A Comparative Study of Earthquake Performance and Material Cost of Braced Tube, Diagrid, Tube-in-tube, and Shear Wall-frame Structures

Abstract

This research study compared the earthquake performance and material cost of braced tube, diagrid, tube-in-tube, and shear wall-frame structures. Recent trends show that tubular systems are already widely used for significantly tall structures in most worldwide areas (Ali & Moon, 2018; Reddy & Eadukondalu, 2018). The shear wall-frame system is also dominant in other parts of the globe (Memon et al., 2020; Reddy & Eadukondalu, 2018). Therefore, this study aimed at identifying the most effective system concerning earthquake performance and cost. This study used 12 building models; every structural system had 12-, 24-, and 36-storey models. The following model parameters were constant for all 12 models: the floor depth and area, the service area, the plan dimensions, the storey heights, and material properties. This research used modal response spectrum analysis per EN 1998-1-1:2004 for the Nairobi city area to obtain the fundamental periods of vibration, top drifts, seismic base shears, and top floor accelerations of braced tube, diagrid, tube-in-tube, and shear wall-frame building models. The study also obtained the overall structural steel mass of the models required to satisfy the seismic design requirements. The overall seismic performance control for the 12- and 24-storey models, in order of preference, comprised the diagrid, braced tube, tube-in-tube, and shear wall-frame structures, respectively. For the 36-storey models, the overall earthquake performance comprises both diagrid and braced tube, tube-in-tube, and shear wall-frame structures, respectively. The braced tube model had the lowest overall structural steel mass among the 12-storey models, while the diagrid models recorded the lowest overall structural mass among the 24- and 36-storey models. Using the assumption that the structural steel mass is directly proportional to the material cost, the braced tube model would achieve the lowest material cost among the 12-storey building models. In contrast, the diagrid model would record the lowest material cost among the 24- and 36-storey models.