Motorway Bridge T4, Greece
Location: Paradeisia-Tsakona, Greece
The 160-km long A7 motorway connects Kalamata in the south to Corinth in the northwest of the Peloponnese peninsula. The principle element being used to close the gap between Paradisia and Tsakona is the 390-m long arched bridge – known as "T4" – whose completion has been scheduled for early 2014. Two-thirds of the 22-m wide bridge superstructure will be suspended on a steel arch and realized using the steel composite construction method. For the northern bridge section, a pre-stressed concrete superstructure variant was selected which features a twin-cell hollow box cross-section.
- The supporting element of the motorway bridge is a huge, almost 30-m high inclined twin-pillar pier with an asymmetric V-shape. On the one hand, this serves as an intermediate support for the in-situ concreted carriageway and, on the other, as a support and starter section for the steel arch.
- Polygonal, 32° to 36° shallow pitched inclined piers on both sides of the bridge, in eight segments, each 4.50 m long.
- Shoring structure for a 2,400 t load
Alpine Bau G.m.b.H. / Terna A.E. Joint venture
PERI convinced us with the best technical and most cost-effective formwork and scaffolding plan. We were thus able to always make the optimal system choice together with PERI’s design engineers – adjusted to the complex project requirements. Apart from the technical support during the planning and construction phase, I would especially like to highlight the jobsite support as well as the provision of material according to the progress at the jobsite.
- Basically, it is two modular construction systems combined with each other which transfer the high loads safely into the ground. The two shoring systems VARIOKIT heavy-duty shoring tower and PERI UP Rosett Flex are exactly adjusted to the static and geometric requirements.
- With help of the PERI UP Rosett Flex modular scaffold system, forming a spatial load-bearing structure for the piers and superstructure formwork is formed, gradually increasing up to the total support height of over 20 m to the rear and upwards respectively. By means of 25, 50 and 75 cm long ledgers, the 150-cm basic grid can be adapted to suit the geometric and static requirements extremely flexibly.
- The VARIOKIT modular construction system also forms the basis for the heavy-duty shoring. In the connecting area between the cast-in-place bridge and steel arch, two 17-m high, 42-leg VARIOKIT heavy-duty shoring towers are used to accommodate high loads. Each of the two towers has to carry loads of 1,200 t and, due to the long utilization time, high earthquake as well as horizontal loads. PERI engineers combine four standard towers, each with a 2.00 m by 2.00 m axis dimension, by means of several bundled 37.5-cm additional frames to form two power packages.
- VARIOKIT heavy-duty shoring towers and truss girders are used as load-bearing shoring for the boundary segments of a 412-m long motorway bridge.