Seismic fragility of existing RC buildings with corroded bars under earthquake sequences

Di Sarno, Luigi ORCID: 0000-0001-6244-3251 and Pugliese, Francesco ORCID: 0000-0003-1829-3473 (2020) Seismic fragility of existing RC buildings with corroded bars under earthquake sequences. Soil Dynamics and Earthquake Engineering, 134. p. 106169.

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Official URL: http://dx.doi.org/10.1016/j.soildyn.2020.106169

Abstract

Earthquakes are not isolated events and, typically, dominated by a larger-magnitude excitation (Mainshock – MS) and many smaller-magnitude motions (Aftershock – AS). Most often, such destructive events bring more damage than a single strong motion. Nowadays, many existing non-seismic designed RC structures are classified as either functional-obsolete or sub-standards. The seismic performance of these aged structures can be even more critical if some phenomena, such as corrosion, occur. The present study aimed at evaluating the seismic vulnerability of typical existing RC structures subjected to earthquake sequences and various levels of corrosion. A probabilistic approach via the fragility analysis, and three different seismic intensity measures (IM), was carried out. A four-story RC building was used as a testbed for Incremental Dynamic Analyses (IDA) via an advanced Finite Element approach. Twenty as-recorded natural motions were selected from international databases and inserted into the three-dimensional model. A new seismic intensity measure was provided and compared to the world-wide accepted peak ground acceleration (PGA) and spectral acceleration at the first natural period of the structure (Sa(T1)); the modified spectral acceleration intensity (MASI). The limit states of limited damage (LD) and severe damage (SD) were considered as capacity thresholds. The outcomes of this numerical investigation showed that multiple excitations and corrosion significantly affect the seismic vulnerability of the investigated building; MASI appeared to be the most effective intensity measure to assess the seismic fragility of corroded RC buildings; modern seismic-based technical codes are no longer conservative for such detrimental phenomena.

Item Type:	Article
Uncontrolled Keywords:	Corrosion, Seismic fragility assessment, Earthquake engineering, Structural modelling, Probabilistic analysis
Depositing User:	Symplectic Admin
Date Deposited:	16 Apr 2020 10:29
Last Modified:	18 Jan 2023 23:54
DOI:	10.1016/j.soildyn.2020.106169
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3083463