Prefabricated Slab House Accident in Zhongxian, Chongqing

On April 11, 2024, a prefabricated slab house in Fengshou Community, Guanba Town, Zhongxian County, Chongqing, experienced a floor slab fracture accident, resulting in 2 deaths and 3 injuries. The preliminary cause was identified as excessive temporary load accumulation on the second-floor slab.

Accident Overview

At around 12:00 PM on April 11, 2024, a three-story prefabricated slab house in Fengshou Community, Guanba Town, Zhongxian County, suffered a floor slab fracture. The ground floor of the house was used as a mahjong parlor, while the second floor served as a goods warehouse. During the accident, the second-floor slab fractured and collapsed due to excessive temporary load accumulation, exceeding the load-bearing capacity of the prefabricated slabs, resulting in severe casualties.

Accident Cause Analysis

Direct Cause: The temporary load accumulation on the second-floor slab exceeded its designed load-bearing capacity. Prefabricated slabs, as common early building components, typically have their load-bearing capacities determined based on their intended design uses (e.g., residential purposes). If, during actual use, the load type, distribution, or total amount exceeds the design values, brittle fractures may occur. In this accident, the second floor was used as a warehouse with temporary stacking of goods, leading to concentrated loads and possible dynamic impacts, causing instantaneous slab failure.

Indirect Causes:

1. Change in Building Use: The ground floor was used as a public space (mahjong parlor), while the second floor was converted into a warehouse. This change in use may not have undergone structural safety assessments, resulting in load distribution inconsistent with the design.
2. Structural Aging: If the prefabricated slab house was built earlier, it may suffer from material aging, connector corrosion, and other issues, further reducing structural safety.
3. Lack of Supervision: After the change in building use, it may not have been promptly reported to relevant departments or undergone reinforcement and renovation, lacking regular safety inspections.

Emergency Response and Subsequent Progress

After the accident, local residents spontaneously participated in rescue efforts. The county's emergency management bureau, housing and construction bureau, and other departments quickly conducted on-site response. The county government established a special task force to handle aftermath work. As of now, one injured person has been discharged from the hospital, while two others continue to receive treatment with no life-threatening conditions. The specific cause of the accident is still under in-depth investigation, but the preliminary conclusion has identified load overlimit as the direct cause.

Science Popularization Extension: Safety Precautions for Prefabricated Slab Houses

1. Avoid Overloading: The designed load capacity of prefabricated slabs is limited. Do not arbitrarily stack heavy objects or change the use, especially converting residential spaces into high-load scenarios like warehouses.
2. Regular Inspection and Maintenance: For old prefabricated slab houses, regularly inspect for slab cracks, connector corrosion, and other issues. Reinforce as necessary.
3. Compliant Renovation: If changing the use of the house, commission a professional institution to assess structural safety and handle relevant procedures in accordance with the law.