PSI - Issue 44

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2022) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000 Available online at www.sciencedirect.com ScienceDirect

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Procedia Structural Integrity 44 (2023) 1640–1647

© 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the XIX ANIDIS Conference, Seismic Engineering in Italy. © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license ( https://creativecommons.org/licenses/by-nc-nd/4.0 ) Peer-review under responsibility of the scientific committee of the XIX ANIDIS Conference, Seismic Engineering in Italy Ab tract This study presen s a novel integrated discrete-analytical approach for n lyz ng the collapse b hav or of th asonry Medici tow r (L'Aquila, Italy). Due to heir slenderness, masonry towers are charact ized by high usceptibility to seismic action and several approaches can be adopt d to analyze their sei mic vulnerability. Generally, engine rs-practitio ers and researchers study the local a d global co lapse m chanisms based on sim lified kinematic a alysis, as pr scribed by national nd international c nstr ction cod r, alternatively, m re sophisticated approaches such as nonlinear finite ele nt methods have been adopted to simulate the response f m sonry tow rs. Although successful in some applications, these methods are lim ted in accurately cap uring crack distributi ns and fracture mechanisms. In fact, they completely ignore t e damage propagation pheno enon, starting from the trigger of the fractu e up to the complet structural failure condition, that is instead fundamental aiming to analyze ntermediate damage states for the check of serviceab lity limi states or to individuate a mor re l stic structural crack distribution in ultim e conditions. This work prop ses a hybrid discrete-kinematic approach: first, the Latti e D crete Particl Model (LDPM), that simulates masonry at meso-sc le, is used t individuate the actual collapse mechanism; next, the individuated cracked conf guration is used in the kinemat c analysis for the analysis in ultimate conditions. The ults show tha the collaps f the Medici tow r due to the 2009 L'Aquila earthquake is well predi ted by LDPM and the corre nding limi analyses demonstrate the efficiency of the proposed hybrid approach applied to this case study. Additional r sults point out that er nt load configur tions, more specifically varia ions n the direction of the seismic action, provoke in ce tain cases a more diffused damage and a clear failure p ttern can not be id ified for kin matic a alyses. In these cases, rely n mainly on comprehensive numerical odels, uch as LDPM, is fundamental to study the fracturing process from the cracks trigger up to the ultimate complex collapse mechanism. © 2022 The Authors. Published by ELSEVIER B.V. This is an ope access article under CC BY-NC-ND lic nse ( https://creativec mmons.org/licenses/by-nc-nd/4.0 ) Peer-review under responsibility of the scientific committee of the XIX ANIDIS Conference, Seismic Engineering in Italy XIX ANIDIS Conference, Seismic Engineering in Italy Analysis of the behavior of the masonry Medici tower resorting on a hybrid discrete-kinematic methodology Micaela Mercuri a, *, Madura Pathirage b , Amedeo Gregori a , Gianluca Cusatis b a University of L’Aquila, Department of Civil, Construction -Architecture and Environmental Engineering, Via G. Gronchi 18, 67100, AQ Italy b Northwestern University, Department of Civil and Environmental Engineering, 2145 Sheridan Road, Evanston, IL 20208-3109, USA Abstract This study presents a novel integrated discrete-analytical approach for analyzing the collapse behavior of the masonry Medici tower (L'Aquila, Italy). Due to their slenderness, masonry towers are characterized by high susceptibility to seismic actions and several approaches can be adopted to analyze their seismic vulnerability. Generally, engineers-practitioners and researchers study the local and global collapse mechanisms based on simplified kinematic analysis, as prescribed by national and international construction codes or, alternatively, more sophisticated approaches such as nonlinear finite element methods have been adopted to simulate the response of masonry towers. Although successful in some applications, these methods are limited in accurately capturing crack distributions and fracture mechanisms. In fact, they completely ignore the damage propagation phenomenon, starting from the trigger of the fracture up to the complete structural failure condition, that is instead fundamental aiming to analyze intermediate damage states for the check of serviceability limit states or to individuate a more realistic structural crack distribution in ultimate conditions. This work proposes a hybrid discrete-kinematic approach: first, the Lattice Discrete Particle Model (LDPM), that simulates masonry at meso-scale, is used to individuate the actual collapse mechanism; next, the individuated cracked configuration is used in the kinematic analysis for the analysis in ultimate conditions. The results show that the collapse of the Medici tower due to the 2009 L'Aquila earthquake is well predicted by LDPM and the corresponding limit analyses demonstrate the efficiency of the proposed hybrid approach applied to this case study. Additional results point out that different load configurations, more specifically variations in the direction of the seismic action, provoke in certain cases a more diffused damage and a clear failure pattern can not be identified for kinematic analyses. In these cases, relying mainly on comprehensive numerical models, such as LDPM, is fundamental to study the fracturing process from the cracks trigger up to the ultimate complex collapse mechanism. XIX ANIDIS Conference, Seismic Engineering in Italy Analysis of the behavior of the masonry Medici tower resorting on a hybrid discrete-kinematic methodology Micaela Mercuri a, *, Madura Pathirage b , Amedeo Gregori a , Gianluca Cusatis b a Universi y of L’Aquila, Departm nt of Civil, onstructio -Archit c ure and Env ronmental Engineering, Vi G. Gronchi 18, 67 0, AQ Italy b Northwestern University, Department of Civil and Environmental Engineering, 2145 Sheridan Road, Evanston, IL 20208-3109, USA Keywords: Seismic action; earthquake; Masonry tower; Discrete Modeling; Fracture Patterns; Kinematic analysis; Existing structures Keywords: Seismic action; earthquake; Masonry tower; Discrete Modeling; Fracture Patterns; Kinematic analysis; Existing structures

* Corresponding author. Tel.: +1-224-3841745 E-mail address: micaela.mercuri@graduate.univaq.it * Corresponding author. Tel.: +1-224-3841745 E-mail address: micaela.mercuri@graduate.univaq.it

2452-3216 © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the XIX ANIDIS Conference, Seismic Engineering in Italy 2452-3216 © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the XIX ANIDIS Conference, Seismic Engineering in Italy

2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the XIX ANIDIS Conference, Seismic Engineering in Italy. 10.1016/j.prostr.2023.01.210