Numerical Investigation of Seismic Behavior of Spatial Asymmetric Multi- Storey Reinforced Concrete Buildings with Masonry Infill Walls

Abstract

Abstract:In order to insure the validity of the seismic performance matrix of the Eurocode EN 1998 for irregular in-plan, torsionally-flexible, spatial, asymmetric, multi-storey reinforced concrete (r/c) buildings with masonry infill walls, an extended parametric numerical investigation has been performed, using non-linear response-history analysis. For this purpose, N representative asymmetric r/c buildings with torsional sensitivity, have been designed according to Eurocodes EN 1990, EN 1992 and EN 1998, for Ductility Class High (DCH), using design global behavior factor q equal to 3.00. Each of the masonry infill walls has been modeled with two nonlinear diagonal bars with hinges at their two ends and with onesided behavior (in compression only). Three seismic levels of the seismic action have been considered with mean return period of 2475, 475 and 275 years, respectively. The above three earthquakes have been used for validity check of the states of "Near Collapse", "Significant Damage" and "Damage Limitation", respectively. In order to apply the non-linear response-history analysis, suitable artificial accelerograms, which are compatible with the elastic response spectrum, for soil category D, of Eurocode EN 1998-1 on the one hand and with Hellenic geological and site-specific data on the other hand, have been used. In the present paper, important guidance on modelling plastic hinges and the masonry infill walls is presented, as well as, a numerical example of a three-storey r/c building is also presented for illustrative purposes Keywords: Inelastic static seismic analysis, non-linear response-history analysis, asymmetric multi-storey building, torsionally-flexible multi-storey building, masonry infill walls, simulation of plastic hinge properties.

Discrete Element Modelling of Masonry Infilled Steel Frames with Multiple Window Openings Subjected to Lateral Load Variations

“…This results a possible change of the seismic demand due to the significant reduction in the natural period of the composite structural system [1,2]. The main reason for neglecting the infill wall effect is for the sake of simplified calculations, while it is partly attributed to incomplete knowledge of the "composite" behaviour of the frame and the infill, as well as due to the lack of conclusive experimental and analytical results to substantiate a reliable design procedure for this type of structures, despite the extensive experimental works [3][4][5][6][7] and analytical investigations [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. So far, it is well understood that an infill wall acts as a diagonal strut connecting the two loaded corners under lateral loads; an approach that is only applicable in the case of infill walls without openings (eg.…”