Seismic response analysis of an unequal height multi-tower structure with connecting corridor

Abstract

This study investigates an innovative design of irregular connected structure, departing from the traditional equal-height twin-tower configurations. The innovative design features three towers of varying heights linked by two connecting corridors at different elevations, with friction pendulum bearings providing flexible connections between the connecting corridors and towers. This design is uncommon in practical engineering and provides a new direction for the innovation of complex connected structures. Because of the relatively limited research on irregularly connected structures in the available literature and the inadequacy of the existing codes for seismic evaluation of irregularly connected structures, this study emphasizes the necessity of studying such structures under rare earthquakes. By establishing a three-tower non-isolated structure and a three-tower isolated structure, a performance-based design methodology is used to perform elastic-plastic time-history analysis under rare earthquakes, evaluating their seismic performance and discussing the effects of different locations of the seismic isolation layer and connecting corridors. It is found that the three-tower isolated structure can effectively control the inter-story drift and internal force of the structure, while the combination of seismic isolation bearings with dampers can absorb seismic energy, reducing the risk of shear damage to the bearing, stress levels in the core tube, and the occurrence of plastic hinges in the frame structure, thereby enhancing overall seismic performance. Additionally, the study assessed the rationality of seismic joints between the connecting corridor and the tower, ensuring structural safety under rare earthquakes. However, the existence of the connecting corridor has a significant effect on the dynamic response of the structure, particularly the complex interaction between the towers, which can easily result in different displacements of the connecting corridor due to the various dynamic characteristics of the superstructures of the towers, and this unfavorable tendency can be reduced by seismic isolation. This study also offers recommendations based on the analysis results of unequal height multi-tower connected structures, aiming to further improve seismic performance and provide references for similar structures.