Seismic responses evaluation of tall tubular structures using viscous dampers in outriggers under far fault excitations

Many investigations have sought to consider the seismic responses of tall buildings against different kinds of loads. However, the effect of the position of viscous dampers in outriggers has not yet been considered on seismic responses. Therefore, this study intends to investigate the aforementioned parameter on the seismic responses of tall tubular structures under far fault excitations through nonlinear time history analysis using OPENSEES software. To achieve this goal, nine models of 50, 60, and 70-story tall tubular structures with conventional outriggers and outriggers equipped with passive nonlinear viscous dampers (PNVDs) are considered under three time history functions taken from the PEER ground motion database and selected according to authentic guidelines. The structural geometries and details from a recent study are adopted to simulate the finite element models. Seismic responses, including drift, acceleration, and energy absorption, are evaluated and discussed for different positions of PNVDs. Results show that locating PNVDs diagonally inside the outrigger systems of 50-story buildings leads to a reduction in structural members’ seismic responses, while in 60 and 70-story structures, the structural members’ contribution mitigates when the PNVDs are located vertically between peripheral columns and outrigger systems. It is important to note that the drifts and accelerations of 50, 60, and 70-story buildings are maximally reduced to 25.56%, 27.40%, 74.05%, 64.98%, 36.88%, and 40.63%, respectively. Finally, it is concluded that choosing the accurate configuration of dampers in outrigger systems, which depends on structure heights and frequencies, is effective in reducing seismic responses to an acceptable range of advised guideline criteria.