Parameter estimation using extended Bayesian method in tunnelling

Effort was made in this paper to formulate a parameter estimation technology by systematically combining the field measurements and the prior information of underground structure. The Extended Bayesian Method (EBM) was adopted for the feedback analysis and the finite element analysis, which was implemented to predict the ground response. Determined in the present study were various geotechnical parameters including the elastic modulus (E), the initial horizontal stress coefficient at rest (K(o)), the cohesion (c) and the internal friction angle (φ). The validity of the feedback system proposed herein was demonstrated through an elasto-plastic example problem. The proposed method was applied to an actual tunnel site in Pusan, Korea and has shown to be highly effective in actual field problems.