Wind-induced vibrations of structures : with special reference to tall building aerodynamics

This chapter examines the wind-induced vibrations of buildings and structures. In particular, the alongwind and the crosswind excitation mechanisms and response processes are discussed. Turbulence buffeting is the dominant excitation mechanism in the alongwind direction. In the crosswind direction, excitations associated with incident turbulence, vortex shedding and motion dependent excitations are the prominent mechanisms causing crosswind response. Many advanced wind codes and standards have adopted statistical and spectral analysis processes to predict wind loads and responses caused by these alongwind and crosswind excitations. The potential impact of interference excitations of tall buildings and beneficial effects of aerodynamic modifications of building shape are also reviewed in this chapter. Interference effects on the alongwind, crosswind and torsional responses of tall buildings from either an upstream or a downstream building are outlined. The beneficial effects and the economic perspectives of aerodynamic modifications of building shape in reducing the wind induced load and response of tall buildings are discussed.