2D SUB-3D STM Approach for Design and Analysis of 3D Structural Concrete

The 2D SUB-3D STM approach for analysis and design of three-dimensional structural concrete is presented in this paper. In the approach, several two-dimensional sub strut-tie models which represent the compressive and tensile stress flows of each projected plane of a three-dimensional structural concrete are utilized in the selection of a three-dimensional sout-tie model, in the evaluation of effective strengths of concrete struts, and in the verification of geometric compatibility condition and bearing capacity of critical nodal zones of the selected three-dimensional strut-tie model. To prove the validity and rationality of the suggested approach, the behavior and strength of a prestressed box girder diaphragm tested to failure are evaluated.