Semiempirical Equations to Evaluate Maximum Deflection in RC Beam and Column under Fire
Publication: Journal of Structural Engineering
Volume 150, Issue 10
Abstract
Many design regulations around the globe rely on member deflection as a governing criterion for resistance assessment in fire. The deflection evaluation in fire is generally achieved by conducting expensive experiments or computationally expensive finite-element analyses. This often restricts practicing engineers from using robust performance-based design philosophy for typical structures. Instead, they rely on objective design guidelines, often resulting in inefficient sizes of reinforced concrete (RC) members. Therefore, semiempirical relations are derived in the current study to determine the maximum deflection of the RC beam and RC column in a fire. Three separate end conditions are considered within the beam category: fixed-fixed beam, propped cantilever beam, and simply supported beam. Plausible variables are first identified that could affect the overall deflection of the member, and their proportionality is subsequently determined by performing one-on-one regression analysis. Furthermore, these relations are developed in terms of the most suitable fire intensity measures derived from the literature, which makes them applicable irrespective of the type of fire framework. The credibility of the deflection equations is validated through visual analysis followed by the three popular error indicator parameters, namely, Pearson’s correlation coefficient, relative root-mean squared error (RRMSE), and performance index. Results indicated that all deflection equations accurately predict the RC member behavior under fire.
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Data Availability Statement
Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.
Acknowledgments
The research work presented herein is supported by the Government of India’s Ministry of Education under its Scheme for Promotion of Academic and Research Collaboration (SPARC) for the project “Fire Safety in Underground Tunnels” (Project Code: P920). The Ph.D. study of the first author is supported by a fellowship from the UQ-IIT Delhi Research Academy (UQIDRA), a joint Ph.D. program of the Indian Institute of Technology (IIT) Delhi, India, and the University of Queensland (UQ), Australia. However, the opinions expressed in the paper are exclusively those of the authors and not necessarily those of the funding agencies.
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Received: Nov 16, 2023
Accepted: May 15, 2024
Published online: Aug 5, 2024
Published in print: Oct 1, 2024
Discussion open until: Jan 5, 2025
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