Simplified discrete method for the design of helical rectangular beams of very large width

Abstract Helical rectangular beams are defined as beams circular in plan and supported only at their two ends. They are in general three-dimensional structures indeterminate to the sixth degree. In the present study only symmetric helical beams of circular plan are considered. The redundancy is therefore reduced to the second degree. They are analysed as linear space structures loaded vertically with a uniformly distributed live and dead load and with a ratio of width to height: b d ⪢ 0.50 . The proposed method has practical application for the design of concrete stairs and rumps. The principle of virtual work [1, 2], is used for the analysis by chosing the appropriate release system to arrive at final expressions which are solved using appropriate design charts prepared for shallow-wide and thin beams, b d ⪢ .50 , b d , with fixed supports. This discretization is necessary because of the shape of selection which defines its structural form. For both types of structures the solutions are valid for beams with both ends fixed. Only shallow-wide beams are considered in this paper. A numerical example is worked out and comparison of the values of stress resultants obtained by the proposed method and other methods. Some conclusions are deduced.