IMPROVEMENT OF TRACK FORMATION ON THE PARIS-BORDEAUX LINE
ASSAINISSEMENT DE PLATE FORME SUR LA LIGNE DE PARIS A BORDEAUX
In the French department of Charente, the Paris-Bordeaux railway line runs through cuttings hewn out of Jurassic marly chalk. In many places, the rock, after exfoliation when in contact with water, changes into white mud which seeps up through the ballast and affects the stability of the track, making maintenance work costly and difficult to programme. The phenomenon is practically confined to the cuttings but these are very frequent in the deeply undulated country crossed by the line over a distance of about 60 km south of Ruffec. Because of the high number of cuttings and their length on a line over which a speed of 200 km/h is practised, attempts have been made to perfect a system which is an improvement on conventional methods, so as to prevent the track formation from coming into contact with rainwater, while at the same time being easy to employ and providing effective protection of the track formation and a rapid consolidation of the track so treated. Between the track formation and the sleeper, working upwards, there is first a 10-cm layer of limed sand, then a waterproof nylon sheet impregnated with vinyl chloride, a layer of river sand, a layer of fine gravel and finally a 20-cm layer of ballast. The originality of the method is firstly the highly-mechanised system employed and secondly the systematic use of vinyl sheeting laid on limed sand forming a slab after it hardens; the threefold purpose of the latter is to provide and maintain a constant slope so that the water runs into the lateral drains, to protect the sheeting against the hard parts of the track formation, and finally to enable levelling to be stabilised quickly. By introducing temporary single-line working between 8 and 10 hours, the length of single track dealt with daily was 100 metres. The results obtained after 3 years' experience seem conclusive and the condition of the track has been found to be remarkable after stabilisation once a year.
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Corporate Authors:
Societe Nationale des Chemins de Fer Francais
92 rue Bonaparte
75 Paris 6e, France -
Authors:
- Cordier, H
- Publication Date: 1972-7
Language
- French
Media Info
- Features: Figures;
- Pagination: p. 523
- Serial:
Subject/Index Terms
- TRT Terms: Drainage; Embankments; Soil stabilization; Waterproofing
- Subject Areas: Geotechnology; Hydraulics and Hydrology; Railroads;
Filing Info
- Accession Number: 00047798
- Record Type: Publication
- Source Agency: International Union of Railways
- Files: TRIS
- Created Date: Feb 20 1974 12:00AM