Vertical orthogonal top exhausting air duct structure of deeply-buried subway station and construction method therefor

A vertical orthogonal top exhausting air duct structure of a subway station, comprising air duct split parts and an air duct main body part, wherein:

• each air duct split part is located at its corresponding one of two sides of the air duct main body part, the air duct split parts and the air duct main body part are constructed simultaneously;
• the air duct split parts comprise a left piston air shaft, a right piston air shaft, an exhaust air shaft, a fresh air shaft, and partial air duct transverse channels, the partial air duct transverse channels comprising a partial left piston air duct transverse channel, a partial right piston air duct transverse channel, a partial exhaust air duct transverse channel and a partial fresh air duct transverse channel;
• the air duct main body part is divided into a first-stage open excavated foundation pit, hidden excavated arch cover parts, second-stage open excavated foundation pits, a third-stage open excavated foundation pit, and remaining air duct transverse channels, the remaining air duct transverse channels comprising a remaining left piston air duct transverse channel, a remaining right piston air duct transverse channel, a remaining exhaust air duct transverse channel, and a remaining fresh air duct transverse channel;
• the partial left piston air duct transverse channel is communicated with the remaining left piston air duct transverse channel and they form a left piston air duct transverse channel, the partial right piston air duct transverse channel is communicated with the remaining right piston air duct transverse channel and they form a right piston air duct transverse channel, the partial exhaust air duct transverse channel is communicated with the remaining exhaust air duct transverse channel and they form an exhaust air duct transverse channel;
• the partial fresh air duct transverse channel is communicated with the remaining fresh air duct transverse channel and they form a fresh air duct transverse channel;
• and the air duct main body part is located between at least one of a left or right running tunnels and a station main body;
• a station main body part is communicated with the third-stage open excavated foundation pit;
• left and right running tunnels are communicated with the third-stage open excavated foundation pit;
• after the subway station is operable and configured to be put into use, a train enters the air duct main body part through the right running tunnel and then enters the station main body part, realizing the train's entrance to the subway station;
• and the train enters the air duct main body part through the station main body part and then enters the right running tunnel, realizing the train's exit from the subway station;
• the piston wind brought by the movement of the train will be carried by the train and enter the air duct main body part and then enter the left and right piston air shafts through the left and right piston air ducts transverse channel, thereby realizing a wind pressure balance between the external environment and the internal environment of a subway track area;
• a turbid gas inside the station main body enters the exhaust air duct transverse channel through ventilation pipelines of the station main body part and the air duct main body part, leads to the exhaust air shaft and then is discharged into the external environment;
• the fresh air from the outside enters the fresh air duct transverse channel through the fresh air shaft, then it enters the air duct main body part, and it finally enters the station main body part, so as to realize the gas exchange between a non-track area of the subway station and the external environment, and ensure the freshness of the air within the station.