Simplified model for estimating the punching load and deformation of RC flat plate based on big data mining

In the previous paper, based on the big data of gathered crack image and load-deformation relationship of laboratory experiments, the bending-shearing critical crack method (BSCCM) has been developed to give the mechanical explanation of the punching shear phenomenon in interior slab-column connections without shear reinforcement and the analytical method could analysis the punching shear strength and deformation capacity simultaneously. Based on the big data of the gathered experiments, this paper firstly validates the accuracy of the BSCCM for the standard specimen with 45 tests data, and secondly deduces the equivalent transformation formulas for non-standard specimen through the yield line theory and verifies the applicability of the BSCCM for the non-standard specimens with 98 tests data. And on this basis, through data mining and factor analysis, this paper studies the factors that affecting the punching shear strength and deformation and proposes the simplified calculation formulas for engineering practice. At last, this paper fully validates the reasonability and accuracy of the formulas with 432 tests data. Results show that the BSCCM is applied to the calculation of punching shear strength and deformation for both standard and non-standard specimens. The simplified formulas which considered concrete strength, yield strength of steel/bar, reinforcement ratio, punching span ratio and perimeter thickness ratio of critical section can accurately and rapidly predict the punching shear strength and deformation of the slab-column connection. The conclusion can be available for engineering application and be used as the basis of the performance design of RC flat plate structure.