Approximate Stiffness Analysis of High-Rise Buildings

Developments in computer software have made many programs available for more exact high-rise space frame design. However, in practical structural engineering design such programs may be too expensive and time consuming especially for the preliminary design. This paper presents a simple, yet reasonably accurate method to solve problems of lateral load distribution among the different frames of a high-rise building by simple programming using small computers. The cantilever method for approximated lateral load analysis is incorporated to derive the flexibility and the stiffness matrices of each frame. By the method presented, the lateral loads are distributed among the frames according to the approximate stiffness matrix of each frame and the final sway of the building can be found. This method can also be used for buildings with a combined system of frames and shear walls.