Architectural Design of Maintenance Hangar (Part 2)

3、Advantages of different structural forms of the hangar

Building units constructing maintenance hangars in earthquake-prone areas need to fully consider their anti-seismic properties, and enhance the flexibility and ductility of maintenance hangars to resist the pulling force during earthquakes. This type of maintenance hangar usually requires a steel structure as the supporting system, and the design of the structure is the core content of the hangar design work. Moreover, the tension exerted by the earthquake on the building is more to make the building move laterally. The total area of the maintenance hangar is large and the weight is not high. Therefore, there are the following two design methods to improve its seismic performance during the earthquake.

(1) Translational maintenance hangar The hangar itself has a translation function, so that the structure will not be damaged due to the lateral tension of the earthquake, thereby reducing the damage suffered in the earthquake. For example, Canada’s Lubu Construction Company once designed a steel structure hangar based on heavy-duty pipe-grade PVC, which can maintain its original shape in the environment of ground subsidence, and is not affected by changes in ground conditions. It has excellent anti-seismic performance.

(2) Rigid movable hangar Although the rigid movable hangar is a rigid structure, it will not suffer serious structural damage during an earthquake. In the event of an earthquake, the hangars can move along with the cracked plates in the ground. For example, a maintenance hangar was built in Afghanistan with a high-width bracing system designed to withstand lateral movement of the hangar in the event of an earthquake. Moreover, if the main door of the hangar is opened when a hurricane occurs around the hangar, the air with a very high velocity will quickly fill the entire hangar, and the influx of air will instantly push against the roof of the hangar and damage the structure of the hangar. Therefore, the architectural design of the maintenance hangar should fully consider the structural damage caused by the air lift, and design a roof structure that can resist the lift, so that the roof and walls can resist both the lateral tension of the earthquake and the force of the hurricane. Longitudinal lift, thereby achieving the stability of the hangar structure.

(3) Arched structure The arched structure can smoothly unload part of the wind and snow load through its own shape, which is more economical than the traditional structural form. It is easier to assemble, thanks to its own shape characteristics, compared with the 2m~4m truss height of the traditional structure, the arched structure can reduce the truss height by 50%~70% under the same load, which is more beneficial Realize the rapid assembly of the structure. It is more conducive to modularization. The fixed-length units are pre-assembled in the factory, and the site only needs to be assembled according to the specified arch shape, size and angle between units, further shortening the construction period and construction costs. The design of the arch structure tends to be reasonable and stable, and the safety of all components is reserved for safety reserves, which can cope with the possibility of various extreme weather. Due to the light weight of the aluminum alloy building structure, the self-weight load is 1/3 of that of the steel structure, and its civil engineering workload and cost are lower than that of the steel structure. Through components that can expand in size and strength, it has structural and functional scalability, can adapt to the development needs of future equipment sizes, and enhance the flexibility of the user’s construction requirements, so that a class of buildings can meet multiple needs, and a building can match multiple needs. generation equipment. It also has the characteristics of fast installation speed. At the same time as the foundation and substructure construction, the centralized production of factory modules is carried out simultaneously. After combined pre-assembly, it is transported to the construction site for precise hoisting. The 100% assembly rate greatly shortens the construction period, compared with traditional The steel structure shortens the construction period by about 30%~50%, and there is no wet operation or hot welding operation on site.

(4) “Frame structure + steel structure” roof hangar form This structure combines the advantages of frame structure and steel structure together, avoids their respective shortcomings, is more reasonable and economical, and is widely used in the field of maintenance hangars in my country application. The frame structure has good seismic performance and flexible space separation, which can meet the requirements of some room function adjustments in the future. The construction standard is also high and the structural integrity is good. As for the roof of the steel structure, the steel has high strength and high elastic modulus, and the fire prevention of the steel structure can be treated with fireproof paint that meets the requirements of the fire prevention code, and the fire resistance level is high. Compared with traditional wood and concrete structures, it has very significant advantages. The ratio of density to yield strength in steel structures is lower. At the same time, its volume and weight are smaller, which is more convenient for transportation and installation. Buildings with larger spans and higher load-bearing requirements (repair hangars require cranes) have reached a perfect “cooperation”. This form not only has the characteristics of solemn appearance, but also avoids the disadvantages of traditional cast-in-place concrete roofs. It is widely used in the maintenance hangars of troops, governments and other units.

(5) The hangar-style lattice column of “lattice column + support + grid roof” is composed of smaller cross-sectional members, so under the same bearing capacity, it is lighter in weight than the solid-web column. , the moment capacity of the lattice column is better and the influence of lateral deformation is minimal. The grid structure is not only more convenient to install, but also has the advantages of high rigidity, uniform force, and environmentally friendly materials. The overall rigidity is good, the shock resistance is also good, the flexibility is good, and steel is saved. This type of structure has a modern appearance, short construction period, greatly saves building materials, and is suitable for large-span maintenance hangars. The most famous hangar with this structure is China Southern Airlines Hangar No. 1 at Beijing Daxing International Airport, covering an area of about 40,000 square meters. Inspection line was born here.

4、Architecture design of maintenance hangar based on corrosion effect

The location of the maintenance hangar is very complicated, it may be in an inland area with a dry climate and a lot of sand and dust, or it may be in a coastal area with abundant sea water and high humidity. There are various influencing factors that may corrode the hangar structure in different regions, such as sunlight, sea water, sand and dust, etc. my country’s land is connected to the Bohai Sea, the Yellow Sea, the East China Sea, and the South China Sea. The inland also contains two major river basins, the Yangtze River and the Yellow River. Maintenance hangars are more threatened by corrosion from various factors. Heavy-duty anti-corrosion floor paint is applied to the hangar ground to prevent acid and alkali and other corrosion sources from directly contacting the ground and causing ground damage. Materials such as polyurethane and phenolic epoxy can be used as raw materials. The development of the anti-corrosion design of the hangar is beneficial to reduce the maintenance cost of the hangar in our country and promote the long-term use of the hangar. At the same time, my country’s Xinjiang, Tibet, Qinghai and other regions are often accompanied by relatively harsh natural environments, and the erosion of the environment on hangars is also a problem that cannot be ignored. In short, the architectural designers of maintenance hangars in our country should pay full attention to the specific conditions of various places to ensure the anti-corrosion function of each hangar in our country. In recent years, my country has also developed an aluminum-based assembled hangar, which adopts an arched structure. It adopts lightweight and high-strength Al-Mg-Si high-strength aluminum alloy material under the protection of oxide film, which has excellent corrosion resistance, super weather resistance and corrosion resistance, and is free of daily maintenance. The material is exported to the United States, Northern Europe, and Canada. It has been verified by weather conditions such as typhoons and rainstorms, and is worthy of promotion and use.

5、Guarantee the fire resistance limit of the hangar

In order to make the hangar have better corrosion resistance and make the construction more economical and efficient, a large number of steel structures are used in the hangar, and many new maintenance materials outside the hangar have been developed, but the fire resistance of these materials is not as good as that of traditional masonry. Block walls and cast-in-place reinforced concrete roof slabs or ordinary steel structures, so how to make up for this disadvantage? Article 3.0.5 of the national standard atlas “Code for Fire Protection of Aircraft Garage Design” (GB50284-2008) clearly states that: the roof load-bearing components of the aircraft parking and maintenance area of the aircraft hangar should be coated with fire-proof and heat-insulating panels or sprayed with fire-proof and heat-insulating coatings, etc. Measures for fire protection, when the foam-water deluge fire extinguishing system or the automatic sprinkler system is adopted, the roof can use metal components without fire protection. Therefore, it is an effective way to make up for the shortage of new materials by cooperating with construction, water supply and drainage, and electrical professions to solve this problem.