Construction method for prefabricated assembly structure from center to periphery of large foundation pit underground engineering

The invention discloses a construction method for a prefabricated assembly structure from the center of large foundation pit underground engineering to the periphery, and relates to the field of foundation pit underground engineering prefabricated assembly construction.The construction method comprises the following steps that S1, underground diaphragm walls are constructed on the periphery of a foundation pit, earth cutting construction is started from the center area of the foundation pit, and a stepped basin-type foundation pit is formed; s2, the prefabricated bottom plate in the center area of the foundation pit is hoisted in a blocked mode; s3, components such as bottom-layer precast beams, columns and floor slabs of the underground structure in the center area of the foundation pit are hoisted; s4, hoisting components such as two layers of precast beams, columns and floor slabs of the underground structure in the center area of the foundation pit; and S5, excavating and hoisting residual areas around th