Earthquake Resistance of Prefabricated Panel Houses
The earthquake resistance of prefabricated panel houses is generally weak, and their seismic capacity is significantly influenced by the construction era, structural type, and construction quality.
I. Differences in Earthquake Resistance of Prefabricated Panel Houses Across Different Eras Prefabricated panel houses built in the 1970s and 1980s had relatively low seismic standards, with designs only requiring resistance to magnitude-6 earthquakes. These houses mostly adopted hollow prefabricated panels and brick-concrete structures, with the panels and columns loosely connected by steel bars. During earthquakes, individual components were prone to independent shaking, leading to overall structural instability. Most of the collapsed houses in the Wenchuan earthquake were of this type. Prefabricated panel houses built after 2000 incorporated pre-stressed technology, theoretically capable of withstanding magnitude-7 to magnitude-9 earthquakes. However, their actual seismic capacity highly depends on construction quality. If steel bar joints are not firmly welded, concrete strength is insufficient, or there is shoddy workmanship, the seismic performance may be directly halved.
II. Current Seismic Conditions of Prefabricated Panel Houses in Different Regions Among brick-concrete houses built in urban areas before 2000, some use hollow prefabricated panels and have weak seismic capacity. In rural areas, there are still a large number of earth-wood and brick-wood structures lacking necessary seismic structural measures. Self-built simple houses in urban villages, urban-rural fringe areas, and areas pending demolition basically lack seismic capacity due to the absence of formal design and construction. These houses are prone to overall collapse or severe local damage during earthquakes.
III. Seismic Reinforcement and Renovation Measures For old prefabricated panel houses, technical means such as external steel plate bonding, adding shear walls, or carbon fiber cloth reinforcement can be used to enhance seismic capacity, typically allowing them to withstand 1-2 additional magnitudes of earthquakes. However, it should be noted that if the house is located in a high-intensity earthquake zone with a magnitude of 8 or above, even after reinforcement, there may still be safety hazards, and a professional assessment is required to decide whether to demolish and rebuild. Since 2022, China has implemented a policy of renovating old buildings, focusing on repairing and renovating prefabricated panel houses, and only demolishing buildings that meet the criteria for dangerous houses. The focus is on solving problems such as house leakage and pipeline aging, indirectly improving seismic safety.
