What is the minimum depth to which pile tips must extend in coastal and flood plains?

The correct answer is that pile tips must extend to a minimum depth of 8 feet in coastal and flood plains. This requirement is established to ensure that the piles are adequately embedded into the ground to provide sufficient support and stability for structures built in these areas. The 8-foot depth helps to reach below the potential effects of soil saturation, erosion, and other environmental factors that can compromise structural integrity in coastal and flood-prone regions. By adhering to this minimum depth, engineers and builders can account for the variable soils and conditions present in those environments, thus reducing the risk of structural failure due to shifting or settling.