Zuverlässigkeitstheoretische Ermittlung der Sicherheit bestehender Tragwerke: Möglichkeiten und Grenzen / Assessing the Safety of Existing Structures using a Reliability Based Framework: Possibilities and Limitations

Safety, reliability and risk are key issues in the preservation of our built, cultural heritage. Several structural collapses make us aware of the vulnerability of our technical and natural environment and demand an adequate engineering response. The architectural preservation process is generally based on a sequence of anamnesis and analysis, diagnosis, therapy, control and prognosis. In the analysis phase, an objective way to assess the safety of the structure is essential. The present raises the need for a reliability based assessment framework for existing masonry structures. As it is a major concern of engineers, the notions of reliability and risk and related theory and practice are no longer working topics for specialists only. Powerful methods are available for the calculation of structural safety values. These permit to calculate the global probability of failure of complex structures, relying on deterministic techniques able to calculate the stability state for a prescribed set of parameters. This paper illustrates how these techniques can be a valid tool to evaluate the bearing capacity of existing structures. The applications focus on the assessment of existing masonry structures.