Cost-Based Design of Nonstructural Elements for Tall Buildings under Extreme Wind Environments

The early stages of the design process of wind-excited tall buildings involve several decisions on structural typology, shape, orientation, optional control system, and type and distribution of nonstructural elements. Focusing on this last aspect, the main issue addressed in this paper is a systematic comparative cost-based analysis accounting for the damage at the nonstructural system level induced by extreme wind loads. This design task is accomplished in this study by making use of a cost-based decision framework developed by the authors, designated life cycle cost wind design (LCCWD), specifically tailored for wind-excited tall buildings. Various design configurations are investigated by comparing the lifetime cost induced by wind-load damage as evaluated by adaptation of the Pacific Earthquake Engineering Research Center (PEER) equation, which was originally conceived for seismic engineering. This choice emphasizes the role of a multihazard-inspired design process. The following items are jointly considered: (1) uncertainties in wind-load characterization, structural response, and damage models; (2) wind directionality; (3) dynamic response model accounting for non-shear-type vibration modes and torsional effects; and (4) monetary loss accumulation by partitioning nonstructural damage effects among various building components. Furthermore, the LCCWD is expanded to include internalization of external costs, whereby acceleration-based perception effects on occupants' comfort lead to business interruptions and consequent downtime losses; these items at are included as indirect costs. Application of the procedure to a case study enables automated, systematic, and cost-effective comparison of various design alternatives.