Bearing Behavior of Reinforced Concrete Column-Isolated Footing Substructures

Under earthquake, the interaction between column footing and soil foundation directly affects the failure mechanism of reinforced concrete (RC) structures. In the present study, to investigate the structural performance and failure mode of RC column-isolated footing substructures on foundation, a test device using rubber-wooden composite blocks to simulate elastic foundation based on Winkler foundation model was designed. Three RC column-isolated footing substructures were tested to evaluate the load-carrying capacity, failure mode, crack distribution, footing slab deflection, subgrade reaction, and rebar strain. The test parameter was the longitudinal bar ratio of the footing slab, and axial compression and lateral loading were applied to the column. Nonlinear analysis model was established in ABAQUS, and the predictions agreed well with the test results. On the basis of the analysis model, a parametric study was performed to investigate the effects of foundation coefficient, axial compression ratio, and footing slab thickness on the load-carrying capacity, failure mode, and column constraint.