Demolition Site of Prefabricated Slab Houses

At the demolition site of prefabricated slab houses, it is essential to strictly follow the correct demolition sequence and implement a safety management system; otherwise, serious accidents can easily occur. The key points are as follows:

I. Demolition Sequence is a Core Safety Factor

1. Prioritize the removal of non-load-bearing structures: First, remove附属构件 (ancillary components) such as non-load-bearing walls, doors, and windows, and then handle the floor slab bedding. After removing non-load-bearing walls, the overall load on the structure can be reduced, creating safer conditions for subsequent operations. For example, in the accident in Banan District, Chongqing, workers directly chiseled the prefabricated slab bedding without removing the brick balustrade of the balcony (a non-load-bearing structure), causing the cantilever beam to lose its load balance and ultimately leading to the overall collapse.
2. Avoid disrupting the stability of the load-bearing system: The cantilever beams and load-bearing walls of prefabricated slab houses are key load-bearing components. If their supporting structures (such as balcony balustrades) are destroyed in advance, it can lead to sudden changes in load distribution and trigger moment imbalance. In the accident, the external moment of the cantilever beam overpowered the internal resistance due to the sudden drop in load, directly demonstrating this principle.

II. A Comprehensive Safety Management System Must be Implemented

1. Enterprise safety system and accountability: Enterprises must establish an effective safety management system and clarify the responsibilities of personnel at all levels. In the Banan District accident, the enterprise's safety system was ineffective and accountability was lacking, resulting in safety measures being mere formalities.
2. Worker training and briefing: All workers must receive safety education and skill briefings to familiarize themselves with the demolition process and risk points. In the accident, workers went on duty without training and had no awareness of the dangers of reverse-sequence operations, directly leading to operational errors.
3. Risk control and emergency preparedness: Projects need to conduct risk grading and hazard identification and develop emergency plans. In this accident, there was no risk assessment, no hazard identification records, and no emergency drills organized. The site supervisor blindly rushed the schedule, ultimately leading to the tragedy.
4. On-site command and management: Reverse-sequence operations or违规操作 (non-compliant operations) are strictly prohibited. The site supervisor should strictly monitor the process, and the company's main responsible person needs to establish a full accountability system to ensure the implementation of safety measures. In the accident, the site supervisor carried out reverse-sequence demolition to rush the schedule, and the company's responsible person failed to fulfill management duties, exposing the complete failure of the management chain.

III. Summary of Accident Lessons
The demolition of prefabricated slab houses should adhere to the principles of "compliant sequence and effective management". Any oversight in any link can trigger a chain reaction. Enterprises should regard safety as a lifeline and form a closed loop from system establishment, training, implementation, to supervision, avoiding sacrificing long-term safety for short-term interests.