Abstract:

Karst caves are encountered in the construction of Jikoushan tunnel. The deformation of the surrounding rock of Jikoushan tunnel under 3 karst cave treatment methods, i.e., excavation and backfilling method, advance grouting method and advance pipe roof support method, is studied and analyzed by means of numerical simulation. The study results show that the deformation of the surrounding rock under advance grouting method is less than that under the excavation and backfilling method, and the deformation of the surrounding rock under the advance pipe roof support method is the largest. The advance grouting method is superior to the excavation and backfilling method and the advance pipe roof support method in terms of control of deformation of surrounding rocks. It proves that it is appropriate to adopt advance grouting method in construction of Jikoushan tunnel.

Key words: karst tunnel, excavation and backfilling, advance grouting, advance pipe roof support, simulation analysis