Using FEM software ANSYS, the effect of small duct grouting reinforcing measures on the construction of large span shallow tunnel with small interval is analyzed. The influence of the reinforcing measures on the displacement of surrounding rocks and the initial supporting structure during construction is evaluated. The results show that, ground surface settlement and displacements of the characteristic positions of the ground decreased in a certain extent, and the maximum moment of the initial supporting structure reduces about 20%~25%. Furthermore, the reinforcing measures are very important to the stability of the surrounding rocks, especially to the middle wall, and the effect of reinforcing is embodied in the process of excavation of the lower bench. The analysis method and conclusion at present may provide some references for the design and construction of small interval tunnels.
