First application of the balanced lowering method to build two bridges in Austria

Abstract

AbstractThis new bridge construction method consists of building the bridge girders in a vertical position and of rotating the bridge girders into the final horizontal position. In order to rotate the bridge girders, additional structural elements, in this case compression struts, are required. In some topographical situations, it will be more efficient to produce the bridge girders with this innovative method than with the traditional incremental launching method or the balanced cantilever method. The span of the bridge girders is reduced by the compression struts, which enables considerable savings in construction materials. This article explains the design and the first application of the balanced lowering method to build two bridges across the Lafnitz and Lahnbach rivers as part of the Fürstenfeld Motorway in the southeast of Austria. The good cooperation of the project participants allowed for the successful first‐time application of the method for the two bridges described in this article. The unproblematic application of the balanced lowering method for the prestressed concrete bridge with 2.0 m high bridge girders proved that considerable savings in resources and costs were possible compared to the originally planned steel‐concrete‐composite bridges with 4.2 and 4.6 m high bridge girders.