Estimation of along-wind moments in RC chimneys

doi:10.1016/S0141-0296(96)00041-7

Engineering Structures

Volume 19, Issue 1, January 1997, Pages 71-78

https://doi.org/10.1016/S0141-0296(96)00041-7 Get rights and content

Abstract

This paper reviews the prevailing international codal recommendations to determine the design along-wind moments in reinforced concrete (RC) chimneys and towers. A comparative study reveals significant disparities among the various codal estimates of the design moments, given the same basic wind speed and terrain condition. These disparities are a matter of concern to practising chimney designers and approving authorities in many countries. The relative accuracy of these differing estimates, which are based on different gust factor methods, have been quantitatively assessed with reference to rigorous stochastic dynamic analyses. This study covers a number of linearly tapered RC chimneys with heights in the range 100–400 m, located in different terrain conditions and subject to the range of wind speeds encountered in practice. It is observed that the estimates of the design moments are generally conservative in varying degrees, and are unconservative only in some cases. In very rough terrains, the lack of appropriate design provisions results in extremely conservative designs. With a view to improving the accuracy in the predictions, modifications to the gust factor method have been proposed in this paper.

References (25)

J. Holmes
Along-wind response of lattice towers — Part III. Effectivc load distributions
Engng Struct
(1996)
A. Kareem et al.
Reliability analysis of concrete chimneys under wind loading
J. Wind Engng Ind. Aerodyn.
(1986)
A.G. Davenport
The application of statistical concepts to the wind loading of structures
Instn Civ. Engrs
(1961)
A.G. Davenport
Gust loading factors
J. Struct. Div., ASCE
(1967)
B.J. Vickery
On the reliability of gust loading factors, Proc, Technical Meeting Concerning Wind Loads on Buildings and Structures
J. Vellozzi et al.
Gust response factors
J. Struct. Div., ASCE
(1968)
E. Simiu
Equivalent static wind loads for tall building design
J. Struct. Div., ASCE
(1976)
G. Solari
Along-wind response estimation: closed form solution
J. Struct. Div., ASCE
(1982)
ACI-307
Standard practice for the design and construction of castin-place reinforced concrete chimneys (ACI 307-88) and Commentary (ACI 307R-88)
(1988)
G.M. Pinfold
Reinforced concrete chimneys and towers
(1984)

NBCC

Supplement to the National Building Code of Canada: Part 4

(1980)

DIN-1056

Solid construction, free standing stacks; calculation, and deisgn

(1984)

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Estimation of along-wind moments in RC chimneys

Abstract

Engng Struct

J. Wind Engng Ind. Aerodyn.

The application of statistical concepts to the wind loading of structures

Instn Civ. Engrs

Gust loading factors

J. Struct. Div., ASCE

On the reliability of gust loading factors, Proc, Technical Meeting Concerning Wind Loads on Buildings and Structures

Gust response factors

J. Struct. Div., ASCE

Equivalent static wind loads for tall building design

J. Struct. Div., ASCE

Along-wind response estimation: closed form solution

J. Struct. Div., ASCE

Standard practice for the design and construction of castin-place reinforced concrete chimneys (ACI 307-88) and Commentary (ACI 307R-88)

Reinforced concrete chimneys and towers

Supplement to the National Building Code of Canada: Part 4

Solid construction, free standing stacks; calculation, and deisgn