Title: Free-Standing Stairs
Author(s): Franz Souter
Publication: Journal Proceedings
Appears on pages(s): 847-870
A direct method for analyzing free-standing stairs with equal upper and lower runs and without landing support is presented for a symmetric loading case. The method is based on Fuchsteiner’s simplification of the stair structure into a space frame composed of linear bar elements. Deformations ore calculated from the work integrol with the application of the principle of least work; and redundants are determined by solving the elastic equations. Selection of a proper statically determinate system allows a direct approach and obviates the tedious calculation of unknown moments by superposing different supporting conditions. This selection also allows consideration of both cases of fixed and simple support conditions at the upper and lower floor levels. Intro-ducing two minor simplifications, the method is further developed to include worked-out formulas for the redundants, and design charts are presented which permit the direct reading of coefficients for the calculation of the un known moments as a function of the geometric properties of the stair and for different loading conditions. The calculation of an otherwise highly complex structure is reduced to a minimum a s shown in on example.