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杆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 support structures use bowl clamp scaffolding, although some use door frame scaffolding as well. For main structure construction, most ground-level scaffolding uses clip scaffolding. The longitudinal spacing of the scaffold uprights is generally 1.2 to 1.8 meters; the transverse spacing is typically 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 relatively large.
2. The connecting joints of the fasteners are semi-rigid, and the stiffness of the joints is related to the quality of the fasteners and the installation quality, with significant variation in joint performance.
3. Scaffold structure and components have initial defects, such as initial bending of bars, rust, large installation size errors, and eccentric loading.
4. The connection points to the wall exhibit significant variation in their restrictive nature to scaffolding. Research on the aforementioned issues lacks systematic accumulation and statistical data, rendering it impossible to conduct independent probability analysis. 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 a combination of semi-probabilistic and semi-empirical approaches. Compliance with the structural requirements specified in this specification is the fundamental condition for design calculations.
