Hazard Factors of Prefabricated Panel Houses
The hazard factors of prefabricated panel houses mainly include the following aspects:
1. Extremely Weak Earthquake Resistance
Prefabricated panel houses have poor integrity. The connections between panels and walls, as well as between panels themselves, are mostly achieved through simple overlapping or filling, lacking reinforcement from rigid structures such as steel bars. During an earthquake, horizontal forces can easily cause the floor panels to separate from the walls instantly, leading to sudden collapse of the house. There is no warning from cracks or deformation buffering, leaving very little time for escape. In historical earthquakes, such houses have had high collapse rates and severe casualties, posing a major隐患 (hidden danger) in earthquake-resistant design.
2. Vulnerable Connection Points
Prefabricated panels are simply overlapped with walls, and the filling materials between panels are prone to aging. Moreover, they lack rigid framework support such as ring beams and structural columns. When the foundation settles or the walls crack, the panels are likely to become misaligned and loose. After long-term use, the connection points weather and the steel bars rust, significantly reducing their strength. After living in old prefabricated panel houses for two to three decades, the floor panels may become precarious, and even slight external forces (such as stacking heavy objects or knocking on walls) can trigger a chain collapse.
3. Widespread Substandard Materials
Some prefabricated panel production involves illegal operations: the diameter of steel bars is insufficient (some even use thin steel wires as substitutes), the concrete grade does not meet the standards, and the thickness of the panels is inadequate. This results in brittle materials with weak load-bearing capacity. When the design load is exceeded, the panels may suddenly break without any warning. Daily activities such as stacking heavy objects, renovation work involving floor pounding, or aging over time can all pose a risk of collapse.
4. Poor Sound Insulation and Thermal Insulation Performance
Prefabricated panel houses have thin walls and many gaps, resulting in poor heat insulation in summer and thermal insulation in winter. Residents commonly report feeling "cold in winter and hot in summer." At the same time, the floor panels have weak sound insulation capabilities, and the sounds of neighbors' daily activities are clearly audible, seriously affecting living privacy and comfort.
5. Limited Internal Structure Modification
Unlike modern commercial houses, the walls of prefabricated panel houses mostly serve as structural supports. Large-scale modifications (such as removing walls or changing the layout) may damage the overall stability, making it difficult for residents to customize their living spaces according to their needs, resulting in low flexibility.
6. High Risk of Water Seepage
As the service life increases, cement components are prone to cracking, and the gaps between panels widen, allowing rainwater or domestic water to seep down to the lower floors, causing disputes among neighbors and accelerating the aging of the house structure.
7. Short Service Life
The design service life of prefabricated panel houses is usually 30-50 years. Most of them were built in the 1970s-1980s and are now approaching or have exceeded their service lives. Aging phenomena are common, such as roof leaks and wall cracks, which not only affect aesthetics but also threaten living safety.
