Appraisal Standard for Prefabricated Panel Houses

The appraisal standard for prefabricated panel houses is primarily based on the 'Standard for Appraisal of Dangerous Houses' (JGJ 125-2016), conducting a comprehensive assessment from three aspects: foundation, load-bearing structure, and overall stability, and classifying dangerous levels from A to D.

I. Foundation Appraisal

1. Major Safety Hazards:
   • Uneven settlement of the foundation occurs, causing wall cracking and tilting, with the settlement rate or cumulative settlement exceeding the allowable values specified in the standards;
   • The foundation slip exceeds 10mm, affecting the safety of the superstructure;
   • The width of cracks parallel to the slope on the ground exceeds 10mm, or the house tilting value reaches H/250 (H being the house height).
2. General Safety Hazards:
   • Slight uneven settlement or cracks that do not meet the criteria for major safety hazards but require continuous monitoring.

II. Load-Bearing Structure Appraisal (Brick-Concrete Structure)

1. Major Safety Hazards:
   • Multiple vertical or diagonal cracks appear in the walls, with crack widths or lengths exceeding the specified limits;
   • Cantilevered components such as balconies and canopies show significant deflection, posing a risk of detachment;
   • The prefabricated panels are severely cracked, deformed, or have loose or detached connections.
2. General Safety Hazards:
   • Vertical cracks in the walls that do not meet the criteria for major hazards;
   • Vertical through-cracks appear at the connections between longitudinal and transverse walls;
   • The prefabricated panels have slight cracks or deformations that do not affect overall safety.

III. Overall Stability Appraisal of the House

Based on the appraisal results of the foundation and load-bearing structure, the overall stability of the house is evaluated:

• If the house shows severe tilting, deformation, or extensive damage to the load-bearing structure (such as walls and prefabricated panels), it is classified as a whole dangerous house (Level D).

IV. Appraisal Level Classification

1. Level A: The structural load-bearing capacity meets the requirements for normal use, with no dangerous points.
2. Level B: The structural load-bearing capacity basically meets the requirements, with individual components in a dangerous state but not affecting the safety of the main structure.
3. Level C: The load-bearing capacity of some structural components is insufficient, with local hazards appearing in the house (such as local wall cracking and deformation of prefabricated panels).
4. Level D: The load-bearing capacity of the structural components is severely insufficient, with overall hazards appearing in the house (such as tilting and collapse risks).

Supplementary Explanation:
In addition to the 'Standard for Appraisal of Dangerous Houses', the Beijing local standard 'Standard for Comprehensive Safety Appraisal of Building Structures' (DB11/T 637-2024) provides more detailed technical requirements, covering investigation and testing, seismic appraisal, etc., and is applicable to the comprehensive assessment of complex structural houses. During the appraisal, it is necessary to combine on-site testing data with the specified limits in the standards to ensure scientific and rigorous results.