Incremental Dynamic Analysis

Quantum mechanics

Engineering

Ground motion

Spectral acceleration

Response spectrum

Seismic analysis

Reinforced concrete

Classical mechanics

Seismology

Geology

Fragility

Peak ground acceleration

Thermodynamics

Physics

Aftershock

Structural engineering

Acceleration

Intensity (physics)

Engineering Structures

This paper presents the seismic vulnerability assessment of existing RC buildings designed according to previous non-seismic codes that are exposed to various levels of corrosion and mainshock-aftershock sequences. A refined finite element model of an existing four-storey reinforced concrete building is adopted. Twenty as-recorded natural ground motions are collected from international databases to perform incremental dynamic analyses for the inelastic response of the testbed building. The effects of corrosion are applied on external beams and columns to simulate a realistic exposure. The robust fragility assessment is conducted for a range of seismic intensity measures. Moreover, a new intensity measure, based on the modified acceleration spectrum intensity, is proposed. Such seismic parameter accounts for the elongation period experienced by structures during earthquake events and appears to be more reliable and accurate for corroded RC structures than the most adopted peak ground acceleration and spectral acceleration at the first natural period. The results of the comprehensive numerical simulations contribute to providing relevant indications on the non-linear response of existing corroded buildings under multiple excitations and, highlight that current seismic codes are no longer conservative for such detrimental phenomena.

Effects of mainshock-aftershock sequences on fragility analysis of RC buildings with ageing