Qualitative methods to estimate seismic damage at urban scale: A case study in Oran (Algeria)

The assessment of urban seismic vulnerability should always account for the robustness and uncertainty of the used methods. This paper presents a comparison on preliminary evaluations of expected damage within an urban district of the city of Oran (Algeria) in order to exploit a non-dedicated set of data issued from a technical survey of the buildings. Three different methods are used (GNDT 2; RISK-UE LM1; and VULNERALP 2.0). Cross-method comparisons highlight a satisfactory agreement between mean damage estimates at the urban scale, despite significant scattering at the single building scale, and uncertainty levels which vary significantly from one method to the other. For a given scenario, the three methods provide damage estimates lying within half an EMS damage degree of one another, with some systematic positive bias for VULNERALP and negative bias for RISK-UE LM1, especially for masonry buildings.