Corrugated steel primary support structure for metro contact passage and construction method thereof

The invention discloses a subway connection channel corrugated steel preliminary bracing structure, which is characterized in that a freezing wall is formed on the inner side of a surrounding rock excavation surface, the bracing structure is formed by sequentially overlapping and splicing two or more than two single-truss corrugated steel plates along the annular inner side wall of the freezing wall, grouting holes are formed in the bracing structure, and the bracing structure seals the exposed surface of the freezing wall; each single-truss corrugated steel plate piece is formed by sequentially overlapping two or more than two corrugated steel plates; the invention further provides a construction method of the supporting structure. The construction method comprises the steps that S1, a soil body of the connection channel is excavated; s2, a supporting structure of a single-truss corrugated steel plate piece is assembled, and the exposed face of the frozen wall is sealed; s3, a circle of grouting holes are fo