The space frame structure is more and more widely used in daily life, especially more suitable for large span steel structure space frame construction projects.
The space frame structure is a form of space grid structure, and most of the space frame structures are made of steel pipe and bolted ball joints. According to the different composition methods, the space frame structure can be divided into four categories: flat truss space frame, quadrangular pyramid space frame, triangular pyramid space frame and hexagonal pyramid space frame.
The roof structure of steam power plants usually adopts a quadrangular pyramid space frame structure. The bottom edge of the space frame quadrangular pyramid is parallel or perpendicular to the boundary, and the pyramid is fully spread on the entire space frame plane. The upper (bottom) chord node of the space frame is the apex of the parallel (inverted) pyramid, and it can also be regarded as the corner point of the bottom edge of the inverted (forward) pyramid, so that the planes of the upper and lower chords in the same direction just forms two groups of parallel lines with half grid spacing difference between each other. The resulting upper and lower chords are usually square, or rectangular when the lengths of the chords in both directions are unequal.