Finite Element Study of the Use of Reinforced Concrete Grids in Large Spans Slabs

Abstract

The research reviewed the structural systems used for buildings with long spans. The use of the grid slabs for long spans was studied using the finite element method. The primary objective was to carry out a parametric study of the effect of spacing and depth of ribs for grid slabs used in long spans. A three – storeys building was selected and analyzed under dead loads using Structural Analysis Program (ETABS). The grid slabs were used as a distribution of fixed width ribs with varying spacings and the depths which were varied until suitable depth and spacing was obtained based on the results of the vertical displacements. This was considered to be the optimum grid system. A six- storeys concrete building, of known results, was then analyzed and designed using the optimum grid system (ETABS). The dead and live loads and wind loads were applied to the building and the results were checked by comparing them with published results. The comparison showed close agreement between the results. This confirmed the accuracy of the optimum grid system. The case study building was chosen as Altadamon tower (ALTBT). The steel truss system used in long spans was replaced by a concrete grid slabs system which was analyzed and designed using the optimum grid system (ETABS). The dead, live and wind loads were applied to the selected building (ALTBT). The design results were verified and checked according to BS 8110 requirements, thus confirming the correctness of the proposed grid system.