Prefabricated Panel Houses After Earthquakes
After earthquakes, traditional prefabricated panel houses often suffer severe damage or even collapse, but the improved prefabricated steel structure systems have significantly enhanced their seismic performance.
The seismic deficiencies of traditional prefabricated panel houses are mainly reflected in their structural design and material properties. Their floors are assembled from prefabricated concrete components, and their walls are mostly made of brick or lightweight materials, resulting in poor overall integrity. Under seismic action, the connection joints of prefabricated components are prone to loosening or breaking, causing floor collapse; the load-bearing capacity of the walls is limited, making it difficult to resist horizontal seismic forces, and cracks, tilting, or even collapse often occur. For example, in the 5.2-magnitude earthquake in Liuzhou, Guangxi, most of the severely damaged houses were prefabricated panel houses; after the earthquake in Gaoxian, Sichuan, some self-built houses of villagers with prefabricated panel structures experienced partial collapse, roof cracking, wall cracks, and tile shedding. These cases indicate that the seismic resilience of traditional prefabricated panel houses is insufficient to meet modern seismic design requirements.
The improved prefabricated steel structure systems have significantly enhanced their seismic performance through technological innovation. Taking the "Post-earthquake Restorable Rapid-assembly Multi-story Prefabricated Steel Structure System" as an example, its prefabrication rate can reach over 90%, adopting key technologies such as replaceable buckling-restrained beam-column joints and energy-dissipating elements with buckling-restrained braces. The replaceable joints are specially designed to undergo plastic deformation preferentially during earthquakes, consuming seismic energy and protecting the main structure from damage; the energy-dissipating elements further disperse seismic forces and reduce structural damage through the reciprocating deformation of buckling-restrained braces. After an earthquake, only the damaged energy-dissipating elements or joints need to be replaced to quickly restore the building's functionality, with short repair times and low costs. This system not only improves the seismic capacity of the structure but also achieves the seismic objectives of "no damage under minor earthquakes, repairable under moderate earthquakes, and non-collapse under major earthquakes," providing technical support for rapid post-earthquake reconstruction.
The seismic problems of traditional prefabricated panel houses stem from their poor structural integrity and insufficient material toughness, while the improved prefabricated steel structure systems effectively solve these problems through modular design, high-strength materials, and the application of replaceable energy-dissipating elements. In the future, promoting prefabricated building technologies with excellent seismic performance will be an important direction for enhancing the seismic capacity of urban and rural buildings.
