Three-Dimensional Modeling and Analysis of Mechanized Excavation for Tunnel Boring Machines

Urban train infrastructures are very important for reliable urban mobility.This paper proposes a three-dimensional modeling of mechanized drilling corridors.Drilling in urban areas is always a risky and complex project.One of the most important issues during the construction of subway tunnels is the investigation of the impact of drilling steps on the ground subsidence and impact on existing structures.For this purpose, different types of mechanized drilling methods are often used, resulting in a considerable reduction in the displacements caused by tunnel drilling.In this study, part of the route of an urban train tunnel, that passes under a traffic interchange, is examined.The shear strength capacity of the slab pile was calculated, using the relevant equations, and then, the modeling of the soil mass was performed, using the PLAXIS 3D finite element program.The proposed depth of the tunnel construction, by the consulting company, is 18 meters.Due to drilling problems, D. Mohammadzadeh S. et al.Three-Dimensional Modeling and Analysis of Mechanized Excavation for Tunnel Boring Machines -214 -a depth of 14 meters has been suggested as an alternative.Analysis of both the depths of 14 and 18 meters, showed that the displacements at both depths, were approximately the same.However, the impact of the tunnel, on the capacity of the piles' tip, at a depth of 18 meters, is greater than at the depth of 14 meters.Thus, the suggested optimum depth is 14 meters, which is more suitable, than the initial suggested depth of 18 meters.