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 should be reduced to the utmost.
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., calculated according to 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.
Hoist specifications, according to the hoisting rope internal force determined. In order to reduce the difference in lifting, the hoist of the same specification is used
The position of the grid support assembly pillar should be measured according to the axis of the installed pillar the accumulation of the axis error during the installation of the pillar.
Pull rod dismantling
After lifting the net frame, the pull rod is surrounded in the net frame, it is advisable to dismantle it by reverse demolition. This method is hanging two pairs of hoisting pulley group at the node of the upper chord of the net frame to hang the pulling rod, then remove the pulling rod the next section.