Hole-entering construction method for tunnel in abrupt slope terrain

The invention relates to a tunnel entry construction method in a steep slope terrain, which is used for ensuring the safety of tunnel entry construction, is suitable for backfilling holes in the steep slope terrain with the height of 30m and above, and provides a scientific basis for solving the problem of difficulty in arrangement of a tunnel hole construction site. Comprising the following steps that S01, a construction road is constructed and introduced into a tunnel portal, and construction road protection measures and portal protection measures are kept coordinated and consistent; s02, a water interception gutter is constructed, and a protection edge upward slope within the range of the bridge protection type open cut tunnel is excavated; s03, a pile foundation joist retaining wall structure at the gentle slope of the hole is constructed; s04, soil and stones are backfilled at the back of the pile foundation joist retaining wall structure in a layered manner to form a backfill body to reach the elevation