Scaffolding is a working platform constructed to ensure the smooth progress of various construction processes. It is categorized by installation location into outer scaffolding and inner scaffolding; by material into wooden scaffolding, bamboo scaffolding, and steel pipe scaffolding; and by construction form into upright pole scaffolding, bridge scaffolding, door scaffolding, suspended scaffolding, hanging scaffolding, cantilever scaffolding, and climbing scaffolding.
Different types of construction projects require different types of scaffolding. Most bridge supports use bowl clamp scaffolding, with some using gate scaffolding. The majority of main structure construction ground scaffolding uses clamp scaffolding, with the longitudinal spacing of the scaffolding uprights typically 1.2~1.8m; the transverse spacing is generally 0.9~1.5m.
Comparatively speaking, scaffolding has the following characteristics in terms of working conditions compared to general structures:
1. The load variability is quite significant.
2. The connecting joints of the fasteners are semi-rigid, and the rigidity of the joints is related to the quality of the fasteners and the installation, with significant variation in joint performance.
3. Scaffold structures and components have initial defects, such as initial bending of rods, rust, significant setup size errors, and eccentric loading, all of which are considerable.
4. The connection points to the wall exhibit significant variability in their constraint on the scaffolding. Research on the aforementioned issues lacks systematic accumulation and statistical data, and does not meet the conditions for independent probability analysis. Therefore, the adjustment coefficient multiplied by the structural resistance is determined by calibrating with coefficients used in the past. Consequently, the design method adopted in this specification is essentially semi-probabilistic and semi-empirical. Compliance with the structural requirements specified in this specification is a fundamental condition for design calculations.
