What are the quality controls for the large-span steel structures construction in cement plants?

Under the new situation, my country’s cement industry is developing rapidly, and large-span steel structure construction projects are increasing day by day. The quality control of long-span steel structure construction has become the core driving force for the development of construction enterprises and has received extensive attention from the industry. The quality control of large-span steel structure construction is directly related to the realization of the target profit, whether the construction enterprise can be in a favorable position in the market competition, and whether it is related to the survival and development of the construction enterprise. Research on the quality control method of large-span steel structure construction Plays a pivotal role in the development of construction enterprises

1 Quality control method of large-span steel structure construction

1.1 Conscientiously do a good job in the incoming inspection and spot check re-inspection of the main structural materials

Due to the importance of large-span steel structure engineering and the complexity of its construction, it is necessary to ensure that the materials selected for construction meet the design requirements of drawings and national standards, and do a good job in the purchase inspection and random inspection of main structural materials, especially It is to carefully check and accept the chemical composition and mechanical properties of the steel used in the project, high-strength bolts, welding materials, fire-resistant coatings, etc. Before selecting materials, a more suitable material supplier must be selected from the company’s common suppliers, and the qualifications of the selected suppliers must be carefully reviewed again. After the materials are delivered to the construction enterprise, the material supply department will carefully check and accept a series of important materials such as the incoming section steel, high-strength bolts, welding consumables, etc., and carefully check the material certificate, qualification certificate, external dimensions, and material appearance quality. careful inspection. After the completion, under the supervision of the supervisory unit and the owner unit, sample the materials, send the samples to the inspection center with corresponding qualifications for re-inspection, and carefully check the chemical composition and mechanical properties of this batch of materials. These materials can only be used for large-span steel structure construction after passing multiple inspections.

1.2 Do a good job in welding seam quality control

The large-span steel structure cement plant construction projects of cement plants generally have the characteristics of a tight construction period, complex structure, a large amount of engineering, and high-quality requirements. Usually, welding is a very important process in the construction of large-span steel structures. Whether the quality control of welds can be done well is directly related to the timely, safe, high-quality and efficient completion of large-span steel structure construction projects.

When designing a 100-meter truss for clinker transportation, many oblique supports were selected, which resulted in many structural welds located at the positions of vertical welding and oblique vertical welding, which made the welding very difficult. The length of the welding seam in the whole project reaches more than 1,000 meters, while the length of vertical welding and oblique vertical welding is about 500 meters, which is 50% of all welding works.

For such external and oblique welds, the position of the large-span steel structure should be combined with its characteristics first, and repeated process tests should be carried out to select the most suitable process parameters and arrange welders with very high welding skills. Carry out construction. At the same time, special safety construction protection measures should also be taken to ensure that the welding work can pass the first time and prevent rework. In this way, the contradiction between the urgent construction period and the heavy welding volume can be effectively solved, which ensures the smooth development of the construction of large-span steel structures. For conventional welds such as butt joints between steel columns and steel beams, techniques are adopted to ensure the improvement of welding quality and avoid welding deformation in the construction of large-span steel structures. For example, preheating before welding and heat preservation after welding are adopted. A series of methods such as symmetrical welding and layer temperature control can effectively ensure the welding quality, thereby achieving the dual effect of improving the economic and social benefits of the construction enterprise.

1.3 Do a good job in the inspection of components and the preparations before hoisting

A very important step to ensure the overall construction quality of large-span steel structure cement bulk storage shed projects is to do a good job in the inspection of components. There will be some problems in the production and transportation of components. Considering the installation characteristics of the large-span truss, it will be very difficult if it is hoisted to a high altitude to deal with its existing problems. At this time, it can only be re-hoisted and then dealt with, which on the one hand leads to The progress of the project is seriously affected; on the other hand, it will also bring great economic losses. Therefore, these problems should be dealt with before the components are lifted into the air. Therefore, it is very necessary to do a good job in the inspection of components before the truss is hoisted.

The 100-meter truss for clinker conveying is divided into two sections. According to the construction requirements, the joints cannot be on a vertical plane. The upper and lower chords should be staggered by a distance of 3.5m, and the four longitudinal chords should be kept on the longitudinal axis. . After simulating the docking of the two trusses, it can be seen that the deviation between the upper chord and the axis is about 3°, and the lower chord is 90mm longer. After straightening again, the axis deviation can be controlled within a range of 1 degree. In order to prevent accidents during aerial docking and facilitate construction, a temporary platform should be built on one side of the middle support column, which must support a weight of about 50t.