Collapse of Prefabricated Panel Houses

The main causes of the collapse of prefabricated panel houses include structural defects, external triggers, and improper human operations, as analyzed in detail below:

1. Structural Defects: Insufficient Integrity and Seismic Resistance
Prefabricated panel houses often adopt brick-concrete structures, assembled by connecting prefabricated floor slabs to walls. Such structures inherently suffer from poor integrity: the connection between floor slabs and walls relies on local steel bars or mortar, lacking the continuous restraint of cast-in-place concrete, leading to uneven load transfer. For example, in the collapse incident of the Railway 55 Dormitory in Xinhua District, Shijiazhuang, a four-story prefabricated panel brick-concrete building constructed in the 1980s experienced brittle failure due to a gas explosion impact, exposing its weak seismic resistance—under lateral forces, prefabricated panels are prone to disengaging from walls, causing instant structural disintegration.

2. External Triggers: Environmental Factors Accelerating Deterioration
Long-term environmental effects can undermine structural safety. In the collapse incident of Tongling Longyuan Community, although the building underwent exterior wall renovation in 2020, its foundation was not reinforced. Heavy rainfall in 2024 led to foundation softening and uneven settlement, ultimately triggering a complete collapse. Additionally, overload is a common trigger: in the prefabricated panel fracture incident in Zhong County, the second-floor slab collapsed due to temporary stacking of heavy objects exceeding its design load capacity, resulting in casualties.

3. Improper Human Operations: Violations in Construction and Renovation
Violations during construction can directly lead to accidents. In the collapse incident in Dongwenquan Town, Banan District, Chongqing, workers failed to remove cantilever beams according to regulations during dilapidated building renovation, causing them to overturn and drag down prefabricated panels, revealing inadequate implementation of corporate safety production responsibilities. Similarly, if old building renovations focus solely on exterior renovation while neglecting structural reinforcement, potential risks may be concealed, as demonstrated in the Tongling Longyuan Community case.

Preventive Recommendations:

• Conduct structural safety assessments on old prefabricated panel houses, focusing on connection nodes, foundation settlement, and panel cracks.
• Prioritize reinforcement measures such as adding structural columns and ring beams or replacing floor slabs with cast-in-place concrete to enhance integrity during renovations.
• Avoid concentrating heavy objects on prefabricated panel floors and strictly control usage loads.
• Develop specialized plans before construction, strengthen safety training for workers, and ensure compliance with regulations during demolition and reinforcement processes.