ABSTRACT
Linear-elastic finite elements are used at making soil-structure interaction calculations to describe models of reinforced concrete (RC) structures. This approach (effective stiffness method) is regarded as applicable in line with recommendations of numerous standards. The account of physically non-linear behavior of reinforced concrete is facilitated by reducing stiffness of elastic elements by conditional effective stiffness coefficients, which values largely differ in literature. The paper analyses relative differential settlements of the building at calculation of a physical non-linear RC model of a building and linear-elastic models with different effective stiffness ratios. Different approaches to assigning effective stiffness of RC lead to considerable differences in calculation results, especially considering soil-structure interaction The objective of the research is to develop a method of soil-structure interaction calculation using linear-elastic model of RC structures, so that its result were in good agreement with the calculations using a non-linear RC strain model. The paper proposes dependencies for estimating effective stiffness reduction ratios. Obtained dependencies allow considering non-linear material behavior without detailed modeling of non-linear behavior itself. It is demonstrated that a correct account of physical non-linearity of structural material is very important for soil-structure interaction calculations.
