Construction method for constructing temporary transverse channel in PBA hole pile method tunnel

The invention discloses a construction method for constructing temporary transverse channels in a PBA hole pile method tunnel. The construction method comprises the following steps that (1) a plurality of construction temporary transverse channels are additionally arranged in a PBA hole pile tunnel section; when the temporary transverse channel is constructed, the height of the top of a small pilot tunnel is locally increased at the position of the longitudinal small pilot tunnel where the temporary transverse channel is preset to be constructed to serve as the top of the pilot tunnel of the temporary transverse channel to be constructed, and a primary supporting structure is constructed; the top limit and the section size of the temporary transverse channel are matched with the limit and the section size in the tunnel of subsequent tunnel excavation; (3) after construction of a pile foundation, a top beam, a longitudinal beam and the like is completed, a secondary arch part primary support is implemented wit