Abstract:In order to study the curtain grouting treatment tech of sand-filled dolomite section in tunnel. Calculation, numerical simulation, and engineering practice were used to investigate four key influencing factors of treatment tech, namely, grouting pressure, material selection, grouting thickness, and grouting process. The results show that: The high pressure splitting grouting should be used in the filling cavity of dolomite sanded section silt fine sand, and the final grouting pressure should be 4~5 MPa. Using the ANSYS modeling analysis, it is concluded that the double liquid slurry is the most suitable for the curtain grouting project of the sand-filled dolomite. The grouting thickness formula can be calculated by empirical formula, which is convenient and simple, and the excavation radius value can be obtained in general stratum. The principle of grouting steps is as follows: from outside to inside, from bottom to top, and interval drilling. Progressive grouting technology can better solve the problem of hole-forming quality, but the length of segments should be adjusted reasonably according to the site conditions. Progressive sectional grouting technology is adopted for dolomite sanding section, and the length of segments is 0.5~1 m. In specific projects, double grouting can be carried out first. Maintenance circle is formed by grouting, and local reinforcement of superfine cement is carried out.. It is concluded that These results can provide reference for similar grouting project in tunnel.