الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Deep excavations become necessary so as to construct the underground structures. The analysis of deep excavation problems involves two main concepts. Material modeling is the first concept, which comprises retaining wall and soil modeling, of which soil modeling is the most important. The importance of the material modeling arises wile analyzing the problem in plastic state. It is worth mention that wall type models are varying from bilinear kinematic hardening model for steel sheet piles to Concrete model for diaphragm and piles. No soil model can, yet, completely simulate its real behavior under different cases of loading. Some idealizations are therefore inevitable to develop a simple model that is applicable within certain limits. Beyond these limits another simple model would be more appropriate. Elastic models have been widely used to model soil behavior at working loading conditions for calculating stresses and settlements, but they fail (0 simulate near, or at failure, where plastic deformation is governing factor. The link between both models was first drawn using the elastic perfectly plastic models, where part of the defonnation is irrecoverable, and this part affects soil behavior in case of reloading. For these models, there exists a fixed yield surface beyond which the behavior changes from elastic to plastic mode. The analysis of deep excavations has been studied with a very good degree of accuracy by lots of researchers. The earlier classical theories for the analysis of excavation were proposed by Coulomb (1773) and Rankine (1857). Terzaghi’s theory (1941) is an improvement over the earlier theories (Terzaghi and Peck, 1967). Substantial progress was achieved during the 1970s in the definition of finite elements adequate for the complete modeling of the system and in the development of techniques for simulating the construction sequence of such works. Recently, the use of numerical models has become an important part of the contributing for safer and more economical solutions, even under more daring and
demanding conditions.