Numerical Investigation of the Retrofitting Interventions of the San Benedetto Church Complex in Ferrara (Italy) from a Seismic Vulnerability Perspective

Abstract

The San Benedetto church complex is an iconic architectural heritage asset of Ferrara, an attractive small city in the North of Italy. This paper investigates two separate parts from the complex, respectively the church, and the bell tower. The construction of the church dates back in the XV century, and many modifications were carried through years. During the second world war the church was severely damaged and then was fully restored to the original design. The bell tower instead is a typical tower of northern Italy, notably inclined by 3°. In the last decade, severe earthquake sequences occurred in the nearby areas, and the occupancy and safety of the structures were compromised. Several observed damages impelled upgrading measures, and consequently, many different retrofitting interventions got executed. Advanced numerical simulations are conducted in order to estimate the seismic vulnerability of each structure, by means of non-linear dynamic analysis. A critical historical evolution of the structure is considered, and two models for each structure are conceived respectively. The church models consist of 1) post-war reconstruction modeled with two distinct materials; 2) post-earthquake intervention with repointing technique and composites. The bell towers models consist of 1) the non-retrofitted tower; 2) the model with steel hooping bars. A comparative analysis is carried out based on the numerical results highlighting the pros and cons of each modeling technique and the efficiency of each intervention. Structural stiffening incorporated with a non-uniform distribution of the resisting capacities of the load-bearing elements highlights the seismic vulnerabilities. The necessity for the advanced numerical simulation emerges by the evidenced vulnerabilities in the performed simulations concerning the overall structural safety.

Full document

References

[1] L. Binda, C. Modena, F. Casarin, F. Lorenzoni, L. Cantini, S. Munda, Emergency actions and investigations on cultural heritage after the L’Aquila earthquake: The case of the Spanish Fortress, Bull. Earthq. Eng. (2011). doi:10.1007/s10518-010-9217-3.

[2] A. Borri, M. Corradi, G. Castori, A. De Maria, A method for the analysis and classification of historic masonry, Bull. Earthq. Eng. 13 (2015) 2647–2665. doi:10.1007/s10518-015-9731-4.

[3] A.B. Habieb, M. Valente, G. Milani, Hybrid seismic base isolation of a historical masonry church using unbonded fiber reinforced elastomeric isolators and shape memory alloy wires, Eng. Struct. (2019). doi:10.1016/j.engstruct.2019.109281.

[4] G. Milani, R. Shehu, M. Valente, Seismic Upgrading of a Masonry Church with FRP Composites, Mater. Sci. Forum. 866 (2016) 119–123. doi:10.4028/www.scientific.net/MSF.866.119.

[5] F. Mollaioli, O. AlShawa, L. Liberatore, D. Liberatore, L. Sorrentino, Seismic demand of the 2016–2017 Central Italy earthquakes, Bull. Earthq. Eng. (2018). doi:10.1007/s10518-018-0449-y.

[6] M. Acito, E. Magrinelli, G. Milani, S. Tiberti, Seismic vulnerability of masonry buildings : Numerical insight on damage, J. Build. Eng. (2019) 101081. doi:10.1016/j.jobe.2019.101081.

[7] M. Valente, G. Milani, Seismic response and damage patterns of masonry churches: Seven case studies in Ferrara, Italy, Eng. Struct. 177 (2018) 809–835. doi:10.1016/j.engstruct.2018.08.071.

[8] A. Aşıkoğlu, Ö. Avşar, P.B. Lourenço, L.C. Silva, Effectiveness of seismic retrofitting of a historical masonry structure: Kütahya Kurşunlu Mosque, Turkey, Bull. Earthq. Eng. (2019). doi:10.1007/s10518-019-00603-6.

[9] L. Sorrentino, L. Liberatore, L.D. Decanini, D. Liberatore, The performance of churches in the 2012 Emilia earthquakes, Bull. Earthq. Eng. 12 (2014) 2299–2331. doi:10.1007/s10518-013-9519-3.

[10] P. Roca, M. Cervera, G. Gariup, L. Pela, Structural analysis of masonry historical constructions. Classical and advanced approaches, Arch. Comput. Methods Eng. 17 (2010) 299–325. doi:10.1007/s11831-010-9046-1.

[11] S. Casolo, S. Neumair, M.A. Parisi, V. Petrini, Analysis of seismic damage patterns in old masonry church facades, Earthq. Spectra. 16 (2000) 757–773. doi:10.1193/1.1586138.

[12] V. Sarhosis, G. Milani, A. Formisano, F. Fabbrocino, Evaluation of different approaches for the estimation of the seismic vulnerability of masonry towers, Bull. Earthq. Eng. (2017). doi:10.1007/s10518-017-0258-8.

[13] M. Shakya, H. Varum, R. Vicente, A. Costa, Seismic vulnerability assessment methodology for slender masonry structures, Int. J. Archit. Herit. 00 (2018) 1–30. doi:10.1080/15583058.2018.1503368.

[14] M. Valente, G. Milani, Effects of Geometrical Features on the Seismic Response of Historical Masonry Towers, J. Earthq. Eng. (2017) 1–33. doi:10.1080/13632469.2016.1277438.

[15] G. Milani, R. Shehu, M. Valente, Seismic vulnerability of leaning masonry towers located in Emilia-Romagna region, Italy:FE analyses of four case studies, AIP Conf. Proc. 1790 (2016) 130002. doi:10.1063/1.4968720.

[16] G. Milani, R. Shehu, M. Valente, Seismic Assessment of Masonry Towers by Means of Non-linear Static Procedures, Procedia Eng. 199 (2017) 266–271. doi:10.1016/j.proeng.2017.09.022.

[17] P.B. Lourénço, R. De Borst, J.G. Rots, A plane stress softening plasticity model for orthotropic materials, Int. J. Numer. Methods Eng. 40 (1997) 4033–4057. doi:10.1002/(SICI)1097-0207(19971115)40:21<4033::AID-NME248>3.0.CO;2-0.

[18] L. Gambarotta, S. Lagomarsino, Damage Models for the Seismic Response of Brick Masonry Shear Walls. Part II: the Continuum Model and Its Applications, Earthq. Eng. Struct. Dyn. 26 (1997) 441–462. doi:10.1002/(SICI)1096-9845(199704)26:4<441::AID EQE651>3.0.CO;2-0.

[19] S. Lagomarsino, A. Penna, A. Galasco, S. Cattari, TREMURI program: An equivalent frame model for the non-linear seismic analysis of masonry buildings, Eng. Struct. 56 (2013) 1787–1799. doi:10.1016/j.engstruct.2013.08.002.

[20] D.S. Simulia, Abaqus 6.14 documentation, (2014).

[21] NTC, Aggiornamento delle “Norme Tecniche per le Costruzioni” - NTC 2018, Italy, 2018.

[22] CNR-DT 215, Istruzioni per la Progettazione, l’Esecuzione ed il Controllo di Interventi di Consolidamento Statico mediante l’utilizo do Compositi Fibrorinforzati a Matrice Inorganica, 2018.

[23] S. Casolo, V. Diana, G. Uva, Influence of soil deformability on the seismic response of a masonry tower, Bull. Earthq. Eng. 15 (2017) 1991–2014. doi:10.1007/s10518-016-0061-y.

[24] EC-8-P-1, Eurocode 8 : Design of structures for earthquake resistance - Part 1, 2014.

[25] G.L. Stockdale, V. Sarhosis, G. Milani, Seismic capacity and multi-mechanism analysis for dry-stack masonry arches subjected to hinge control, Bull. Earthq. Eng. (2020). doi:10.1007/s10518-019-00583-7.