Reconstruction of Masonry Structures during the Widening of the Federal Motorways in the New German Countries

Abstract

The German Unity Traffic Program includes seven projects in the New German Countries with about 2000 km of motorway. Four of these projects are completely new motorways, the other three projects consist of the widening of existing motorways, which were built between 1934 and 1939, and which were left without much alteration and maintenance until the change of government in 1989. In most sections these three motorways have been and will be widened from 24 m to 37 m, combined with a redevelopment of the lines, gradients and junctions. However, often the new location and geometry are not completely different from the old ones, and in these cases the preservation of existing bridges is an option to be considered. The old bridges were deficient in many different areas. Nevertheless, in several cases investigations succeeded in working out solutions with affordable rehabilitation actions. In most cases these were structures of historic engineering value or with a special presence as a landmark. The examples include the reconstruction of large natural stone piers for the use of the two new carriageways and the widening of a multi-span stone masonry arch bridge for the use of one carriageway. Furthermore, the preservation of a large masonry arch overpass by the construction of an underpinning structure is described.