Prefabricated Panel House Design

The design of prefabricated panel houses requires comprehensive consideration of factors such as structural characteristics, service life, and safety. The following are key design points:

1. Structural Type and Load-Bearing System

Prefabricated panel houses typically adopt a brick-concrete structure, where walls bear the main vertical loads, and floor and roof panels are made of prefabricated concrete components. During the design process, it is necessary to clarify the collaborative working mechanism between walls and prefabricated panels:

• Wall Design: Prioritize materials with good load-bearing performance (such as fired bricks and concrete blocks) to ensure that wall thickness and strength meet the requirements for vertical load transfer.
• Prefabricated Panel Selection: Choose solid or hollow prefabricated panels based on span and load requirements. Hollow panels achieve lightweighting by reducing non-load-bearing concrete, but their flexural and shear capacities must be checked to prevent cracking due to excessive local loads.
• Connection Nodes: Reliable measures (such as reserved steel bar anchoring and cast-in-place concrete overlay layers) must be adopted for the connections between prefabricated panels and walls or beams to prevent horizontal displacement or detachment.

2. Design Service Life and Durability

The design service life of prefabricated panel houses is typically 30-50 years, which is much shorter than that of modern reinforced concrete structures (80-100 years). Therefore, durability must be specifically enhanced during the design process:

• Material Selection: The concrete strength grade of prefabricated panels should be no less than C25, and steel bars should be of HPB300 or HRB400 grade to ensure corrosion resistance. Wall materials must meet requirements for weather resistance and moisture protection.
• Construction Measures: Waterproof mortar or sealant should be used to fill the joints between prefabricated panels to prevent rainwater leakage. Roof panels should be provided with a slope (≥3%) and a drainage system to avoid accelerated concrete carbonation due to water accumulation.
• Maintenance Cycle: The design documents should specify regular inspections (e.g., every 5 years) of cracks in prefabricated panels and rusting of connection nodes, with timely repairs or reinforcements carried out as needed.

3. Seismic and Safety Design

Old prefabricated panel houses have weak seismic performance, so seismic construction measures must be supplemented during the design process:

• Ring Beams and Structural Columns: Cast-in-place concrete ring beams should be added at key locations such as the top and bottom of walls and stairwells to form a "weak frame" system with structural columns, improving overall integrity.
• Prefabricated Panel Reinforcement: For prefabricated panels with large spans, steel supports can be added at the bottom of the panels or carbon fiber sheets can be pasted to improve collapse resistance.
• Load Limitation: Strictly control the live load on floors (e.g., ≤2.0 kN/m² for residential buildings) to avoid structural damage caused by overloading.

4. Applicability and Renovation Restrictions

Renovation of prefabricated panel houses should be carried out with caution to avoid damaging the original structure:

• Space Adjustment: Random removal of walls or creation of openings is prohibited. If renovation is required, structural verification must be carried out, and reinforcement measures (such as adding steel beams) should be taken.
• Equipment Installation: Pipes and wiring should be laid away from the joints of prefabricated panels to avoid drilling and damaging steel bars. Large equipment (such as water tanks) should have independent foundations and should not be placed directly on floor panels.