Calculation of monolithic buildings structures taking into account the nonlinear operation of reinforced concrete

Abstract

Buildings and structures made of reinforced concrete are currently designed, as a rule, under the assumption of linear work of the material. However, in accordance with the requirements of modern standards, it is necessary to take into account the nonlinear operation of concrete and reinforcement in calculations. In the research presented in the article, using the example of a building with a wall structural system, the influence of taking into account the physical nonlinearity of reinforced concrete on the operation of its structures was considered. It was received that due to the nonlinear operation, there is a prospect of a possible reduction in the calculated forces affecting the strength and width of crack opening, and, consequently, the reinforcement consumption. In addition, when taking into account the work of reinforcement in the zone of yield stresses in ceilings and walls, local plastic areas may form that require reinforcement, which are not fixed in linear calculations. The calculations were performed in the LIRA-CAD 2021 software package. The results of the calculations showed that taking into account the nonlinear operation of reinforced concrete when considering the floors of a building allows reducing the design efforts compared to calculations performed in a linear formulation by about (3 - 30)%, and when calculating walls, on the contrary, taking into account the physical nonlinearity of reinforced concrete, internal forces increase in some cases more more than twice. Taking into account the physical nonlinearity of reinforced concrete work also leads to a more correct assessment of floor deflections.