JSTE_V5_N4_RP5 T. Sharvani B.D.V. Chandra Mohan Rao Journal on Structural Engineering 2320 - 2343 5 4 30 37 Modal Analysis, Fundamental Frequency, Base Shear, Top Displacement, Response Spectrum Analysis, Geometric Parameters H/D, D/T Ratios of Chimney Reinforced Concrete chimneys are commonly used in major industries and power plants .Chimneys are slender structures, and loads acting on the chimney are self weight, wind loads, earthquake loads, and temperature loads. The designs of chimneys are normally governed by wind or earthquake loads. The dynamic characteristics of the RC chimney will vary in a wider range with respect to the aspect ratio (ratio of height to longitudinal section). In this paper, Dynamic analysis of an RC chimney in zone III is carried out by Response spectrum analysis as per IS 1893:2005 for different top and bottom diameters of the chimney and varying thickness of the shell using software SAP2000 version 18.0.1. Grade of concrete used is M25. The influence of various geometric parameters H/D and D/T ratios on the modal parameters and dynamic response of the structure, i.e., top displacement, fundamental frequencies, and Base shear are investigated. December 2016 - February 2017 Copyright © 2017 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=11389