Scaffolding is a working platform designed to ensure the smooth progress of various construction processes. It is categorized by its placement as external scaffolding and internal scaffolding; by material, as wooden scaffolding, bamboo scaffolding, and steel pipe scaffolding; and by construction form, as upright杆scaffolding, bridge scaffolding, portal scaffolding, suspended scaffolding, hanging scaffolding, cantilever scaffolding, and climbing scaffolding.
Different types of construction projects require different types of scaffolding. The majority of bridge supports use bowl coupling scaffolding, with some also using door frame scaffolding. For main structure construction, most ground-level scaffolding uses clamp scaffolding; the longitudinal spacing of the scaffold posts is generally 1.2~1.8m; the transverse spacing is generally 0.9~1.5m.
Scaffolding, compared to general structures, has the following characteristics in terms of working conditions:
1. The load variability is quite significant.
2. The connection nodes of the fasteners are semi-rigid, and the rigidity of the nodes is related to the quality of the fasteners and the installation quality, with significant variations in node performance.
3. Scaffold structures and components have initial defects, such as initial bending of rods, rust, significant dimensional errors in assembly, and eccentric loading, all of which are considerable.
4. The connection points with the wall exhibit significant variation in constraint to the scaffold. Research on the above issues lacks systematic accumulation and statistical data, and does not meet the conditions for independent probability analysis. Therefore, the value of the adjustment coefficient multiplied by the structural resistance is determined by calibrating with the coefficients used in the past. Consequently, the design method adopted in this specification is essentially semi-probabilistic and semi-experimental. Compliance with the structural requirements specified in this specification is the basic condition for design calculations.
