FRAGILITY ANALYSIS OF OPEN GROUND STOREY RC BUILDING DESIGNED USING VARIOUS MULTIPLICATION FACTORS

D. J. Chaudhari, Prajakta T. Raipure

Abstract: The vulnerability of an element is defined as the probability that the said element will sustain a specified degree of structural damage given a certain level of ground motion severity. Significantly low stiffness and strength in any storeys compared to adjacent storeys is generally referred to as soft ground storey. As the columns of this Open ground storey are weakest element, ground storey is most vulnerable. Open ground storey framed buildings are generally analyzed in practice ignoring infill wall stiffness (linear bare frame analysis). Design codes impose a multiplication factor on the design forces in the columns of ground storey. The present study attempts to estimate and compare performance of open ground storey building designed with three different multiplication factors given by Indian code and Israel code. Thus fragility curves are derived using nonlinear dynamic time history analysis carried on a (G+9) OGS building by using method suggested by Cornell. Probabilistic seismic demand models are developed by using power law model. Results show that performance of upper storeys while applying multiplication factor only to the ground storey needs to be checked. The first storey is more vulnerable than the ground storey except for Israel code.

Keywords: Open ground storey, multiplication factors, fragility, performance levels, PSDM Model

DOI: https://doi.org/10.15623/ijret.2015.0404130