Physics-based flood risk vulnerability analysis of buildings    

 

Funding

Austrian Science Fund (FWF)

Applicant

  • Ass.-Prof. Dr. Bernhard Gems
    Unit of Hydraulic Engineering, University of Innsbruck (UIBK)

Partners

  • Institute of Mountain Risk Engineering (IAN)
    University of Natural Resources and Life Sciences (BOKU), Vienna

  • Assoz.-Prof. Dr. Bruno Mazzorana
    Institute of Environmental and Evolutive Sciences, Universidad Austral de Chile (UAC), Valdivia, Chile

Staff

  • Ass.-Prof. Dr. Bernhard Gems (project coordinator, UIBK)
  • DI Michael Sturm (UIBK)
  • BSc. Hannah Göttgens (UIBK)
     
  • Priv.-Doz. Dr. Sven Fuchs (BOKU)
  • Dr. Maria Papathoma Köhle (BOKU)
     
  • Assoz.-Prof. Dr. Bruno Mazzorana (UAC)

Project duration

     3 years, 07/2015 - 06/2018

 

Objective of the project

The present project deals with the vulnerability analysis of buildings exposed to torrential hazard processes in the Alpine region. At present, the determination of expected losses at buildings due to torrential hazards and its comparison with reconstruction costs is based on empirical loss functions. Straightforward relations of process intensities and the extent of losses, gathered by the analysis of historic flood events and the information of object-specific restoration values, are used therefore. The ascertainment of loss is commonly accompanied by the modelling of the relevant processes and, there, the definition of specific scenario intensities and occurrence intervals. This approach for the vulnerability analysis of buildings does not represent a purely physics-based and integral concept since relevant and for the extent of damages mostly crucial processes, as the intrusion of the fluid-sediment-mixture into elements at risk, are not explicitly considered. Further, a structural response analysis of the considered building, verifying object stability and usability under the influence of impacting loads from torrential hazards, is not performed.

The project will basically extend the findings and models of present risk research in the context of an integral, physics-based vulnerability analysis concept. Therein, all damage-relevant, morphodynamic processes impacting the considered elements at risk are adequately modelled, both experimentally within a physical scale model test and numerically. The dynamic impacts on the building envelopes are gathered quantitatively and spatially distributed by the use of a set of force transducers. A structural response model of the buildings, considering the impacts from the process modelling, is further applied in order to provide a link between the impact scenario simulations and the vulnerability analysis. Within the project, specific focus is put on the analysis of flood discharges with a rather high fraction of sediments. The experimental analysis is firstly done by analysing the impacts on artificial, vertical and skewed plates, including also openings for material intrusion. Further, the impacts on specific buildings within the test site of the project, the fan apex of the Schnannerbach torrent in Tyrol (Austria), are analysed in detail. The buildings are entirely reconstructed within the physical scale model (1:30), including basement and first floor and thereby all relevant openings on the building envelopes. In addition to a general vulnerability analysis, local technical protection measures are tested. Further, the interaction of the buildings in terms of a geo-statistical analysis is analysed.

The project results and the applied vulnerability analysis concept mean a significant expansion of the present methods for flood risk assessment. Further, for practical application, they are of basic importance, as they provide extensive information to support during hazard zone mapping and management and as well during the planning phase of local technical protection measures.

Work packages

Test site