An approximate method is presented for the analysis of the distribution of lateral forces among the components of a 3-dimensional building structure that consists of assemblies of shear walls, coupled walls, rigidly jointed frames and cores, subjected io both bending and torsion. The load distribution on each assembly is assumed to be represented sufficiently accurately by a polynomial in the height coordinate, together
with a concentrated interactive force at the top. The presence of the latter is essential for obtaining accurate results as simply as possible. A set of flexibility influence coefficients, relating the deflection at any level to any particular load component, is established for each assembly, the continuum approach being used to analyse individual cores and coupled shear walls, and the shear cantilever analogy for the frame elements. By making use of the equilibrium and compatibility equations at any desired set of reference levels, the load distribution on each assembly may be determined. Good results appear to be achieved.for regular structures by using no more than about six reference levels.
Professor A. Coull and T.H. Mohammed