Modified interactive strut-and-tie modeling of reinforced concrete deep beams and corbels

Abstract

In this study, a strut-and-tie model (STM) for predicting the shear strength of reinforced concrete deep beams and corbels was proposed. The model was derived on the basis of two independent force-transferring mechanisms, namely, diagonal strut and truss mechanisms. The first mechanism was modified from the so-called interactive strut-and-tie model (ISTM). The novelty comprises the derivation of a new proposed failure criterion of concrete used to develop the strength contributed by the strut mechanism. The truss mechanism represents the strength contribution from the orthogonal web reinforcement. The combination of the strength contributions from the two mechanisms results in the predicted shear strength. The model was calibrated on a large database of 682 deep beams and 338 corbels and verified using tenfold cross-validation. The shear strength predicted by the proposed STM was benchmarked against those computed using the original ISTMs and other state-of-the-art models. The comparison indicates that the proposed STM affords a more accurate prediction than the benchmark approaches.