Finite element modelling of the three-dimensional ground deformations due to tunnelling in soft cohesive soils: Part I — Method of analysis

Abstract The authors' research is directed towards the development of techniques for estimating surface settlements caused by tunnelling in soft ground. A three-dimensional elasto-plastic finite element formulation is developed to allow simulation of the construction sequence and subsequent ground displacements and stress patterns around the tunnel face and at the ground surface. This paper describes an 11-noded non-conforming element, excavation simulation, a procedure for solution of the non-linear problem and an elasto-plastic soil model suitable for a 3-D tunnelling analyses. The special requirements associated with using a supercomputer for the analysis are discussed. The computer processing time is compared for a number of different computers.