Coastal and Floodplain Construction Inspector's Practice Exam

What is the minimum depth for pile tip penetrations in erodible soils?

1. 5 feet below the mean water level.

2. 10 feet below the mean water level.

3. 15 feet below the mean water level.

4. 20 feet below the mean water level.

The correct answer is: 10 feet below the mean water level.

The minimum depth for pile tip penetrations in erodible soils is established to ensure that the piles are anchored securely and resistant to potential undermining or lateral movement caused by erosion, especially in coastal or floodplain areas. A depth of 10 feet below the mean water level is generally considered sufficient for this purpose, as it allows for the anchoring of the piles below the zone of significant soil disturbance and erosion impacts. This provides a stable foundation while taking into account potential fluctuations in water levels and soil conditions. In contrast, options providing greater depths, such as 15 feet, 20 feet, or even 5 feet, may not align as well with engineering practices or local regulations, which emphasize a balance between sufficient anchorage and economic feasibility in construction. The chosen depth of 10 feet has been derived from a combination of empirical evidence and engineering judgment to provide a safe and effective foundation in navigating the risks associated with erodible soils.