Performance-based design with life-cycle cost assessment for damping systems integrated in wind excited tall buildings

摘要

The application of performance-based design (PBD) is gaining increasing interest in the wind engineering community. A popular design approach to minimize wind induced vibrations in flexible civil structures is to size structural stiffness and supplemental damping systems in order to restrict the motion to a given threshold for providing safety and comfort, while ensuring that structural components meet strength requirements. In this paper the PBD paradigm is extended to wind excited tall buildings equipped with motion control systems. The objective is to improve the design of damping systems under different wind events while considering maximum acceleration as performance measure. In addition, since the installation of damping devices implies additional costs (e.g., installation and maintenance costs) while it helps decreasing the costs associated with performance failure, a life-cycle analysis (LCA) is integrated in the PBD. In the LCA framework, the percentage of building occupants affected by discomfort and motion sickness caused by excessive wind-induced vibrations is considered to account for the consequences of different target performance levels. The developed PBD is applied to a 39-story building that has documented issues with excessive vibrations under wind events. The wind load is simulated as a multivariate stochastic process, in the time domain. Two passive vibration mitigation strategies are investigated: viscous and friction dampers, both designed to meet the target performance levels. LCA are conducted for the building equipped with each damper type, and benchmarked against the one without dampers. Results show that the PBD leads to a rational and economically effective approach for the design of the damping systems in wind excited tall buildings.