Key Points of Space Frame Construction Quality Control(1)

The space frame structure is a structural form applied in large spaces and long spans, and its comprehensive advantages are relatively significant. However, from the perspective of quality management, the special requirements of the space frame structure increase the difficulty of quality control.

1 Overview of space frame structure

The space frame structure is a space structure formed by connecting multiple rods through nodes according to a certain space frame form. It has the advantages of small space force, light weight, high rigidity, and good seismic performance. For large public buildings, the space frame structure has a wider range of application scenarios and can meet many application requirements of large public buildings. However, there are many factors that affect the construction of the space frame structure, and its comprehensive quality control is difficult. If the management is not in place, the quality problems of the space frame construction will occur frequently, which will not only affect the quality of the building, but even cause large-scale collapse accidents.

2 Case Overview

This paper takes the space frame installation project of the grandstand of the university track and field field as an example, and analyzes the key points of construction quality control of the space frame project. In order to meet more extensive use needs and enhance the overall use effect of the building, the construction party plans to carry out overall renovation of the original track and field. The project includes the removal, production and installation of the outdoor stand space frame. The space frame canopy adopts a square pyramid space frame structure, and the canopy of the stands is made of 0.9mm thick pressed aluminum magnesium manganese plate, the grade is 3004, and the work hardening state is H24 or H26. The coating is polyvinylidene fluoride. The roof panel adopts the standing seam type, and the peak height is not less than 40mm; the surrounding panels around the roof panel adopt the lap joint type, and the peak height is not less than 20mm. From the perspective of project management, as a campus project, the project has higher use intensity and quality requirements. In addition, the construction of this project is to meet the needs of holding large-scale activities on campus, so it is very necessary to carry out quality management work on it. The editor personally participated in this project, and analyzed the difficulties and key points of quality control of the project, and further clarified the key points and technical content of the quality control of the space frame construction project.

3 Difficulties in engineering quality control

Through the actual requirements of the overall university track and field grandstand space frame installation project, it is found that the difficulties in quality control include the following five aspects.

1)The project is a spherical space frame project, and its location is relatively open. Considering the impact of winter wind and snow in Beijing, relevant staff need to calculate wind pressure loads and rain and snow loads during the construction design process.

2)The space frame structure of this project is a cantilevered structure, and the pre-embedded construction of the cantilevered connection points does not belong to the scope of this project. The staff need to use the removed support as the support point for installation. The staff surveyed and found that the quality of the original support embedded parts did not meet the requirements, and its size was also different from the design requirements, which could easily bring quality hazards to the later space frame construction.

3)The construction site of the project is the campus stadium. In order to minimize the inconvenience caused by the construction to the students, and at the same time limited by the site, the site construction of the project does not have the vertical hoisting conditions, and the site assembly and overall hoisting cannot be carried out. It can only be used in the air. Assembled construction process. Obviously, compared with site assembly and overall hoisting, the quality control of aerial assembly construction is more difficult.

4)The space frame in this project is a cantilevered component as a whole, the force system of rods and bolt balls is complex, and the requirements for deflection detection are high, which put forward high requirements for materials, technology, and process management.

5)In this project, there are a large number of rods, and workers often use welding and bolting to connect these rods together. Due to the high risk of space frame work in the air and the complex site conditions, it is difficult to control the quality of rod connection.

4 Main points of construction quality control of space truss engineering

4.1 Material quality control

Various types of materials will be used in the construction of the space frame structure, and the strength and stability of the space frame structure are closely related to the performance of the material. In the construction process of the space frame project, the main materials include the main body of the space frame and the connecting parts, and the auxiliary materials include bolt balls, sleeves, sealing plates, connecting plates, etc. If any material has quality problems, it will directly affect the function and safety of the project. During the construction of the space frame project, the staff need to control the material quality from the following perspectives:

One is to determine the specifications, models and performance requirements of the material according to the actual needs of the project, such as strength requirements and usage scenarios;

The second is to do a good job in the acceptance management of materials, and submit the main materials for inspection according to industry requirements;

The third is to do a good job in on-site management of materials, and check whether the appearance of materials meets the requirements of use before use;

The fourth is to actively do a good job in material classification to avoid the occurrence of mixed materials. Comprehensive control of material quality can effectively guarantee the overall quality of the project. In addition, material quality control is also one of the key contents in the construction process of space frame engineering.