Effect of support method modeling on R\C Dual system structures behavior with different heights taking nonlinearity of materials inconsideration

Abstract

The research presents an analytical study of the behavior of a reinforced concrete structure with a dual structural system of (4 - 8 - 16) floors height, when taking the soil-structure interaction (SSI). This is for different supporting cases including fixed support - Winkler Springs (BNWF) – soil medium according to the finite element method (FEM)) under the influence of seven seismic earthquake records. Initially, the reinforced concrete structure was modeled with a frame structural system (4-8) floors with a fixed and flexible support conditions (Winckler Springs (BNWF) – gravel clay soil) through the ABAQUS 2019, and when calibrating these models with the reference study the results were close to each other under the influence of the applied loads. The structure of the dual structural system was modeled with heights of (4-8) floors with the addition of a R\C wall in the second span. Then increasing the number of floors to 16 and adding a new form of support (fixed - Winkler Springs (BNWF) – gravel clay soil - Soil sandy clay). Finally, the behavior of the original structure was studied for each case separately by using the nonlinear dynamic analysis (Time History Analysis), and when taking the average response to the applied records, the results indicated that the increase in height led to an increase in the values of both base shear, period, and floor drifts. The height of the structure led to a change in the behavior of the response of the structure and according to the variable supporting cases, there was a clear difference in the behavior of the structure between the two cases of elastic Winckler Springs (BNWF) and soil modeling (FEM), which confirms that the representation of the soil with Winkler Springs (BNWF) does not give the true representation of soil especially when then material of both soil and structure yields significantly.