Seismic assessment of free-standing artifacts: Full-scale tests on large shake table

Recent severe earthquakes highlighted the high vulnerability of artistic assets. Thus, the seismic assessment and formulation of preservation strategies of artifacts are key challenges of modern earthquake engineering, which require theoretical and experimental investigations. The present paper discusses the outcomes from large scale shake table tests carried out on full-scale free-standing artifacts. The study is also aimed at evaluating the reliability of existing simplified formulations to predict the rocking motion activation. Emphasis is on prototypes of marble busts with solid and hollow pedestals with different geometries. Comprehensive tests were performed within "Seismic Resilience of Museum Contents" (SEREME) project, which was recently funded by H2020 Framework Programme - Seismology and Earthquake Engineering Research Infrastructure Alliance for Europe (SERA). Uniaxial and biaxial earthquake natural records with different amplitudes and frequency contents were considered to assess the rocking motion of the sample specimens. Response parameters such as uplift, horizontal and vertical accelerations, angular velocity were measured to assess the rocking response of the sample freestanding busts and pedestals. Coefficients of amplification (CAF) of acceleration were also computed. The value of CAF showed that for solid pedestals they were not significantly influenced by peak ground acceleration (PGA) and earthquake type. Conversely, hollow pedestals, which were characterized by larger values of CAF than solid counterparts, ranging between 1 and 7, were affected by PGA and earthquake characteristics. Finally, the outcomes of the presented shake table tests showed that uplifts and angular velocity are effective measures for assessing rocking occurrence of tested artifacts.