EFFECT OF MEMBER THICKNESSES ON DESIGN FORCES IN RCC BUILDING FRAMES

Abstract

The aim of structural analysis is primarily to determine the various forces in the structure so that as far as possible the actual forces in the various members are simulated to a considerable extent. Therefore proper selection of an appro-priately idealised structure becomes imperative. However, building frames are in conventional analysis, idealised by their centro-idal axis and the effect of member thicknesses is not taken into account. The present study makes an earnest endeavour to look into the effect of member thicknesses, On design forces with Particular reference to RCC building frames. Hence the method of analysis that accounts for member thicknesses, the FEM, is employed, and among..thenoenventional methods the stiffness method is used. The results obtained by the two methods are compared and examined. Moreover, the Portland Cement Association' (PCA) recommended modification was, once again, compared with the FEM results. The assumptions incorported in, the conventional method of analysis were critically appraised and a realistic approach of analysis was recommended in the light of the results and contours prepared. The variation of principal stresses at the joints and their direction were identified and recommendation for proper detailing of reinforcement at junctions was made.