Structural design suite
Folded Plate Staircase Designer
IS 456:2000 limit state design, shell finite element analysis and construction drawings for rise-and-tread (zig-zag) stair slabs.
IS 456:2000 limit state design, shell finite element analysis and construction drawings for rise-and-tread (zig-zag) stair slabs.
Preliminary design aid. Simply supported flight with landings in span; check supports, fixity and detailing and have a licensed structural engineer verify before construction.
Every value below is recomputed from the inputs. Clause numbers refer to IS 456:2000 unless stated; confirm against your edition before submission.
Because the folded plate is prismatic and uniformly loaded across its width, a unit-width strip of the tread and riser plates with rigid folds is an exact cylindrical-bending shell model. It captures the axial and bending action in every plate that a simple slab model ignores. It is elastic and uncracked; edge effects across the width, cracking and long-term deflection are not included. It does not change the design above: use it to compare and to judge the folded depth option.