Probability of Collapse of Prefabricated Panel Houses
The probability of collapse of prefabricated panel houses is influenced by multiple factors, with the overall risk being significantly higher than that of cast-in-place structural houses, especially under earthquake or aging conditions.
1. Comparison of Overall Collapse Risk According to national accident statistics for 2023, the casualty rate due to collapse in prefabricated panel houses is 23 times higher than that in cast-in-place houses. This data indicates that under the same usage conditions, the structural safety of prefabricated panel houses is significantly lower than that of cast-in-place structures, with their overall collapse risk being at a high level.
2. Collapse Rate Under Earthquake Conditions Earthquakes are one of the primary triggers for the collapse of prefabricated panel houses. Shaking table tests conducted by the Institute of Engineering Mechanics, China Earthquake Administration, show that the failure probability of prefabricated panel joints under a magnitude 7 earthquake (equivalent to the intensity of the Tangshan earthquake) is as high as 82%. In actual earthquake cases, during the 2023 magnitude 5.5 earthquake in Pingyuan, Shandong, the collapse rate of prefabricated panel school buildings was 11 times that of cast-in-place frame structures; during the 2008 Wenchuan earthquake, the collapse rate of prefabricated panel houses was approximately twice that of cast-in-place floor houses. These data indicate that the collapse probability of prefabricated panel houses increases exponentially under earthquake conditions, with weak joint connections being a major defect.
3. Proportion of Hidden Dangers Under Normal Conditions According to safety appraisal data from the Ministry of Housing and Urban-Rural Development in 2024 for prefabricated panel houses, D-grade dilapidated houses (overall danger) account for 12%, and C-grade dilapidated houses (partial danger) account for 28%. This means that out of every 8 prefabricated panel houses, 1 is at risk of overall collapse, and out of every 3, 1 is at risk of partial structural danger. Such hidden dangers often stem from aging of the prefabricated panels, rusting of connectors, or construction defects, leading to the potential for structural failure and collapse even without external forces.
Conclusion The collapse probability of prefabricated panel houses is jointly influenced by structural type, earthquake intensity, and the degree of house aging. In non-earthquake zones, the collapse risk due to daily hidden dangers is approximately 12%-28%; in magnitude 7 earthquake zones, the collapse probability can rise to over 80%. It is recommended to regularly conduct structural safety appraisals and promptly reinforce or demolish C/D-grade dilapidated houses to reduce risks.
