Seismic performance assessment and base-isolated floor protection of statues exhibited in museum halls

Abstract

A study concerning the evaluation of seismic response of statues exhibited in art museums, and a base-isolated floor strategy for their enhanced protection, are presented in this paper. Attention is particularly focused on statues made of small tensile strength materials, whose behaviour is simulated by a smeared-crack finite element approach. Seismic performance is assessed by referring to four levels specially postulated herein, and namely: (1) Rest conditions; (2) No rocking; (3) Damage control; and (4) Collapse prevention. The response is investigated via incremental dynamic analysis, by progressively increasing the amplitude of the ground motion histories adopted as inputs, and by relating output data to the limit conditions fixed for the above-mentioned performance levels. The assessment procedure is applied to a demonstrative case study, represented by a marble statue to be exhibited in the museum wing situated at the ground level of a medieval castle in Italy, according to an architectural hypothesis of partial rebuilding and reuse of the stronghold. The design solution for the base-isolated floor consists in a system of double-friction pendulum isolators. The finite element model constitutive laws and parameters, the dynamic analyses carried out in fixed-base and base-isolated floor conditions, and the practical implementation of the assumed performance assessment criteria are reported for the statue examined, along with a selection of technical details of the floor design. © 2014, Springer Science+Business Media Dordrecht

Geomatic 3d Modeling of a Statue (Also) for Structural Analysis and Risk Evaluation: The Example of San Giovannino Martelli in Florence

“…For the St. John the Baptist example, concerning its material, taking into consideration that no characterization tests were carried out, mechanical properties were established by referring to typical values suggested in literature, particularly adopting coefficients of a similar case treated by Sorace and Terenzi (2015) and reported in the following Regarding the restraints, since it was supposed that no movement on the base of the statue is possible, a fixed end was there adopted. No other restrains were considered.…”

“…In order to design the restoration and with the purpose to find a less invasive and more reversible approach of reconstruction, the conservators decided to preliminary study all the aspect laser scanning the fragments of the statue, virtual reconstructing the model of the statue and finally analysing it with FEM. The last example considered was the work of Sorace and Terenzi (2015) which concerns the evaluation of seismic response of statues exhibited in art museums and a strategy of baseisolated floor for their enhanced protection. The analysed statue is a marble copy of a Hellenistic sculpture of the Greek philosopher Socrates: in this case, the structural analysis has been carried out onto a simplified 3D model of the statue.…”

Modelling of Rocking and Sliding Effects in the Seismic Analysis of a Free-Standing Column

“…Unlike the geometrically complex marble statue examined in (Sorace and Terenzi, 2007;2015), where a smeared-crack numerical model was adopted to detect the evolution of cracking-related damage in the most stressed portions of the mesh, the simple shape and structural configuration of the examined column allowed limiting its assessment analysis to the elastic field. Indeed, these characteristics help easily locate the most critical zones where crack can arise and grow at the foot of the drum, checked by comparing the maximum computed tensile stress values with the corresponding strength ftm.…”

“…However, although meeting the desired stability requirements, base-fixing strategies imply that the seismic accelerations occurring at the base of the objects are fully transmitted to them. This causes severe damages at the BDE and MCE levels, even leading to strength-related (instead of overturning-induced) collapses, especially in artworks made of low tensile strength materials (Borri and Grazini, 2006;Sorace and Terenzi, 2015). An effective alternative installation strategy, increasingly investigated and applied during the last decade, is represented by seismic isolation, either of single objects (Contento and Di Egidio, 2009;Vassiliou and Makris, 2012;Chiozzi et al, 2016) or of groups of artefacts placed on the same floor (Sorace and Terenzi, 2015).…”

“…The response of the column is examined according to the seismic assessment procedure proposed in (Sorace and Terenzi, 2007;2015) for any type of art object, articulated on a set of four seismic performance levels expressly formulated to the purpose, and namely: 1) Rest, 2) No rocking, 3) Damage control/Cultural value safety and 4) Collapse prevention.…”