In this chapter, probabilistic analyses are applied to non-linear 3D FE models for two real-life case studies: (1) a deep excavation retained by a braced slurry wall and (2) the construction of a tunnel under a sensitive building. The use of accurate meta-models allows sensitivity and reliability analy ses to be performed in a reasonable time frame, in parallel with construction works if needed. It is shown that these FE computations have helped design engineers to make the following decisions: (1) eliminating a fourth level of struts for the braced excavation thanks to a live Bayesian analysis; (2) defining the optimal excavation steps for a tunnel excavation beneath a sensitive building, with the help of a reliability analysis considering two different excavation procedures.