Use of twin girder auxiliary bridges in the course of an emergency project for crossing the BAB 40
On 2020/09/17 a damaged fuel tanker completely burnt‐out under a railway bridge over the German motorway A 40 between Duisburg and Mülheim a. d. R. Three out of five bridges had been damaged by the extremely high temperature that the structural and transport safety could no longer be ensured. Therefore the affected railway tracks of the DB Netz AG had to be shut. Immediately after the recording of damages, one bridge structure had been demolished. Due to the immediate detailed design for the replacement and the DB‐internal as well as the governmental approvals the erection of the complete structure, including foundations, auxiliary bridges and rail system could be realized in a minimum amount of time. The initial operation of the bridges took place on 2020/12/28 (bridge 3) and 2012/09/06 (bridges 2, 4). Only by the use of twin‐girder‐auxiliary‐bridges type ZH26 of the DB Netz AG the short‐term replacement of the damaged bridges could be realized. Subsequent the whole building process is described. The available auxiliary‐bridge‐systems of the DB Netz AG and their limitations of use are summarized additionally. The use of the auxiliary‐bridges as a structural chain as well as the use as permanent makeshift require DB‐internal approvals. The required verifications, especially fatigue design, and the therefore required expertise for the durability of the bolted connections are described as well.