Seismic Structure of Prefabricated Panel Houses

The seismic resistance of prefabricated panel houses varies significantly depending on their construction era and design specifications, with modern prefabricated buildings demonstrating notably superior seismic performance compared to older prefabricated panel buildings.

Structural Characteristics and Seismic Resistance

• Older Prefabricated Panel Buildings (1970s-1980s):
  Floor slabs are typically made of prefabricated hollow or solid panels, connected through steel bar lapping or mortar jointing; walls are primarily brick-masonry structures with poor overall connectivity between components. Designed according to the "Code for Seismic Design of Buildings" (TJ 11-78), the seismic fortification intensity is generally 6-7 degrees (with some areas like Beijing designed for 7 degrees). They can only withstand earthquakes of magnitude 6-7 (corresponding to intensity 6-7 degrees), with little protection against earthquakes above magnitude 8.

• Modern Prefabricated Buildings:
  Designed according to the current "Code for Seismic Design of Buildings" (GB 50011-2010), they employ high-strength concrete, prestressed technology, and steel bar sleeve connections, significantly enhancing overall integrity. For example, prefabricated shear wall structures can withstand earthquakes above magnitude 8, capable of resisting earthquakes of magnitude 7-9 (corresponding to intensity 7-9 degrees), with specific performance depending on design and construction quality.

Key Factors Affecting Seismic Resistance

1. Connection Quality: The connection between prefabricated panels and walls or beams is crucial. Poor welding, concrete pouring defects, or inadequate jointing can directly weaken seismic performance.
2. Height Limitations: Prefabricated panel buildings below six stories are generally safer, with regions like Beijing explicitly prohibiting prefabricated panel buildings from exceeding 12 stories.
3. Structural Type: Brick-masonry walls have weaker seismic resistance compared to frame structures; foundation depth or pile foundation design also significantly impacts seismic effectiveness.

Reinforcement Measures

1. Enhanced Connections: Insert steel frames or pour concrete into walls, and lay steel mesh at joints to improve collaborative load-bearing capacity between components.
2. Installation of Seismic Isolation Bearings: Absorb seismic energy through isolation devices, reducing structural vibration, akin to "putting running shoes on a building."
3. High-Ductility Cement Reinforcement: Applying high-ductility cement-based composite materials for surface coating can enhance seismic resistance to intensity level 7 while increasing wall ductility.

Summary: The seismic performance of prefabricated panel houses should be comprehensively evaluated based on construction era, structural design, and reinforcement measures. Older buildings are recommended to undergo professional inspections and adopt reinforcement measures, while modern prefabricated buildings must strictly adhere to seismic design codes to ensure construction quality.