A hybrid method for the vulnerability assessment of R/C and URM buildings

Abstract

The methodology followed by the Aristotle University (AUTh) team for the vulnerability assessment of reinforced concrete (R/C) and unreinforced masonry (URM) structures is presented. The paper focuses on the derivation of vulnerability (fragility) curves in terms of peak ground acceleration (PGA), as well as spectral displacement (s d ), and also includes the estimation of capacity curves, for several R/C and URM building types. The vulnerability assessment methodology is based on the hybrid approach developed at AUTh, which combines statistical data with appropriately processed (utilising repair cost models) results from nonlinear dynamic or static analyses, that permit extrapolation of statistical data to PGA's and/or spectral displacements for which no data are available. The statistical data used herein are from earthquake-damaged greek buildings. An extensive numerical study is carried out, wherein a large number of building types (representing most of the common typologies in S. Europe) are modelled and analysed. Vulnerability curves for several damage states are then derived using the aforementioned hybrid approach. These curves are subsequently used in combination with the mean spectrum of the Microzonation study of Thessaloniki as the basis for the derivation of new vulnerability curves involving spectral quantities. Pushover curves are derived for all building types, then reduced to standard capacity curves, and can easily be used together with the S d fragility curves as an alternative for developing seismic risk scenarios.

Integrating rockfall risk assessment and countermeasure design by 3D modelling techniques

“…The latter is a scenario-specific parameter defined as "the degree of loss to a given element or a set of elements within the area affected by the hazard" (ISSMGE TC32, 2004). In the field of natural hazards, well-established methods for the estimation of physical vulnerability have been developed for earthquake (Kappos, 2006) and flood risk (USACE, 1996). For landslides, the quantitative assessment of vulnerability is made difficult by the lack of accurate damage data and by the inherent complexity of landslide kinematics and interaction Fig.…”

Fragility Curves and Loss Estimation for Traditional Timber-Framed Masonry Buildings in Lefkas, Greece

“…The lognormal distribution is adopted here since it describes adequately the evolution of damage (Kircher et al 2006). This distribution is expressed by the equation: (Kappos et al 2006;Kircher et al 2006): (i) uncertainty due to the ground motion β D , (ii) uncertainty in the response of the structure (capacity curve), and (iii) uncertainty in the definition of damage states. A reasonable and convenient assumption is to consider that these 21 three sources of variability are statistically independent and thus, the total standard deviation β ds,i is estimated as the square root of the sum of the squares of each term.…”

“…Four damage states have been considered here, ranging from DS1 (negligible to small damage) to DS4 (total collapse); their designation is provided in Table 4. Each damage state is related to a certain degree of loss, usually defined in terms of structural performance or of cost of repair (monetary index) (Kappos et al 2006). In the latter case loss may reach values over 100% due to an excessive repair cost with respect to the cost of replacement.…”

“…A reasonable definition of the damage states is in line with the similar category of unreinforced masonry buildings (Barbat et al 2008;Kappos et al 2006;Pujades et al 2010):…”

Approach to Prediction of R/C Buildings’ Seismic Damage as Pattern Recognition Problem Using Artificial Neural Networks

“…Respectively, the researches belonging to the second category led to the development of methodologies that can accomplish the approximate assessment of the seismic vulnerability of buildings' groups with common structural characteristics (e.g. rapid screening methods; damage probability matrices; fragile curves, see for example [4,5,6]. These methods can be used in order to estimate the buildings' seismic vulnerability in a very short time comparing with the methods of the first category, with the price of losing accuracy.…”