General requirements for erection of main structure scaffolding

1. Requirements for pole structure
1) The bottom poles of the scaffolding are arranged in a staggered manner with steel pipes of different lengths. The distance between the joints of two adjacent columns in the height direction should not be less than 500mm; the distance between the center of each joint and the main node should not be greater than 1/3 of the step distance. The lap length of the column should not be less than 1m, and it should be fixed with no less than two rotating fasteners. The distance from the edge of the end fastener cover plate to the rod end should not be less than 100mm.
2) The poles standing on the ground should be equipped with pads, and sweeping rods in the vertical and horizontal directions should be set, connected to the footing rods, about 20cm away from the base.
3) The vertical deviation of the pole should be controlled to be no more than 1/400 of the height.

2. Setting of large crossbars and small crossbars
1) The spacing of the large crossbars in the height direction of the scaffolding is 1.8m so that the vertical net can be hung. The large crossbars are placed inside the poles, and the extension length on each side is 150mm.
2) The outer frame is equipped with a small crossbar at the intersection of the vertical bar and the large crossbar, and the two ends are fixed to the vertical bar to form an overall force of the spatial structure. The extension length of the small crossbar on the side close to the wall should not be greater than 300mm.
3) The large crossbar is set on the small crossbar and fastened to the horizontal horizontal bar with a right-angle fastener. The spacing of the large crossbars at the operating layer should not be greater than 400mm. The length of the large crossbar should generally not be less than 3 spans and not less than 6m. The longitudinal horizontal bars should generally be connected with butt fasteners, and can also be overlapped. The butt joints should be staggered and should not be set in the same synchronization and span. The horizontal distance between adjacent joints should not be less than 500mm and should avoid being set in the span of the large crossbar. The length of the overlap joint should not be less than 1m, and three rotating fasteners should be set at equal distances. The distance from the edge of the end fastener cover to the rod end should not be less than 100mm.

3. Scissor brace
1) The number of columns spanned by each scissor brace should be between 5 and 7. The width of each scissor brace should not be less than 4 spans and not less than 6m, and the inclination angle of the diagonal rod to the ground should be between 45 degrees and 60 degrees.
2) For scaffolding below 20m, a scissor brace must be set at both ends of the outer facade, and set continuously from bottom to top; the net distance of each scissor brace in the middle should not be greater than 15m.
3) Except for the top layer, the joints of the diagonal rods of the scissor brace must be connected by butt fasteners. The overlap requirements are the same as the above structural requirements.
4) The diagonal rods of the scissor brace should be fixed to the extended end of the horizontal rod or the column intersecting with it by rotating fasteners. The distance between the center line of the rotating fastener and the main node should not be greater than 150mm.
5) The diagonal rods of the horizontal support should be arranged continuously in a zigzag shape from bottom to top within 1-2 steps, and the diagonal rods should be fixed to the extended end of the column or horizontal rod intersecting with it by rotating fasteners.
6) Both ends of the I-shaped and open double-row scaffolding must be provided with horizontal supports, and one should be provided every 6 spans in the middle.

4. Guardrails
1) The inner and outer uprights of the scaffolding should be fully covered with scaffolding boards, without probe boards.
2) A 0.9m high guardrail must be provided on the outside of the scaffolding, and there should be no less than 2 top-row guardrails, with heights of 0.9m and 1.5m respectively.
3) If the inner side of the scaffolding forms an edge (such as large-span door and window openings, etc.), a 0.9m guardrail should be provided on the inner side of the scaffolding.

5. Wall ties
1) Wall ties should be evenly arranged in a flower row, and the wall ties should be set close to the main node, and rigid nodes should be used. The distance from the main node should not be greater than 300mm. The rigid wall ties are shown in the figure below.
2) The scaffolding and the building are 4.5m in the horizontal direction and 3.6m in the vertical direction, with a tie point.
3) The anchor points are denser within the corner and at the top, that is, an anchor point is set every 3.6 meters in the vertical direction within 1 meter of the corner.
4) The anchor points should be guaranteed to be firm to prevent them from moving and deforming and should be set at the joints of the large and small cross bars of the external frame as much as possible.
5) The anchor points in the exterior wall decoration stage must also meet the above requirements. If the original anchor points are removed due to construction needs, reliable and effective temporary anchors must be re-installed to ensure the safety and reliability of the external frame.
6) The vertical and horizontal spacing of the wall ties should generally not be greater than 6m. The wall ties must be set from the first longitudinal horizontal bar at the bottom step. When it is difficult to set it there, other reliable measures should be used to fix it.
7) When the wall ties cannot be set at the bottom of the scaffolding, a go-stay can be used. The go-stay should be reliably connected to the scaffolding with a full-length rod, and the inclination angle with the ground should be between 45 and 60 degrees. The distance between the center of the connection point and the main node should not be greater than 300mm. The go-stay can be removed only after the wall ties are fully connected.
8) The wall tie rod in the wall tie should be horizontal and vertical to the wall surface. The end connected to the scaffolding can be slightly tilted downward, and it is not allowed to tilt upward.

6. Enclosure inside the frame
1) The net distance between the vertical rods in the frame of the scaffolding and the wall is 300mm. If it is greater than 300mm due to structural design restrictions, a standing plate must be laid, and the standing plate must be set flat and firm.
2) The outer frame below the construction layer is closed every 3 steps and at the bottom with a dense mesh or other measures.

7. Door opening construction requirements:
The additional diagonal rod at the opening should be fixed to the extended end of the horizontal rod intersecting with it with a rotating fastener, and the distance between the center line of the rotating fastener and the center node should not be greater than 150mm. The additional horizontal supports on both sides of the opening should extend out of the ends of the additional diagonal rods; a safety fastener should be added to the ends of the additional short diagonal rods. To ensure the personal safety of pedestrians and construction workers, protective sheds are set up at the entrances and exits of the first and bottom floors of the project. The scaffolding is covered with colored strips, and the first-floor protective shed is set up in double layers according to the specifications.

8. Requirements and precautions for protective engineering
1) The outside of the scaffolding is closed with a qualified green dense mesh safety net certified by the construction authority, and the safety net is fixed to the inside of the scaffolding outer pole to prevent people or objects from falling to the outside of the scaffolding. The vertical net should be firmly tied to the scaffolding pole and crossbar with 18 lead wires, the tying spacing should be less than 0.3m, and it must be tight and flat. Horizontal safety nets are set at the bottom and between layers of the scaffolding, and safety net brackets are used. The safety net bracket can be directly fixed on the scaffolding.
2) The safety baffles on the outside of the scaffolding are laid on the 4th and 8th floors of each building. They are required to be laid tightly and set along the length of the outer frame to ensure that people working on the safety baffles do not fall to the ground through the safety baffles due to accidentally falling objects. It is strictly forbidden to throw the scaffolding materials directly onto the ground. They should be stacked neatly and hung on the ground with ropes. The schematic diagram of the safety baffle on the outside of the scaffolding is as follows.
3) Horizontal holes below 1.5×1.5m in the building should be covered with fixed covers or full-length steel mesh covers. Holes above 1.5×1.5m should be surrounded by guardrails not less than 1.2m high, and horizontal safety nets should be supported in the middle.
4) The verticality of the whole frame is less than 1/500 of the length, but not more than 100mm at most; for scaffolding arranged in a straight line, its longitudinal straightness is less than 1/200 of the length; the horizontality of the crossbar, that is, the height deviation at both ends of the crossbar is less than 1/400 of the length.
5) Regularly inspect the scaffolding during use, and it is strictly forbidden to pile it up randomly. Clean up the accumulated debris on each layer in time, and do not throw scaffolding components and other objects from too high places.
6) Before dismantling, the scaffolding should be thoroughly inspected, all unnecessary items should be removed, a dismantling area should be set up, and personnel should be prohibited from entering. The dismantling sequence should be from top to bottom, layer by layer, and the wall parts can only be dismantled when the layer is dismantled. The dismantled components should be lowered with a hoist or manually handed down, and throwing is strictly prohibited. The dismantled components should be promptly classified and stacked for transportation and storage.


Post time: Dec-25-2024


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