Fragility analysis of typical RMG buildings of Bangladesh for progressive collapse

Abstract

In the modern era of industrial outburst, the phenomenon of progressive collapse has become one of the primeconcerns in the sector of infrastructural development. This type of structural failure gains its optimal significance when reinforced concrete structures are usually extended vertically for an increased number of floor spaces. Initiating from a localized portion, the phenomenon of progressive collapse follows a chain reaction leading to a massive structural damage. However, there are no significantstudies in Bangladesh for the behaviorof Reinforced Concrete(RC) structures towards progressive failure and no specific local code guidelines to account for the phenomenon in structural design. This necessitates an initial study in this aspect to account for this type of structural failure in structural design and analysis of RC structures. In this paper, the phenomenonof progressive collapse was analyzed for RMG buildings in around Dhaka City. A survey was conducted on typical garments buildings at different locations of the city to obtain uniform sample size of four, six and eight stories models. Each of the model was later analyzed by ETABS for three cases of column removal and fragility curves were obtained for axial loading of adjacent columns and shear force and bending moment of adjacent beams. The obtained graphs can be used to obtain the probability of exceedance for different Demand-Capacity ratios to account for axial, shear and flexural failure in adjacent columns and beams. Hence, this study will also play a substantialrole towards safeguarding safety assurance of RC structures against progressive failure.