Lecture by Professor Ziegler at the 37th Christian Veder Colloquium 2023 in Graz, Austria

The 37th Christian Veder Colloquium took place in Graz from April 13 to 14, 2023. The annual event is held and organized by the Institute of Soil Mechanics, Foundation Engineering and Numerical Geotechnics of TU Graz. The topic of this year's colloquium was "Condition Survey, Evaluation and Rehabilitation of Aged or Damaged Geotechnical Structures". It was chosen because more and more geotechnical engineering structures are currently reaching or exceeding their predicted life span and the assessment of the current condition and the associated risks are often major challenges.

During the first morning session, Professor Ziegler presented the "Wotanstraße Railway Overpass" project, addressing "allowable deformations and retrofit measures for an existing natural stone vault". The paper was written by Professor Ziegler, Dr.-Ing. David Koppmann (ZAI Ziegler und Aulbach Ingenieurgesellschaft GmbH), Dr.-Ing. Wolfgang Rieken (DB Netz AG) and Dipl.-Ing. Christian Schmidt (Krebs + Kiefer Ingenieure GmbH).

Apart from the project itself, Professor Ziegler addressed the issue of occurring deformation of the existing natural stone vault of the Wotanstraße overpass as a result of directly adjacent excavation pits as well as the determination of permissible deformations based on the consideration of the actual load-bearing behaviour of the vault. Furthermore, he discussed the monitoring carried out for the application of the observation method in the project and the dimensioning of a safety measure by means of steel straps subsequently installed in the vault.