Construction of road bridge over the Sava river near Ostružnica

• Main Authors: Bizetić Bojan, Đurđević Igor, Tomašević Goran
• Format: Article
• Language: English
• Published: Society for Materials and Structures testing of Serbia 2020-01-01
• Series: Građevinski Materijali i Konstrukcije
• Subjects: road bridge; ostružnica; reinforced concrete approaching structures; continuous steel box main girders; cantilever bridge construction; launching of steel structure
• Online Access: https://scindeks-clanci.ceon.rs/data/pdf/2217-8139/2020/2217-81392001019X.pdf

Road bridge over the Sava river near Ostružnica, with a total length of 1.963 m, consists of reinforced concrete approach structures on the left and right riverside, while the middle structure over the Sava River is 5-span continuous steel box girder, with a total length of 586 m. Construction of steel structure was originally planned by cantilever installation of 56 sections, using a floating crane and temporary supports - steel piles placed in the river bed. After the high-resolution magnetic survey of the riverbed, this methodology has proved to be highly risky due to the possible existence of unexploded ordnance (UXO) left after NATO bombing, that could be activated during the piling into the riverbed. To avoid installation of temporary supports in the riverbed, the original methodology for the assembly of the steel structure had to be revised. After considering possible alternatives and to preserve already executed works, new methodology that includes (I) incremental launching over floating support of the bridge section S4-S6 with a total length of 187 m, (II) cantilever assembly of structure segments over river piers S1, S2, S3 and S4 and (III) lifting of 3 structure sections L=77(68) m, was selected as optimal under the given conditions.