Development of a Fast Seismic Assessment Procedure

In the framework of a large campaign aimed at the seismic assessment of existing masonry buildings subjected to induced seismicity in the Groningen (NL) area we were mandated with the task of developing a Fast Assessment Procedure for the seismic evaluation of URM building stock.

The request for such procedure comes from the need of being able to obtain in a fast and easy way a qualitative idea of the vulnerability of an existing building. When facing the task of assessing a large number of structures there is the need to create a priority list in order to identify which structures are more vulnerable than others.

The proposed Fast Assessment Procedure is based on the idea that the results of the seismic assessment of a few chosen structures representative of a certain structural typology can be extended to all the other structures of the same typology.

The development of this tool required to analyse the full batch of structures under assessment to identify and group them in different structural typologies was performed in collaboration with the Dicar of University of Pavia. Then, for each typology a few structures were chosen and their seismic assessment was performed via non-linear static analyses (pushover) using the software 3Muri and following the Dutch guidelines NPR9998. Finally, some empirical relationships were developed allowing to extend the assessment results obtained for the reference structures to the whole batch of structures of the same typology.

This procedure was employed also in the framework of the Krewerd Experiment. The latter is a campaign of seismic assessment of the buildings located in the village of Krewerd which is located in the North-East of the Groningen region. The idea behind this experiment is to bypass the full assessment procedure based on numerical calculations and to produce retrofit plans based on engineering judgment in order to speed-up the entire retrofit procedure. In this framework the Fast Assessment Procedure proved being an helpful tool to assist the engineer in their decisions.