DSI Supplies Comprehensive Scope of Products for Oparno Bridge

In November 2007, construction work began on the last section of the highway that will link Prague and Dresden. The highway is another outstanding example of how countries in Europe are drawing together. It is also important for promoting and improving tourism in the region.

The last Czech section runs through the Oparno Valley in the Bohemian low mountain range and includes an arch bridge, for which two DSI partners made significant contributions. DSI’s licensee for the Czech Republic, SM7 Prague, and Doprastav, Slovakia, are the two companies that co-operated for this project. SM 7 carried out the geotechnical work for the bridge piers, and Doprastav supplied post-tensioning systems, carried out posttensioning work for the bridge superstructure and installed temporary stay cables for the bridge’s arch.

The bridge consists of two parallel structures. The main deck is 273 m long, with 13 spans in lengths varying from 17.5 m to 24 m. Each superstructure has a 1.2 m x 14.25 m double T-beam cross section that will accommodate two lanes and a pedestrian walkway. The bridge deck is supported by 12 columns, eight of which are connected to an arch with a span of 135 m.

A total of 116 DYWIDAG Strand Anchors with 7x15.7mm Ø, St 1570/1770 strands were installed for the foundation of the pillars. 48 DYWIDAG Strand Anchors were fabricated as temporary anchors in lengths of 19m in SM7’s factory in Brandýs nad Labem. 68 DYWIDAG Strand Anchors were produced as permanent double corrosion protected DYWIDAG Strand Anchors in lengths of 19-25 m by DSI Austria.

Post-tensioning of the bridge deck required 160 t of 18x15.7mm Ø DYWIDAG Strand Tendons as well as type MA6819 anchorages and type R6819 couplers. The bridge’s arch is divided into two cantilevers with 14 segments that were built using a form traveller. From segments 2 to 14, two temporary stay cables were stressed for each segment. 12-strand and 18-strand stay cables were installed in the pier using temporary type MA6812/19 anchorages. Type ZF6812/19 anchorages were used as passive anchorage in the arch.

The dorsal stay cables were anchored in the pier as well as in the foundation of the adjacent pier. The stay cables were individually inserted into PE ducts and coupled using type D6801 couplers. In addition to supplying the post-tensioning systems, Doprastav also provided the necessary installation and stressing equipment.