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Shear behavior of reinforced concrete deep beams under static and dynamic loads Shahnewaz, Md

Abstract

Reinforced concrete (RC) deep beams predominantly fail in shear which is brittle and sudden in nature that can lead to catastrophic consequences. Therefore, it is critical to determine the shear behavior of RC deep beams accurately under both static and dynamic loads. In this study, a database of the existing experimental results of deep beams failing in shear under static loading was constructed. The database was used to propose two simplified shear equations using genetic algorithm (GA) to evaluate the shear strength of deep beams with and without web reinforcement under static loads. Reliability analysis was performed to calibrate the equations for design purposes. The resistance factors for the design equations were calculated for a target reliability index of 3.5 to achieve an acceptable level of structural safety. A deep beam section designed following the building codes considering only static loads may behave differently under dynamic loading condition. Therefore, in this study, deep beams were analyzed under reversed cyclic loading to simulate the seismic effects. The ultimate load capacity, energy dissipation capacity, and ductility capacity were calculated in deep beams with different reinforcement ratios. In RC structures, deep beams have interaction with other structural elements through connections. Therefore, to predict the shear behavior of deep beams in real structure under seismic loads, it is necessary to analyze a full structure with a deep beam. A seven storey RC office building with a deep transfer beam was designed following the CSA A23.3 standards. The structure was analyzed using non-linear pushover and non-linear dynamic time history analysis. The deep beam was evaluated for the shear deficiency under different earthquake records for the soil condition of the City of Vancouver. The analysis results showed a significant shear deficiency of about 25% in the deep beam. The use of carbon fibre reinforced polymer (CFRP) resulted in increasing the shear capacity of a deep beam by up to 82%.

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Attribution-NonCommercial-NoDerivatives 4.0 International