The truss can be supported by upper lower strings. For example, vertical inclined side trusses should be formed at the side of the support when lower strings are used. A column cap should be set for the multi-point supporting network frame. The cap should be placed below the lower chord plane above the upper chord plane
For floors of multi-storey buildings with a span of no more than 40m roofs with a span of no more than 60m, the combined grid structure with reinforced concrete slabs can be used instead of the upper chord structure. It is advisable to choose the right quadrangle frame, the right quadrangle frame, the right quadrangle frame, the right quadrangle frame the honeycomb trigonal frame.
The following methods can be used to find the slope of roof drainage
A. Add A small column to the upper chord node to find the slope (when the small column is high, pay attention to the stability of the small column itself);
B. Changing the height of the grid;
C. Ramp up of grid structure
The grid height grid size of the grid should be determined according to the span size, cylinder size, grid form, roofing material, structural requirements building functions, etc. The ratio of the grid height is preferable 1/10-1/18. The number of grids in the short span should be less than 5. Determine the mesh size so that the Angle between adjacent members is less than 30 degrees.
The plane shape is circular, regular hexagon close to regular hexagon is supported around the grid, according to the specific situation can choose the three-direction grid, triangular cone grid extractive triangular cone grid. To small span, also can choose honeycomb shape tricone net frame.