Stair Stringer Design

Design of uniformly loaded simple stair steel stringers. This design is in accordance with the American Institute of Steel Construction (AISC) 13th Edition requirements - Section F. The worksheet can also be used to check or investigate an existing stringer steel section.

Here are the key points about the calculation:

1. Design Basis: The design is based on user-selected limits on stringer depth and the allowable deflections. If necessary, the user can also define upper and lower limits on the width of the stringer flange for verifying a railing connection to the top of the stringer. The stringer types are limited to C channel, MC channel, and rectangular tubes.

2. Automatic Selection: Based on the user-defined selection criteria and the applied loads, the worksheet automatically makes a maximum of 16 selections from the AISC steel shape database. These selections are tabulated along with their relevant section properties.

3. Assumptions: The following assumptions are made in the calculations:

   • Channel stringers are assumed to be simply supported on each end and continuously laterally braced along their length by the stair pan.
   • All current ASTM A6 C, MC, and tubes are compact.
   • Stringers are assumed to be pinned at the top & bottom such that vertical loads are distributed equally to the top & bottom supports.

4. Input: The user defines the uniform loads, the allowable deflection criteria, and the upper and lower bounds on stringer depth. To check an existing stringer section, the user can input the appropriate limits on the section properties to match the section in question. If the section shows up in the results table, then it is an appropriate selection.

Stair Design

Structural Steel Design