Norwegian contractor Reinertsen is constructing this new bridge between Løding and Vikan, part the Rv 80 trunk road. Reinertsen chose Doka as its preferred formwork supplier due to extensive experience and know-how in advising, planning, designing and supplying formwork for similar, complex projects for the main contractor.
The Tverlandsbrua Bridge is 670m long, has a longitudinal gradient up to 4.5%, and is being built in the form of a spiral with a transition curve with varying radii. The seven-span bridge crosses the Saltfjord between Løding and Vikan, with piers up to 13m high. Doka supplied four of its cantilever forming travellers (CFTs) for the bridge deck with 3 longitudinal trusses spanning the 22.6m width of the superstructure deck. The tapering geometry of the bridge deck webs required the lower soffit formwork to adjust its width with each pour. Doka designed the CFT, the formwork and access platforms to be slide mounted allowing the site team to safely and efficiently adjust the formwork for the construction of the each bridge segment.
Super-sturdy shoring construction
The 10m high waves of the fjord combined with the high wind speeds created a very challenging working environment for the construction of the piers, demanding formwork of exceptional strength. Doka designed and supplied its large-area formwork Top50 and Wall formwork FF20 systems to form the piers. The twin piers were each poured in a single concrete lift. To stabilise the pier formwork, platforms were built onto the foundations beneath the piers; the high wind loads were then transferred into these platforms by Doka’s spindle struts using its CFT and SL-1 system beams in constructing the stabilising platforms.
This equipment was then used to construct the pier cross-heads again with a unique solution. The CFT & SL1 beams were supported on cantilever support frames, transmitting the heavy loads from the concrete pier-heads. Each pier-head was poured in three lifts: Large-area formwork Top 50 was used to form the bottom slab, Large-area formwork Top50 and Wall formwork FF20 to form the webs, and the Bridge formwork ParaTop, Large-area formwork Top 50 and Load-bearing tower Staxo systems to form the upper deck slab. A key benefit in using ParaTop for the construction of cantilever sections of the bridge deck was it eliminated the need vertical shoring. Construction started in April 2011 and the project is on schedule for completion at the end of 2013.