摘要：There are numerous structural lateral systems used in multi-story buildings design such as the shear wall, frame system, framed with core, dual systems and superframes, etc. Additionally, the system of slabs such as (Solid Slab, Flat Slab, Flat plates, Hollow blocks, ... and Waffle Slabs). Generally, the structural systems of multi-story buildings are considered to be different types. Multi-story buildings are commonly used in residential, commercial and administrative projects; therefore, determining the structural system with minimum cost is the top priority of the structural designer. This research aims to introduce recommendations for the optimum structural system for a multi-story Reinforced Concrete (R.C.) building from a perspective of direct cost to help decision-makers in the preliminary design for choosing the optimum structural system. This paper outlines the development of charts to predict optimal structural system costing, using the status of early conceptual design as the charts input. In order to achieve that goal, a parametric study was carried out using 27 RC buildings with several stories ranging between 5 to 50 floors and grid spacing ranged between 6.0 to 12.0 m. Three floor systems were considered which are solid, ribbed and flat slabs.
