DYNAMIC BEHAVIOR OF A RC COLUMN UNDER AXIAL-LATERAL IMPACT

Abstract

The analysis of the collapses of buildings and structures that have occurred in recent decades, as well as the results of experimental studies, shows that a sudden failure of a column of the load-bearing system of a building leads to dynamic effect on structures adjacent to the site of initial local destruction. In this case, the columns adjacent to the site of the initial local destruction can be subjected to the simultaneous action of the axial shock loading and the lateral displacement of the support nodes. In this regard, the subject of the paper is the dynamic behavior of a reinforced concrete column under axial-lateral impact. The paper proposes an analytical solution to the differential equation of the axial-lateral buckling of a reinforced concrete column under accidental impact caused by a sudden structural transformation of the load-bearing system. Nonlinear behavior of material and energy dissipation due to damping have been considered. As a criterion for the bearing capacity assessment, the achievement of zero resistance is accepted, i.e., the ability of cross-section to resist the increment of forces along the height of the column. The results of numerical modeling are compared with the experimental data for lateral displacement obtained by the authors for the model of a two-story reinforced concrete frame with slender columns. The obtained analytical solution allows approximate evaluation the progressive collapse behavior of eccentrically compressed reinforced concrete columns.