Deformation of reinforced concrete frames of multi-storey buildings in extreme conditions under special influences

In order to increase plasticity during destruction along inclined sections and to protect against progressive collapse of reinforced concrete frames of multi-storey buildings, a variant of cross reinforcement of crossbars in such frames is proposed. The results of a numerical study of the reinforced concrete frame of a multi-storey building with a special impact in the form of an extraordinary hypothetical removal from the work of one of the columns are presented. The modeling of the deformation of the frame is carried out in three versions: the frame of the entire building in the rod setting, a fragment of the building in the column removal zone and a fragment of crossbars adjacent to the column being removed using volumetric finite elements. The obtained results showed the effectiveness of the proposed variant of cross-reinforcement of crossbars to protect a multi-storey frame building from progressive collapse, as well as the effectiveness of using the proposed variant of three-level models for calculating the parameters of static-dynamic deformation of the carcasses of multi-storey buildings under the considered special impacts.