Modern and Unique Architecture: A Perspective from the Wind Tunnel

摘要

The architecture of a building characterizes its aerodynamic behavior, which drives the steady and fluctuating forces resulting from wind loading. This in turn defines the level of structural resistance required for cladding, components, and the main wind force resisting system (MWFRS) of a building or other structure. For tall buildings, the wind loads developed by the exterior geometry can contribute to unfavorable occupancy conditions, such as high accelerations due to across-wind response (i.e., vortex shedding). Much is known about the aerodynamics of 'classic' prismatic geometries (i.e., square, rectangular), and data for these types of shapes comprise the backbone of most wind design standards (i.e., ASCE 7). With a growing focus being placed on distinct, or 'landmark' buildings and structures, the bounds of architectural design are being pushed considerably, resulting in structures characterized by unique exterior geometry and equally unique aerodynamics. Distinctive shapes or features may result in unexpected wind pressure distributions, excessive vibration of components, or Aeolian noise. The emergence of versatile high-strength, but more flexible, building materials has contributed to the variety of architectural features observed on modern structures. The movement towards sustainability has led to features such as solar panels, green roofs or walls, and more energy-efficient curtainwall systems being integrated into many new buildings. Each of these aspects of modern and unique architecture have likely posed challenges to architectural and structural teams at some point in the design process, the wind tunnel testing component included. This paper provides a background on the development of wind loading provisions specified in design standards and codes, and discusses some of the situations encountered when assessing the wind loading and response of unique structures using the wind tunnel approach. A brief background on building aerodynamics and the wind tunnel testing procedure is provided. Approaches to assessing the wind loads and response of various architectural features, including parapets, spires and long-span roofs, are summarized. Additional considerations such as pedestrian level wind speeds, applications of sustainable design, and urban planning are briefly discussed.