The principles that should be followed in the selection of space frame structure

First of all, when the planar shape is a rectangular peripheral support or a space frame with three side supports and one side opening, when the side length ratio (that is, the ratio of the long side to the short side) is less than or equal to 1.5, it is advisable to choose a square pyramid space frame, an oblique space frame, etc. Place the quadrangular pyramid space frame, chessboard-shaped quadrangular pyramid space frame, positively vent the evacuated quadrangular pyramid space frame, two-way orthogonal oblique space frame, and two-way orthogonal normal space frame. When the side length ratio is greater than 1.5, it is advisable to choose a two-way orthogonal space frame, a square pyramid space frame or a space frame with an evacuated square pyramid.

Secondly, the space frame with rectangular planar shape and multi-point support can be selected according to the specific situation, such as square pyramid space frame, square pyramid space frame with evacuation, or two-way orthogonal space frame.

Thirdly, for the space frame whose plane shape is circular, regular hexagon, etc., the surrounding support can be selected from three-way space frame, triangular pyramid space frame or evacuated triangular pyramid space frame according to the specific situation. For small and medium spans, a honeycomb triangular pyramid space frame can also be used.

Finally, the grid height and grid size of the space frame should be determined according to factors such as span size, load conditions, column grid size, support, grid form, structural requirements, and building functions. The height-span ratio of the space frame can be 1/18 ~1/10. The number of grids in the short span of the space frame should not be less than 5. When determining the grid size, the angle between adjacent members should be less than 45°, and should not be less than 30°.

The space frame structure is generally a high-order hyperstatically indeterminate structure, which can better withstand concentrated loads, dynamic loads and asymmetric loads, and has good seismic performance. The space frame structure can adapt to the requirements of public buildings and factory buildings with different spans and different supporting conditions, and can also adapt to different building planes and their combinations.