PREDICTING THE NON-LINEAR SHEAR BEHAVIOUR OF DEEP BEAMS BASED ON A TWO-PARAMETER KINEMATIC MODEL

The evaluation of deep transfer girders subjected to extreme loading requires computationally effective methods and tools for predicting their complete pre- and post-peak shear behaviour. This paper discusses such an approach which stems from a two-parameter kinematic theory (2PKT) for the shear strength and deformation capacity of deep beams. The 2PKT includes equations for equilibrium, compatibility of deformations, and constitutive relationships for the mechanisms of shear resistance. In this paper the constitutive relationships of the 2PKT are modified to allow for the computation of the complete response of deep beams. The extended 2PKT approach is validated with tests of deep beams showing excellent results. The test properties are varied to study the effect of concrete strength and amounts of longitudinal and transverse reinforcement on the shear behaviour. It is shown that deep beams with high-strength concrete exhibit brittle snap-back failures. Increasing the amount of longitudinal reinforcement decreases the displacement capacity of deep beams while the opposite trend is observed with the addition of transverse reinforcement. Increased amounts of longitudinal and transverse reinforcement result in increased peak and post-peak resistance