Key points of steel structure installation technology and trends of prefabricated buildings

1 Measurement
According to the planning materials, remeasure the horizontal elevation, axis lines and column intervals of the foundation. Mark the cross interlaced lines of the longitudinal and transverse axes on the top surface of the foundation as the positioning reference for the equipment columns.
2 Column equipment
To address the impact of errors in the manufacturing of the column length on the column elevation, before hoisting, measure 1 meter from the upper plane of the corbels as the theoretical elevation section, mark a significant symbol, and use it as the reference for adjusting the column elevation. On the upper surface of the column base plate, mark the cross lines of the longitudinal and transverse axes passing through the center of the column, which are used as the reference for positioning the column equipment. When installing the equipment, align the cross lines on the column with those on the foundation. First, use a level to correct the elevation of the column based on the symbol at the theoretical elevation on the column. Then, secure it firmly with spacers and tighten the anchor bolts. Then, use two theodolites to correct the verticality of the columns from the two axis directions. After meeting the requirements, tighten the bolts with double nuts. For single unstable structure columns, temporary protection measures such as adding wind cables can be relied upon. For columns planned with inter-column supports, the inter-column supports can be relied upon to enhance the structural stability.
Crane girder equipment
Before installing the crane girder, it should be inspected. Only when the deformation does not exceed the limit should the equipment be adjusted. After the single piece of the crane girder is hoisted into position, it should be promptly connected to the corbels with bolts, and the connecting plate between the upper edge of the girder and the column should be connected. Use a level and a compass to align and adjust. Once the requirements are met, tighten the bolts.
4 Roof beam equipment
Before assembling the roof beams on the ground, the components should be inspected. Only when the deformation of the components does not exceed the limit, the bolt connection contact surfaces are free of sand, sand and other debris, and it is confirmed that the contact surfaces are flat and dry, can they be assembled on the ground. When assembling, oil-free sleepers are used to prop up the components, and wooden rods are used to support both sides of the components to enhance stability. The assembly of roof beams takes the space between two columns as one unit. After the units are spliced, they need to be inspected
① Straightness of the beam;
② The standard for the intervals of bolt holes combined with other components (such as columns). After the adjustment and inspection meet the requirements, tighten the bolts.
5 Accessory Equipment
The installation of roof purlins and wall purlins is carried out simultaneously. Before installing purlins, inspect the deformation condition of the components. If there is any over-limit, handle it and remove oil stains, sand and other impurities on the surface of the components. Take several purlins as a group and hoist them together. After the equipment of one span is completed, check the slope of the purlins. The straightness of the purlin should be controlled within the allowable error range; otherwise, it should be adjusted by using connecting bolts (with shims).
6. Re-inspection and adjustment, welding, and touch-up painting
After the hoisting is completed, all components shall be re-inspected and adjusted. Once they meet the planning requirements, on-site welding shall be carried out and the damaged areas of the paint on the components shall be repaired.