ANALYSIS AND BEHAVIOUR OF SHELL ROOFS UNDER EARTHQUAKE LOADS

Abstract

Behaviour of shell roof ,under the action of earth-quake 'rtes depends on the direction of earthquake. For the dynamic analysis of shell when earthquake forces are acting in transverse direction, it is necessary to know the dynamic characteristics of shell i.e. frequencies and mode shapes. In case earthquake forces are acting in longitudinal direc-tion, the effect of column top moment assumes greater imp-ortance. Attempt has been made in this thesis to find out eff/ct of column top moment on the stresses of two bays shell using Holland Theory. The study of column top moment indicates that 21 terms of Fourier series are required to be considered for moments and shears in beam to converge. Study also indicates that the method is applicable for long shells. F re q ue nc ies fo r symmetric al and antisymmet ric al modes are obtained using DKJ theory. The first mode symm-etrical frequency agrees well with the Rayleioh's frequency. The first two frequencies for symm