Eurailmag - #15 - March 2007 - (Page 72)

Infrastructure EAST EUROPEAN HIGH-SPEED LINE – TESTING CONCRETE TRACK RÉSEAU FERRÉ DE FRANCE, CHIEF CONSTRUCTOR OF THE EAST EUROPEAN HIGH-SPEED LINE, IS TO TEST A SECTION OF BALLASTLESS TRACK ON THE LINE. WHEN TRAINS RUN OVER THE HIGH SPEED RAILS, MICRO PARTICLES ARE SUCKED UP AND DAMAGE THE SURFACE OF THE RAIL AS WELL AS SPEEDING UP WEAR OF THE TRACK. he engineering department at SNCF is responsible for designing the test track on concrete slabs. Results of the trial will be used to define construction costs and the maintenance required for this kind of solution. Until now, in France, this ballastless technique has been used in underground construction projects such as the RER, Channel tunnel and several HSL linking tunnels, plus the Mediterranean HSL. And Germany, the Netherlands and Japan have all opted to use concrete, despite the fact one kilometer is two or three times more expensive. T TEST ZONE The test zone is approximately 1,800 m long and covers the two main tracks plus three track devices at the Chauconin post, from PK 18+600 to 20+430 along the East European HSL in Seine-et-Marne. It includes four, 320 km/hr live power transitions between the ballast and concrete tracks, and an 80 km/hr transition at the heel, rerouted with a tg 0,0654 track device providing siding access. Key slab design features: • most importantly, high rigidity strength – vertical movement under 17 tonne loads must not exceed 0.2 mm, to ensure the vertical elasticity of the system can cope with high speed demands (sinking of 8.5 tonne wheel limited to 1 or 2 mm) • long lasting: traction constraints must not exceed traction resistance for the concrete when subject to loads and drops in temperature • high performance when localized platform subsidence occurs The track is laid with D430IP supports featuring SATEBA type shells, joined to FASTCLIP-type track fastenings with pre-fitted components. The shell method is also being used for the bottom of track devices with NABLA G4 type fastenings. TESTS AND MONITORING Design checks carried out before the track is put into service include: • checking overall rigidity for the live line and track devices • checking flexibility of track support slabs • checking slab performance/temperature fluctuations at the ends of anchorage zones. TECHNICAL DETAILS The slab is made up of a traditional reinforced concrete reservoir (B1) with filling concrete (B2) poured between the transversal bi-blocks. The B2 concrete has self-levelling or self-posititioning fibers for a clean join. Both elements - the traditional and self-positioning filling concrete are seamless. The lack of any joint ensures unbroken, vertical rigidity and long-lasting strength. But on the other hand, both types of concrete suffer traction pressure when the concrete shrinks. This is why they are reinforced. The traditional, metal framework on the casing is made up of high adherence FeE500 steel wiring. The non-metallic fibers (polypropylene) in the concrete filling ensure electromagnetic compatibility. To boost the lifetime of the system, a resin-based (polyurethane), watertight shell is placed between the B1 casing and B2 filling concrete. This ensures the casing will last as long as the bridges in reinforced concrete (estimated lifetime 100 years). The filling concrete can be replaced, if necessary, when the track is renewed. The B1 casing is poured over a 20 cm layer of treated aggregate to give the EV2 support foundations rigidity strength of 100 Mpa. MONITORING THE SERVICE IN USE Monitoring the pilot zone will involve further studies prior to entering into operation, plus security checks. Investigations into preliminary signs of ageing include: • regular measurements of thermal/heat performance one year after debuting service © CAPA-RFF Laying metal framework for slab B1 Issue 15 EURAILmag Business & Technology © CAPA-RFF

Table of Contents for the Digital Edition of Eurailmag - #15 - March 2007

SOMMAIRE
NOTICE BOARD
COATINGS
NEWS
SERVICES
INFRASTRUCTURE
HIGH-SPEED LINES
TUNNELS
PEOPLE
ROLLING STOCK
WEBSITE DIRECTORY

Eurailmag - #15 - March 2007

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