CONSTRUCTION | ARCHITECTS | Earthmoving and Embankment Construction

Earthmoving and machines

Earth moving and Embankment Construction: Key Considerations

Site Preparation and Material Requirements

For successful embankment construction, the land must be adequately prepared. The embankments should be constructed on land that has been cleared of any vegetation, and where topsoil, silt, or loose soil that cannot be compacted has been removed. 
The materials used for the embankments should meet the specific requirements of the project, including:

- Particle Size: Materials must be of a suitable size for compaction.
- Plasticity: The materials should have the correct plasticity characteristics to ensure stability.
- Strength: The materials should possess sufficient strength to support the load.

Embankment Construction and Compaction

Embankments must be built in layers, with each layer having a thickness designed to ensure adequate compaction. The following guidelines should be adhered to:

- Layer Thickness: Each layer should be thick enough to allow for proper compaction.

- Density Requirements: Specifications typically set the minimum required density as a percentage of the maximum density at optimum moisture content. This minimum must be consistently achieved across the entire embankment. 

- Uniformity: The uniformity of the embankment, especially in road construction, is critical. Any areas that do not meet the specified density standards should be reconstructed.

Before laying the first layer of material, the surface of the embankment should be prepared as follows:

- Scarification: The seating surface should undergo scarification to a depth of 30 cm to break up the soil and improve compaction
.
- Compaction: After scarification, the surface must be compacted to achieve a minimum density of 85%.

Compaction Guidelines

Compaction is a critical process for ensuring the stability and durability of the embankment. The following guidelines should be followed:
- Layer Thickness: 
  - Layers should not exceed 30 cm in thickness for initial compaction.
  - The uppermost layers should not exceed 15 cm in thickness.
  
- Compaction Equipment: The compaction equipment used must be appropriate for the soil type. It should apply the necessary pressure to achieve the desired density.
- Test for Minimum Passes: A test should be conducted to determine the minimum number of passes required by the compaction equipment to reach the desired density.

Quality Control and Testing

Quality control is essential to ensure the embankment meets the required standards. The following testing procedures should be carried out:
- Quality Tests:  
  - Tests should be conducted before 24 hours have passed after compaction.
  - For road construction, three tests should be conducted every 100 meters along the centerline, right side, and left side of the embankment.
  - For truck parking areas, three tests should be conducted every 1000 m²

Role of the Work Inspector

The work inspector plays a key role in ensuring the embankment construction meets the project specifications. The inspector's responsibilities include:

1. Verification of Material and Soil Conditions

- Removal of Topsoil: Ensure that all topsoil has been properly removed from the construction site.

- Soil Type Compliance: Verify that the soil provided for embankment construction matches the specifications outlined in the soil study.

2. Monitoring Compaction and Identifying Weak Areas

- Observing Compaction Behavior: Watch the behavior of the embankment during the compaction process to identify weak areas. If weak spots are observed, they should be marked for further attention.

- Recompaction of Weak Areas: Weak areas must be excavated, replaced with suitable material, and recompacted to ensure homogeneous support for the embankment.

3. Thickness Control and Testing

- Layer Thickness: Carefully monitor the thickness of each compaction layer. If the required compacted thickness is 30 cm, the loose soil layer should be approximately 30% thicker, i.e., 39 cm.
  
- Proctor Test: Control and supervise the Proctor test to ensure the compaction meets the required standards.

Conclusion

Embankment construction involves a detailed process of site preparation, material selection, layering, and compaction to ensure the stability and strength of the structure. Adhering to these specifications and performing rigorous quality control tests are essential for achieving the desired results.
The role of the work inspector is crucial in maintaining compliance with the project requirements and ensuring the embankment's uniformity and stability throughout the construction process.