Seismic Evaluation of Reinforced Concrete Cores in High-Rise Buildings with Void Tube in Tube Systems

In this paper, the seismic behavior of reinforced concrete (RC) high-rise buildings with frame-core tube systems as one of the lateral bearing systems are studied. In order to investigate the effect of the core tube system on the seismic behavior of the high-rise building, the structural model is evaluated in two cases with the inner core tube and without the inner core tube. Three methods of equivalent static analysis, dynamic nonlinear time history analysis and nonlinear static analysis (push-over analysis) are used. Also, a 25-story high-rise building with a frame-core tube system having voids in the last floors is implemented. The results showed that the use of RC core as a central tube significantly reduces the lateral displacement and drift of floors. Also, the results obtained from the nonlinear static analysis indicated that using the central RC core, the ultimate capacity of the building as well as the ductility of the building increase significantly. Finally, the results obtained from the nonlinear time history showed that the nonlinear static analysis have good accuracy in calculating the maximum displacement of the structure.