In the method of high-altitude assembly, the steel grid is installed by the method of high-altitude assembly, which firstly sets up the assembly bracket at the design position, then USES the crane to lift the components ( blocks) of the grid bracket to the design position in the air, then assembles the spherical grid bracket on the bracket. This method sometimes does need the large lifting equipment, but the assembly support consumption is large, the height work is much. Therefore, it is more suitable for high-strength bolt-connected steel network frame steel pipe network frame made of section steel bolt ball joints. The integral installation method is to assemble the network frame on the ground as a whole, then lift it to the design position by lifting equipment for fixing. This construction method does need tall assembly bracket, less work at height, easy to ensure welding quality, but the need for heavy lifting equipment, more complex technology. Therefore, this method is more suitable for the steel net frame with ball nodes (especially the three-way net frame with more rods).
The arrangement of the lifting point of the network frame is only related to the lifting scheme, but also related to the mechanical performance of the network frame during lifting. In the process of lifting the frame, only the internal force of some members may exceed the calculated internal force at the time of design, but also the symbol of internal force may change make the members unstable. Therefore, the number position of hoisting points should be determined by checking calculation of the hoisting network. However, on the premise of satisfying lifting capacity, lifting stress network frame stiffness, the number of pulling rods lifting points can be reduced. In order to increase the overall stability, the layout of the cable wind rope should make the multiple pulling rods connect into a whole. There shall be at least 6 cable wind ropes for each pull rod, the cable wind ropes shall be selected according to the load of wind load, lifting weight, pull rod deflection, cable wind rope initial stress, etc., after the combination of adverse conditions. Anchors also need to be calculated determined. The load calculation of lifting pulley block can be carried out according to the actual load, according to the calculation results to choose the size of the pulley.
Axis control the position of the assembled strut should be measured according to the axis of the installed pillar so as to eliminate the accumulation of axis error when the pillar is installed. After the rod pulling rod is lifted, the rod pulling rod is enclosed in the net frame.