The following points need to be paid attention to when performing truss welding:
1.Cleaning work: before welding, the interface must be cleaned of rust and surface stains to ensure welding quality.
2.Reserve shrinkage: In the process of welding, it is necessary to reserve welding shrinkage to prevent problems caused by processing and fabrication errors and transportation deformation.
3.Positioning Welding: Before formal welding, the starting point and closing arc of the positioning welding need to be trimmed to a gentle slope to ensure that there are no defects such as unfused and shrinkage holes.
4.Environmental conditions: During the welding process, special attention needs to be paid to environmental conditions, such as wind speed. If the wind speed is too high, windproof measures need to be taken, such as setting up a windproof shed.
5.Safe Operating Procedures: Operators must have the qualifications and skills to perform welding operations and comply with the relevant safe operating procedures and operating practices, including wearing appropriate labor protective equipment, maintaining a dry environment, and removing debris and flammable materials from the work area.
6.Power safety: Ensure that the power supply in the work area is wired correctly and reliably, and meets national and local safety standards, and is kept away from water sources and flammable materials to prevent electric shocks, fires and other dangers.
7.Prevention of electric shock: Staff should maintain a dry environment, wear suitable insulated gloves and shoes, avoid bringing their hands or bodies close to the welding electrodes, and avoid touching the ends of the electrodes to avoid electric shock.
8.Measurement acceptance: The quality of measurement work is the main key task for high precision assembly of steel joist. Measurement acceptance should be carried through to the beginning and end of each process, with comprehensive positional monitoring of constructional measurement, tracking and testing of each process.
9.Observation of Tire Frame Settlement: In order to prevent the deformation of the tire frame due to the settlement of the rigid platform, an observation point for the settlement of the tire frame should be established next to the tire frame. During construction, when the structural weight is fully loaded on the roadway subgrade, attention should be paid to whether there is any change in elevation. If there is any change, adjustments should be made in time and welding should be carried out after the settlement is stabilized.
10.Measurement with level meter: Mark the horizontal projection point of truss control point on the platform (horizontal, error within 2mm) and add labels or other obvious signs; use level meter or other level meters to measure the vertical height of truss control point.
11.Integral arrangement of trellis: In order to make sure the joints between segmental trusses are assembled together, the trellis must be arranged as a whole. The quality of ground assembly will directly affect the quality of overhead segment assembly.
12.Minimize overhead work: According to the lifting performance of crane, try to expand the assembly unit of trusses on the ground in order to reduce the amount of overhead work, which can reduce the risk of overhead work and ensure the quality of the project.
These precautions above help to ensure the safety and quality of welding work. In actual operation, relevant regulations and safety operation procedures should be strictly observed to avoid accidents.