Bearing capacity of fastener steel tube full hall scaffolds

In fastener steel tube full hall scaffolds (FSTFHSs), the upper load is transferred to the posts through the top horizontal tubes. Further, the posts and horizontal tubes are not always in the same plane owing to the eccentricity of the coupler connections. Moreover, building materials and construction machinery are usually eccentrically stacked atop the FSTFHSs. Therefore, the members in FSTFHSs are subject to eccentric axial loading. This paper reports a systematic experimental and analytical study on the bearing capacity of FSTFHSs with eccentric axial loads on the tubes. Five full-scale FSTFHS specimens were built and tested for failure to obtain the strength and failure modes of FSTFHSs whose members are subject to eccentric axial loads. Advanced nonlinear finite element analysis (FEA) was conducted on the specimen models to obtain the strength and failure modes of the FSTFHS under eccentric axial load of the member and to compare with the experimental results. Parametric studies were conducted based on the FEA results to investigate the influence of eccentric axial loads on the bearing capacity of FSTFHSs with different geometric properties. The experimental and analytical results show that eccentric axial loading negatively affects the FSTFHS bearing capacity and that the main failure mode of FSTFHS is the local instability of the posts in the heaped load areas, accompanied by the twisting of the entire structure and bending of the top horizontal tubes.