PhD exam

Bastian Wilding defended successfully his PhD thesis "Out-of-plane stability of thin reinforced concrete walls under seismic loading". The members of his committee were Prof. Sergio Lagomarsino (University of Genova, Italy), Prof. Michael Griffith (University of Adelaide, Australia), Dr. Pierino Lestuzzi (EPFL), Prof. Alain Nussbaumer (EPFL, exam president) and Prof. Katrin Beyer (PhD advisors).

In his thesis, Bastian develops a mechanical model, the Critical Diagonal Crack model (CDC model), for predicting the entire force-displacement response of modern URM walls failing in shear, flexure or a hybrid mode. The covered masonry typologies comprise modern clay and calcium-silicate brick walls, with a focus on vertically perforated units. The model is first derived for monotonic loading and based on a formulation that accounts both for shear cracking in the wall and decompression of bed-joints. He then extends this model to a cyclic response, investigating further the effect of the load history on the wall behaviour by means of simplified micro-models. Based on the CDC model, Bastian develops closed-form analytical equations for the effective stiffness and the drift capacity of modern URM walls, which are directly suitable for implementation in structural engineering codes. He shows that the new models are more accurate than current code equations.

Bastian has already published his work in several articles, which can be accessed through https://eesd.epfl.ch/publications or the following infoscience link.