Supporting structure of soft soil foundation pit and construction method thereof

The invention discloses a supporting structure of a soft soil foundation pit and a construction method thereof and relates to the technical field of soft soil foundation pit supporting. The key of thetechnical scheme is that the supporting structure comprises the foundation pit, multiple soil nails, a transverse sealed channel steel and a vertical channel steel, wherein the transverse sealed channel steel connects the heads of all the soil nails into a single stretch, the bottom ends of the heads of the soil nails are sleeved with square steel plates, and the soil nails, the square steel plates and the transverse sealed channel steel are locked through multiple nuts; an integrated unloading platform is formed on the soil body on the upper part of the foundation pit through excavation in layered and segmented manners; a reinforcing steel bar mesh is laid on the slope face of the integrated unloading platform; and steel fiber reinforced concrete layers are sprayed on the slope faces ofthe upper stage and the lo