Statement of the problem. Development of a practical calculation model of reinforced concrete structures in torsion with bending of square cross-sections, most fully reflecting the features of the actual work of the structures. Results. The bearing capacity criterion from the intensity of the limit deformations and projection diagrams of complex elastoplastic tensors of compressed concrete in the calculation model of reinforced concrete structures under the joint action of forces for the constructed bilinear spatial crack is obtained. The reactions from the deformation effect of concrete and reinforcement in a crack were determined using the deformation effect and a dual-console element. The hypothesis of relative angular deformations for deplanation and gradients in the fracture was proposed. Here crack opening is the accumulation of relative concentrated mutual displacements of reinforcement and concrete. Conclusions. In the spatial section, the limit deformations were obtained by projecting the diagram of complex elastoplastic tensors of compressed concrete. The internal stresses from the deformation effects of concrete and reinforcement in the crack were found. The article includes an important algorithm and numerical example.