Installation Sequence of Prefabricated Beams in Houses

The installation sequence of prefabricated beams in houses follows the principle of 'primary beams first, secondary beams next; lower levels first, higher levels next'. This principle is crucial for ensuring structural safety and efficient construction. The specific reasons and operational key points are as follows:

1. Primary Beams First, Secondary Beams Next: Building a Stable Framework
Primary beams are the core load-bearing components in a building structure, directly bearing vertical loads from floors, walls, etc., and transferring them to the foundation through columns or walls. During installation, it is essential to prioritize the positioning and fixation of primary beams to form a stable framework system. For example, in a frame structure, primary beams are typically arranged horizontally or vertically along the building, and their installation accuracy directly affects the connection quality of secondary beams. If primary beams are not installed properly, the loads from secondary beams may not be effectively transferred, leading to local stress concentration or structural deformation.
Secondary beams are used to share the loads from primary beams, further dispersing floor loads to primary beams or walls. Their installation should be carried out after the primary beams have formed a stable framework to ensure precise对接 (docking, here meaning connection) of the connection nodes (such as welding or bolt connections) between secondary and primary beams. Additionally, the installation sequence of primary beams should consider construction convenience, typically progressing from the middle of the building to both ends to reduce cumulative errors.

2. Lower Levels First, Higher Levels Next: Ensuring Support Reliability
In the vertical direction, the installation of lower-level components should take precedence over higher-level components. Lower-level components (such as ground-floor primary and secondary beams) serve as the support foundation for higher-level components. If higher-level components are installed first, they may be at risk of hanging in the air or tilting due to a lack of support. For example, in a multi-story building, the installation of ground-floor primary beams should be completed before proceeding with the hoisting of upper-floor primary beams to avoid destabilizing the lower structure due to the self-weight or construction loads of upper components.
Furthermore, the installation of lower-level components provides an operating platform for the construction of higher-level components. For instance, when installing high-rise primary beams, construction personnel can work on the completed lower-level beams, improving construction efficiency and safety. If the principle of 'lower levels first, higher levels next' is violated, the installation of higher-level components may require additional temporary supports due to insufficient support, increasing costs and construction time.

3. Precautions During Installation

• Surveying and Setting Out: Before installation, precise measurements of the positions of primary and secondary beams should be conducted to ensure that the component axes align with the design drawings, avoiding uneven structural loading due to positioning deviations.
• Temporary Fixation: After installing primary beams, immediate temporary fixation (such as with diagonal braces or guy wires) should be carried out to prevent displacement caused by wind loads or construction vibrations.
• Node Inspection: When connecting secondary beams to primary beams, special attention should be paid to inspecting the welding quality or bolt tightness at the connection nodes to ensure a smooth load transfer path.
• Safety Protection: During high-altitude operations, safety nets, guardrails, and other facilities should be set up to prevent personnel or materials from falling.

By adhering to the principle of 'primary beams first, secondary beams next; lower levels first, higher levels next', the structural safety and construction efficiency of the installation of prefabricated beams in houses can be effectively ensured, laying a solid foundation for subsequent processes (such as floor pouring and wall masonry).