Portal frame is a traditional structural system. The upper main frame of this kind of structure includes rigid frame inclined beam, rigid frame column, support, purlin, tie bar, gable frame, etc.
Steel structures of light-weight buildings with gabled frames are widely used in industrial, commercial, cultural and entertainment public facilities and other industrial and civil buildings because of their simple stress, clear force transmission path, fast component manufacturing, easy industrialized processing and short construction cycle. The steel structure of light-weight buildings with gabled frames originated in the United States. After nearly a century of development, it has become a structural system with relatively perfect design, fabrication and construction standards.