PSI - Issue 44

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

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ScienceDirect

Procedia Structural Integrity 44 (2023) 618–625

XIX ANIDIS Conference, Seismic Engineering in Italy The soil-structure interaction effect on the seismic vulnerability assessment and retrofitting of existing bridges

Marco Gallo a *, Romeo Tomeo a , Emidio Nigro a a Department of Structural Engineering, Via Claudio 21, Naples 80125, Italy

© 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. Abstract The bridges seismic vulnerability is a relevant subject, since a significant part of existing bridges has been designed without considering any seismic action or using technical references that suggested seismic actions generally lower than those currently defined. This generally leads to unsuitable structural performance of existing bridges against earthquakes. Moreover, it must be considered that, in the response spectrum analysis method, the seismic stresses are significantly dependent on the structure vibration periods, which is also a consequence of modelling structure base constraint. This work aims to study the effect of soil-structure interaction (SSI) on the seismic vulnerability of typical reinforced concrete viaducts, considered by modelling the deformable base constraint. Starting from the real case study of a viaduct with prestressed concrete beams and reinforced concrete piles, the carried out analyses show the soil-structure interaction effect in terms of the ratio between stress and resistance of the piles, also varying the soil type and the piles slenderness. It is also possible to draw some interesting remarks in terms of the influence of the soil structure interaction on the possible seismic retrofitting interventions. © 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 Keywords: Bridges; seismic vulnerability; soil-structure interaction; seismic assessment; seismic retrofitting. 1. Introduction The issue of seismic vulnerability of bridges is particularly important, given that most of the existing bridge stock was designed and built in the second half of the 1900s. As a result, they were designed using technical regulations that 22 The Authors. Publishe https://creativecomm

* Corresponding author. Tel.: +39-331-26 66 818. E-mail address: marco.gallo@unina.it E-mail address: marco.gallo@unina.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 © 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.2023.01.081