Earthquake Behaviour of Buildings with Transfer Structure

Transfer storeys in buildings introduce unique challenges to their earthquake behavior, often resulting in unexpected damages or even collapse during earthquakes. Despite their prevalence, specific design guidelines tailored for buildings with transfer structures are lacking, highlighting the need to identify critical parameters governing their behavior. In this study, a comprehensive analysis of 2D moment-resisting frame (MRF) buildings is conducted, including a conventional building, buildings with transfer storeys near the ground, and the bottom three storeys. Along with their elastic behaviour (modal characteristics, natural period, maximum interstorey drift, storey shear, and storey stiffness), inelastic behaviour is studied using nonlinear static analysis (NLPoA). The presence of transfer storeys enhances the overall rigidity of the building, leading to a reduction in the modal mass participation ratio and natural period. Moreover, an increase in the number of transfer storeys results in decreased displacement and storey shear, albeit with an irregular elevation pattern due to sudden stiffness changes. Notably, buildings with transfer storeys exhibit greater lateral strength and stiffness compared to their conventional counterparts, albeit at the expense of increased susceptibility to damage. To mitigate potential damage, it is recommended to equip transfer storeys with stiff structural walls. These insights emphasize the importance of considering transfer structures in earthquake design practices, as well as the necessity for tailored guidelines to ensure the structural integrity and safety of such buildings.