Definition
The wall connection achieved by connecting wall parts is very important to strengthen the overall stability of the scaffold, improve its stable load-bearing capacity and avoid major accidents such as toppling or collapse. role.
Classification
Flexible wall-tie parts
Flexible tie-down parts are generally made of thin steel bars, ropes, double or multi-strand iron wires. It only bears tensile force and mainly plays the role of preventing the scaffold from cambering, but it does little to help the stability of the scaffold (that is, stable bearing capacity). This method can generally only be used for exterior scaffolding of buildings with 10 floors or less, and a certain number of rigid ties must be installed accordingly to withstand the horizontal pressure.
Rigid connecting wall parts
The connecting wall parts are composed of rigid tie rods or components such as steel pipes, fasteners or embedded parts. The connection structure can withstand both tension and pressure. The connection and fixation method of the wall-attached end can be determined according to the engineering conditions, generally including:
a. The tie rod passes through the wall and is fixed on both sides of the wall;
b. The tie rod passes through the door and window opening, and is clamped by cross bars and fixed with back wedges on both sides of the wall;
c. Install pre-embedded iron parts in the wall structure and securely connect them to tie rods equipped with flower basket bolts. Use flower basket bolts to adjust the tie spacing and the verticality of the scaffolding;
d. Pre-embedded iron parts are installed in the wall and fixed with fixed-length tie rods.
Rigid wall-mounted parts are generally used in double-row scaffolding.
Structural requirements
According to the requirements of the "Safety Technical Specifications for Fastened Steel Tube Scaffolding in Construction" (JGJ130-2011), the scaffolding wall parts should meet the following requirements:
1. The location and quantity of connecting wall parts should be determined according to the special construction plan. They can usually be arranged as three steps and three spans, two steps and three spans, two steps and two spans, etc. Generally, each connecting wall piece covers an area of ??20~ 40 m2.
2. The wall-connecting parts should be arranged close to the main node, and the distance from the main node should not be greater than 300mm; they should be installed starting from the first longitudinal horizontal rod on the bottom floor. When there are difficulties in setting there, Other reliable measures should be used for fixation; diamond-shaped layout, or square or rectangular layout should be preferred.
3. Wall-connecting parts must be installed at both ends of the open-type scaffolding. The vertical spacing between the wall-connecting parts should not be greater than the floor height of the building and should not be greater than 4m.
4. The connecting wall rods in the connecting wall parts should be set horizontally. When they cannot be set horizontally, they should be connected diagonally toward one end of the scaffolding.
5. Wall-connecting parts must be constructed to withstand tension and pressure. For double-row scaffolding with a height of 24m or more, rigid wall fittings should be used to connect to the building.
6. When the lower part of the scaffold cannot be temporarily connected to the wall, anti-overturning measures should be taken. When erecting the throw support, the throw support should use full-length rods and be fixed on the scaffolding with rotating fasteners. The inclination angle with the ground should be between 45° and 60°; the distance from the center of the connection point to the main node should not be greater than 300mm. , the throw brace should be removed only after the wall-connecting parts are erected.
7. When the elevated height exceeds 40m and there is wind vortex effect, wall-connecting measures to resist the upturn effect should be adopted.