A Simple Mathematical Method for Optimal Preliminary Design of Tall Buildings with Peak Lateral Deflection Constraint

Abstract

The classic methods of structural design based on trial-and-error are generally highly iterative and computationally intensive, especially in a tall building consisting of thousands of structural members. This paper presents a closed-form solution for a minimum weight design problem which may be used at the early-stage design of a high-rise and slender structure. Before considering the weight-based problem, an intervening optimization formulation is introduced in advance which for a fixed amount of material presents an optimal pattern for its distribution. The obtained pattern is then used in the main problem, in which the total weight is considered as the objective function while satisfying the peak lateral deflection constraint and some practical requirements. The flexural stiffness in its general form is selected here as the design variable, so the proposed method is not restricted to a particular system, and any structural system may be addressed. A braced-tube 61-storey building example is presented to be designed based on the proposed technique to illustrate the effectiveness and practicality of the method.