Complete closure of the A8 near Pforzheim - KREBS+KIEFER ensures the safety of the execution

From 30 November 2018, 22:00 to 03 December 2018, 06:00, the steel superstructure of the new railway overpass of the DB line 4200 over the motorway was moved from the manufacturing position to the end position, during a complete closure of the A8 between Pforzheim East and Pforzheim North.

The steel superstructure is a timber-frame construction with a construction height of 8.50 m and a span width of 55 m. It was built north-west of the DB line and moved longitudinally to the east and then south during the full closure of the motorway.

The shift was carried out with two special vehicles, so-called SPMT's (self propelled modular trailers) from the company Sarens, on which a stiffened steel substructure was placed to directly support the superstructure. With the help of these special vehicles, each of which has 12 axles with four wheels each and each axle can be controlled hydraulically, the 720 t structure could be moved and brought into its final position with millimetre precision.

A week earlier, the two armored concrete abutments, which were also manufactured northwest of the DB line, were brought into their final position by means of a transverse thrust. The shifting of the constructions, each 2700 t heavy, took place on a shifting construction with 12 load modules of the company Hebtec.

The test in structural engineering and random monitoring of the execution of these construction measures, including the complicated auxiliary construction, was carried out by Dr.-Ing. Ioannis Retzepis, managing associate of KREBS+KIEFER Ingenieure GmbH, Karlsruhe.

In the field of steel construction, the test in structural engineering was carried out by Prof. Dr.-Ing. Thomas Ummenhofer, and in the field of welding by Prof. Dr.-Ing. Michael Volz.