###### Abstract
It is used to achieve the purpose of anti-infiltration and water blocking and increase the tensile and compressive strength of the rock-soil mass. This measure has the advantages of low cost, quick effect, and simple operation. It is increasingly applied to the stratum reinforcement and infiltration prevention of hydraulic engineering [12; 13], tunnels [14; 15; 16; 17], foundations [18; 19], slopes [20], etc. In tunnel construction, surface grouting pre-reinforcement is mainly used for surrounding rock reinforcement in fault fracture zones, shallow buried sections of portals, and soft rock sections. Due to the concealment of grouting engineering and the complexity of the injected stratum structure, there are still many problems in surface grouting technology that need to be solved urgently. In recent years, many scientific and technological workers have carried out a lot of research and practice on grouting projects in the shallow buried section of the tunnel, and made many valuable achievements [7; 8; 9; 14; 15; 16; 17]. [PERSON] et al. [14] obtained the foundation parameters of the rock-soil mass of the injected stratum by drilling test holes on site. The surface deep hole grouting was used to pre-reinforce the fault fracture zone of the first Yarlieshan tunnel with cement water glass double liquid material to cooperate with the pre-support of small conduits, so that the tunnel excavation could be carried out smoothly. [PERSON] et al. [15] used cement single slurry and cement sodium silicate double slurry as grouting materials. The shallow broken surrounding rock of Guangzhou tunnel was treated by surface high-pressure pre-grouting. Through numerical analysis and on-site monitoring, it was found that the integrity and strength of the surrounding rock after reinforcement were significantly improved. The convergence values of clearance in tunnel surface and vault subsidence were small. [PERSON] et al. [16] proposed the feasibility of grouting reinforcement in the fully strongly weathered granite stratum through the surface grouting test study of the Xiang'an undersea tunnel. [PERSON] et al. [17] studied the surface grouting test in the shallow buried section of Tongluoshan tunnel. He found that low-pressure grouting can prevent the grout from spreading too far along long cracks or groundwater flow in the crack development section. However, from the analysis of the results from previous work, it can be seen that the pre-reinforcement parameters of surface grouting are taken according to the field test results or construction experience, and the basic characteristics of the injected medium are rarely considered, resulting in a poor grouting effect or waste of materials. In order to obtain a good grouting effect, based on the cylinder diffusion theory, this paper analyzes the stratum structure characteristics of the shallow buried section of the Botanggou tunnel in Qinhuangdao to study its injectability. Twelve groups of test slurry were prepared with ordinary Portland cement and ultra-fine cement. Through the analysis of the slurry parameters of each group, two groups of infiltration grouting materials suitable for the shallow buried section of Botanggou tunnel are selected. During grouting construction and before and after tunnel excavation, three inspection methods, including the P-Q-t control method, deformation monitoring method, and excavation observation method, are used to evaluate the grouting effect. The research results are expected to provide a reference for the surface grouting pre-reinforcement of the shallow buried section of the same type of tunnel.