The Response Of Unreinforced Masonry To Low-amplitude Recurcive Loads: Case Of Groningen Gas Field

Abstract

Unreinforced masonry (URM) is a fragile material that responds to cyclic load reversals in a non-ductile way, unless special measures are taken. Damage occurs in large amplitude loads causing partial or total collapse in some cases, as it was observed in the past earthquakes. Response of URM to recursive, frequent but low-amplitude seismic loads, on the other hand, is a relatively new topic that needs experimental and analytical validation. This paper focuses on Groningen URM buildings that have been subjected to low-amplitude load reversals in the last decades, especially in the very last decade, due to the induced seismicity caused by gas extraction. In the paper, previous experimental findings are reviewed mostly focusing on the range of low amplitudes. An exercise with existing hysteresis rules, trying to find residuals after recursive seismic actions, has been presented.