| 摘要 |
PURPOSE: To improve appearance by fitting a bent part on the upper end of a riser to the side wall part on the rise side of a stepboard from above, and covering the bent part of the riser and the lower end part front surface with the concrete filled in the stepboard. CONSTITUTION: A stepboard 3 formed by cutting and bending a plated steel plate into a tray form is mounted between a lateral pair of open strings 1 by a bolt. A riser 5 formed by bending a plated steel plate is mounted, stradding the stepboards 3 on the upper step side and the lower step side. A turned part 7 on the upper end of the riser 4 is fitted to the side wall 8 on the rise side of the upper stepboard 3 from the upper end to cover a cut end 11 on the upper end of the side wall 8, and the lower end of the riser 4 is suspended so as to be situated on the inside of the side wall 9 opposite to the rise side of the lower side stepboard 3. Further, concrete 10 is filled into the stepboard 3 to a level higher than the side wall of the stepboard 3. Thus, the rusting and soil of each cut part can be suppressed, and replating can be dispensed with to reduce the cost. |
