Large-angle sloping roof steel structure and construction method thereof

A large-angle sloping roof steel structure connected to a main body structure, comprising:

• an intermediate platform (2), inclined main supporting steel columns (3) circumferentially connected at four corners of the intermediate platform, tectonic steel
• columns (4) and wind-proof surrounding beams (5) connected between top ends of the inclined main supporting steel columns (3), wherein roof purlins (6) are connected between the adjacent inclined main supporting steel columns (3) at intervals;
• a main body of the intermediate platform (2) is a double-layer grid frame, and comprises an upper rectangular grid frame and a lower rectangular grid frame arranged in parallel at intervals, and vertical connecting bars (25) and oblique connecting bars (24) connected between the upper rectangular grid frame and the lower rectangular grid frame, wherein a lateral side of the upper rectangular grid frame is connected with a side bar (27) parallel to the lateral side through a horizontal connecting bar (26), and wherein a first diagonal supporting bar (28) is connected between the side bar (27) and a lateral side of the lower rectangular grid frame;
• the four corners of the intermediate platform (2) form conical grooves, wherein an end point of the side bar (27) is an external convex point, and an end point of the lateral side of the upper rectangular grid frame is an internal concave point;
• the inclined main supporting steel column (3) is a spatial three-dimensional structure, and comprises two planar triangular trusses (30) and an intermediate inclined chord (33) positioned between the two triangular trusses (30), wherein the middle part of the triangular truss (30) is supported at the external convex point of the intermediate platform, and the middle part of the intermediate inclined chord (33) is supported at the internal concave point of the intermediate platform (2).