Identification of a fault zone ahead of the tunnel excavation face using the extended Kalman filter

• Extended Kalman filter (EKF) as a fast and reliable identification method.
• EKF outperforms the PSO method in identification of model geometric parameters.
• No strict constraints on the a priori choice of model parameters are required.

Simulation of mechanized tunneling and on-site excavation require very good knowledge of the geomechanical and material properties. Identification of the material must be fast and continuously performed during tunnel excavation for the best possible strategies for advancing the tunnel boring machine. We present in this work the use of the extended Kalman filter (EKF) for identification of the inclined fault zone ahead of the face. The EKF showed fast and stable convergence of the model parameters under study. In comparison with the particle swarm optimization technique applied to the same back analysis problem, faster convergence of the identified parameters as well as high robustness with respect to the choice of the initial parameter values have been observed.