There is no uniform standard for determining the structure of heavy steel and light steel structure, but some data can be taken into account and judged.
1, plant crane lifting weight: greater than or equal to 25 tons, can be considered as heavy steel structure.
2, the amount of steel used per square meter: greater than or equal to 50KG/㎡, can be considered a heavy steel structure.
3, the thickness of the main components steel plate: greater than or equal to 10MM, light steel structure with less.
In addition, there are some reference values: such as the cost per square meter, maximum component weight, maximum span, structural form, eave height, the above can provide empirical data in determining whether the plant is heavy steel or light steel, of course, many buildings are now light and heavy steel. But there are some we can say with more certainty is heavy steel: such as: petrochemical plant facilities, power plant plants, large-span stadiums, exhibition centers, high-rise or super high-rise steel structure.
in order to distinguish the light housing steel structure, perhaps it is more appropriate to call the general steel structure as “ordinary steel”. Because the scope of ordinary steel structure is very wide, can include a variety of steel structures, regardless of load size, even including many elements of light steel structure, light housing steel structure technical regulations only for its “light” characteristics and provide some more specific content, and the scope is limited to single-story portal frame.
One is the current “Code for Design of Steel Structures” (GBJ 17-88) in Chapter 11, “Light Steel Structures of Round Steel and Small Angles”, which refers to light steel structures made of round steel and angles smaller than L45*4 and L56*36*4.
It can be seen that the difference between light steel and heavy steel is not in the lightness of the structure itself, but in the lightness of the envelope material it is subjected to, and the structural design concept is still the same.
Take the steel structure plant as an example, the lifting adopts the principle of “first middle, then outside, first column, then beam, first down, then up”, forming a stable frame system in the middle part of the plant, then pushing forward to both ends, symmetrically installing the rest of the steel column and steel beam components, in the following order.
Footing bolt retesting → steel components unloading → components into the field inspection → car crane direct lifting in place → footing bolt temporary fastening → cable temporary tie solid → steel column axis position, verticality adjustment → steel column bolts and column foot pressure plate fastening, welding → the next steel column installation → steel column ties installation → the formation of the first stable lattice system → steel roof frame ground assembly into a whole and double lifting in place, the composition of the first steel roof frame → both sides of the symmetric installation of columns, roof frame system → …… → and so on → steel structure installation is complete, structural acceptance.
