Improving the wind-induced human comfort of the Beijing Olympic Tower by a double-stage pendulum tuned mass damper

With five sub towers and a maximum height of 246.8 m, the Beijing Olympic Tower (BOT) is a landmark of Beijing. The complex structural properties and slenderness of the BOT render it prone to wind loading. As far as the wind-induced performance of this structure is concerned, this paper thus aims at a tuned mass damper-based mitigation system for controlling the wind-induced acceleration response of the BOT. To this end, the three-dimensional wind loading of various wind directions are simulated based on the fluctuating wind force obtained by the wind tunnel test, by which the wind-induced vibration is evaluated in the time domain by using the finite element model. A double-stage pendulum tuned mass damper (DPTMD), which is capable of controlling the long period dynamic response and requires only a limited space of installation, is optimally designed at the upper part of the tower. Finally, the wind-induced response of the structure with and without DPTMD is compared with respect to various wind directions and in both the time and frequency domains. The comparative results show that the wind-induced accelerations atop the tower with the wind directions of 45, 135, 225, and 315 degrees are larger than those with the other directions. The DPTMD significantly reduces the wind-induced response by the maximum acceleration reduction ratio of 30.05%. Moreover, it is revealed that the control effect varies noticeably for the five sub towers, depending on the connection rigidity between Tower1 and each sub tower.