Mechanical safety of reinforced concrete frames under complex emergency actions

Строительная механика

An approach to the calculation of the frame reinforced concrete structures taking into account the potential risk of financial losses in an emergency is proposed. The simplified conditions for the strength of structural components considering the potential relative risk of the financial losses for the structure during emergency failure of these components is formulated. The strain-stress state analysis using the finite element method based on bar models can be performed in dynamics. The reinforced concrete structural component in the form of a package of concrete and reinforcement layers that can be deformed according to actual diagrams approximated by piecewise linear functions. The calculations were considered by accounting geometric, structural and physical nonlinearity. As an example, illustrating the operability of the presented approach, were considered the frame of the building with several scenarios for emergency actions. This is a complete or partial exclusion of one column from the calculation model, accompanied by a horizontal impact. The exclusion of 0.75 and 0.5 parts of the cross section of the column as well as its complete exclusion, accompanied by a horizontal impact pulse were examined. A collision of a damaged structure with a rigid barrier and with a deformable base were simulated. The proposed approaches to modeling the stress-strain state and strength conditions of the bar reinforced concrete systems have prospects for using in algorithms of optimum parametric synthesis of structures based on metaheuristic approaches.