Estimation of initial stress state based on observed displacements during tunnel excavation

Abstract

Described is a numerical procedure to back-analyze the initial state of the ground based on the monitored displacements during tunnel excavation. The unknown stress parameters to be estimated are the generalized overburden pressure, the coefficient of earth pressure at rest, the unit weight and the direction of principal stress. Firstly, the proposed procedure is verified with hypothetical case studies. Subsequently, the procedure is applied to model tests and actual case studies and comparisons are made with observed initial stress.