Seismic Behavior of Multistory Infilled R.C Frame with Or without Opening Including Stilted Storey by Using “Equivalent Diagonal Strut Method”

Shubham Krishna Atray , S. Ashok Kumar

Abstract

In many cities of India, it is very common to leave the first storey  of masonry infilled reinforcement concrete (RC) frame building open preliminary to generate parking space or any other purposes. Open first storey building is also known as “stilted buildings”, “pilotis”, or “soft storey”. The presence of infill wall alters the behavior of the building. This type of building is showed vulnerability during past earthquakes. The failure pattern was observed in the open first buildings during the Jabalpur earthquake (1997), Bhuj earthquake. Generally, engineers analysis the building without considering the infill wall stiffness for conservative design. But this may not be always true, especially for vertically irregular buildings with discontinuous infill walls. Hence, the modelling of infill walls in the seismic analysis of framed buildings is imperative.  Upper storeys are much stiffer than the open ground storey. Thus, the upper storeys move almost together as a single block, and most of the horizontal displacement of the building occurs in the soft storey itself. In this paper, symmetrical Special RC moment-resisting frame building situated in seismic zone V is considered with different height G+3, G+6, G+9. In the present  study, it is attempt to access the effect of infill walls with support condition (fixed and hinged), opening at centre and corner (10%, 20%,30%) and infill wall panel at each corner of building frame on the seismic behaviour of  OFS  buildings.