International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 p-ISSN: 2395-0072 Volume: 08 Issue: 04 | Apr 2021 www.irjet.net © 2020, IRJET | Impact Factor value: 7.529 | ISO 9001:2008 Certified Journal | Page 549 Progressive Collapse Analysis of R.C.C. Framed Structure using Etab’s Anjali G. Dhole 1 , Prof. D.H. Tupe 2 , Dr. G.R. Gandhe 3 1 PG Student Department of Civil Engineering, DIEMS Aurangabad, Maharashtra, India 2 Assistant Professor, Department of Civil Engineering, DIEMS Aurangabad, Maharashtra, India 3 Head of Department of PG in Civil Engineering, DIEMS Aurangabad, Maharashtra, India ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - A structure experiences progressive collapse when a primary structural member (generally column) fails due to manmade or natural causes. The failure of a member in the primary load resisting system leads to redistribution of forces to the adjoining members and if redistributed load exceeds member capacity it fails. This process continues in the structure and eventually the building collapses. This phenomenon is referred as progressive collapse of the structure. In the present study progressive collapse potential of 15-storey symmetrical concrete framed building is evaluated. Linear static and dynamic analysis is performed by following the General Service Administration (GSA-2003) guidelines for evaluating progressive collapse potential. Modeling, analysis and design of the buildings are performed using ETABS 2019 for three different threat-independent column removal conditions by following the alternate load path method. It is observed that demand capacity ratio (DCR) in beams and columns are exceeding the allowable limit for all the cases. This indicates the building considered for study is having high potential of progressive collapse. To reduce the potential of progressive collapse various approaches for mitigation of the progressive collapse are implemented in this research. Different approaches like providing bracing at floor level, moderate increase in the size of beam at all the storey levels. Comparison between the approaches is presented in this study by analyzing progressive collapse of G+15 RCC Framed structure. Key Words: Progressive Collapse, ETABs, IS Code, DCR, PMM Ratio, story displacement, story drift. INTRODUCTION The progressive collapse of building structures is a complicated mechanical behavior of entire structural systems under large deformation. However, limited researches have been conducted to investigate this issue at the last century due to the lack of the experimental technique and numerical simulation for entire structural systems under large deformation. In recent years, with the development of the experimental technique and numerical simulation, the progressive collapse of building structures is studied in depth and the exciting progresses have been reported. A progressive collapse of a building is initiated by an unexpected event that causes local damage and subsequently propagates throughout the structural system, leading to a final damage state in large- scale or entire collapse of the building. A progressive collapse can be triggered by accident actions, including fire hazard, gas explosion, terrorist attack, vehicle collision, design and construction errors, and environmental corrosion. With the development of industrialization, the buildings with multi- function and high complication become more common of which the safety and stability are far more concerned. However, the current ultimate limit state design based on the structural reliability theory is commonly used for regular structures to ensure their safety. On the other hand, during the long-term use, the structure may suffer unexpected accidental actions, causing local damage or failure. Hence if the remaining structural system cannot absorb or contain the internal force variation caused by the initial failure, it will lead to a further damage even the collapse of whole structure, causing huge loss of life and property. Stages in Structural Design Every structure follows a specific path from its initiation to ultimate design as follows: 1) Structural planning of the building. 2) Calculation of applied loads. 3) Structural analysis of the building 4) Design of the building as per analysis. 5) Drawing and detailing of the structural members. 6) Preparation of tables and graphs. 7) It is the responsibility of the structural engineer to construct the building structurally good, considering all the loads acting on the building. There are so many methods of conducting these design we use E-tab software. Introduction to E-tab ETABS-Extended 3D analysis of Building Systems”, is a product of Computers and Structures Inc. It is an engineering software that is used in construction. It has highly efficient structure analysis and design programs developed for catering to multi-story building systems. It is loaded with an integrated system consisting of modeling tools and templates, code- based load prescriptions, analysis methods, and solution techniques. It can handle the largest and most complex building models and associated configurations. ETABS software is embedded with CAD-like drawing tools with an object-based interface and grid representation. Integration, productivity and technical innovation. ETABS software has the following implications in the construction, designing, and modeling industry: