HK1057771B - Ballastless railway construction method and tie plate for carrying out the method - Google Patents

Description

The invention relates to a process for the construction of a railway track and in particular to a process for the construction of a railway track on a concrete slab in which the concrete slab is cast around anchorages for the attachment of railway rails supporting saddles.

It is now known for subways or trams to lay a railway track on a concrete slab by bringing rails directly pre-mounted on saddles to the place where the track is to be laid, the rails being held in suspension in their final position by means of a portico with the saddles attached to the rail by fasteners. A concrete slab is then cast under the rails to the height of the saddles, the latter supporting anchorages consisting of threaded rods running through the saddles and having a lower part being sunk into the concrete slab.

However, such a railway construction method has the disadvantage of being subject to air bubble problems under the saddles during the casting of the concrete, which prevents the formation of a smooth flat concrete support surface under the saddles. For example, when clamping the nuts on the threaded rods to immobilize the saddles after the concrete is taken, it is common for a displacement of the saddle to occur due to the poor construction of the support surface.

The purpose of the present invention is to propose a method for the construction of a railway track which ensures the formation of the supporting surfaces on which the rails are supported without major defects and which is simple and economical to construct.

The purpose of the invention is to construct a railway track on a concrete slab in which the concrete slab is cast around anchorages for the attachment of railway rails.

The process is characterised by the following steps: the suspension of temporary saddles at the place where the final saddles supporting the railway track are to be placed,the temporary saddles supporting anchorages intended to be partially submerged in the concrete and having vents to release air trapped under the bottom of the temporary saddle when the concrete slab is cast,the rolling of a concrete slab to the height of the temporary saddles,the removal of the temporary saddles after the concrete slab has been removed from the slab,the precise positioning of the final saddles supporting the rails in their final position and the fixing of the saddles on the anchorage elements.

According to another feature of the invention, the rails are suspended by means of a portico above the place where the concrete slab is to be cast, the rails having final seats pre-mounted on the rails, the provisional seats being arranged under these final seats and then brought to the desired position by means of the portico.

According to another feature of the invention, after the extraction of the provisional saddles and before the installation of the final saddles, any spots formed on the surface of the concrete slab are removed by scraping by lifting the concrete through vents.

The invention also concerns a temporary saddle for the implementation of the above-described railway construction process, characterised by a body with a vent on the lower face, which is intended to be licked by the concrete during the casting of the concrete slab.

Depending on the particular manufacturing methods, the provisional saddle of the invention may have one or more of the following characteristics taken individually or in all the combinations technically possible: the body of the temporary saddle consists of a plate with multiple outlets; the periphery of the plate has a step with an upper edge which is inclined to the plane of the lower face of the plate to serve as a reference when the concrete surface of the track slab is being constructed when the concrete surface must be sloped to ensure drainage; the body of the temporary saddle has openings of a diameter larger than the diameter of the vents to allow passage of anchorage elements;

The purposes, aspects and advantages of the present invention will be better understood by reference to the following description of a particular embodiment of the invention, given as a non-limiting example, by reference to the attached drawings, in which: Figure 1 is a top view of a provisional saddle according to a particular embodiment of the invention; Figure 2 is a side view of the provisional saddle according to Figure 1; Figure 3 is a detail view representing a cut of the provisional saddle according to lines III to III of Figure 1; Figure 4 is a detail view representing a cut of the provisional saddle according to lines IV to IV of Figure 1; Figure 5 is an overview of a device for implementing the construction process according to the invention; Figure 6 is a magnified view of one of the rails represented in Figure 5.The rail is fitted with a temporary saddle according to a particular method of manufacture of the invention; Figure 7 shows a detailed view, using a cut similar to that in Figure 3, of the means of attaching the temporary saddle to the final saddle intended to support the rail; Figure 8 shows a side view, with a partial cut, of the final saddle after mounting it on the concrete slab.

To facilitate the reading of the drawing, only the elements necessary for the understanding of the invention have been represented.

Figures 1 and 2 show a temporary seat 1 according to a particular embodiment of the invention. In accordance with these figures, the temporary seat 1 has a body 11 formed by a rectangular metal plate with multiple vents 10 opening on the lower and upper sides of the metal plate 11. These multiple vents 10 are formed by holes, some of which, shown in more detail in Figure 4, have a slightly converging circular section, the diameter of these holes 10 being for example 7 mm at the level of the lower face of the plate 11 and 5 mm at the level of the upper face.

The plate 11 also has two openings 12 arranged at diagonally opposite ends of plate 11 These openings 12 receive guide sockets 13 having an outer diameter adjusted to the diameter of the plate 12 and an inner bore adjusted to accommodate a threaded rod 4 not shown in Figures 1 and 2.

In accordance with Figure 3, the guide sockets 13 have a shoulder in their lower part which is inserted into a suitable cavity on the lower side of plate 11 when the sockets 13 are inserted into the openings 12 through the lower side of the provisional seat 1.

The clearance 14 consisting of cylindrical washers is placed on the upper side of plate 11 around the guide sockets 13, these clearance 14 having an inner bore slightly greater than the outer diameter of the guide sockets 13.

The outer periphery of plate 11 has a step 15 with a bisecting edge towards the lower face of plate 11, the upper edge of step 15 on the longitudinal side of plate 11 being inclined with respect to the plane of the lower face of plate 11.

The temporary seat 1 also has extraction handles 16 to facilitate the grip of the temporary seat 1.

The use of the provisional saddle 1 described above and the construction process according to the invention will now be described by reference to Figures 5 to 7.

As shown in Figure 5, a portico 6 is used to bring two rails 2 above the place where a concrete slab 3 is to be cast. These two rails 2 are suspended by tweezers 61 connected to a motorised beam 62, the latter sliding vertically on to portico 6 to precisely bring the two rails 2 to the desired location. As can be seen in more detail in Figures 6, 7 and 8, the two rails 2 are connected to seats 5 by fasteners 9, these seats 5 consisting classically of a base 51 consisting of a sensitive pleural plate intended to be supported on the concrete slab 3 by means of a semi-diametrically resistant base, represented in Figure 20, in material which is electrically and advantageously insulating.

A temporary seat 1 as described above is placed under each seat 5 so that the guide sockets 13 supported by the temporary seat 1 engage in adjusted openings 52 of the base 51, the lower face of the base 51 being supported on the top of the spacers 14 supported by the temporary seat 1, a space then resulting between the lower face of the base 51 and the upper face of the plate 11 of the temporary seat 1. The temporary seat 1 is held in this position under the seat 5 by the anchorage elements of the seat 5 on the concrete slab 3 anchored by round threaded rods 4 inserted into the guide sockets 13 and their upper part in which the 18 pins are placed, thus forming a 4 threaded rods 4 which are placed on the front of the seat 1 and 1 which are intended to be placed in a loosely spaced area on the face of the seat 13 with a 4 threaded rods 4 which are intended to be placed in a loosely spaced area on the front of the seat 13.

Before casting concrete slab 3, the lower face of the temporary saddles 1 is coated with a decompression oil and the beam 62 of the gate 6 is driven to bring the lower face of the temporary saddles 1 to the place where the support surfaces of the saddles 5 intended to support the rails 2 of the track to be constructed are to be placed.

A concrete slab 3 as shown in Figure 5 in mixed line is then cast by gravity to the height of the provisional saddles 1 by sinking the part of the threaded rods 4 that overflows under the plate 11.

After a drying time to allow the concrete slab 3 to be taken, the 18 nuts present on the threaded rods 4 are removed and the rails 2 pre-mounted on their saddles 5 are lifted by means of the gate 6.

Any concrete spots formed on the surface of concrete slab 3 by lifting concrete through vents 10 of the temporary saddles 1 are then easily removed by simply scraping the surface, followed by blowing.

Electrically insulating gaps 19, as shown in Figure 8, are then placed inside the 52 openings of seat 5; these gaps 19 have a body with a cylindrical part, which fits into the 52 openings, and whose inner and outer diameters are identical to the inner and outer diameters of the guide sockets 13, i.e. adjusted to the diameter of the 52 openings and the threaded rods respectively.

The rails 2 pre-mounted on their saddles 5 are then lowered after inserting the resilient material sole 20 under the lower face of the base 51, this sole 20 having holes in the right of the threaded rods 4. An additional sole 21, simply electrically insulating, is conveniently placed under the previous sole 20, the whole being brought into contact with the concrete slab 3 by passing the threaded rods 4 overhanging the concrete slab 3 through the soles 20,21 and the outer layers of the insulating interlocks 19 arranged in the openings of the seats 5 as shown in Figure 8.

The saddles 5 are then held in the conventional manner by means of nuts 18 screwed onto the threaded rods 4 which are supported on the upper face of the saddle 5 by means of the insulating gap collar 19.

This construction method, using temporary seats conforming to the invention, makes it possible to obtain a homogeneous support surface for the seats easily and quickly, which avoids any displacement of the seats during the clamping of the nuts and ensures a stable positioning of the seats over time.

The present invention is of course not limited to the method of manufacture described and illustrated, which has been given only as an example.

Claims (6)

1. A method of construction of a railway on a concrete slab (3) in which said concrete slab (3) is poured around anchorage members (4) permitting the fixing of tie plates (5) supporting the rails (2) of the railway, characterized in that it comprises the following steps:

   - suspending temporary tie-plates (1) at the point where the tie-plates (5) supporting the railway are to be placed, said temporary tie-plates (1) supporting anchorage members (4) intended to be partially embedded in the concrete (3) and including vents (10) permitting the evacuation of the air trapped beneath the lower face of the temporary tie-plate (1) during the pouring of the concrete slab (3),

   - pouring a concrete slab (3) up to the height of the temporary tie-plates (1),

   - withdrawing the temporary tie-plates (1) after drying of the concrete slab (3),

   - accurate installation of the tie-plates (5) supporting the rails (2) in their final position and fixing the tie-plates (5) on the anchorage members (4).
2. A method of construction of a railway according to claim 1, characterized in that said rails (2) are suspended by means of a gantry (6) above the point where the concrete slab (3) is to be poured, said rails (2) including tie-plates (5) pre-mounted on the rails (2), and in that said temporary tie-plates (1) are arranged beneath said tie-plates (5) and are then brought into the desired position by means of the gantry (6).
3. A method of construction of a railway according to either claim 1 or claim 2, characterized in that, after the step of withdrawal of the temporary tie-plates (1) and before the step of installing the tie-plates (5), any points formed on the surface of the concrete slab (3) by the rising up of concrete through the vents (10) are eliminated by scraping.
4. A temporary tie-plate (1) for the implementation of the method of construction of a railway according to any one of claims 1 to 3, including a body (11) the lower face of which is intended to be lapped by the concrete during the pouring of the concrete slab (3), characterized in that said body is constituted by a plate (11) including a multiplicity of through holes (10) and in that said plate (11) includes withdrawal handles (16).
5. A temporary tie-plate according to claim 4, characterized in that the periphery of the plate (11) includes a step (15) having an upper edge which is inclined with respect to the plane of the lower face of the plate (11).
6. A temporary tie-plate according to either claim 4 or claim 5, characterized in that said plate (11) includes apertures (12) having a diameter greater than the diameter of the vents (10) to permit the passage of anchorage means (4).