COMPARATIVE NUMERICAL ANALYSES OF A REINFORCED CONCRETE STRUCTURE UNDER SEISMIC ACTION

Abstract

Numerical procedures for predicting reinforced concrete (RC) frames behavior, subjected to severe solicitation in particular earthquake, is nowadays a very important challenge in earthquake engineering field. The development of finite element (FE) codes generated multiple models of discretization associated to various rules of concrete and steel materials behavior. Indeed, both the coupling of these highly heterogeneous materials requires a fairly extensive behavior study including a maximum of parameters for better structure response simulation under seismic actions. Although, theoretically the most satisfying RC frames seismic analysis model involves the application of inelastic time-history dynamic analysis of three dimensional model of RC frames. Nowadays, this model seems to be too expensive or impractical due to the structures size and complexity. However, the simplified models applied to nonlinear static method can offer a good damage and safety evaluation of buildings' dynamic behavior. Other aims for RC structures seismic analysis are to be noticed, either for safety margins determination of the existing structures or the new buildings design. This work aims to expose the most used existing approaches in seismic numerical analysis and carry out a comparative study with the goal of evaluating the capacity of each method. Four models of seismic analyses are considered: dynamic, static, linear and nonlinear. Predictions are confronted with experimental results obtained from shake table tests. Furthermore, aiming to have a complete seismic analysis, three FE discretization models were studied for different scales. Hence, detailed knowledge of each approach was gotten from this procedure, deducing as a result the advantages and disadvantages of each model (reliability, computational time and domain of applicability), and providing a full database for reliability development and numerical methods robustness in earthquake, complying with the seismic design European standard recommendations. Comparing numerical and experimental results, a satisfying concordance is obtained when considering the initial structure damage. These results will be a good asset to assess the impact of uncertain parameters on seismic hazard and nonlinear response, through robust and simplified approach development of RC structures vulnerability estimating in civil engineering.