Damage Assessment of RC Flat Slabs Partially Collapsed Due to Punching Shear

The aim of this study is to determine the causes of brittle collapse of existing reinforced concrete (RC) flat slab supported by columns under vertical loading. This paper focuses on the assessment of RC flat slab structures from the point of punching shear resistance. The entire process is illustrated using a case study from a parking structure. In the examined structure, the second storey slab was collapsed to the first storey slab without any earthquake and impact effects. A partially collapsed RC flat slab structure is examined within the scope of a field survey, lab studies, and numerical analyses. The first stage of the study examines the existing state of the collapsed structure and its compliance with architectural and structural drawings. Second, mechanical tests are conducted on samples gathered from the structure, based on observational research and lab environment. At the final stage, the structure's three-dimensional finite element model is prepared and the causes of the collapse of the structure are determined. The analysis shows that the lack of shear reinforcement, unforeseen loadings, and design errors are remarkably harmful to the slab-column connection resulting in punching shear resistance