Scaffolding is a working platform designed to ensure the smooth progress of various construction processes. It is categorized by its installation location into external scaffolding and internal scaffolding; by material into wooden scaffolding, bamboo scaffolding, and steel pipe scaffolding; and by construction form into vertical 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. For the construction of the main structure, the most common type of scaffolding used is the coupler scaffolding, with the longitudinal spacing of the scaffolding posts generally being 1.2~1.8m; the transverse spacing is typically 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, with significant variation in node performance.
3. The scaffold structure and components have initial defects, such as initial bending of rods, corrosion, significant setup dimension errors, and loading eccentricities.
4. The points of connection with the wall exhibit significant variability in their constraint on scaffolding. Research into these issues lacks systematic accumulation and statistical data, thus not meeting the conditions for independent probability analysis. Therefore, the adjustment coefficient applied to the structural resistance, which is less than 1, is determined by calibrating it against previously used coefficients. 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 the basic condition for design calculations.
