My first Magazine dsi-info-23-en | Page 122

Construction—EMEA—Bosnia and Herzegovina—Hydro & Marine Structures Ready for the Future: DYWIDAG Strand Anchors with DYNA Force ® Sensors secure Grancarevo Dam ˇ The Grančarevo Dam is located on the Trebišnjica River in the southeast of Bosnia and Herzegovina near its border with Montenegro. With a height of 123m, this arch dam, near the town of Gornje Grančarevo in the municipality of Trebinije, is the country’s highest dam. The adjacent Bileča Reservoir is the largest reservoir in Bosnia and Herzegovina in terms of active storage. The Grančarevo Dam went into operation in 1967, and the two hydroelectric power plants, Trebinije-1 and -2, with a total output of 188MW were completed in 1968 and 1979. El-Iso Strand Anchors in lengths of up to 61.5m. This system has been approved for permanent use (applications with a 100+ year design life). Recently, the monitoring systems for the safety of the dam were rehabilitated and modernized. In order to ensure the long-term stability of the dam, permanent Type 12-0.62" DYWIDAG Double Corrosion Protected (DCP) Strand Anchors were installed in the right flank of the slope directly underneath the arch dam. The anchors used were electrically testable By electrically uncoupling the anchor head and the tendon from the anchor plate, a resistance test between the anchor and the soil can be carried out – the integrity of the corrosion protection sheathing can be tested at any point of time in the future by the use of standardized resistance tests. Furthermore, the El-Iso System complies with SIA requirements. 122 In order to allow the owner to continuously monitor the prestressing forces in the strand anchors, 46 DYNA Force ® Sensors were installed in the bond length of 23 anchors. The DYNA Force ® Sensors also provided an additional mechanism for monitoring the forces during tensioning. Additionally, DSI supplied 4 multiplexers with a stainless steel casing for permanent outdoor use that were connected to the DYNA Force ®  Sensors in the anchors. Furthermore, DSI engineers installed a readout unit and a controller to automatically read the data.