ABSTRACT
Accurate prediction of anomalous zones ahead of a TBM tunnel is essential for stable and efficient construction. This study developed an optimization model to predict characteristics of anomalous zones based on the electrical resistivity survey. The harmony search algorithm (HS) was adopted in the optimization process. An analytical solution of the electrical resistivity corresponding to the anomalous zone was derived for the objective function of the developed model. The HS optimal operators were determined by evaluating the prediction errors of the optimization model. Parametric studies were conducted to validate the reliability of the optimization model in predicting the characteristics of the anomalous zone. The prediction errors between the optimized values and experimental results were less than 10% for all the characteristics. It is concluded that the developed optimization model can accurately predict the anomalous zone ahead of a tunnel face, which enables stable tunnel excavation.
