Research conclusions：(1) During the grouting, more attention should be paid to the grouting pressure and adjusting the pressure if necessary to avoid the damage to the structure. (2) The attention should be paid to inspection of stringing and leaking the slurry. (3) To avoid the stringing slurry by grouting hole, the skipping boring method should be adopted and the intermittent grouting method should be adopted with multiple times of grouting from high pressure to low pressure. (4) Lowering the tube for boring should not damage the internal main reinforcement the tunnel to avoid the appearance of damage arisen by the stress concentration, resulting in lowering the safety coefficient.