الفهرس 
chapter 1Only 14 pages are availabe for public view
 |  | from | 192 |  |  |
| | | from | 192 | | |
Abstract
In an earlier research, the author developed a computer program named NARC to conduct material nonlinear analysis of reinforced concrete plane frames provided with perfect supports. In this research, the finite element model is further developed to take the geometrical nonlinear behavior and soil-structure interaction effects into consideration. Nonlinear behaviors of concrete and reinforcing steel are considered both in compression and in tension up to failure. The model also takes into account number, diameter, and distribution of rebars over each cross section. The failure takes place when the stress in either concrete or steel reaches its ultimate value. Soil behavior is taken into consideration using four different models; namely: linear-, nonlinear Winkler’s models, and linear-, nonlinear continuum models.
A second version of computer program named (NARC II) is specially developed in order to perform the analysis. The main contribution of this thesis is developing new software called NARC II. Through this software, researchers and engineers can analyze the plane reinforced concrete framed structure up to failure, taking into account both the geometrical and material nonlinear effects, besides soil-structure interaction. Material nonlinearity is considered for concrete, reinforcing steel, and soil. Usually, these effects are neglected in the traditional analysis. The results achieved by the present model show good agreement with both theoretical and experimental results in the published literature.
For demonstration the geometrical and material nonlinear behavior up to failure of a simple rectangular structure resting on perfect supports and soft soil is introduced using the proposed model. In addition, the nonlinear geometrical and material behavior of large span reinforced concrete arched structures considering soil-structure interaction is investigated. All computations were carried out based on the proposed numerical model through NARC II computer software. This study might be considered very useful for the structural engineer as it gives important design recommendations for optimal design of large span reinforced concrete arched structures. Moreover, problems arising from differential settlement in multi-bay multi-story structures are studied using NARC II. The role might be played by diagonal bracing systems to overcome such problems is also discussed.