Experimental and Analytical Investigations of Scaffolds With Anchor Rod and Plank

This paper investigates the influence of anchor rods, planks and inner knee braces on the critical load of scaffolding systems under concentric and eccentric loads in construction. The steel rebar of grade 3 is used in place of the patent anchor rod in this study. The results show that the critical load of the scaffolding system increases by 1.5 times when anchor rods of a length of 30 cm are used on two sides of each story of the scaffolding system. The critical load increases by 4 times when the scaffolding system has both the anchor rods and plank. The critical load of the scaffolding system with the anchor rods placed on each story is twice as large as that with anchor rods added every two stories; the failure mode of the system also switches from the in-plane to out-of-plane mode. The 30-cm-long anchor rod, used in place of a steel bar of grade 3, provides a good lateral restraint to the scaffolding system. Moreover, the setup plank can significantly elevate the critical load of the scaffolding system; the critical load increases approximately 1.5 times under the concentric load, and increases up to 2.2 times under the TL/4 eccentric load, defined as a load applied at a quarter distance from the end. The anchor rod and the plank should always be included in a scaffolding system to improve its stability, especially under the eccentric loads in construction.