Demolition of Three-Story Prefabricated Panel Houses

The demolition of three-story prefabricated panel houses must strictly adhere to safety regulations, with safety measures implemented from pre-demolition preparation, control during the demolition process, to post-demolition handling. Specific precautions are as follows:

I. Pre-Demolition Preparation

1. Safety Appraisal
   A professional agency must be commissioned to conduct a structural safety appraisal of the house, focusing on the stability of the connections between prefabricated panels and load-bearing components, and confirming the presence of any cracks, deformations, or corrosion hazards. The appraisal results will directly influence the design of the demolition plan. For example, if loose connections between prefabricated panels are found, temporary support measures must be included in the plan.

2. Formulate Demolition Plan
   Based on the appraisal results, a detailed plan should be formulated, specifying the demolition sequence (e.g., top-down layer-by-layer demolition), methods (e.g., mechanical crushing or manual dismantling), tool allocation (e.g., electric hammers, cutting machines, cranes), and personnel assignments. The plan must be reviewed by experts to ensure compliance with the requirements of the 'Technical Code for Safety in Building Demolition Engineering'.

3. Personnel Training
   All personnel involved in the demolition must undergo safety training, covering topics such as protection for work at heights, tool operation specifications, and emergency escape routes. Training records must be kept to ensure personnel master key safety skills.

II. Safety Measures During Demolition

1. Set Up Warning Areas
   Warning lines and signs should be set up within a 10-meter radius around the demolition site, with dedicated personnel on duty to prohibit non-staff from entering. If the demolition involves higher floors, protective sheds should be set up on the ground to prevent injuries from falling objects.

2. Use Professional Tools
   Priority should be given to low-noise, low-vibration electric tools, avoiding the use of equipment like pneumatic picks that may trigger structural resonance. When cutting prefabricated panels, they must be securely fixed to prevent fragment splashing.

3. Follow Demolition Sequence
   Non-load-bearing structures (e.g., partition walls, doors, and windows) should be demolished first, followed by load-bearing structures (e.g., beams and columns). After each floor is demolished, the stability of the remaining structure must be checked, and temporary supports added if necessary. Cross-operations or simultaneous demolition of upper and lower floors are strictly prohibited.

4. Real-Time Monitoring
   Dedicated personnel should be arranged to monitor the demolition process throughout, focusing on observing the connection points between prefabricated panels and changes in wall cracks. If abnormalities (e.g., unusual noises, settlement) are detected, operations must be immediately stopped, and emergency plans activated.

III. Post-Demolition Handling

1. Site Cleanup
   Construction waste should be promptly sorted and disposed of, with metal components recycled and concrete fragments transported to designated disposal sites. The site must be kept clean to avoid residual sharp objects or exposed rebar.

2. Safety Inspection
   A comprehensive inspection of the demolished site should be conducted to confirm the absence of residual hazards (e.g., unremoved electrical wires, flammable materials). If subsequent construction is required, the bearing capacity of the foundation must be re-evaluated.

3. Record and Report
   Key data from the demolition process (e.g., demolition time, tool models, personnel work hours) should be recorded in detail. If a safety accident occurs or significant hazards are discovered, a report must be submitted to the local housing and construction department within 2 hours, and cooperation provided in the investigation.