Hierarchical stochastic model of terrain subsidence during tunnel excavation

Applying Bayesian approach to predict deformations during tunnel construction

“…This may also support the resulting distribution of parameter α promoting this variable to be considered as almost deterministic. We should remind that this parameter, controlling the shape of the settlement line, is primarily linked to shear stiffness of the soil much similar to the well‐known Winkler‐Pasternak subsoil model. The fact that it is well approximated by exponential functions b ( d ) in Equation is illustrated in Figure C,D showing approximations of the terrain settlement associated in turn with the excavation of top segment (the theoretically derived solid line in Figure C) and bench (the solid line in Figure D).…”

“…Since these algorithms are implemented in several statistical programs, we can concentrate only on the definition of the stochastic model and the prior distribution of its parameters. This strategy has successfully been applied to the analysis of glued laminated timber beams and later in the prediction of settlements during tunnel excavation using a simple excavation model originating from a rather complex quasi 3‐dimensional soil structure interaction analysis . The knowledge gained through the solution of these 2 projects is elaborated here to address the design of gradually excavated tunnels supported by ongoing monitoring in the light of stochastic modeling .…”