ABSTRACT
Analytical and numerical models to evaluate tunnel excavation stability are discussed. Multi layered soil profiles and groundwater flow are included into these models. Collapse and blow out type of failures, for both drained and undrained conditions, are considered. Comparative example applications are given. Analytical model calculations are straightforward and suited to preliminary studies. However, due to a series of limitations, analytical models should be replaced by more accurate three dimensional numerical models, as design progresses into detailed stages.
