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.
From a safety perspective, according to decades of domestic practical experience and surveys of domestic scaffolding, ground-type scaffolding with a single-tube pole is generally below 50m, and it is easy to be dangerous if it exceeds 50m. When the required erection height is greater than 50m, strengthening measures are adopted more cautiously, such as using double-tube poles, segmented unloading, and segmented erection.
Specifications for erection of ground-type scaffolding
First, the pole foundation setting specifications
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 rod should be fixed on the pole at a distance of no more than 200mm from the base with a right-angle fastener, and the transverse sweeping rod should be fixed on the pole close to the bottom of the longitudinal sweeping rod with a right-angle fastener. When the pole foundation is not at the same height, the longitudinal sweeping rod at the high position must be extended to the lower position by two spans and fixed to the pole, and the height difference should not be greater than 1m. The distance from the pole axis 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 pole foundation to keep the 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, canopies, balconies, etc. If necessary, the structural safety of the roof, canopy, balcony, and other parts should be verified 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, pole erection specifications
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 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 shall be used for erection. The height of the auxiliary pole in the double pole shall 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. 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 horizontal horizontal rod should be set at the intersection of the scaffolding vertical rod and the longitudinal horizontal rod, and both ends should be fixed on the vertical rod to ensure safe force.
2. Except for the top step of the top layer, the vertical rod extension must be butt-jointed at all other layers and steps. The overlap length should not be less than 1m, and no less than three rotating fasteners should be fastened.
3. During the use of the scaffolding, it is strictly forbidden to remove the longitudinal and transverse horizontal rods at the main node.
4. The longitudinal horizontal rod should be set on the inside of the vertical rod, and its length should not be less than 3 spans.
5. The longitudinal horizontal rod extension should be connected by butt fasteners or overlap. When using butt fasteners, the butt fasteners of the longitudinal horizontal rod should be staggered. When overlapping, the overlap length of the longitudinal horizontal rod should not be less than 1m, and 3 rotating fasteners should be set at equal intervals for fixing. The distance from the edge of the end fastener cover to the end of the overlapping longitudinal horizontal rod should not be less than 100mm.
6. The length of the edge of the fastener cover plate at both ends of the horizontal bar should not be less than 100mm and should be kept consistent as much as possible.
7. The overlap and butt joint 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 scissor braces and transverse diagonal braces
1. The scissor braces should be set continuously from the bottom corner to the top along the length and height direction;
2. The diagonal bars of the scissor braces should be connected to the protruding ends of the vertical bars or horizontal horizontal bars. The extension of the diagonal bars should be overlapped, with an inclination of 45º~60º (45º is preferred), and each scissor brace spans 5~7 vertical bars, 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 one-line and open double-row scaffolding; a horizontal diagonal brace should be set every 6 spans in the middle.
4. The erection of scissor braces and transverse diagonal braces should be synchronized with the erection of vertical bars, longitudinal and transverse horizontal bars, etc.
5. The scissors brace should be overlapped, with an overlap length of not less than 1m, and fastened with no 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 in parallel at the four corners, and the junction should be flat and without probe plates. The scaffolding should be replaced in time when it is damaged.
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 at each step on the outside of the scaffolding, and a guardrail of the same material is set at 0.6m and 1.2m high. If the inner side of the scaffolding forms an edge, the protection method of the outer side 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 tie 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, reinforcement measures should be taken. When the wall tie is located near 1/2 of the pole step, it must be adjusted.
2. The wall tie should be set from the first step of the longitudinal horizontal bar on the bottom layer. When it is difficult to set it there, other reliable fixing measures should be adopted. The wall tie should be arranged in a diamond shape, and can also be arranged in a square or rectangular shape.
3. The wall tie should be connected to the building with a rigid wall tie.
4. The wall tie should be set horizontally. When it cannot be set 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 building corner and 800mm of the top.
6. Wall ties must be set 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 should not exceed two steps above the adjacent wall ties at one time.
8. It is strictly forbidden to remove wall ties during the use of the scaffolding. Wall ties must be removed layer by layer with the scaffolding. It is strictly forbidden to remove the wall ties first 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 connection parts 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 connection measures to resist rising and overturning should be taken.
Post time: Nov-01-2024