ACROSS-WIND LOADING ON REINFORCED-CONCRETE CHIMNEYS OF CIRCULAR CROSS-SECTION

Published in December 1993, this report from the Boundary Layer Wind T unnel Laboratory of the University of Western Ontario presents a model for assessing across-wind loads on reinforced concrete chimneys. Beca use the report provides a basis for proposed changes in the ACI chimne y design standard, this report condenses and summarizes some of the re port findings. Across-wind loading and the induced dynamic response ar e due primarily to a more or less regular shedding of vortices from th e chimney. This has long been recognized as a significant design consi deration for slender structures with a bluff as opposed to streamlined cross section. Across-wind loading is also induced hy lateral gustine ss in natural wind and by lateral velocity fluctuations in the wake of an upstream structure such as another chimney in a grouped arrangemen t The report deals primarily with loading due to vortex shedding, but makes some reference to buffeting in the wake of an upstream structure .