In the seismically active zones of southern and central Europe, unreinforced masonry (URM) structures are one of the most common types of buildings. Some of them possess a high historical value and could therefore be classified as part of the architectural heritage, requiring special attention with regard to their preservation and retrofitting measures. In practice, however, the accurate prediction of the seismic response of such structures often proves to be difficult, not only due to the complex geometrical features of their individual architectural parts, but also due to the composite and non-homogeneous nature of URM. Due to the great variety of structural configurations and materials used, rational approaches for the assessment of the seismic safety levels of such buildings are needed. The paper analyses the applicability of two contemporary seismic strengthening measures, namely the use of fibre-reinforced polymer composites and the implementation of base-isolation to achieve the desired, code-based seismic protection levels. A three-storey masonry building was considered in the study. Non-linear static analyses for different levels of seismic intensities were conducted on a mathematical model of the fixed-base, FRP-strengthened and base-isolated variants of the structure.
base isolation, fibre-reinforced polymers, historic masonry structures, seismic rehabilitation
 Prota, A., Manfredi, G. & Nardone, F., Assessment of design formulas for in-plane FRP strengthening of masonry walls. Journal of Composites for Construction, 12(6), pp. 643–649, 2008.
 Kelly, J.M., Robinson, B.W.H. & Skinner, R.I., Seismic Isolation for Designers and Structural Engineers, Robinson Seismic Limited, New Zealand, 2007.
 Petrovčič, S. & Kilar, V., Seismic failure mode interaction for the equivalent frame mod- eling of unreinforced masonry structures. Engineering Structures, 30(54), pp. 9–22, 2013.
 Petrovčič, S. & Kilar, V., Seismic retrofitting of historic masonry structures with the use of base isolation—modeling and analysis aspects. International Journal of Architec- tural Heritage, 11(2), pp. 229–246, 2016. https://doi.org/10.1080/15583058.2016.1190881
 Parisi, F. & Augenti, N., Seismic capacity of irregular unreinforced masonry walls with openings. Earthquake Engineering & Structural Dynamics, 42(1), pp. 101–121, 2013. https://doi.org/10.1002/eqe.2195
 Kappos, A.J. & Papanikolaou, V.K., Nonlinear dynamic analysis of masonry buildings and definition of seismic damage states. The Open Construction and Building Technol- ogy Journal, 10(1), pp. 192–209, 2016. https://doi.org/10.2174/1874836801610010192
 Magenes, G. & Calvi, G.M., In-plane seismic response of brick masonry walls. Earth- quake Engineering & Structural Dynamics, 26(11), pp. 1091–1112, 1997. https://doi.org/10.1002/(sici)1096-9845(199711)26:11<1091::aid-eqe693>3.3.co;2-y
 CSI – Computers and Structures, SAP2000 Ultimate (v18.2.0) – Structural Analysis Program. Berkeley, USA, 2016.
 CNR – Advisory Committee on Technical Recommendations for Construction, Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Existing Structures. CNR, Rome, 2016.
 Marcari, G., Manfredi, G., Prota, A. & Pecce, M., In-plane shear performance of masonry panels strengthened with FRP. Composites Part B: Engineering, 38(7), pp. 887–901, 2007.
 CEN – European Committee for Standardisation, Eurocode 8: Design of structures for earthquake resistance – Part 3: General rules, seismic actions and rules for buildings, Design Code EN 1998-3. CEN, Brussels, 2005.
 Fajfar, P., A nonlinear analysis method for performance-based seismic design. Earth- quake Spectra, 16(3), pp. 573–592, 2000.
 Dolšek, M. & Fajfar, P., Simplified non-linear seismic analysis of infilled reinforced concrete frames. Earthquake Engineering & Structural Dynamics, 34, pp. 49–66, 2005. https://doi.org/10.1002/eqe.411