Prefabricated Slab House Collapse Cases

Cases of prefabricated slab house collapses are often related to overloading, improper construction, structural aging, and external triggers. Here are specific case analyses:

1. Overloading Leading to Brittle Fracture
On April 11, 2024, a three-story prefabricated slab house in Zhong County, Chongqing, experienced brittle fracture and collapse of the second-floor slab due to temporary stacking of goods that exceeded the design load-bearing capacity of the prefabricated slabs. Such accidents are common in buildings where the ground floor is used as a shop and the upper floors as warehouses. Prefabricated slabs are brittle materials sensitive to concentrated loads, and overloading can easily trigger sudden fractures. The accident resulted in 2 deaths and 3 injuries, highlighting the importance of load management.

2. Improper Construction Sequence Leading to Overturning
On May 22, 2024, during the renovation of a dilapidated building in Banan District, Chongqing, demolition workers failed to first remove the balcony railings on the outer side of the cantilever beams and directly chiseled the cushion layer of the prefabricated slabs, causing a change in load distribution. The cantilever beams, with reduced outer loads, experienced an overturning moment exceeding the anti-overturning moment, leading to the collapse of the prefabricated slabs and personnel. The accident resulted in 1 death and 3 injuries, with direct economic losses of 882,000 yuan, reflecting the critical impact of construction sequence on structural stability.

3. Structural Aging Combined with External Triggers
On August 19, 2026, an old prefabricated brick-concrete structure building from the 1980s in Shijiazhuang collapsed due to a gas leak explosion. The building had poor integrity and weak earthquake resistance. The explosion was merely a trigger, with the root cause being structural aging leading to brittle failure. The accident resulted in 3 fatalities, exposing the serious deficiencies of old prefabricated slab houses in terms of earthquake and explosion resistance, necessitating regular inspections and reinforcements.

4. Water Accumulation Leading to Subsidence
A house in Hubei experienced subsidence as the prefabricated floor was soaked by long-term water accumulation, softening the foundation and causing 4 people to fall into a nearly 2-meter-deep basement water area. The connection points between the prefabricated slabs and the walls are prone to loosening due to water corrosion, triggering local subsidence. Although there were no casualties, it serves as a warning to promptly inspect the drainage system to prevent water damage to the structure.

Prevention Recommendations:

• Strictly control the load on prefabricated slabs and avoid concentrated stacking of heavy objects;
• Follow the principle of 'support first, remove later, and balanced unloading' during construction and renovation;
• Regularly inspect the structural integrity of old prefabricated slab houses and reinforce them if necessary;
• Strengthen drainage maintenance to prevent water erosion of the foundation.