EARTHQUAKE AND WIND EXCITED VIBRATIONS OF CHIMNEYS

Abstract

The general design practice for wind forces in chimneysis to allow a certain horizontal force acting along the height of the chimney. But this practice is not ration-al. In this investigation, dynamic analysis of chimneys is carried out for two simulated wind records. The displacement, velocity and acceleration response for these wind records are determined and by changing the time base of the records, their effects are also studied. The distribution of moments and shears have been examined for few chimneys. The moments and shears are expressed in tenlis of the displacement response. The effect of damping and number of modes is also studiedl The moment and shear distribution along the height both for the wind forces and earthquake forces are drawn. rhe percentage increase in cost is determined due to wind and earthquake forces for various heights of the chimneys