Reliability assessment of steel scaffold shoring structures for concrete formwork

Many failures of concrete structures during construction are traceable to the collapse of formwork shoring systems. A reliability analysis for typical steel scaffold shoring structures is presented herein utilizing recent survey data on geometric and mechanical properties of steel scaffold members, and a second-order inelastic structural analysis model. Published shore load surveys were analyzed to develop the probabilistic models for loads acting on scaffolds during concrete placement. The paper investigates the mode of failure, the effects of different random variables on the variability of structural strength, and the reliability of the analyzed scaffold structures. The reliability framework can be used to improve the current working load limit basis for the design of steel scaffold structures and make scaffold design risk-consistent.