PSI - Issue 44

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

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

Procedia Structural Integrity 44 (2023) 363–370

© 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 design of beam-column joints is a crucial step of the design of seismic-resistant RC framed structures. Premature joint failure may prevent yielding of beams and the achievement of the target collapse mechanism. Hence, an effective capacity model is essential. In the past, Italian building code in force before NTC (2008) required that a minimum amount of ties, equal to that used in the column, be provided in the joint, but it did not stipulate any verification of the joint. Eurocode 8 (2005) and subsequently Italian NTC (2008 and 2018), recognize that shear in beam-column joint is higher than in columns and recommend the explicit verification of the joint. The suggested capacity model is based on stress analysis and is very demanding in terms of joint ties. The new draft of Eurocode 8 (2020) provides a different capacity model, based on research carried on by Fardis (2021), which better reflects the state of art on this topic under both theoretical and experimental point of view. This paper examines the capacity model for shear resistance of joints adopted in Eurocode 8 draft, underlining its advantages but also some difficulties in practical application. Based on a parametric analysis of a wide set of RC joints, it is showed that it is possible to assume that the joint rebars are yielded when the joint attains its ultimate limit state. This assumption does not determine any significant loss of precision in evaluating the shear resistance of the joint and leads to a capacity model consistent with other models adopted in Eurocode 8, e.g. those for shear resistance of RC beams. Furthermore, it allows a closed form solution of the problem that leads to a very simple procedure both for the verification of joint resistance and for the optimization of the design of horizontal and vertical rebars of the joint. © 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: seismic design; capacity design; RC joint. XIX ANIDIS Conference, Seismic Engineering in Italy A simple but effective capacity model for check and design of beam-column joints in RC seismic buildings Francesca Barbagallo a , Melina Bosco a , Aurelio Ghersi a, *, Edoardo M. Marino a , Francesco Sciacca a a DICAR, University of Catania, Via Santa Sofia 64, 95125 Catania, Italy Abstract The design of beam-column joints is a crucial step of the design of seismic-resistant RC framed structures. Premature joint failure may prevent yi lding of beams and the achiev men of the target collapse mechanism. Hence, an effectiv c pacity model is essential. I the past, Italian buildi g code in force before NTC (2008) required that a minimum amount of ties, equal o that used in the column, be provided in the joint, but it did not stipulate any verification of he joi t. Eurocode 8 (2005) and subsequently Italian NTC (2008 and 2018), recog ize that shear in beam-column joint is higher than in columns and recommend the explicit ver fication of the joi t. The suggested capacity model is based on stress analysis and is very dema ding in ter s of joint ti s. The n w dr ft of Euroc de 8 (2020) provi es a d fferent capacity m del, based on research ca ried on by Fardis (2021), which better r flects the state f art on this topic un r both theoretical and experimental point of view. This paper ex mines the capac ty mod l for shear resistance of joints adopte in Eurocod 8 dr ft, underlini g its advantages but also some difficulties in practica application. Based on a parametric analysis of a wi set of RC joints, it is showed th t it is possible t assume tha the joint rebars re yielded when the joint ttains its u timate lim t state. This assumption d es no determine any significant loss of precision in evaluating the shear res stance of the joint nd leads o a capacity model consi tent with other models adopted in Eurocode 8, e.g. those for shear r sistance of RC beams. Furthermore, it allows a cl sed f rm olution of pr bl m that l ads to a very simple pr c du e both for the v rification of joint resistance and for the optimization of the design of horizontal nd vertical rebars of th joint. © 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 u der re ponsibility of scientific committe of the XIX ANIDIS Conference, Seismic Engineering in Italy K ywords: seismic design; capacity design; RC joint. XIX ANIDIS Conference, Seismic Engineering in Italy A simple but effective capacity model for check and design of beam-column joints in RC seismic buildings Francesca Barbagallo a , Melina Bosco a , Aurelio Ghersi a, *, Edoardo M. Marino a , Francesco Sciacca a a DICAR, University of Catania, Via Santa Sofia 64, 95125 Catania, Italy

* Corresponding author. Tel.: +39-320-439-1967. E-mail address: aurelio.ghersi@unict.it * Corresponding author. Tel.: +39-320-439-1967. E-mail address: aurelio.ghersi@unict.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.2023.01.048