Safety Assessment of Prefabricated Panel Houses

The safety assessment of prefabricated panel houses should focus on housing quality and structural safety, classify hazard levels according to the 'Standard for Appraisal of Dangerous Houses' (JGJ 125-2016), and implement the assessment in accordance with specific procedures and content.

I. Classification of Assessment Levels The hazard level of houses is divided into four grades: A, B, C, and D:

• Grade A: No dangerous components, and the structure meets safety requirements for use.
• Grade B: Some components are dangerous, but they do not affect the safety of the main structure.
• Grade C: Some load-bearing structures do not meet safety requirements for use, and parts of the house are in a dangerous state.
• Grade D: The load-bearing structures no longer meet safety requirements for use, and the entire house is in a dangerous state.

II. Core Content of the Assessment

1. Inspection of Structural Integrity and Foundation
   • Foundation: Check for signs of ground settlement around the house, differences in indoor and outdoor ground levels, and diagonal cracks at the bottom of walls caused by uneven foundation settlement.
   • House Tilt: Visually inspect whether the house is tilted or twisted as a whole.
2. Special Inspection of Core Components
   • Prefabricated Floor Slabs: Observe horizontal through-cracks in the ceiling, cracks at the joints between slabs, check for deflection deformation of the floor slabs, and inspect for loose concrete and rusted steel bars at the end support positions.
   • Load-Bearing Walls: Focus on checking vertical and diagonal cracks, cracks or downward deformation of lintels above door and window openings, weathering and spalling of bricks at the bottom of walls on the ground floor, and whether ring beams and structural columns are installed (for brick-concrete prefabricated panel houses of three stories or more, the absence of these structures significantly reduces earthquake resistance and safety).
   • Node Connections: Check whether the support length of prefabricated panels complies with regulations (should not be less than 80mm), and whether there are separations or cracks at the corners and junctions of walls.
3. Inspection of Public Facilities and Usage Environment
   • Aging of Pipelines: Check for aging, leaks, tripping, and blockages in water and electricity pipelines.
   • Unauthorized Renovations: Verify whether there have been unauthorized demolitions of load-bearing walls, additions on rooftops, or changes in the purpose of the house (such as converting residential spaces into commercial premises).

III. Assessment Process

1. Preliminary Inspection: Conducted by professional technicians or institutions focusing on structural integrity, component conditions, and usage and renovation situations.
2. Professional Appraisal: If safety hazards are identified, entrust a qualified unit to conduct a detailed appraisal and issue a report.
3. Government Approval and Public Announcement: Demolition plans must be approved by the government and publicly announced to ensure residents' right to know.

IV. Application of Assessment Results

• Grade C Houses: Require partial repairs or reinforcement.
• Grade D Houses: Require accelerated demolition and reconstruction.
• Impact of Government Planning: If demolition is required for public interests, it must be carried out in accordance with the 'Regulations on the Expropriation and Compensation of Houses on State-owned Land'.