How to prevent steel supports from slipping or breaking during use?
To prevent steel supports from slipping or breaking during use, it is necessary to control the entire process of design, installation, use, and maintenance, combined with mechanical characteristics and engineering practice. The specific measures are as follows:
1、 Design phase: Strictly control load and node strength
Calculate the cross-sectional dimensions of steel supports based on engineering loads (dead load, live load, wind load, etc.) to ensure that the strength, stiffness, and stability meet the specifications (such as the "Steel Structure Design Standard" GB50017) and avoid using beyond the specifications.
Optimize node design: prioritize the use of rigid connections (such as snap on and bolted flange connections) to reduce the risk of slip in fastener type connections; The included angle between slant support and upright and cross bar shall be controlled at 45 °~60 ° to ensure reasonable force flow transmission.
2、 Installation phase: Strengthen node fixation and accuracy
The connection part must be tightened in place: the pre tightening force of the fastener bolt should not be less than 40N · m and not exceed 65N · m; the socket type node should be fully inserted into the lock hole, and the bolt connection should be equipped with spring washers to prevent loosening.
Strictly control installation accuracy: the vertical deviation of the upright pole is ≤ 1/1000, and the horizontal deviation of the horizontal bar is ≤ 50mm; the contact surface between the steel support and the foundation or structure needs to be flat, and a cushion plate (area ≥ 100mm × 100mm) should be added to disperse pressure and avoid local settlement causing slippage.
3、 Usage stage: Real time monitoring and load control
Overloading is strictly prohibited: The stacking load of scaffolding shall not exceed the design value (such as uniformly distributed load ≤ 2kN/m ²), and centralized stacking of materials shall be avoided; When lifting heavy equipment, separate supports need to be set up, without relying on scaffolding for stress.
Dynamic monitoring: For high formwork and large-span support systems, install stress sensors or regularly observe node displacement. If bent members or loose nodes are found, immediately stop work for rectification.
4、 Maintenance phase: Regular inspection and anti-corrosion treatment
Daily inspection: Check the connection parts every week and replace rusted or slippery fasteners or bolts; Check the deformation of the steel support every month (deflection ≤ L/250, where L is the support span), and immediately scrap any members that exceed the bending limit.
Anti corrosion and rust prevention: Regularly apply anti rust paint, and when stored outdoors, elevate it to prevent moisture and avoid contact with corrosive media; Clean up accumulated water promptly after rain or snow to prevent material degradation caused by freeze-thaw cycles.
Through the above measures, the risk of slip and fracture can be reduced from the root, ensuring the structural safety of steel supports during the construction period.
