Influence of masonry infill on seismic response of reinforced concrete frames

摘要

The graduation thesis deals with seismic analysis and design of fifteen storey reinforced concrete frame building for ductility class medium according to standard SIST EN 1998-1. The elastic analysis is performed with computer program SAP2000. Storey displacements and the influence of P-Δ are checked. The frame is designed according to capacity design rules for a peak ground acceleration equal to 0,25 g. The design process is presented in detail for selected beams and corresponding exterior and interior columns. Furthermore the same reinforced concrete frame with masonry infill is analised and designed. Masonry infill panels are modelled by means of diagonal struts. Similarly to the bare frame all the necessary verifications are made in order to design selected structural members. The design shear force of column is defined due to two most frequent failure mechanisms. The first one represents the shear strength of bed joints while the other corresponds to shear (diagonal) failure of masonry infill. Since infill is in contact with column, the design shear force is increased due to the effect of masonry infill. Based on the comparison of results for the bare frame and infilled frame it can be concluded that masonry infill has a significant influence on seismic response of reinforced concrete frames, since it reduces the storey drift demands and increases storey lateral force resistance.