Collapse of Prefabricated Panel Houses in Earthquakes

Prefabricated panel houses are prone to collapse during earthquakes, mainly due to their poor structural integrity caused by the construction method. The specific reasons are as follows:

Construction method similar to 'building blocks', with poor fixing effect

The construction method of prefabricated panel houses involves extending steel bars from both ends of the prefabricated floor slabs and directly placing them on the walls. Although a small amount of concrete is poured for fixing, this fixing method is basically ineffective under the intense shaking of an earthquake. For example, in the 5.2-magnitude earthquake that occurred in Liuzhou, Guangxi, in the early morning of May 18, 2026, most of the 13 collapsed buildings were old prefabricated panel houses. The fixing method of the prefabricated panels in these houses could not withstand the impact of wall cracking during the earthquake, causing the floor slabs to be easily thrown off from the weakly fixed ends.

After wall cracking, floor slabs are easily thrown off, triggering a chain collapse

During an earthquake, once the walls crack, the heavy prefabricated panel floor slabs will be directly thrown off from the walls due to poor fixing and crash into the lower structures. This chain reaction will cause the entire building to collapse layer by layer from top to bottom like dominoes, and the occupants often do not have time to escape. In the Liuzhou earthquake, the collapse of many prefabricated panel houses was precisely due to the overall collapse triggered by the throwing off of the floor slabs.

Comparison with cast-in-place houses: strong structural integrity and excellent seismic performance

Unlike prefabricated panel houses, cast-in-place houses are constructed by directly binding steel bars, setting up formwork, and pouring concrete into a whole on the construction site, forming a solid structural body consisting of floor slabs, beams, and columns. This design with strong structural integrity enables the various parts of the house to bear forces and deform together when an earthquake occurs, dispersing the energy and thus avoiding local collapse. For example, in the Liuzhou earthquake, houses built using the full cast-in-place process remained intact, while a large number of prefabricated panel houses collapsed, fully demonstrating the seismic advantages of cast-in-place houses.