Identifying, Evaluating, and Correcting Punching Shear Deficiencies in Flat Plate Construction

The 2021 collapse of Champlain Towers South in Surfside, FL has emphasized the importance of identifying, evaluating, and correcting punching shear deficiencies in flat plate construction. In practice, punching shear related cracking can be challenging to identify as cracking is usually concealed. Current and previous code equations are of limited use for evaluating the punching shear capacity of slabs with excessive top cover and low reinforcement ratios. This presentation describes approaches to screening for punching shear deficiencies, field evaluation of existing conditions, and punching shear strength evaluation. Also presented are cost-effective retrofits for strengthening slab/column regions where deficiencies have been identified. Learning Objectives -List prior punching shear related building failures -Predict the strength for punching of flat plates considering flexural reinforcement and slab thickness -Assess flat plate construction for punching shear related distress -Identify appropriate retrofits for punching shear related distress or deficiencies.