Excavation sequences optimization for tunnels in Egyptian soil conditions
Optimization is operated with a lot of underground structures in the soil in Egypt. The soil in Egypt and especially in Cairo city is mostly soft soil varying between clay and sand layers. Ground surface settlements and excavation step have to be optimized to control the ground movements and shotcrete stresses. In this paper, a lot of sections are used in comparisons to illustrate how the shape affects the deformations of the soil and straining actions results. Numerical modeling studies in the context of plane-strain Finite Element (FE) analyses are presented, comparing different types of divisions for the tunneling section. Analysis results from different models show that the soil behavior is affected with using different divisions of advanced section and suitable type of division is depended on soil properties and dimension of tunneling section.