Pattern load analyses for irregular floor systems

Abstract

It is commonly accepted that pattern load effects are important considerations for the structural design of flooring systems. However, most currently available guidelines are primarily proposed for conventional regular continuous beams and slabs with orthogonal grids, which may often be unclear when applied to more general situations. Derived from the influence line concept, and with simple yet rigorous mathematics, an accurate, simple, robust, well-defined and computationally efficient alternative approach is presented in this paper for pattern load analyses of arbitrary multiple-way spanning floor systems. Designed to work seamlessly with existing commercial finite-element analysis packages, the proposed alternative method provides more realistic estimations of the design load on structural members, and is proved to be practical for daily design practices. It also minimises the need for engineering judgement in the analyses, which will help the future development of computerised automation and optimisation of structural designs to be applicable to the detail design stage.