A physical approach on flood risk vulnerability of buildings

Abstract

Abstract. The design of efficient hydrological risk mitigation strategies and their subsequent implementation relies on a careful vulnerability analysis of the elements exposed. Recently, extensive research efforts were undertaken to develop and refine empirical relationships linking the structural vulnerability of buildings to the impact forces of the hazard processes. These empirical vulnerability functions allow estimating the expected direct losses as a result of the hazard scenario based on spatially explicit representation of the process patterns and the elements at risk classified into defined typological categories. However, due to the underlying empiricism of such vulnerability functions, the physics of the damage-generating mechanisms for a well-defined element at risk with its peculiar geometry and structural characteristics remain unveiled, and, as such, the applicability of the empirical approach for planning hazard-proof residential buildings is limited. Therefore, we propose a conceptual assessment scheme to close this gap. This assessment scheme encompasses distinct analytical steps: modelling (a) the process intensity, (b) the impact on the element at risk exposed and (c) the physical response of the building envelope. Furthermore, these results provide the input data for the subsequent damage evaluation and economic damage valuation. This dynamic assessment supports all relevant planning activities with respect to a minimisation of losses, and can be implemented in the operational risk assessment procedure.

Vulnerability curves vs. vulnerability indicators: application of an indicator-based methodology for debris-flow hazards

“…Analytically and Although the indicators may give an overview of the actual situation, the links between natural process statistically sound and degree of loss, as well as the reaction of a structure to the natural process according to its characteristics, are not fully understood and, therefore, further research is required (Mazzorana et al, 2014).…”

3-D hydrodynamic modelling of flood impacts on a building and indoor flooding processes

“…Within the context of an analysis of a torrential hazard event, thereby explicitly focusing on the morphodynamic processes and not taking into account any geo-mechanical processes or the building's physics, Mazzorana et al (2014) applied the proposed concept for a residential building located at the alluvial cone of the Grossberg torrent in the Italian Alps. The study highlighted the circumstance that for medium hazard intensities, vulnerability of buildings critically depends on the patterns of water and material intrusion through openings such as doors, light shafts and windows.…”

“…Due to the underlying empiricism of such vulnerability functions, the physics of the damage-generating mechanisms remains unveiled, and, as such, the applicability of the empirical approach for planning hazard-proof buildings is rather limited. Mazzorana et al (2014) identified the following essential requirements for vulnerability assessment of buildings exposed to fluvial hazard processes. a.…”

“…In the case of numerical modelling, significant advances in modelling techniques and the augmented computational power presently allow for analyses of complex issues and scenarios (e.g. Gems et al, 2014a, b;Mazzorana et al, 2014;Chiari, 2008). They enable the simulation of hazard processes on a large spatial scale (e.g.…”

“…Quantification of the resulting impacts on a building envelope and detection of possible material intrusion processes require an analysis of the geometrical structure of the building with respect to the time-varying flow field of the impacting process and, if geo-mechanical actions may interfere, with respect to the residual bearing capacity of the soil layers in which the object is situated. Referring to these basic requirements, Mazzorana et al (2014) defined a five-step procedure according to Fig. 2 in order to reliably assess the physical vulnerability of elements at risk.…”