English：

In order to explore the formation mechanism and control effect of advanced groutingreinforcement zone in broken soft rock tunnel, based on the actual project, the diffusion, splitting andcompaction process of slurry in broken rock mass were systematically analyzed by means of numericalsimulation and field monitoring, and the formation mechanism of asymmetric reinforcement area underhigh pressure grouting was obtained. By comparing the monitoring data of grouting and non-groutingsections, the influence of advanced grouting reinforcement on the deformation of surrounding rock, thestability of tunnel face and the stress state of initial support structure was quantitatively evaluated. On thisbasis, the key design parameters of grouting hole length, spacing and interpolation angle were optimized.The research results show that advanced grouting reinforcement can effectively control the deformation ofsurrounding rock and improve the stress mode of supporting structure.