Optimization of tunnels excavation sequences in Egyptian soil conditions

Abstract EN

Construction of huge metro projects in congested areas in Cairo City, Egypt, calls for optimization of the underground excavation process.

The soil profile in Cairo city, Egypt, is generally characterized as soft soil containing layers of clay and sand.

To control the ground movements and shotcrete stresses, it is necessary to optimize the ground surface settlements and excavation step.

In this paper, several tunnel sections were compared to illustrate how the tunnel shape affects the soil deformations and straining actions results.

Results of numerical modeling using plane-strain finite elements are presented; different types of sequences for the tunneling excavation of each section are compared.

Analysis results from different models show that using different tunnel section excavation sequences affects the soil behavior differently, and that suitability of the sequence is determined by the soil properties and the dimensions of the tunneling section.