Abstract: In this case history of highway tunnel in the mountain area, the geological hazard alarming and control of tunnels in groundwater rich fractured zone are studied by using geological prediction (induced polarization) and numerical analysis methods. The results indicate that the induced polarization method can reliably locate the groundwater rich fractured zone and its horizontal and vertical limits. The predicting of the fractured zone can provide a better control of tunneling activities through the adverse geological condition. The distributions of seepage, stress and strain around the fractured zone after the tunnel excavation can be predicted by the numerical analysis. Therefore, appropriate tunnel excavation and supporting schemes can be selected based on the predicting and analysis results.

Key words: groundwater rich fractured zone, induced polarization, numerical simulation, hazard minimization