Systems for High Speed Railway
For a few years there have been many construction activities in the Netherlands, which are directly related to the extension of the European rail network of High Speed Lines (HSL). The connection between Brussels and Amsterdam is one of the most significant links in the system.
DSI Netherlands has been involved in the construction of many bridges, viaducts and tunnels for this mega-project. One section of the HSL project, the so called continuous railway viaduct DSV near Bleiswijk crossing the motorway A12 The Hague-Utrecht. DSV consists of approximately 160 bridges with a length of 35 m each.
DSI and Spanstaal B.V. formed a Joint Venture, Spancom, for this project and have been awarded the post-tensioning contract by the main contractor Joint Venture HSL Zuid-Holland Midden. Construction of foundations and piers commenced in 2001, the first bridge superstructure was cast in the middle of 2002. At this moment, there are two independent construction teams providing two new bridge superstructures in weekly cycles.
Each bridge consists of two 17.5m long spans. The W-shaped cross section is 11.5m wide. In each side girder there are four 19-strands (Ø15.7mm and grade FEP1860)tendons with DYWIDAG Anchorages MA 6819 and in the middle girder there are six 27-strands tendons with BBR-CONA anchorages BC 2706. Since the bridges are built one next to the other these longitudinal tendons can be tensioned from one end only. The layout of tendons provides tensioning one half of the tendons at each end of the bridge. The deadend anchorages are situated behind the bearings, underneath box-outs for the stressing anchorages. Due to limited space for box-outs compact tensioning jacks had to be used.
In addition, four 6-strand tendons with DYWIDAG SD 6805 anchor plates are used for the transverse post-tensioning at each end of the bridge.
The reinforcement cages with longitudinal post-tensioning tendons are prefabricated on a centrally located prefab-yard on the site. The separate cages for girders and for slabs between girders are transported by trucks and installed in the formwork where transvee tendons and additional reinforcement are completed. Three days after casting (concrete B20) partial post-tensioning is applied so that the formwork can be moved to the next location. Twenty-one days after casting (concrete B45)tendons are fully tensioned and subsequently grouted.
Thanks to the successful collaboration between all parties involved in design and construction of the HSL-DSV project, the bridges were optimized and the weekly cycle of erection was achieved. The entire superstructure was finished on schedule in 2004. The Know-how and experience of DSI was extensively utilized in this project and we are proud of results gained.