The problems and solutions of steel structure construction

In the process of steel structure processing, quality problems are easy to occur and it is difficult to deal with the special and important processes. The proportion of quality problems in general processes is very small. In the above construction process, special processes are welding, painting, important processes are blanking, assembly.

1. Welding procedure. This process is a hidden project, and it is also one of the processes most prone to quality problems. According to the product quality report of a company in 2004, among the quality problems of this process: Because the welding quality of weld repair rate above 80%, the second is due to the process caused by improper operation and the operating personnel's technical issues accounted for about 10% of weld quality problem, this problem belongs to the direct impact on the main problems of engineering quality, so this type of problem must be through the professional testing company with professional testing tools to testing and evaluation, Generally, according to the defect type in the weld, it is divided into slag inclusion, undissolved, porosity and so on.

2. Coating process. This process also belongs to the covert process, the impact on the structure is less than the impact on the building function. It is also a process prone to quality problems. The quality problem of the process is mainly manifested in: the paint film on the surface of the component falls off in a large area and part, the paint film on the surface falls off, the phenomenon of flow hanging, the thickness of the paint film is not enough, the thickness of the paint film is not evenly distributed, and the color difference of the paint film is large.

3. Lofting and blanking process. This process belongs to the leading member before processing, its quality has a direct impact on the next process, and even lead to the scrapping of all the parts of the blanking, this situation is very common, so before blanking, it is very important and necessary to strengthen the quality control of the process. The quality problems of this process are mainly shown in: for long strip and thin plate type parts in the cutting deformation is more severe; Due to the existence of cutting gas or plate slag and uneven distribution of components and resulting in the cutting surface of horse teeth, nodule, cut mark depth beyond the standard; Gas cutting or sawing parts do not consider the shrinkage deformation of the subsequent process caused by the size of parts exceed the standard; Batch parts scrapped due to errors in process documentation; The size of cutting material seriously exceeds the requirements of the standard.

4. Assembly process. This process occupies an important position in the quality of component processing, and its quality is greatly affected by the previous process, so it is very important to strengthen the monitoring of the process before assembly. The quality problems caused by this process are mainly shown in the following aspects: the position of the assembled parts is wrong, such as the 3450mm is packed into 4350mm; The use of parts error, should have assembled 2# parts, but assembled 3# other parts; Parts are incorrectly assembled in the correct position, such as 45mm hole on the board originally facing outward, but actually 45mm is installed inward; The assembly clearance of the assembled parts exceeds the requirements of the specifications and technical documents, and the clearance of 3mm is 7mm; Some parts are assembled without correction, and the existing deformation after assembly cannot be eliminated; The operator to save trouble for the diagram secretly cut caused by parts on the hole location size exceeding the standard; No surface treatment is carried out in the welding area; Assembly errors due to dimensioning errors on drawings.