Strength calculation of risers near the supports of reinforced concrete three-hinged frames based on the concrete plasticity theory

The necessity of estimation of residual strength of risers sections near supports of reinforced concrete three-hinged frames at their reuse after operation in aggressive environment conditions and damages presence is indicated. The method of calculating the elements strength under the shear on the joint action of the transverse and longitudinal forces based on the plasticity theory is elaborated. The variational method, the virtual velocities principle, discontinuous solutions are applied. The kinematically possible failure schemes, the realization of which depends on the values ratio of transverse and longitudinal forces are proposed. The application boundary of these schemes is defined. The permissible level of concrete class reduction and the degree of its integrity violation were established, under which the residual strength of serial three-hinged frames near the supports was provided.