Use of Electrically Isolated Anchors to Secure a Stay Cable Bridge
When completed, the Ponte Europe will connect the expressways IC2 and IP3. This asymmetrical stay cable bridge has a span width of 330m and about 2km of approach spans across the Mondego River near the city of Coimbra.
DSI Portugal supplied 60t GEWI® reinforcing systems for 87 precast segments of the stay cable bridge; each segment weighed 150t. The coupler splices were pre-torqued at SUSPA-DSI's plant in Königsbrunn, Germany, and delivered preassembled.
The Ponte Europe is the first structure in Portugal to be secured with electrically isolated strand anchors. The strand anchors, fabricated by DSI Austria, have an average length of 25m. Among other things, they serve to accommodate the horizontal loads at the abutment which partly result from the asymmetrical structure of the bridge. The installation of the 19 anchors, the measurements of the electrical resistance test and the suitability test were supervised by DSI Portugal and DSI-TS Munich.
The anchor installation works were successfully completed in June 2003.
To facilitate this first use of electrically isolated strand anchors in Portugal, a test of the structural principle of the DSI Anchor was performed. Under the supervision of the approval authorities, DSI-TS assembled, installed, stressed and later excavated an electrically isolated strand anchor on a site in Lisbon. The electrical resistance measurements after the installation, grouting and stressing was positive as was the appraisal of the anchor after it had been removed from the ground. Thereupon, the DSI Anchor was given the recommendation of the responsible authorities and installation in Coimbra was made possible.