Abstract:

The application of vibrationminimizing blasting technology in the construction of a highelevation diversion tunnel adjacent to an operating main tunnel is expounded. It is emphasized that the layout of the highelevation diversion system and the downward deep hole grouting are key factors for the aggressive treatment of the karst. The study shows that the service conditions of the lining system of the operating tunnel can be recovered and the safety of the lining structure can be guaranteed by building a diversion tunnel at higher elevation and drilling largediameter boreholes from the diversion tunnel to release the karst water and filling materials.

Key words: operating tunnel, karst cave, aggressive treatment, vibrationminimizing blasting, water diversion tunnel at higher elevation