What is the maximum particle size permitted below 24 inches in an embankment?

What is the maximum particle size permitted below 24 inches in an embankment?

• A. Not to exceed 6 inches or compacted thickness of the layer, whichever is less
• B. Not to exceed 12 inches or compacted thickness of the layer, whichever is less
• C. Not to exceed 18 inches
• D. Not to exceed 24 inches

Answer: (B)

In embankment fills, controlling how large the particles can be in a layer is key to getting stable, well-compacted material. If a layer is placed below a depth of 24 inches, the largest particle size must be limited to ensure the material can be spread and compacted evenly, avoiding bridging and voids that would weaken the fill. The rule means: pick the smaller of the layer’s compacted thickness or 12 inches. If the layer is thicker than 12 inches, you cap the particle size at 12 inches. If the layer is thinner than 12 inches, you cap it at the actual layer thickness. This guarantees that the material can be properly compacted with standard equipment and creates a uniform, stable embankment. Therefore, the permitted maximum particle size is not to exceed 12 inches or the compacted thickness of the layer, whichever is less.

In embankment fills, controlling how large the particles can be in a layer is key to getting stable, well-compacted material. If a layer is placed below a depth of 24 inches, the largest particle size must be limited to ensure the material can be spread and compacted evenly, avoiding bridging and voids that would weaken the fill.

The rule means: pick the smaller of the layer’s compacted thickness or 12 inches. If the layer is thicker than 12 inches, you cap the particle size at 12 inches. If the layer is thinner than 12 inches, you cap it at the actual layer thickness. This guarantees that the material can be properly compacted with standard equipment and creates a uniform, stable embankment.

Therefore, the permitted maximum particle size is not to exceed 12 inches or the compacted thickness of the layer, whichever is less.