FR2663054A1 - Level crossing flooring (paving) consisting of three longitudinal beams and slabs made of reinforced concrete - Google Patents

Abstract

Level crossing flooring, characterised in that it includes three prefabricated reinforced concrete longitudinal beams (1) parallel to two lengths of rail. These longitudinal beams make it possible to support and fasten slabs (4), also made of prefabricated reinforced concrete, with a weight slightly less than 100 kg.

Description

Z LEVEL CROSSING PLATFORM
The present invention relates to level crossing decking (PN
History of level crossing decks (PN)
In the origins of the railway, the superposition of the two modes of transport (trains and road vehicles) to (PN), was resolved by making a railroad embedded in the pavement and by practicing along the rails two grooves called ruts intended to leave the free passage of the wheels of railway vehicles.

 This practice made it difficult to maintain the railway, which consists in ensuring the durability of the rail fasteners on the sleepers, and above all, with the increase in speeds, the periodic resumption of leveling.

rails.

 To allow frequent dismantling, the location of the roadway was made up of wooden sills fixed by lag bolts on the sleepers; these sills serving as a tread for road vehicles.

 To these advantages is added another necessity. It is that of ensuring as best as possible the electrical isolation of the railway track with respect to the ground to avoid losses of traction current in the ground and that also of the two rows of rails between them, to use these rails as circuit signaling.

 This decking system showed its limits when the concrete sleepers appeared. As it was not possible, and in any case not easy, to fix the wooden decking on these sleepers, the networks still used wooden sleepers in (PN) to be able to fix the wooden decking there.

 There was therefore an alternation of wooden sleepers and concrete sleepers which adversely affected the homogeneity of the railway.

 To overcome this drawback, we thought of using concrete decking laid on concrete sleepers and bearing, either on the heads of sleepers, or on these same heads and the track ballast; the decking being made integral with the track by fittings fixed to the rail. These fittings are a major annoyance during leveling operations on the track by mechanical machines (self-leveling tamping machines) which require their removal and their installation to allow work.

 These concrete decks gave satisfaction since they allowed both the use of concrete sleepers and ensured a good running surface for road vehicles.

 However, the constituent parts of the concrete decking being very heavy (250 to 300 kg) required, during fairly frequent operations to maintain the geometry of the railway, the presence of handling equipment.

 The idea then came to seek to eliminate the two disadvantages of these systems.

 a) limit the weight of the concrete parts of the decks to allow their manual handling.

 b) remove the fittings for fixing to the rails which hamper the operation of the self-leveling tamping machines.

 It is the system defined below which responds to these concerns.

innovation cu proposed system
The system which has made it possible to overcome the drawbacks stated, is characterized in that it consists in placing three reinforced concrete beams parallel to the track, two on either side ensuring the transltion between the roadway and the decking ( 1), the third in the middle (2).

 The central sill (2) is hollowed out at the bottom to span the one-piece sleepers or the struts (8) of the two-piece sleepers.

 In these sills are embedded plastic sheaths which will allow to fix blocks (4) weighing very slightly less than 100 Kg using special lag bolts (5).

 These pavers which constitute the road tread are fixed by lag bolts (5) in the "plastic" sheaths (3) of the sills and recesses against the file of the rails (9) between the clearance of the mushroom and that of the shoe (see sketch) .

 They rest on the struts (1) and the crosspieces by means of elastic cushions glued on hollow bosses (7) formed in the concrete of the lower part of the pavers to form cavities which cover the upper part of the crosspieces. These hollow bosses contribute, with the raised bosses (6) which are supported on the web of the rail (9), to the self-alignment of the blocks.

 The initial installation requires, to achieve this, the use of a frame for fitting and fixing to the rail which supports the sills for the time necessary for their leveling and for compacting the ballast under these sills, by means of manual tamping machines.

 Subsequently, during leveling operations, it is sufficient with two men or even a single one equipped with a light gantry for handling, to deposit the paving stones and to rest them after the passage of the railway mechanical tamping machine.

 The time required for this dismantling and reassembly of the decking is very reduced compared to that required for the same work carried out on heavy decking.

Claims (3)

 1) Level crossing decking characterized in that it comprises three reinforced concrete sills parallel to the rails two outside the track (1) and one between the two rail lines (2), on which are fixed concrete pavers (4) weighing slightly less than 100 Kgs, whose stability is ensured by fasteners on the sills and self-alignment by recessed bosses (7) made on the pavers at the location from contact with railway sleepers and raised bosses (6) in contact with the rail core.  2) Decking according to claim 1 characterized in that the sills provide via plastic sheaths (3) embedded in the concrete and special lag bolts (5), and by this single device, the subjection of the pavers on sills without any attachment on the rails.  3) Decking according to claim 1 characterized in that the pavers located between the two rows of rails are self-aligned by the presence of bosses or hollow concrete (6) and (7) which ensure positioning without any artifice of the set of more paved sills between the two rows.