The growing demand for sustainable, efficient and aesthetically innovative tall buildings has led to the development of advanced structural systems. Among these, diagrid structures have emerged as a prominent solution due to their geometric efficiency, structural performance and architectural flexibility. This thesis analyses the buckling behavior of spatial diagrid structures, focusing on their stability and resistance in the case of extreme situations, studied by means of a progressive collapse analysis to highlight the resilience of such structures. The following study involves the development of a model based on numerical analysis for the efficient and effective description of these behaviors. Thus, compared to existing methodologies based on the definition of the structure's shear and bending stiffness, and on finite element models, the proposed approach is based on the direct calculation of the structure's stiffness matrix.