Container House Foundation Methods

The foundation methods for container houses need to be comprehensively designed according to the usage scenario, soil conditions, and house type. The core principle is to provide a uniform load-bearing foundation and prevent uneven settlement. Here are the specific methods and key points:

I. General Principles for Foundation Treatment

1. Ground Leveling and Compaction
   Remove loose soil and debris from the ground surface and compact the original soil layer until there are no obvious soft areas. If the soil is soft soil, backfill soil, or silt, it should be replaced with sand or graded crushed stone and compacted in layers until the bearing capacity meets the standard (usually ≥150kPa).

2. Moisture Prevention and Drainage
   The top of the foundation should be at least 150mm higher than the surrounding ground to prevent rainwater from flowing back. For long-term usage scenarios, it is recommended to set a drainage slope with a gradient of ≥2% and dig drainage ditches around the foundation.

II. Foundation Solutions for Different Types of Container Houses

1. Temporary Usage Scenarios (e.g., Construction Site Dormitories)

   • Folding/Fixed Container Houses: Place them directly on a leveled ground or pour a 100-150mm thick C15 concrete cushion.
   • Packing Container Houses: No foundation may be required, but the ground flatness error should be ≤10mm. If reinforcement is needed, a strip foundation (width 30-50cm, depth determined according to the frost line) can be used.

2. Long-term Fixed Usage Scenarios (e.g., Residences, Offices)

   • Concrete Strip Foundation:
     • The width is recommended to be 30-50cm, and the depth should penetrate the soft soil layer to the hard soil layer (usually ≥0.5m, and in cold regions, it should go below the frost line).
     • The horizontal error of the foundation top surface should be ≤5mm, and pre-embedded bolts or steel plates should be used to fix the bottom beam of the container.
   • Independent Pile Foundation:
     • Suitable for soft soil foundations or slopes, using reinforced concrete piles (diameter ≥300mm, depth ≥1.5m), with a pile cap poured at the top to connect the container.
   • Raft Foundation:
     • Pour a reinforced concrete slab as a whole (thickness ≥200mm), suitable for scenarios with complex geology or high load requirements.

III. Key Construction Points

1. Soil Investigation: Before construction, the soil bearing capacity should be tested. Soft soil foundations require replacement or pile foundations.
2. Foundation Curing: After concrete pouring, it should be covered and kept moist for curing for ≥7 days, and the container can be installed only when the strength reaches more than 75%.
3. Fixed Connection: The bottom beam of the container and the foundation should be fixed with expansion bolts or welding to prevent sliding or overturning.
4. Corrosion Prevention: The foundation reinforcement should be painted with anti-rust paint, and anti-seepage agents (such as UEA expansion agent) should be added to the concrete to improve durability.

IV. Treatment for Special Scenarios

• Slope Foundations: Use stepped foundations or the cut-and-fill balancing method to ensure that the container is placed horizontally.
• High-humidity Areas: Lay a 300mm thick crushed stone cushion at the bottom of the foundation and set a moisture-proof layer (such as a two-fabric-one-membrane composite geomembrane).
• Seismic Requirements: Add diagonal braces or shock absorbers at the connection between the foundation and the container, and configure anti-crack reinforcement in the concrete.