Method for double-side-wall pilot tunnel of large-section underground excavation tunnel of metro

The invention discloses a method for double-side-wall pilot tunnels of a large-section underground excavation tunnel of a subway. The method comprises the steps of pilot tunnel division, left pilot tunnel excavation construction, right pilot tunnel excavation construction, middle pilot tunnel excavation construction, excavation monitoring, supporting structure monitoring and soil body compactness detection. The construction method has the beneficial effects that in the construction process of the large-section subway tunnel, deformation of a primary support structure can be effectively reduced through double-side-wall pilot tunnel method construction, and stability of the tunnel structure is facilitated; and the deformation of the earth surface and the vault can be better controlled. The research of the double-side-wall pilot tunnel method can provide certain reference significance for selection of the construction method of the large-section subway tunnel, and a theoretical basis is provided for application