IJIRST –International Journal for Innovative Research in Science & Technology| Volume 3 | Issue 07 | December 2016 ISSN (online): 2349-6010
Comparative Design and Analysis of Self Supporting and Guyed Steel Chimney R. Boopathiraja Assistant Professor Department of Civil Engineering The Kavery College of Engineering, India
K. Kayalvizhi Assistant Professor Department of Civil Engineering The Kavery College of Engineering, India
R. Vanathi Assistant Professor Department of Civil Engineering The Kavery College of Engineering, India
Abstract The area proposed for the construction of this chimney is at an industry in Metter. They have already provided 43m self-supporting steel chimney. In addition to that, analysis and design of 72m steel chimney (Self-supporting Vs Guyed) for eco-friendly purpose. Here we design and analysis a steel chimney having a height of 72m steel chimney and structural elements of the chimney such as foundation are designed. By comparing the moments of self-supporting steel chimney and guyed steel chimney from manual design. The base moment of guyed steel chimney is less than the self-supporting steel chimney and hence Guyed Steel Chimney is safe at that site. Keywords: Auto CADD, STAAD pro, guy ropes, cylindrical shell _______________________________________________________________________________________________________ I.
INTRODUCTION
Our project deals with the design of a steel structure. The type of chimney that we have taken for our project is industrial chimney with steel. Here design of loads and the design of self weight and foundation were carried out manually. The various drawings were drafted by AutoCAD 2013.And the analysis is done by STAAD pro 2007. Usually the design of the structural elements carried out manually and it takes more time but we can learn more things. If the structure is small than the calculation will be simpler and can also be completed quickly. But for the chimney, the calculation for the design of the structural elements will be tedious and time consuming. Chimneys are used to emit the exhaust gases, higher up in the atmosphere, so that diffusion of gases takes place. There are mainly three types of chimney structures: - R.C.C chimney, Steel chimney, Brick chimney. For project, considered steel chimney structure. II. DESIGN OF SELF-SUPPORTING STEEL CHIMNEY Basic Dimensions of Chimney: Total height of chimney = 72m Height of flare = H = 1/3(72) = 24 m Diameter of the flare =1.6x3 = 4.8m. Computation of wind pressure: The design wind speed at any height z is given by Vz=Vb.k1.k2.k3 Where, Vb = basic wind speed at the site =47m/s for salem. k1=probability factor (risk coefficient) =1.0for general buildings and structures. k3=topography factor =1.0 for flat topography k2=terrain, height and structure size factor Vz= 47 x 1 x 1 x k2 Now design wind pressure Pz= 0.6Vz2N/m2 Pz=0.6(47k2) x10-3 kN/m2= 1.3254k22 KN/m2 For chimney, adopting a shape factor of 0.7 Pz= (pz.D.∆z)0.7
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