A computational strategy for solving three-dimensional tunnel excavation problems

Large-scale finite element simulations are necessary to model realistically the processes involved in the construction of transportation tunnels and their effects on adjacent structures and utilities. Such calculations must incorporate the complex non-linear response of the surrounding soil, local instabilities at the advancing tunnel heading, ancillary operations such as grouting and local interaction effects between the soil and tunnel lining system. Improved computational efficiency is essential such large-scale numerical simulations are to be achieved. The authors have implemented a FETI domain decomposition technique for parallel finite element computations of tunnel excavation problems. The paper summarizes the key elements of the numerical formulation and demonstrates its parallel efficiency and scalability using a cluster of 16 interconnected commodity computers.