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Arpan Singh – RC wall-frame buildings

Arpan Singh, supervised by Dr. Sunitha Palissery received his Master of Science in Civil Engineering (CE). Here’s a summary of his research work on Seismic Design of Low-rise RC wall-frame buildings for preferred performance:

Hospital buildings are expected to remain Occupiable after earthquakes to cater to the post-disaster response and rescue efforts. This requires a stiffer and stronger structural system compared to the commonly adopted moment frames in normal buildings; wall frame systems are recommended in these buildings. But, in addition to merely providing the wall-frame structural system, it is also essential to adequately design the wall-frames to meet the desirable Occupiable seismic performance. Appropriate seismic structural configuration, Structural Plan Density (SPD) of structural walls, and seismic design parameters are presented of typical hospital buildings located in Seismic Zone IV, that helped meet the desirable performance. A displacement-based limit state of structural damage in line with classic displacement demand estimation is proposed, to confirm the performance. Fibre inelasticity in walls and moment frames in study frames and buildings are defined, for performing displacement controlled nonlinear static pushover analyses and nonlinear time history analyses in commercial software PERFORM 3D. Alongside, limit states of structural damages, namely yielding of longitudinal reinforcement in beams or columns in tension, yielding of vertical longitudinal reinforcement in structural walls in tension, crushing of confined concrete in compression in beams, crushing of confined concrete in compression in columns, and spalling of unconfined concrete in compression in structural walls are also monitored to grade the damages, and in turn the seismic performance of wall-frames. Results suggest, numerical models with fibre inelasticity help predict nonlinear behaviour reasonably well. Moment frames do not provide desired seismic performance, but wall-frames with plan-aspect ratio more than 4 enhances lateral stiffness, strength, and ductility of wall-frames, thereby meeting the desired performance. Further, at least 3% SPD of structural walls is essential in typical wall-frame hospital buildings to ensure accountability performance after earthquakes. Furthermore, Column-to-Beam Strength Ratio of minimum 2 is also required in hospital buildings to remain Occupiable. 

July 2023