Appraisal of masonry infill walls effect in the seismic response of RC framed buildings: A case study

Abstract In the last few decades, the scientific community has been extensively involved in the investigation about the interaction between infill masonry walls and RC frames in the seismic structural behavior, both for new and for existing buildings. With respect to this issue, some extensions of the N2 Method have been proposed in order to evaluate the contribution of masonry infill to the structural response. This paper presents an extensive case study regarding the analysis of an existing RC framed building located in a high seismic risk area in Calabria (Southern Italy), for which the project, dated back to the early ‘70s, provided only the presence of vertical loads. In order to collect the data required for the application of the safety assessment procedure and achieve the necessary knowledge level, a broad experimental test campaign was performed on the building in order to assess the condition and quality of both RC elements and infill walls. A number of non-linear static (pushover) analyses were performed on proper structural models of the building, considering both the bare framed structure and the infilled one, in order to appraise the influence of infill walls on the failure mechanisms. In particular, a sensitivity analysis was performed by assigning different Partial Safety Factors (PSF) to the mechanical parameters of infill walls, in order to investigate their effect on the overall structural response of the building.

[1]  Peter Fajfar,et al.  THE N2 METHOD FOR THE SEISMIC DAMAGE ANALYSIS OF RC BUILDINGS , 1996 .

[2]  Wael W. El-Dakhakhni,et al.  THREE-STRUT MODEL FOR CONCRETE MASONRY-INFILLED STEEL FRAMES , 2003 .

[3]  B Stafford Smith,et al.  A METHOD OF ANALYSIS FOR INFILLED FRAMES. , 1969 .

[4]  Peter Fajfar,et al.  Capacity spectrum method based on inelastic demand spectra , 1999 .

[5]  Peter Fajfar,et al.  Inelastic spectra for infilled reinforced concrete frames , 2004 .

[6]  Domenico Raffaele,et al.  Prime considerazioni sul comportamento delle costruzioni nel terremoto de L’Aquila , 2009 .

[7]  Peter Fajfar,et al.  Simplified non‐linear seismic analysis of infilled reinforced concrete frames , 2005 .

[8]  Matjaž Dolšek,et al.  The effect of masonry infills on the seismic response of a four-storey reinforced concrete frame — a deterministic assessment , 2008 .

[9]  P. Benson Shing,et al.  FINITE ELEMENT MODELING OF MASONRy-INFILLED RC FRAMES , 1997 .

[10]  Gian Michele Calvi,et al.  Experimental and numerical investigations on the seismic response of bridges and recommendations for code provisions , 1996 .

[11]  B. S. Smith,et al.  Lateral Stiffness of Infilled Frames , 1962 .

[12]  Paolo Negro,et al.  Irregularities induced by nonstructural masonry panels in framed buildings , 1997 .

[13]  Rui Pinho,et al.  SIMPLIFIED EQUATIONS FOR ESTIMATING THE PERIOD OF VIBRATION OF EXISTING BUILDINGS , 2006 .

[14]  M. L. Beconcini Costruzioni in zona sismica : con riferimento alle norme tecniche per le costruzioni DM 14.01.2008 , 2013 .