Scaffolding is a working platform constructed to ensure the smooth progress of various construction processes. It is categorized by installation location into external and internal scaffolding; by material into wooden, bamboo, and steel pipe scaffolding; and by construction type into vertical pole, bridge, gate, suspended, hanging, cantilever, and climbing scaffolding.
Different types of construction projects require different types of scaffolding. Most bridge support scaffolding uses bowl clamp scaffolding, with some using gate scaffolding. For the construction of the main structure, most ground scaffolding uses clamp scaffolding, with the longitudinal spacing of the scaffolding uprights typically ranging from 1.2 to 1.8 meters; the transverse spacing is generally from 0.9 to 1.5 meters.
Scaffolding, compared to general structures, has the following characteristics in terms of working conditions:
1. The load variability is quite significant.
2. The connecting 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, rusting, large assembly size errors, and eccentric loading, etc.
4. The points of connection to the wall exhibit significant variation in their restrictive characteristics for scaffolding. There is a lack of systematic accumulation and statistical data on the above issues, and the conditions for conducting independent probability analysis are not met. Therefore, the value of the adjustment coefficient, which is multiplied by the structural resistance and is less than 1, is determined through calibration with 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 a fundamental condition for the design calculation of the scaffolding.
