The erection height of ground-type scaffolding should not exceed 50m but can exceed 24m. If it exceeds 50m, it needs to be reinforced by unloading, double poles, and other methods. From an economic point of view, when the erection height exceeds 50m, the turnover rate of steel pipes and fasteners will decrease, and the foundation treatment cost of the scaffolding will also increase.
Specifications for erection of ground-type scaffolding
First, the foundation setting specifications of the pole
1. The foundation should be flat and compacted, and the surface should be hardened with concrete. The ground pole should be placed vertically and stably on a metal base or a solid base plate.
2. Vertical and horizontal sweeping poles should be set at the bottom of the pole. The longitudinal sweeping pole should be fixed to the pole not more than 200mm above the base with a right-angle fastener, and the horizontal sweeping pole should be fixed to the pole close to the bottom of the longitudinal sweeping pole with a right-angle fastener. When the pole foundation is not at the same height, the longitudinal sweeping pole at the high position must be extended to the low position by two spans and fixed to the pole, and the height difference should not be greater than 1m. The distance from the axis of the vertical pole above the slope to the slope should not be less than 500mm.
3. A drainage ditch with a cross-section of not less than 200×200mm should be set on the outside of the vertical pole foundation to keep the vertical pole foundation free of water, and concrete hardening should be used within a wide range of 800mm on the outside.
4. External scaffolding should not be supported on roofs, awnings, balconies, etc. If necessary, the structural safety of roofs, awnings, balconies, and other parts should be verified separately, and specified in the special construction plan.
5. When there are equipment foundations and pipe trenches under the scaffolding foundation, excavation should not be carried out during the use of the scaffolding. When excavation is necessary, reinforcement measures should be taken.
Second, the vertical pole erection specification
1. The step height of the bottom step of the steel pipe scaffolding shall not exceed 2m, and the rest shall not exceed 1.8m. The vertical distance of the vertical pole shall not exceed 1.8m, and the horizontal distance shall not exceed 1.5m. The horizontal distance should be 0.85m or 1.05m.
2. If the erection height exceeds 25m, double poles or the method of reducing the spacing must be used for erection. The height of the secondary pole in the double pole should not be less than 3 steps and not less than 6m.
3. The bottom step pole must be equipped with longitudinal and transverse sweeping poles. The longitudinal sweeping pole should be fixed to the pole not more than 200mm from the base epidermis with right-angle fasteners, and the transverse sweeping pole should also be fixed to the pole below the longitudinal sweeping pole with right-angle fasteners.
4. The bottom row of poles, sweeping poles, and scissor braces are all painted yellow and black or red and white.
Third, rod setting specifications
1. A transverse horizontal pole should be set at the intersection of the scaffolding pole and the longitudinal horizontal pole, and both ends should be fixed on the pole to ensure safe force.
2. Except for the top step of the top floor, the pole extension can be overlapped, and the remaining steps must be butt-jointed. When overlapping, the overlap length is not less than 1m, and it is fastened with no less than three rotating fasteners.
3. During the use of the scaffolding, it is strictly forbidden to remove the longitudinal and transverse horizontal bars at the main node.
4. The longitudinal horizontal bar should be set on the inside of the vertical bar, and its length should not be less than 3 spans.
5. The longitudinal horizontal bar should be connected by butt fasteners or overlap. When butt fasteners are used, the butt fasteners of the longitudinal horizontal bar should be staggered. When overlap is used, the overlap length of the longitudinal horizontal bar should not be less than 1m, and 3 rotating fasteners should be set at equal intervals. The distance from the edge of the end fastener cover plate to the end of the overlapped longitudinal horizontal bar should not be less than 100mm.
6. The length of the edge of the fastener cover plate at both ends of the transverse horizontal bar should not be less than 100mm and should be kept consistent as much as possible.
7. The overlap and butt joints of adjacent bars must be staggered by one span, and the joints on the same plane shall not exceed 50%.
Fourth, the setting specifications of the scissors brace and transverse diagonal brace
1. The scissors brace should be set continuously from the bottom corner to the top along the length and height direction;
2. The diagonal bar of the scissors brace should be connected with the protruding end of the vertical bar or transverse horizontal bar. The extension of the diagonal rod should be overlapped, with an inclination of 45º~60º (45º is preferred), and each scissor brace spans 5~7 vertical poles, with a width of not less than 4 spans and not less than 6m.
3. Horizontal diagonal braces should be set at both ends of the I-shaped and open double-row scaffolding; a horizontal diagonal brace should be set every 6 spans in the middle.
4. The scissor brace and horizontal diagonal brace should be erected synchronously with the vertical poles, and longitudinal and transverse horizontal poles.
5. The scissor brace should be overlapped, with an overlap length of not less than 1m, and fastened with not less than three rotating fasteners.
Fifth, scaffolding and guardrail specifications
1. The scaffolding of the external scaffolding should be fully laid at each step.
2. The scaffolding should be laid horizontally and vertically on the wall. The scaffolding should be fully laid in place without leaving any space.
3. The scaffolding should be tied firmly with 18# lead wire double strands in parallel at the four corners, and the intersection should be flat and without probe plates. When the scaffolding sheet is damaged, it should be replaced in time.
4. The outside of the scaffolding should be closed with a qualified dense mesh safety net. The safety net should be fixed to the inside of the scaffolding outer pole with 18# lead wire.
5. A 180mm footboard (pole) is set on each step of the outside of the scaffolding, and a protective railing of the same material is set at a height of 0.6m and 1.2m. If the inside of the scaffolding forms an edge, the protection method of the outside of the scaffolding should be followed.
6. The outer pole of the flat roof scaffolding should be 1.2m higher than the eaves. The outer pole of the sloping roof scaffolding should be 1.5m higher than the eaves.
Sixth, the frame and the building tie specification
1. The wall connection should be set close to the main node, and the distance from the main node should not be greater than 300mm. When it is greater than 300mm, there should be reinforcement measures. When the wall connection is located near 1/2 of the pole step, it must be adjusted.
2. Wall ties should be installed from the first step of the longitudinal horizontal bar on the bottom floor. When it is difficult to install there, other reliable fixing measures should be adopted. Wall ties should be arranged in a rhombus shape, and can also be arranged in a square or rectangular shape.
3. Wall ties should be connected to the building with rigid wall ties.
4. Wall ties should be installed horizontally. When they cannot be installed horizontally, the end connected to the scaffolding should be connected diagonally downward, and should not be connected diagonally upward.
5. The spacing between wall ties should meet the requirements of the special construction plan. The horizontal direction should not be greater than 3 spans, the vertical direction should not be greater than 3 steps, and should not be greater than 4 meters (when the frame height is above 50m, it should not be greater than 2 steps). Wall ties should be denser within 1m of the corner of the building and 800mm of the top.
6. Wall ties must be installed at both ends of the I-shaped and open scaffolding. The vertical spacing of the wall ties should not be greater than the floor height of the building, and should not be greater than 4m or 2 steps;
7. The scaffolding should be erected by the construction progress, and the erection height at one time should not exceed two steps above the adjacent wall ties.
8. During the use of scaffolding, it is strictly forbidden to remove the wall ties. The wall ties must be removed layer by layer with the scaffolding. It is strictly forbidden to remove the wall ties in one layer or several layers before removing the scaffolding; the height difference of the segmented removal should not be greater than two steps. If the height difference is greater than two steps, additional wall ties should be added for reinforcement.
9. When the original wall ties need to be removed due to construction needs, reliable and effective temporary tie measures should be taken to ensure the safety and reliability of the external frame.
10. When the frame height exceeds 40m and there is a wind vortex, wall ties that resist the rising and overturning effect should be taken.
Seventh, the internal closure specification of the frame
1. The net distance between the internal poles of the scaffolding and the wall should generally not be greater than 200mm. When the requirements cannot be met, a standing plate should be laid. The standing plate should be set flat and firm.
2. The scaffolding should be horizontally closed and isolated from the building every 3 steps at and below the construction layer, and horizontal closed isolation should be set on the first and top floors.
Eighth, the specification of the ramp of the external scaffolding
1. The ramp is attached to the outside of the scaffolding and shall not be cantilevered. The ramp should be set up in a back-and-forth folding shape, with a slope of no more than 1:3, a width of no less than 1m, and a platform area of no less than 3 m2 at the corner. The ramp poles should be set up separately, and the scaffolding poles shall not be borrowed, and a connection should be set up every step or longitudinal distance in the vertical and horizontal directions.
2. 180mm footboards (poles) should be set on both sides of the ramp and the periphery of the corner platform, and a guardrail of the same material should be set at a height of 0.6m and 1.2m and closed with a qualified dense safety net.
3. Scissor braces should be set on the side of the ramp and the outside of the platform.
4. The scaffolding of the ramp should be laid horizontally, and an anti-slip strip should be set every 300mm. The anti-slip strip should be made of 20×40mm square wood and tied firmly with multiple wires.
Ninth, door opening erection specifications
1. The scaffolding door opening should adopt the structure of rising diagonal rods and parallel chord trusses, and the inclination angle between the diagonal rods and the ground should be between 45º and 60º;
2. The eight-shaped support rods should adopt full-length rods;
3. The eight-shaped support rods should be fixed on the extended end of the small crossbars or the small crossbars between spans with rotating fasteners;
4. The two side vertical rods under the door opening truss should be double vertical rods, and the height of the secondary vertical rods should be 1 to 2 steps higher than the door opening;
5. The ends of the rods extending from the upper and lower chords in the door opening truss should be equipped with an anti-slip fastener. The anti-slip fastener should be close to the fasteners at the main node.
Post time: Oct-30-2024