What to Do if Prefabricated Houses Are Not Earthquake-Resistant

For prefabricated houses that are not earthquake-resistant, various reinforcement measures can be taken to improve their earthquake resistance. The specific methods are as follows:

Foundation Reinforcement

The foundation is the key support for a house's earthquake resistance and needs to be strengthened first. Increasing the foundation size can disperse the impact of seismic forces on the foundation; deepening the foundation can utilize the stability of deep soil layers to enhance earthquake resistance; installing a steel reinforcement mesh can strengthen the overall integrity of the foundation structure. Additionally, adding reinforcing agents or sealing materials to the foundation can fill pores, increase density, and further enhance the foundation's load-bearing capacity.

Structural Reinforcement

For key parts such as walls, stairs, and roofs, it is necessary to increase material strength to enhance overall stability. Installing steel beams, columns, and plates can form a rigid frame, enhancing the house's lateral force resistance; injecting reinforced concrete into the walls can transform brittle walls into ductile structures, significantly improving earthquake resistance. These measures increase structural redundancy, reducing the risk of overall collapse caused by local damage under seismic action.

Frame Reinforcement

Installing a metal frame on the exterior walls of the house can form a second line of earthquake defense. The frame is connected to the original structure through bolts or welding, effectively constraining wall deformation and enhancing overall stiffness. Using reinforcing agents or sealing materials at frame joints can reduce stress concentration and prevent connection failure during earthquakes.

Seismic Isolation Reinforcement

By introducing seismic isolation devices, the efficiency of seismic energy transfer can be reduced. Spring or rubber seismic isolators installed between the foundation and the structure can extend the structure's natural vibration period, avoiding the main frequency bands of seismic waves, thereby reducing horizontal and vertical seismic forces. Such devices can reduce seismic response by 50%-80% in moderate to small earthquakes, significantly protecting the safety of the superstructure.

Other Special Reinforcements

• Steel Reinforcement: Adding steel bars to walls, stairs, beams, and columns enhances structural ductility by increasing material tensile strength.
• Increasing Floor Slab Thickness: Pouring a ≥40mm thick reinforced concrete layer on the upper and lower surfaces of prefabricated floor slabs can enhance floor stiffness and load-bearing capacity, preventing continuous collapse caused by floor slab damage.
• Grouting Reinforcement: Injecting cement-based grout into cracks in walls or foundations can fill voids, restore structural integrity, and is suitable for repairing minor damage.
• Steel Mesh Reinforcement: Laying a steel mesh on the surface of walls or floor slabs and spraying concrete forms a composite structural layer, effectively inhibiting crack propagation.
• Steel Plate Bonding Reinforcement: Bonding steel plates to cracked walls or floor slabs with adhesives allows the plates to work in conjunction with the structure, quickly restoring load-bearing capacity.
• Adding Braces: Installing diagonal or cross braces on walls or roofs can change the structural load transfer path, enhancing lateral force stability.

The above measures should be selected based on the degree of house damage, structural type, and seismic design requirements. It is recommended to have a professional institution conduct a seismic assessment and then formulate a reinforcement plan to ensure the scientific validity and effectiveness of the measures.