Seismic Performance of Asymmetric Rocking ‘Steel Braced’ and ‘Concrete Shear Wall’ Buildings
摘要
Building performance is a critical factor in resilience planning for post-crisis recovery, such as after an earthquake. Residual deformations and drifts from large earthquakes can compromise a building's functionality and serviceability. Retrofitting these structures is often impractical or extremely challenging, demanding considerable time and financial investment. An effective strategy to improve seismic performance involves systems that prevent damage to primary building components, like structural systems designed to rock. This study examines asymmetric rocking models for steel and concrete buildings using nonlinear time history analysis. The utility of rocking behavior in asymmetric steel braced frames to manage seismic torsional response is evaluated using seven earthquake records. It also explores the enhancement of structural response through the adjustment of tendon prestress levels, yielding encouraging outcomes. The innovative system is then applied to concrete shear wall buildings. The results show that this system enables the asymmetric structure to stay mostly within the immediate occupancy performance level. Post-tensioned cables lead to a reduction in structural deformation by more than 70%. The introduction of a repairable shear wall with rocking motion makes the first vibration mode more dominant, showing marked differences between the torsional and the first two transverse modes.