This lesson illustrates the use of PLAXIS for the analysis of the construction of a NATM tunnel. The NATM is a technique in which ground exposed by excavation is stabilized with shotcrete to form a temporary lining. Rapid and consistent support of freshly excavated ground, easier construction of complex intersections and lower capital cost of major equipment are some of the advantages of NATM. Some of the limitations of this method are that it is slow compared to shield tunnelling in uniform soils, dealing with water ingress can be difficult, and it demands skilled man power.
This exercise requires the VIP module in order to be able to use the Hoek-Brown material model.