ICE rail link Hamburg-Berlin soon to be 230 km/h Paulinenaue – a site of superlatives

After the abandonment of the project for the high-speed magnetic rail link between Hamburg and Berlin, the German Rail company, Deutsche Bahn AG, decided in favour of a second stage improvement of the existing track. Peak speeds of 230 km/h will reduce the journey time from Hamburg (Main Station) to Berlin (Zoo) to around 100 minutes. The whole project will cost 650 million euro. The shortened journey time is to be included in new timetables from the end of 2004.

An earlier reconstruction at the end of the 90s had seen the speed for this line increased to 160 km/h. In terms of construction, the greatest challenges to be overcome were on a 14.5 km length between Paulinenaue and Friesack, which formed part of the Spandau-Neustadt section.

The boggy ground there is capable of taking very little load. In the earlier construction stage, the rail embankment had been founded on 40,000 partially injected vibro columns (PIVC) and geogrid reinforcement.
                   

Full closure – and 76 days of round-the-clock working

A consortium led by the engineering management of Wittfeld (Wallenhorst), H.F. Wiebe (Achim), Gebr. von der Wettern (Cologne), Ludwig Freytag (Oldenburg) and Matthäi (Verden) was awarded the contract for the section and formed the joint venture company "ABS Hamburg-Berlin, PRA 1".

During the planning phase, DB Projektbau GmbH was at first in favour of a partial closure with single track operation, as had been adopted in other sections. In order to ensure that this demanding and high quality project was executed in the best possible manner, a decision in favour of a specified period of full closure was

made in consultation with the joint venture partners. Exactly 76 days were allowed for this to take place in summer 2003.

A seven-day week, three-shift working system was introduced so that the Herculean task could proceed smoothly all around the clock. The job was planned down to the smallest detail before construction began. People living and working nearby were kept fully informed about the works and their understanding obtained for the unavoidable nuisances.

Several sites on the section running in parallel

Work on the section started simultaneously at several sites. First the existing track bed, along with the associated groundworks was completely removed. The original boggy ground was then replaced to the level of the groundwater table. Approximately 1 metre of the partially injected vibro columns forming the piled foundations was then exposed and cut off to existing ground level. Their condition was recorded and repairs carried out where necessary.

The new embankment was then constructed on this foundation. The first geogrid layer was placed over a 200mm layer of graded aggregate. There then followed three layers of Fortrac^® PVA geogrid type R 200/200-30 M placed at intervals of 300mm.

The 14-metre wide rolls of geogrid were placed transversely to the track and overlapped by one metre. Each layer of geogrid was precisely installed to laser accuracy and tolerances of less than 10mm, in accordance with the manufacturer's recommendations. Huesker manufactured the custom-made geogrid in 210-metre long rolls.

This kept waste to a minimum. For the critical construction phase – the time of full closure – Huesker had reserved additional capacity at its production plants to ensure that extra geogrid could be supplied very quickly if required.

The Supersite in figures

23 km track removed

• 45,000 m³ old stone track bed removed

• 115,000 m³ existing frost protection and sub-ballast removed

• 150,000 m³ railway embankment removed

• 60,000 m³ peat removed

• 135,000 m² geogrid removed

• 40,000 partially injected vibro columns shortened

• 85,000 tonnes mixed stone placed

• more than 350,000 m² Fortrac^® geogrid installed

• 400,000 tonnes embankment fill placed and compacted

• 130,000 tonnes sub-ballast placed

•  60,000 tonnes ballast placed

• 23 km track constructed