FE-analysis of reinfoced tunnel face

Although finite element models are frequently used for calculating displacements caused by tunnel excavation, analytical models are still predominantly employed for assessing face stability. A brief overview on conventional methods is given in this paper for completeness but emphasis will be put on three-dimensional finite element studies investigating face stability. The method for calculating a factor of safety of a stable tunnel face by means of the so-called strength reduction technique is presented. Various studies showing the influence of face reinforcements indicate that the finite element method can be readily applied to this type of problems and successfully used in the design of support measures.