From rapid visual survey to multi-hazard risk prioritisation and numerical fragility of school buildings

In: Natural hazards and earth system sciences: NHESS, Band 19, Heft 7, S. 1365-1386

Abstract

Abstract. Regional seismic risk assessment is paramount in
earthquake-prone areas, for instance, to define and implement prioritisation
schemes for earthquake risk reduction. As part of the Indonesia School Programme to Increase Resilience (INSPIRE), this paper
proposes an ad hoc rapid-visual-survey form, allowing one to (1) calculate the
newly proposed INSPIRE seismic risk prioritisation index, which is an
empirical proxy for the relative seismic risk of reinforced concrete (RC)
buildings within a given building portfolio; (2) calculate the Papathoma
Tsunami Vulnerability Assessment (PTVA) index, in any of its variations; (3) define one or more archetype buildings representative of the analysed
portfolio; (4) derive detailed numerical models of the archetype buildings,
provided that the simulated design is used to cross-check the model assumptions.
The proposed INSPIRE index combines a baseline score, calibrated based on
fragility curves, and a performance modifier, calibrated through the
analytic hierarchy process (AHP) to minimise subjectivity. An attempt to
define a multi-hazard prioritisation scheme is proposed, combining the
INSPIRE and PTVA indices. Such a multi-level framework is implemented for 85
RC school buildings in Banda Aceh, Indonesia, the most affected city by
the 2004 Indian Ocean earthquake–tsunami sequence. As part of the proposed
framework, two archetype buildings representative of the entire portfolio
are defined based on the collected data. Their seismic performance is
analysed by means of non-linear static analyses, using both the analytical
simple lateral mechanism analysis (SLaMA) method and numerical finite-element pushover analyses to investigate the expected plastic mechanisms and
derive displacement/drift thresholds to define appropriate damage states.
Finally, non-linear dynamic analyses are performed to derive fragility
curves for the archetype buildings. This paper demonstrates the
effectiveness of the INSPIRE data collection form and proposed index in
providing a rational method to derive seismic risk prioritisation schemes
and in allowing the definition of archetype buildings for more detailed
evaluations/analyses.