Prefabricated Slab Fracture and House Collapse
The collapse of houses caused by prefabricated slab fractures is mainly triggered by factors such as overload, improper construction, and foundation impact.
Overload: When the load borne by a prefabricated slab exceeds its designed load-bearing capacity, it is prone to fracture. For example, on April 11, 2024, in the Fengshou Community, Guanba Town, Zhong County, Chongqing, a house collapsed. At noon that day, due to the temporary accumulation of loads on the second-floor slab exceeding the load-bearing capacity of the prefabricated slab, the slab underwent brittle fracture and fell, ultimately resulting in 2 deaths and 3 injuries. This indicates that during actual use, if the load-bearing capacity of the prefabricated slab is underestimated and loads are increased arbitrarily, the risk of house collapse will be significantly increased.
Improper Construction: Non-standard construction operations can undermine the structural stability of prefabricated slabs, leading to house collapse. The collapse incident in Dongwenquan Town, Banan District, Chongqing, on May 22, 2024, serves as a typical case. During the demolition of structures above the second-floor cantilever beams, the demolition workers followed an incorrect sequence. Instead of following the previous sequence of first removing the walls and then chiseling and cleaning the prefabricated slab floors, they proceeded to chisel and clean the floor cushions and slab joints of the second-floor prefabricated slabs before the brick railings on the outer balconies of the cantilever beams were fully removed. This reduced the load on the prefabricated slabs, causing the overturning moment outside the cantilever beams to exceed the anti-overturning moment inside, ultimately leading to the overturning of multiple prefabricated slabs and personnel to the ground, resulting in 1 death, 3 injuries, and direct economic losses of approximately 882,000 yuan.
Foundation Impact: The stability of the foundation is crucial for house safety. If the foundation is damaged or affected, it can cause uneven stress on the prefabricated slabs, leading to fractures. On May 27, 2024, Building 48 in Longyuan Community, Datong Town, Suburban District, Tongling City, Anhui Province, collapsed. This house, built in 2001 with a brick-concrete prefabricated slab structure, was initially analyzed by experts to have possibly collapsed due to the foundation being soaked by heavy rainfall, indicating that external factors affecting the foundation can indirectly lead to prefabricated slab fractures and house collapse.
