Staggered-distance double-hole small-clear-distance tunnel portal section supporting structure and construction method

The invention discloses a staggered-distance double-hole small-clear-distance tunnel portal section supporting structure and a construction method.The supporting structure comprises a retaining wall and further comprises grouting anchor rods and steel pipes, the grouting anchor rods and the steel pipes are arranged between a rock-soil body on the outer side of a staggered-distance tunnel and the retaining wall, and a plurality of uplift piles are arranged on a bottom foundation of the retaining wall; a plurality of anti-slide piles are arranged at the outer side wall foot of the retaining wall; the grouting anchor rods, the steel pipes, the uplift piles and the slide-resistant piles are all fixedly connected with the retaining wall. The staggered-distance double-hole small-clear-distance tunnel portal section supporting structure conforms to the principle of preventing the staggered-distance tunnel from being damaged, and the staggered-distance double-hole small-clear-distance tunnel portal section supporting