Portal steel frame is a structural type of steel structure building. It is mainly composed of steel frame and horizontal beam, forming a portal structure that can provide good support and load-bearing capacity. Portal frame structures are suitable for places that require large space coverage and high strength requirements, such as factories, logistics centers, warehouses, stadiums, etc. It has the advantages of easy construction, stable structure and long service life, and is widely used in industrial and commercial buildings.
Compared with other steel structures, portal steel frames generally have the following characteristics
- The cross-sectional size of the structural components is small, which can effectively utilize the building space, reduce the height of the house, and make the building beautiful in appearance. So the weight is relatively light.
- The portal frame has good stiffness and light weight. The beams and columns can be assembled. It has a high degree of industrialization and can basically be completed in the factory. It provides favorable conditions for production, transportation and installation. Moreover, the layout of the column grid is flexible.
- The amount of steel used in the roof rigid frame is only 1/5-1/10 of the amount of steel used in ordinary steel roof trusses. It is an economical and reliable structural form.
The main components of the portal steel frame are: main load-bearing frame (portal steel frame), purlins, wall beams (cold-formed thin-walled steel), roofs, walls (color steel veneer or sandwich panels), roofs and walls Insulation cotton, supports, etc.
Portal steel frame performance:
- The integrity of the portal rigid frame roof system can be ensured purlins and corner braces, there reducing the number of roof supports. At the same time, the supports are mostly made of round steel, which is very light.
- The beams and columns of the portal frame mostly use variable-section rods, which can save materials.
- The rods that make up the components are thin and require high requirements for production, painting, transportation, and installation.
- The bending stiffness and torsional stiffness of the components are relatively small, and the overall stiffness of the structure is also relatively soft.
The lightweight portal steel frame has the characteristics of simple structure, light weight, reasonable stress, convenient construction, and convenient for factory processing and standardized production. Portal steel frame structure is already a relatively mature and commonly used type of steel structure. It is suitable for light factory buildings, single-story house structures without bridge cranes or light bridge cranes with a lifting capacity of no more than 20 tons. Due to the thin thickness of the portal steel frame panels, they are not suitable for environments with strong corrosive media.
According to the structure type, portal rigid frames can be divided into single-span, double-span, multi-span rigid frames, and rigid frames with overhangs and adjacent houses. The connection between the middle column and the inclined beam of the multi-span rigid frame is generally hinged. The multi-span rigid frame should adopt a double-slope or single-slope roof. If necessary, a multi-span rigid frame composed of multiple double-slope roofs can also be used. The cross-sections of beams and columns can be constant or variable, and the column feet are generally hinged or rigidly connected.
Main applications of portal steel frames: light factories, logistics centers, large supermarkets, gymnasiums, exhibition halls, mobile homes, additional storey buildings, etc.