MASCIOTTA, MARIA GIOVANNA1; LOURENÇO, PAULO B.2; RAMOS, LUÍS F.3; VASTA, MARCELLO4; STURM, THOMAS5; CAMPOS-COSTA, ALFREDO6

1) PhD Candidate, ISISE, Department of Civil Engineering, University of Minho, Guimarães, Portugal, mg.masciotta@gmail.com

2) Full Professor, ISISE, Department of Civil Engineering, University of Minho, Guimarães, Portugal, pbl@civil.uminho.pt

3) Assistant Professor, ISISE, Department of Civil Engineering, University of Minho, Guimarães, Portugal, lramos@civil.uminho.pt

4) Associate Professor, Department of Engineering and Geology, University “G. d’Annunzio”, Pescara, Italy, mvasta@unich.it

5) PhD candidate, ISISE, Department of Civil Engineering, University of Minho, Guimarães, Portugal, tsturm@civil.uminho.pt

6) Director of the NESDE, LNEC, alf@lnec.pt

Conservation of ancient built heritage plays a leading role for modern societies. Knowledge about ancient building methods, essentially based on the use of natural materials such as earth, stone and wood, is fundamental to plan interventions aimed at preserving the architectural heritage. Due to the growing research on sustainable technologies, the interest in structural systems built using natural materials has been rising more and more. Taking an earthen mock-up construction as model, the paper focuses on the dynamic behaviour of such a system tested on a shaking table. Detailed descriptions of the model, its mechanical features, the seismic test performed and the damage pattern obtained are first presented. Then, the dynamic identification of the structure during damage occurrence is performed through the decomposition of the power spectral density matrix. Damage evolution and localization are also analyzed by an index based on the complex eigenvectors estimated from the matrix. Finally, comparisons between experimental and analytical results are addressed.

Keywords: Earth construction, dynamic identification, damage localization, spectral-based identification technique, shaking table test, earthquake.