Influence of variation of material properties on interstorey drift of RC frame buildings

Abstract

The main ingredients that provide load-resisting capacity to RCC members are concrete and steel. They possess very different physical properties in elastic as well as inelastic range. Their production processes contribute to variation in their properties, and thereby the resultant behaviour of the RCC members. This paper aims to quantify the effects of material variation on the seismic resistance capacity of RCC buildings. The study uses 3-bay 2D RC frame of two building types, low-rise (G + 3) and mid-rise (G + 7) which are designed as per Indian standards. Both building types are further divided into three categories based on ground floor height. Interstorey drift ratio (IDR) is used to evaluate the influence of variation in steel and concrete properties on the seismic resistance of the buildings. It is observed that at lower and higher IDR, concrete variation governs the structural response. However, at middle range of IDR, it is steel property variation that governs structural behaviour. It is also found from plot of IDR versus PGA and PGV that PGV is a better indicator of IDR, and thus structural damage for both building heights.