Micro steel pipe pile for strengthening weak permeable stratum in tunnel

The utility model discloses a steel pipe micro pile for strengthening an aquitually permeable stratum in a tunnel, which comprises a steel pipe, an inner slurry layer and an outer slurry layer, the inner slurry layer is positioned inside the steel pipe, the outer slurry layer is a casing material layer positioned outside the steel pipe, a grouting hole is arranged on the steel pipe, and the grouting hole is communicated with the inner slurry layer and the outer slurry layer. The rubber membrane is arranged outside the grouting hole of the steel pipe in a sleeving mode, the outer slurry layer is located outside the rubber membrane, and the outer slurry layer is a casing material layer; under the action of grouting pressure, the sleeve shell material layer can be locally broken, the sleeve shell material on the outer wall of the rubber membrane is crushed, slurry flows into a stratum, an expanded head is formed at the pile end, and the pile end bearing capacity of the steel pipe micro pile is remarkably improve