Survivability of multi-storey building frame with prestressed elements

Abstract

The results of theoretical studies of dynamic additional loads in prestressed structures of reinforced concrete frames of multi-storey buildings in beyond design states caused by special or emergency effects are presented. A numerical study of the deformation and destruction of reinforced concrete frames with a sudden change in power flows in them was carried out using level primary and secondary design schemes in two versions of design solutions: 1) with reinforcement of beams with prestressed reinforcement installed in the lower section of the beam, 2) with double reinforcement with prestressed reinforcement in the upper and lower zones. The influence of various schemes and levels of prestressing of structures on the values of the coefficients of dynamic additional loads in the considered structurally and physically nonlinear systems with a sudden change in force flows caused by unstable failure of stretched concrete at the time of cracking and structural restructuring of the structural system has been established. The obtained solutions are compared with the results of experimental studies. Recommendations are given on the use in the structures of reinforced concrete frame structures of multi-storey buildings to increase their survivability and protection against progressive collapse.