SHM for historical buildings: preventive and post-earthquake controls

Structural health monitoring (SHM) is being more and more applied in the study of cultural heritage (CH) buildings, as a key activity to increase the knowledge on their structural behavior and to have a deeper insight on their conditions. This knowledge allows to carry out with more confidence (and only if necessary) possible strengthening interventions, but also to prevent the execution of intrusive repair works, if they are not justified by an experimentally demonstrated worsening of the structural conditions. The use of monitoring systems applied under ordinary conditions and installed on CH structures allows to: (i) validate the functioning of the adopted structural models; (ii) identify the ongoing damaging processes; (iii) validate the effectiveness of the strengthening interventions. In case of a seismic event, SHM can furthermore prove its usefulness in order (i) to quantitatively evaluate the progression of the assessed damage pattern, (ii) to design effective and urgent interventions if an unsafe displacement patterns is recorded, (iii) to define an early warning procedure for the safety of the workers employed in the strengthening interventions. Monitoring can also be effective when implemented on seriously damaged buildings, if the time schedule for the interventions is difficult to be a priori planned. In this framework, the authors (University of Padova, Italy) in collaboration with the officer of the Cultural Heritage Authority, the university of Nagoya (Japan), the National Institute of the Conservation and Restoration (ISCR) designed and installed SHM systems on six representative and emblematic CH buildings in L’Aquila after the devastating earthquake occurred on the 6th of April 2009 in the Abruzzi Region. The selected case studies SHM systems – presented in the paper – will allow to confirm the effectiveness of the use of structural monitoring during and after the emergency activities in case of a seismic event.