| 摘要 |
PURPOSE: To increase the effective width of stairs, by providing the upper and lower stairs constituting the turning-back stairs within a column-beam frame to form a stairs unit and eliminating columns at the outside of the turning-back stairs. CONSTITUTION: Two first and second columns 14A, 14B and a connection beam 14C laid between the columns 14A, 14B are rigidly joined together to form a column-beam frame 12 constituted of H-shaped frames 14 having a frame structure. The lower stairs 11A and the upper stairs constituting the turning- back stairs 11 are installed in the column-beam frame 12 and the columns 14A, 14B are arranged only at the boundary between the lower and upper stairs 11A, 11B. And the sum of the effective stairs width of the lower and upper stairs 11A, 11B is made to be about the figure that the sectional dimension of only one column is subtracted from the full width of the stairs unit 10. Accordingly, the effective stairs width and effective dimension of landing can be designed to be sufficiently wide. |
