Port areas are 'hot' when it comes to new construction. Ships are getting bigger and bigger and Europe is strongly committed to waterborne transport for environmental reasons. And if a port city then also expands, expansion of the port is soon necessary. Hendriks supports this trend with formwork for quay walls. Boskalis is using these in the realisation of a new port in Stockholm.
Port city Stockholm already has a total of seven ports, some of which are used by international cruise ships and for local transport. The new Norvik port will be the home base for all container transport and should, in the future, become the port from which all freight transport via the Baltic Sea is handled.
The port will have seven berths for container ships and RoRo vessels. To berth these ships, Boskalis has been asked to build a 1,100-metre quay wall. The main part of this wall consists of a 3-metre-high concrete sloof that will be placed on a combi wall with tubular piles and whose concrete will be poured under water.
This construction 'in the wet' places special demands on the formwork. In particular, the connection to and sealing around the underlying structure are important. Hendriks developed a solution with three 16-metre quay wall formworks. To fix the formwork to the sheet piling, nuts are needed that are welded to the combi piling by divers underwater. Hendriks managed to minimise this costly and time-consuming welding work by cleverly and carefully selecting the number of fastening points.
The formwork itself consists of a bottom section that accurately matches the round shape of the tubular piles and a one-sided wall section. The whole is suspended from profiles cast in the tubular piles. To suspend the formwork from these profiles, Hendriks opted for a gallows construction at the top of the formwork.
The connection of the bottom section against the tubular piles of the combi wall is essential; a challenging task due to the round shape of the tubular piles. Without a good connection, the concrete would run off into the sea. To prevent this, the shape of the bottom section closely follows the shape of the tubular piles. The different parts of the bottom box can be moved using a spindle so that they fit properly and accurately to the piles. A rubber sealing element at the interface of formwork and pile ensures a completely closed underside.
The one-sided wall formwork standing on the bottom formwork is partly attached to the combi wall under water. The maximum concrete pressure occurring is 65 kN/m2. A pouring scaffold is provided on the outside of the formwork for safe and health and safety-friendly execution of the pouring process.
