SEISMIC ASSESSMENT OF COMPLEX ASSETS THROUGH NONLINEAR STATIC ANALYSES: THE FORTRESS IN SAN FELICE SUL PANARO HIT BY THE 2012 EARTHQUAKE IN ITALY

!This!paper!proposes!a!procedure!for!the!seismic!assessment!of!unreinforced!ma2 sonry! complex! structures! together!with! a! first! application! to! the! case! of! fortresses.! The! proposal!of!such!procedure!arises!from!different!reasons:!firstly,!Standards!suggest!proce2 dures!mainly!addressed!to!ordinary!structures;!furthermore,!even!those!Recommendations,! which!are!more!specifically!addressed!to!monumental!assets,!state!only!general!principles,! without!specifying!operational!targeted2procedure!for!their!seismic!assessment.!The!dam2 age!occurred!after!past!earthquakes,!and!in!particular!the!one!hit!the!Emilia!region!in!Italy,! highlighted! that! fortresses! are! characterized! by! an! aggregation! of! bodies! with! an! own! seismic!behavior!which,!however,! is!strongly!affected!by!their!dynamic! interaction!due!to! the! mutual! boundary! conditions.! Hence,! the! adoption! of! a! numerical! three2dimensional! model!of!the!whole!structure!is!necessary!to!take!into!account!explicitly!the!effect!of!such! interactions.! The! proposed! procedure! requires! the! execution! of! a! modal! analysis! of! the! whole!structure!in!order!to!define!the!modes!involving!the!dynamic!response!of!each!units! and!their!modal!shapes.!Then,!fitting!the!modal!shapes,!proper!load!patterns!are!defined!to! pass! to! the! execution!of!pushover!analyses.! In!particular,! one! load!pattern! is!applied! for! each!unit!but!considering!the!whole!numerical!model.!The!pushover!curve!of!each!unit! is! then! converted! in! the! capacity! curve! to! finalize! the! seismic! assessment! and! verification.! The!proposed!procedure!is!applied!in!the!paper!to!the!case2study!of!San!Felice!sul!Panaro! fortress,!significantly!hit!by!the!Emilia!earthquake,!2012!allowing!the!comparison!between! the!occurred!damage!and!the!one!simulated!by!the!nonlinear!static!analyses!and!to!vali2 date!the!procedure.!The!potentialities!of!the!proposed!procedure!seem!relevant!in!order!to! provide!a!reliable!seismic!assessment!also!of!other!typology!of!complex!structures.! Available online at www.eccomasproceedia.org Eccomas Proceedia COMPDYN (2017) 2291-2300 © 2017 The Authors. Published by Eccomas Proceedia. Peer-review under responsibility of the organizing committee of COMPDYN 2017. doi: 10.7712/120117.5567.17917