Peri formwork helps shape bridge
By Becca Wilkins13 August 2009
Formwork from Peri is helping to construct a 258 m long motorway bridge which crosses the Oparno Valley in the Bohemian area of the Czech Republic.
The reinforced concrete arched bridge, with a span of 135 m, straddles the valley without any bridge piers and transfers the loads in the form of compressive forces into the foundations.
Peri's Variokit, rail climbing system (RCS) as well as Peri Up modular scaffold are being used in the bridge's development. It involves two separate parallel structures being simultaneously constructed in both driving directions.
The concrete arch is being built using two formwork and scaffolding units in the form of a cantilevered construction. This enables concrete loads for the 5 to 6 m long arched sections to be transferred into the previously completed load-bearing sections.
During the moving procedure, hydraulic units provide the lifting power so that work can be carried out without crane support. Peri said any adjustments needed due to the continuously changing arch geometry can be carried out simply and quickly with the cantilevered construction.
Components from Peri's Variokit also form the basis of constructing the double-webbed T-beam cross-sections.
The 53 m long formwork carriage and the formwork system itself form a supporting structure. For moving around the piers the formwork is simply folded downwards, the company added.
Mobile hydraulic pumps, which also ensure that the Peri RCS can operate crane-independently, allow the striking and shuttering procedures to take place as simply as possible.
The bridge piers are constructed in 3,1 to 3,6 m cycle heights with RCS climbing units. The formwork scaffolding with climbing rail is permanently connected to the structure using climbing shoes during the entire climbing procedure. Peri said drifting is therefore prevented in strong wind conditions and climbing can take place quickly and safely.
Meanwhile, Peri Up stairs and access ladders as well as working platforms allow workers to reach and assemble the temporary bracing for the arched supporting structure. A Peri Up protective roof over the railway line running through the valley ensures normal operation of rail services during the project.
The Oparno bridge is located on what is known as the A17 motorway in Germany and D8 in the Czech Republic, which connects Dresden and Prague. This road is part of the pan-European corridor which extends to Budapest and then on to Istanbul.