The Specification Of Portal
Portal Steel Frame Buildings use the portal frame as the force carrier, and the enclosure structure is a system of thin-walled C/Z-shaped steel purlins and colored profiled steel plates. It is a new type of building structure system that is widely used. It has the advantages of being lightweight, having a high degree of industrialization, having a short construction period, having high comprehensive economic benefits, and having a flexible column network layout.
To complete the building, cold-formed thin-walled steel in C or Z is used for the purlins and wall girts, while corrugated metal sheets are the roof and walls. For insulation, various materials, such as polystyrene foam, rigid polyurethane foam, rock wool, mineral wool, and glass wool, can be utilized to keep the interior temperature regulated. Additionally, a proper bracing system is installed to reinforce the structure further.
Compared to a reinforced concrete structure, a portal steel frame boasts several advantages, such as being lightweight, having high rigidity, allowing for a flexible design, exhibiting reasonable force, and offering convenient construction.
Form of Rigid Frame
The portal frame structure comes in several shapes, including single-span, double-span, high-low-span, and multi-span, with options such as a single ridge, multiple ridges, single slope, double slope, multiple slopes, and a flat slope. Single-span rigid frames are commonly used in buildings that don’t need much lateral space and have spans ranging from 18 to 36 meters. The beams and columns of these frames are usually made of welded or rolled H-shaped sections and are positioned and adjusted in height based on the span and the bending distance diagram. The multi-span rigid frame is ideal for large buildings, with a similar cross-section to the single-span rigid frame but with a center column that typically has an equal cross-section. Currently, the maximum span of a portal frame has reached 72 meters.
The composition of Portal Steel Frame Buildings
1.Primary framing includes transverse rigid frames (including middle and end rigid frames), floor beams, crane beams, support systems, etc.
2. Secondary framing: roof purlin and wall girt, etc.
3. Envelope structure: roof and wall panels;
4. Auxiliary structures: stairs, platforms, handrails, etc .;
5. Foundation.
The primary force skeleton of portal frame steel buildings comprises steel columns, roof beams, and bracing systems. This is considered to be the primary framing. The roof and wall panels act as the envelope and closure for the structure, enhancing its overall stiffness. The roof purlins and wall girts also support the roof and walls and lateral support for the main structural beams and columns, forming the secondary framing.
