Two-dimensional grid strut-tie model approach for structural concrete

Although approaches implementing strut-tie models are valuable tools for designing disturbed regions of structural concrete, the provisions of current design codes have to be improved because of uncertainties in terms of the selection of the strut-tie model and the structural type of strut-tie model. To improve the uncertainties, a grid strut-tie model approach is presented in this study. The presented approach, which allows for a consistent and effective design of structural concrete, employs a single type of grid strut-tie model whereby various load combinations can be considered. In addition, the approach performs an automatic selection of an optimal strut-tie model by evaluating the capacities of struts and ties using a simple optimization algorithm. The validity and effectiveness of the presented approach is verified by conducting the analyses of the eight reinforced concrete deep beams tested to failure and the design of the shear wall with two openings.