The invention relates to a method for expanding excavation of a large-
diameter shield tunnel for
subway station construction through a
pile arch wall support. The method comprises the steps that a single-hole double-track tunnel of a
station portion is used as a part of the
station structure,
pipe segment structures at the bottom and the top of a shield are reserved, and a bottom longitudinal beam, a middle partition wall and a top longitudinal beam of the
station structure are constructed; the remaining station structures on the two sides of the shield tunnel are formed through expanding excavation, an air
flue at the end of the station is used as a working plane, expanding excavation is carried out on the two sides of the large-
diameter shield tunnel by the adoption of a hole
pile method, the
pipe segment structures on the two sides of the shield are removed in the expanding excavation process, and meanwhile the connection measure between a cast-in-place structure and the remaining
pipe segments is taken to form the single-layer double-span side platform
subway station. The method for expanding excavation of the large-
diameter shield tunnel for
subway station construction through the
pile arch wall support has the advantages of being definite in stress, reasonable in conversion, convenient to construct and the like.