Steel Structure Material, Design and Construction Standards
Introduction
The steel structure is a structure made of steel material, which is composed of steel beams, steel columns, steel trusses, and other components made of steel and steel plates. The steel structure can bear a certain amount of static load and dynamic load, which is suitable for all types of large-span structures such as buildings, bridges, plants, towers, and so on. Steel structures have the advantages of light weight, large modulus, good rigidity and strong anti-seismic performance, so they are widely used in the construction industry at present. In order to ensure the quality of the steel structure, relevant standards must be followed in the design, materials selection, Construction and welding of steel structures,
Design Standard
Steel structure design shall conform to the standard JGJ81, standardized expression of design requirements of steel structure buildings, and shall be designed in accordance with relevant laws and regulations. The design of the steel structure shall pay attention to the following aspects:
1. The safety requirements of the steel structure shall be in line with the relevant national regulations. No matter whether the structure is static, constant or dynamic load, the stress should not exceed the allowed stress value in the design. The over-allowed stress should not be exceeded in any case.
2. Load size should conform to the specifications of national standards in the whole span and deformation ratio to control the stress of various structural members. Relevant calculation methods should also be provided.
3. Calculated stress, displacement limits and buckling modulus should be considered when designing steel structures and determining the section size of structural members. Stress and other factors should also be considered to determine the stiffness of the connection of various components.
4. The buckling stability and fatigue properties of the steel structure should be considered when designing the common parts of the steel structure.
Material Standards
The selection of materials for steel structure shall conform to the regulations of GB50017--2003, standards for structural design codes of steel structures. According to the regulations, when selecting the suitable structural steel materials, the following issues need to be considered:
1. The chemical composition of structural steel needs to be considered. Carbon steel and low alloy steel are used as structural materials in general. The carbon content of carbon steel is generally below 0.2%, while the carbon content of low alloy steel is 0.2-0.5%. It is necessary to determine whether both of them meet the requirements of the chemical analysis range.
2. The mechanical properties of steels should be considered. The required mechanical properties include yield strength, tensile strength, elongation and reduction of area, impact energy and so on. The requirements for these aspects are different for different parts of the steel structure. The larger the load, the higher strength requirements should be given.
3. In addition, it is also necessary to consider the corrosion resistance, weldability and fracture toughness of the steel material. The fracture toughness should be considered in the design of most steel structures due to the possibility of rapid fracture caused by the impact of the dynamic load.
Construction and Welding Standards
Construction and welding standards for steel structure include national standard GB50205--2002 and national standard GB50206--2002.
1. Operations must follow safety rules and regulations. This includes the use of appropriate tools and safety clothing. The erector must be able to parse and communicate the erection plan well.
2. Connections between steel components should be fastened and matched in accordance with the rules, and welded or riveted. If a bolt connection is selected, its strength and tightening torque should meet the requirements.
3. Before welding, it is necessary to make a welding plan according to the drawings, calculate the preheating temperature, flux type and other conditions.
4. All welding material and equipment should have quality certificates to ensure the quality of the welding. And during the welding process, it is necessary to ensure the welding effect, specific welding parameters and welding process records. The appearance and quality of the weld should also be checked.
5. Finally, the grinding and coating of the weld should be done according to the requirements, and the overall steel structure should be inspected to ensure the quality of the steel structure.
Conclusion
Steel structure is widely used in all kinds of large-span structures. In order to ensure the quality of the steel structure, relevant standards should be followed in the design, materials selection, Construction and welding of steel structures. These standards involve not only the design standard, but also the material standard, construction and welding standard, which must be strictly complied with to guarantee the performance and safety of the steel structure.
