For a building located in a coastal high hazard area, what is the preferred foundation type?

In a coastal high hazard area, the preferred foundation type is the pile-supported foundation. This type of foundation elevates the building above potential flood levels and provides substantial stability in the event of wave action, storm surges, or soil erosion. Piles penetrate through the unstable or saturated soil layers to reach more stable soils or bedrock, which enhances the overall structural integrity of the building in such challenging environments.

Pile-supported foundations are specifically designed to withstand the lateral forces that can arise from flooding or heavy winds, making them suitable for areas subject to severe weather events. Additionally, they minimize the risk of water damage by keeping the building structure elevated above the highest expected flood level.

Other options, such as concrete wall foundations or slab-on-grade foundations, may not offer the necessary protection or stability against the dynamic forces present in coastal high hazard areas. Additionally, heavily compacted fill can settle or wash away, which poses risks during flood events. Therefore, the pile-supported foundation is the most effective choice for ensuring safety and resilience in coastal construction.