The Effect of Belt Truss Level on the Performance of Steel High-Rise Buildings Subject to Near Field earthquake

In this study based on conducting several non-linear dynamic time history analyses subjected to the both types of near and far field three components earthquake records, the seismic response parameters of inelastic behavior of tall buildings with belt truss frameworks have been investigated. A three-dimensional basic outrigger braced tube model as well as three other resistant skeletons which contain different configurations of belt trusses in height, have been designed according to the Iranian seismic code 2800 (4th edition) and Iranian national building code (steel structures-division 10). The dynamic response parameters of all studied structures have been assessed under influence of free field three components earthquake records. Because the overall dynamic response of the studied structures would change subjected to record by record separately, the corresponding response velocity spectra of each of the selected records were notified numerically. Furthermore, in order to denote the effects of higher modes, the aforementioned response velocity spectra were evaluated corresponding to the natural period of the studied structures. Having accurate evaluation of the analytical results indicate that the existence of belt truss causes a significant increase in structural stiffness and mitigates drift and base bending moment. Also the highest drift demand obtained for the model without belt truss and the model with belt truss located at 0.5H, occurs relatively in 0.83 to 0.9 of normalized height. This demand parameter calculated for the model with the top belt truss occurs in 0.5 to 0.8 of normalized height.