Structural risk assessment of corroding RC structures under seismic excitation

Durability of reinforced concrete structures is a well known critical issue and civil engineers are aware of the need for durable design, as well as of the importance of maintenance, inspection and, if necessary, reparation/rehabilitation interventions. Furthermore, the assessment of RC constructions, especially of existing ones, is concerned with inevitable high uncertainties about geometry, material properties, applied loads and damage state, thus requiring a probabilistic approach for a reliable evaluation of the present and future performance. These issues become even more crucial in presence of natural hazards striking the structure, such as seismic excitations. In this paper, the major effects of aggressive environments on the seismic response of RC members are analyzed along with a probabilistic risk management procedure. In particular, a 4-steps methodology is developed to investigate the variation of the seismic behavior of a real case study over its service life, in presence of increasing degradation levels. Finally, the seismic risk associated with the long-term performance of the construction is calculated, providing a significant support in the implementation of efficient strategies for risk reduction.

► The seismic response of structures depends on the level of degradation.
► Probabilistic approach has been used for safety assessment of existing RC structures.
► The structural risk has been evaluated by considering two independent hazards.