Study of Along and Across Wind Load effects on RCC Chimneys

Chimney is a hollow, tall and slender structure to discharge smoke or pollutants at a height so that after dilution due to atmospheric turbulence, their concentration and that of their entrained solid particulates is within acceptable limits on reaching the ground under various atmospheric conditions. As large scale industrial developments are taking place all over the world a large number of chimneys would be required to be constructed. As for chimneys the predominant load is mainly wind load. This paper is aimed at deriving standard curves with the help of which one can easily calculate approximate wind load on chimney in shell completed condition. The curves have been plotted for chimneys of various heights, top internal diameter, taper and located in different wind zones. The importance of these curves would be in finalization of initial sizing of chimney and its supporting structure. Wind Analysis is done as per code IS 4998: 2015 and IS 875 (Part 3): 2015. SAP 2000 software is used to determine mode shapes. MS-Excel spreadsheets are used for loading calculations.