Experimental and numerical studies of practical system scaffolds

• Scaffolds attract a high rate of collapse in recent years.
• We investigate the failure modes of the system scaffolds in various configurations.
• This paper quantifies the load capacity of a system scaffold against various factors.
• Comparison between analyses and experiments confirmed member joint stiffness.
• Using the joint stiffness, the ultimate design loads of the system scaffolds are computed.

Scaffold design has become a popular research topic in recent years, likely because of the high rate of collapse for this structural form and its nature of under estimated loads close to the design loads, as opposed to permanent structures under remote statistical live and wind loads. This paper investigates the load capacities and failure modes of the system scaffold structure in various setups in construction and it is based on experimental tests supplemented by analyses. The parameters for system scaffolds studied in this paper include number of stories, ground heights, boundary conditions, presence of diagonal bracings and joint positions. The numerical studies quantify the load capacity of a system scaffold against addition of diagonal bracings. However, the load capacities of a system scaffold structure with varied spigot-joint positions on vertical props and with varied ground heights do not affect much the load capacity. Since the axial force of diagonal bracings on a system scaffold structure does not significantly increase with the vertical load, the diagonal bracings of the structure can be reduced in size for cost saving. A comparison between analyses and experimental tests conducted in this study confirmed the joint stiffness of different members used in the system scaffolds. Using the joint stiffness, the ultimate design loads of the system scaffolds with different number of stories were computed and quantified. The findings will be useful for accurate determination of the ultimate load capacity of complex system scaffolds used in construction sites.