Earthquake Resistance of Brick Prefabricated Panel Houses

The overall earthquake resistance performance of brick prefabricated panel houses is relatively poor, and their seismic capacity is significantly influenced by factors such as the construction era and structural reinforcement measures.

Earthquake Resistance Characteristics

Prefabricated panel houses use prefabricated hollow floor slabs and brick-concrete structures, with weak integrity and insecure connections between components, similar to a 'jigsaw puzzle' structure. This design leads to issues such as the detachment of prefabricated panels and the collapse of staircase walls during earthquakes. For example, during the 2008 Wenchuan earthquake, a high proportion of such houses collapsed, exposing their seismic deficiencies.

Differences in Seismic Resistance Grades

• Old houses built before the 1980s: They have low seismic standards and can typically only withstand earthquakes of magnitude 6 (equivalent to the weaker destructive force in a magnitude 6 earthquake), making it difficult to cope with strong earthquakes.
• Newly built prefabricated panel houses: The seismic standard has been raised to magnitude 7, but it is still lower than that of cast-in-place reinforced concrete structures, with limited safety.
• After structural reinforcement: By adding steel bars, pouring concrete, installing seismic isolation bearings, or using high-ductility cement, the seismic capacity can be increased to magnitude 7, significantly enhancing safety.

Key Factors Affecting Seismic Resistance

• Building height: Houses with fewer than 6 floors are safer than high-rise buildings. Beijing stipulates that prefabricated panel houses must not exceed 12 floors to reduce the risk of collapse.
• Structural type: Frame structures are superior to brick-concrete structures, as the latter has fragile walls like 'cookies' that are prone to crushing damage during earthquakes.
• Foundation: Deep excavation of the foundation or pile driving can enhance stability and reduce structural damage caused by foundation settlement.

Renovation and Governance Paths

• Identified as Grade C dilapidated houses: Walls, beams, columns, and floor slabs need to be reinforced, and seismic upgrades should be carried out. The central budget supports renovation projects, with subsidies not exceeding 70% of the total investment.
• Renovation of old residential areas: Houses identified as Grade A or B can improve living conditions through roof repairs, pipeline replacements, elevator installations, etc. (For example, 379 elevators were installed in Yangzhou during the '14th Five-Year Plan' period).
• Expropriation and demolition: Houses can only be legally demolished when they are included in urban renewal or public facility projects.

Recommendation: Residents should confirm the safety appraisal grade of their houses, understand local renovation plans, clarify property rights, and negotiate renovation意愿 (renovation willingness) with neighbors. If the house has insufficient seismic resistance, they can prioritize applying for government subsidies for reinforcement to reduce earthquake risks.