CONTINUUM METHOD FOR OVERALL STABILITY OF TALL ASYMMETRIC BUILDINGS

A solution for the buckling loads of asymmetric tall buildings with uniform cross section is presented, using a three-dimensional continuum model and including the effects due to normal strains in columns and shear walls. The layout of the stiffening elements in the plane of the structure is arbitrary, without restrictions as to shape of the shear wall cross section, direction of its principal axes, and orientation of the frames. The equilibrium equations for rotation, lateral and normal displacements are formulated in variational terms. Buckling loads are calculated by means of infinite polynomial series, using the existence criterion for a nonzero solution of the homogeneous system of differential equations. For practical application of the method, the use of a computer is essential. The numerical example worked out shows that for slightly deformable connecting beam systems, largely overestimated buckling loads may result by omission of axial strains.