Abstract
Existing buildings can easily present material mechanical properties which can largely vary even within a single structure. As a consequence of the high strength variability, at the occurrence of seismic events the structure may evidence unexpected phenomena, like torsional effects, with larger experienced deformations and, in turn, with reduced seismic performance. This work is focused on the reduction in seismic performance due to the concrete strength variability. The analysis has been performed on a case-study, i.e. a 3D RC framed 4 storey building. A normal distribution, compatible to a large database, has been taken to represent the concrete strength domain. Due to the introduced strength variability, a stiffness and strength eccentricity arises at the first storey of the structure, with a consequent increase in its seismic response. The capacity (C) of each column of the case study, found according to EC8 prescriptions, has been compared to the demand (D), for three different limit states. The seismic performance found by accounting for the strength variability has been compared to the one provided by the EC8 standard procedure, which has resulted to be conservative in the seismic response estimation and in the evaluation of the torsional effects, while it is not conservative in quantifying the seismic performance of the case-study.
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References
Anagnastopoulos SA, Alexopoulou C, Kyrkos MT (2009) An answer to an important controversy and the need for caution when using simple models to predict inelastic earthquake response of buildings with torsion. Earthq Eng Struct Dyn 39:521–540
Anagnastopoulos SA, Kyrkos MT, Stathopoulos KG (2013) Earthquake induced torsion in buildings: critical review and state of art. Proc. ASEM13, Jeju
Bosco M, Ghersi A, Marino EM (2012) Corrective eccentricities for assessment by the nonlinear static method of 3D structures subjected to bidirectional ground motions. Earthq Eng Struct Dyn 41:1751–1773
Bosco M, Marino EM, Rossi PP (2013) An analytical method for the evaluation of the in-plan irregularity of non-regularly asymmetric buildings. Bull Earthq Eng 11:1423–1445
Cristofaro MT (2009) Metodi di valutazione della resistenza a compressione del calcestruzzo di strutture in c.a. esistenti. PhD Dissertation, Università di Firenze
Cristofaro MT, D’Ambrisi A, De Stefano M, Pucinotti R, Tanganelli M (2012) Studio sulla dispersione dei valori di resistenza a compressione del calcestruzzo di edifici esistenti. Il giornale delle prove non distruttive, monitoraggio, diagnostica., vol. 2/2012, pp. 32–39, ISSN: 1721-7075
De Stefano M, Tanganelli M, Viti S (2013a) Effect of the variability in plan of concrete mechanical properties on the seismic response of existing RC framed structures. Bull Earthq Eng. doi:10.1007/s10518-012-9412-5
De Stefano M, Tanganelli M, Viti S (2013b) On the variability of concrete strength as a source of irregularity in elevation for existing RC buildings: a case study. Bull Earthq Eng. doi:10.1007/s10518-013-9463-2
De Stefano M, Tanganelli M, Viti S (2014) Variability in concrete mechanical properties as a source of in-plan irregularity for existing RC framed structures. Eng Struct. doi:10.1016/j.engstruct.2013.10.027
De Stefano M, Tanganelli M, Viti S (2015a) Torsional effects due to concrete strength variability in existing buildings. Earthq Struct 8(2):379–399
De Stefano M, Tanganelli M, Viti S (2015b) Seismic performance sensitivity to concrete strength variability: a case-study. Earthq Struct 9(2):321–337
EC 2 (2002) Eurocode 2: design of concrete structures. European Committee for Standardization (CEN), Brussels
EC 8–3 (2005) Design of structures for earthquake resistance, part 3: strengthening and repair of buildings, European standard EN 1998-3. European Committee for Standardization (CEN), Brussels
Franchin P, Pinto PE, Rajeev P (2007) Confidence factor? J Earthq Eng 14(7):989–1007
Jalayer F, Iervolino I, Manfredi G (2008) Structural modeling: uncertainties and their influence on seismic assessment of existing RC structures. Struct Saf 32:220–228
Monti G, Alessandri S, Goretti A (2007) Livelli di conoscenza e fattori di confidenza. XII Convegno ANIDIS, L’ingegneria sismica in Italia. Pisa 10–14 Giugno 2007
Rajeev P, Franchin P, Pinto PE (2010) Review of confidence factor in EC8-Part 3: a European Code for Seismic Assessment of Existing Buildings, International Conference on Sustainable Built Environment ICSBE 2010, Kandy
Seismosoft (2006) Seismostruct version 5.2.2 – a computer program for static and dynamic nonlinear analysis of framed structures. Available online from URL: www.seismosoft.com
Acknowledgements
The financial support provided by ReLUIS within the project “ReLUIS-DPC 2014” (Progettazione e valutazione della sicurezza e della vulnerabilità di edifici ed opere) is gratefully acknowledged.
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Viti, S., Tanganelli, M., De Stefano, M. (2016). The Concrete Strength Variability as Source of Irregularity for RC Existing Buildings. In: Zembaty, Z., De Stefano, M. (eds) Seismic Behaviour and Design of Irregular and Complex Civil Structures II. Geotechnical, Geological and Earthquake Engineering, vol 40. Springer, Cham. https://doi.org/10.1007/978-3-319-14246-3_13
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DOI: https://doi.org/10.1007/978-3-319-14246-3_13
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