TAKING INTO ACCOUNT FLEXIBILITY WHEN CALCULATING THE STRENGTH OF CENTRALLY COMPRESSED SQUARE-SECTION TUBULAR CONCRETE COLUMNS

The method of calculating the load-bearing capacity of centrally compressed tubular concrete columns of square section is considered. The technique is based on the use of a nonlinear deformation model of reinforced concrete. Accepted deformation diagrams of concrete core and steel pipe take into account their complex stress state. The proposed method takes into account the variable stiffness of different sections in height of the compressed rod when assessing the effect of its flexibility. The maximum load corresponding to the loss of strength or stability of the element is determined by the same method using the same formulas. As a result, there is no need for a separate formula for calculating the critical force. A comparison of theoretical and experimental data indicates the acceptability of the proposed calculation methodology for project practice.