eprintid: 1575831 rev_number: 20 eprint_status: archive userid: 608 dir: disk0/01/57/58/31 datestamp: 2017-10-01 01:55:25 lastmod: 2020-02-12 16:14:19 status_changed: 2018-05-04 12:19:39 type: proceedings_section metadata_visibility: show creators_name: Ragni, L creators_name: Freddi, F creators_name: Tubaldi, E creators_name: Dall'Asta, A title: Probabilistic performance assessment of low ductility r.c. frames retrofitted by elasto-plastic braces ispublished: pub divisions: UCL divisions: A01 divisions: B04 divisions: C05 divisions: F44 keywords: Vulnerability of low ductility r.c. frames, seismic retrofit, fragility curves, elasto-plastic devices. note: This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. abstract: The paper illustrates a probabilistic methodology for assessing the vulnerability of existing r.c. buildings with limited ductility capacity and retrofitted by means of dissipative braces. The methodology is based on the development of single component and system fragility curves before and after the retrofit. The proposed approach allows to highlight the possible changes in the most significant collapse modalities before and after the retrofit and to evaluate the effectiveness of the retrofit by taking into account the probabilistic properties of the seismic behaviour of the considered systems. A benchmark 2-dimensional reinforced concrete frame with low ductility capacity is considered as case study. The frame is designed for gravity-loads only and does not comply with modern anti-seismic code requirements. It is retrofitted by introducing elasto-plastic dissipative braces designed for different levels of their target base-shear capacity, following a design method involving the pushover analysis of the system before and after retrofit. The obtained results show that the use of braces yields a significant increase in the seismic capacity, though an increased dispersion of the behaviour is observed in the retrofitted system. date: 2011-09-22 date_type: published publisher: ANIDIS official_url: http://convegno.anidis.it/index.php/anidis/2011/index oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 1424064 lyricists_name: Freddi, Fabio lyricists_id: FFRED33 full_text_status: public place_of_pub: Bari, Italy event_title: XIV National Conference ANIDIS, L'Ingegneria sismica in Italia event_location: Bari, Italy event_dates: 18 September 2011 - 22 September 2011 institution: XIV National Conference ANIDIS, L'Ingegneria sismica in Italia book_title: Proceedings of the XIV National Conference ANIDIS citation: Ragni, L; Freddi, F; Tubaldi, E; Dall'Asta, A; (2011) Probabilistic performance assessment of low ductility r.c. frames retrofitted by elasto-plastic braces. In: Proceedings of the XIV National Conference ANIDIS. ANIDIS: Bari, Italy. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/1575831/1/Freddi_Ragni%20et%20al.%202011_ANIDIS_Probabilistic%20performance%20assessment%20of%20low%20ductility%20r.c.%20frames%20retrofitted%20by%20elasto-plastic%20dissipative%20braces.pdf