Abstract：Abstract：Because of continuous precipitation and cracked surrounding rock，collapse of tunnel was found in the section YK73+955–YK73+925. According to engineering geology and in-situ construction condition，ahead ductile grouting method was applied to the surrounding rock consolidation of the tunnel. In order to investigate consolidation effect，two cross-sections of collapse zone measurement were increased；and finite element simulation analysis was applied to a cross-section. Measurement and calculation results of convergence displacement and vault subsidence show that tunneling collapse zone was consolidated by ahead ductile grouting method successfully.
