layer of polyethylene foam 9. In the places where the bearing surfaces 2 and 3 are, this layer 9 has square holes 10 and 11. Consequently, the holes 10 and 11 are bounded on all sides by the layer of polyethylene foam. This layer of polyethylene foam is applied on the plates in advance.Now, when the plate is placed onto the earth bed 1, cement, synthetic resin or equivalent stabilising material 22 is injected through the passages 7 and 8, so that the holes 10 and 11 are filled, and the parts 2 and 3 of the earth bed are stabilised and form rigid supporting surfaces for the plate 4. The plate 4 is provided on its sides with projections 12 and 13. During the laying of the plate, it can be handled by means of these projections, and they may also be used to adjust the plate vertically and laterally. In each end of each plate is a semicylindrical recess. A pipe 21 is inserted into each pair of facing recesses. Provided in the upper surface of the plate 4 are grooves 14 and 15 in which the rails 16 and 17 are mounted. The rails are secured with synthetic resins or elastomers, and thereafter the grooves are completely filled. The upper surface of the plate 4 is slightly deepened at 18 and the plate has a passage 19, so as to permit rain-water to be drained to a side. The plates 4 rest on the stabilised parts 2 and 3 of the earth bed through interposed elastic layers 20. These elastic layers 20 may be inserted into the holes 10 and 11 in advance; however, they may also be injected in the form of a curable synthetic resin later on. To readjust the level of the track, after it has been used for a certain time, the layer 20 may be supplemented with an additional layer, so that the rails come to lie again at the right level. It will be obvious that the vertical and the lateral adjustment are carried out by adjustment of the entire track, that means by adjusting the plates 4. Consequently, it is not necessary to detach and to readjust the rail structure itself. WHAT WE CLAIM IS:

1. A railway track laid on an earth bed without ballast, comprising rail structure

secured on a supporting construction, the supporting construction being composed of oblong prefabricated concrete plates resistant to bending and having a length extending in the longitudinal direction of the rails and a width greater than the gauge of the track, each plate at end portions having bearing surfaces supported on levelled areas of the earth bed, these supporting areas being stabilised by means of cement, synthetic resin or equivalent stabilising material, and there being a cavity between the plate and the earth bed between the levelled areas, this cavity being filled with polyethylene foam or a material of similar elastic properties.

2. A railway track according to claim 1, in which the concrete plates are provided with carrying members to handle the plates by means of cranes or the like.

3. A railway track according to claim 1 or claim 2, in which the plates rest on the levelled stabilised parts through one or more interposed elastic layers.

4. A railway track according to any of claims 1 to 3, in which the plates have horizontally directed complementary semicylindrical recesses in the ends facing each other.

5. A railway track according to any of claims 1 to 4, in which the plates have between the bearing surfaces slightly recessed areas.

6. A method of constructing a railway track according to any of claims 1 to 5, comprising levelling the earth bed; laying the concrete plates on the earth bed; stabilising the earth bed where the bearing surfaces of the concrete plates are supported; and filling the cavities extending under the concrete plates between the bearing surfaces with a layer of polyethylene foam or of a material of similar elastic properties.

7. A method according to claim 6, in which the plates are adjusted and held at the right level; each bearing surface is surrounded by a margin of synthetic resin foam confining, together with the concrete plate, the bearing surface on all sides; and cement, synthetic resin or equivalent stabilising material is injected through passages in the concrete plates.

8. A method according to claim 7, in which concrete plates are used which are each, before laying, provided on their undersides with a layer of polyethylene foam, or of a material of similar elastic properties, and openings of the size of the bearing surfaces of the plates are left in the end portions of said layer.

9. A method according to any of claims 6 to 8, in which an elastic layer interposed between a bearing surface of the concrete plate and a supporting area of the earth bed consists of a layer of material which is attached to the concrete plate before laying.

10. A method according to claim 7 or claim 8, in which a layer of elastic material under the bearing surfaces is injected in the state of a curable synthetic resin after the concrete plates have been adjusted at the right level.

11. A railway track according to claim 1, substantially as described with reference to the accompanying drawing.