ABSTRACT
ABSTRACT: During the construction of prestressed concrete motorway bridge near the town of Levocˇa in Slovakia in 2012 the bridge falsework collapsed under the weight of fresh concrete. This accident has claimed four lives and 12 workers were injured. Girder bridge, now completed, crosses the valley at a height of approximately 25 meters with 5 spans of standard lengths (for this type of structure), 28 + 3 × 40 + 28 m. Its cross-section consists of three, cast in place, T-shaped girders. Bridge was built by the span by span method using steel falsework, which originally consisted of three supporting steel towers. Two towers were located around the piers and one in the middle of the span, which was then under construction. Steel towers were supporting the longitudinal beams, which were subsequently supporting the shuttering. These steel towers were designed in such a way, that they could be easily modified to different heights. They consisted of four columns interconnected in the transverse and longitudinal direction by means of statically effective K-shaped braces. However, apparently due to the intention to erect the steel towers directly on the pier footing and also to use them without modification on the parallel bridge, which differs by the number of columns in the transverse direction, the standard braces were replaced with non-standard elements. Steel falsework collapsed during the casting of the second span, which was at that moment almost finished. As the first, the steel tower at the pier no. 3 has buckled and subsequent progressive collapse of the whole falsework followed. Our article deals with a detailed technical description of the possible causes of this tragedy.
