1. According to the materials used: steel tube scaffolding, wooden scaffolding, and bamboo scaffolding. Among them, steel tube scaffolding can be divided into disc-type scaffolding (the latest and safest scaffolding at present), steel tube fastener type, bowl-type, door type, etc.
2. According to the position relationship with the building: external scaffolding and internal scaffolding.
3. According to the purpose: operating scaffolding, protective scaffolding, and load-bearing support scaffolding. Operating scaffolding can be divided into structural operation scaffolding and decoration operation scaffolding, etc.
4. According to the frame method: rod assembly scaffolding, frame assembly scaffolding, lattice assembly scaffolding and scaffolding, etc.
5. According to the number of rows of vertical poles: single-row scaffolding, double-row scaffolding, multi-row scaffolding, cross-circle scaffolding, full-house scaffolding, full-height scaffolding special-shaped scaffolding, etc.
6. According to the support method, there are ground-type scaffolding, cantilever scaffolding, attached lifting scaffolding horizontal movable scaffolding, etc.
Common problems in design
1. There should be a clear understanding of heavy-duty scaffolding. Generally, if the floor thickness exceeds 300mm, it should be considered to be designed according to heavy-duty scaffolding. If the scaffolding load exceeds 15KN/㎡, the design plan should be organized for expert demonstration. It is necessary to distinguish which parts of the steel pipe length change have a greater impact on the load. For the formwork support, it should be considered that the length of the center line of the top horizontal bar from the template support point should not be too long, generally less than 400mm is appropriate. When calculating the vertical pole, the top and bottom steps are generally the most stressed and should be used as the main calculation points. When the bearing capacity does not meet the group requirements, the vertical poles should be increased to reduce the vertical and horizontal spacing or the horizontal poles should be increased to reduce the step distance.
2. Domestic scaffolding generally has unqualified materials such as steel pipes, fasteners, top supports, and bottom supports. These are not taken into account in theoretical calculations during actual construction. It is best to take a certain safety factor in the design calculation process.
Common problems in construction
The sweeping rod is missing, the vertical and horizontal intersections are not connected, the distance between the sweeping rod and the ground is too large or too small, etc.; the scaffolding board is cracked, the thickness is not enough, and the overlap does not meet the requirements of the specification; after the large template is removed, there is no anti-fall net between the inner vertical pole and the wall; the scissors brace is not continuous in the plane; the open scaffolding is not equipped with diagonal braces; the spacing between the small horizontal bars under the scaffolding board is too large; the wall connection parts are not rigidly connected inside and outside; the spacing between the guardrails is greater than 600mm; the fasteners are not tight, and the fasteners slip, etc.
Common problems in deformation accidents
1. Local deformation of scaffolding caused by foundation settlement. Set up eight-shaped braces or scissor braces on the horizontal section of the double-row frame, and set up a group for every other row of vertical poles until the outer row of the deformation area. The bottom of the eight-shaped brace or scissor brace must be set on a solid and reliable foundation.
2. If the deflection of the cantilever steel beam on which the scaffolding is based exceeds the specified value, the rear anchor point of the cantilever steel beam should be reinforced, and the steel beam should be supported by steel support and U-shaped support after being tightened to support the roof. There is a gap between the embedded steel ring and the steel beam, which must be tightened with a wedge. Check the steel wire ropes at the outer end of the hanging steel beam one by one, tighten them all, and ensure uniform force.
3. If the unloading and tensioning system of the scaffolding is partially damaged, it should be restored immediately according to the unloading and tensioning method formulated in the original plan, and the deformed parts and rods should be corrected. For example, to correct the outward deformation of the scaffolding, first set a 5t fall chain for each bay, tighten it with the structure, loosen the rigid tensioning point, and tighten the fall chain inward at each point at the same time until the deformation is corrected, do a good job of rigid tensioning, and tighten the steel wire ropes at each unloading point to make it uniformly stressed, and finally release the fall chain.
Post time: Nov-04-2024