There is really no uniform standard for determining the structure of heavy steel and light steel structure. Many experienced designers or project managers often cannot fully explain it, but we can consider and judge with some data:

 

1. Lifting weight of the plant: 25 tons or more, which can be considered as heavy steel structure.

 

2. The amount of steel per square meter: greater than or equal to 50KG / M2, can be considered a heavy steel structure.

 

3. The main component steel plate thickness: greater than or equal to 10MM, light steel structure used less.

 

4. In addition, there are some reference values: such as the cost per square meter, the maximum component weight, the maximum span, the structural form, the high height, etc. These can provide empirical data when judging whether the plant is heavy steel or light steel. Of course, many buildings now. Both are light and heavy steel. But there are some that we can say with certainty that it is heavy steel: eg petrochemical plant facilities, power plant buildings, large-span stadiums, exhibition centers, high-rise or super high-rise steel structures.

 

5. In fact, there is no heavy steel in the national norms and technical documents. In order to distinguish the steel structure of light-duty houses, it may be more appropriate to call the general steel structure “Pugang”. Because of the wide range of ordinary steel structures, it can contain a variety of steel structures, regardless of the size of the load, and even the light steel structure, the light steel structure technical regulations only specify some more specific for its "light" characteristics. Content, and the scope is limited to single-story portal frames.

 

6. light steel is also a relatively vague term, generally can have two understanding. One is the eleventh chapter of the current "Code for Design of Steel Structures" (GBJ 17-88) "Light steel structure of round steel and small angle steel", which refers to round steel and less than L45*4 and L56*36*4. The light steel structure made of angle steel is mainly used for small structures that are not suitable for reinforced concrete structures when the steel is lacking. It has been basically not used, so this steel structure design specification has basically been removed. The other is a single-layer solid belly-type rigid frame structure with a light roof and a light exterior wall (which can also be conditionally used for external walls) as stipulated in the Technical Specification for Steel Structures for Lightweight Houses of Portal Frames. The light weight here mainly means that the enclosure is made of lightweight materials. Since the former one has been canceled quickly, the current light steel meaning mainly refers to the latter.

 

7. It can be seen that the distinction between light steel and heavy steel is not the weight of the structure itself, but the weight of the enclosing material is still the same, and the concept of structural design is consistent.

 

Steel structure installation note:

 

The prefabrication and assembly of steel components on the steel platform according to the installation sequence and process requirements shall ensure the quality of the welding.

 

The spacing between the splicing seam of the splicing flange plate of the section steel and the splicing seam of the web shall be greater than 200 mm. The length of the flange plate splicing shall not be less than 2 times the width of the plate; the splicing width of the web shall not be less than 300 mm and the length shall not be less than 600 mm.

 

In order to facilitate the welding and ensure the welding quality, the reinforcing ribs, connecting plates, backing plates and picking beams (beams) on the columns and beams should be grouped and welded on the ground steel platform according to the construction drawing size.

 

In addition to the construction drawings and specifications required for the steel components prefabricated on the steel platform, the processability and installation dimensions of the on-site installation should also be considered.