Abstract
In 1966 the author found through the dynamic response analysis that tall reinforced concrete chimneys designed by the Japanese seismic code are very strong in their bottom portion but extremely weak in their upper portion. Then in order to renew this absurdity, the author tried to establish a tentative proposal of the earthquake resistant design method on which effect of the dynamic behavior is reflected. Namely, such parameters as chimney heights, chimney proportions, foundation conditions, damping assumptions and earthquake waves are selected for investigating the vibration characteristics of tall chimneys by means of the direct earthquake response analysis. Thus, a tentative method for manual calculation of dynamic earthquake forces acting on chimneys is proposed on the basis of the analyzed vibration characteristics. The main formulas recommended in this paper are as follows : 1) Determination of chimney proportion 2) First natural period 3) Coefficients of both base shear and base overturning moment 4) Distribution of both shear and bending moment along chimney height
