Professor, Slovenian National Building and Civil Engineering Institute; Ljubljana, Slovenia
miha.tomazevic@zag.si
ABSTRACT
The paper presents Slovenian experience regarding seismic redesign of old masonry buildings and application of traditional and up-to-date methods of strengthening. Among Eurocodes, European standards for structural design, a standard to regulate the seismic assessment and strengthening of existing buildings has been prepared, where the procedures and requirements to ensure the fulfillment of minimum demands are specified. Although the basic principles of earthquake resistant design are followed, some requirements regarding the seismic redesign of old masonry buildings of historic importance need to be modified, like the requirement to simultaneously use of confidence and partial material safety factors for the reduction of experimentally obtained values of mechanical properties of masonry in seismic resistance verification. As the analysis of damage to retrofitted masonry buildings, subjected to design-level earthquakes twice in just a few decades, indicated, such a requirement is too conservative and would lead to unacceptable (and unnecessary) structural alterations. The applicability and efficiency of various strengthening methods, using traditional and synthetic materials, is also discussed. Whereas the use traditional materials and methods (reinforced cement/concrete/ shotcrete coating, repointing, injecting) has been already verified by both, laboratory tests and earthquakes, it is not all clear as regards the application and efficiency of various methods based on the use of carbon or glass fiber reinforced polymers.
KEYWORDS: old masonry buildings, assessment, seismic redesign, strengthening methods, code requirements
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