Interpretation of Anti-Settlement Design Code for Crude Oil Tank Foundations in Coastal Areas

Anti-settlement design of crude oil tank foundations in coastal areas should follow API 650 standards, focusing on soft soil foundation treatment and ring wall foundation structure design. The bearing capacity of the foundation should be determined through geological surveys, and gravel piles or concrete cast-in-place piles should be used for reinforcement. The settlement amount should be controlled within 0.1% of the tank diameter. The top surface of the foundation should be more than 2 meters above the groundwater level and a waterproof and oil-resistant layer should be installed to prevent capillary water erosion.

Actual case studies show that after a coastal refinery adopted a composite foundation (pile + sand cushion), the settlement of a 150,000 m³ tank was only 12mm, far below the specified limit (150mm). Key parameters include: pile foundation depth ≥ 20 meters, concrete strength above C30, ring wall width ≥ 1.5 times the tank wall thickness. Dynamic monitoring systems (such as hydrostatic leveling instruments) can provide real-time early warning of uneven settlement, with error controlled within ±2mm.

A technical challenge lies in the risk of foundation liquefaction in tidal zones, which requires the addition of drainage boards or vacuum preloading processes. Future trends will move towards intelligent monitoring (such as fiber optic sensing) and adaptive foundations (hydraulic leveling) to ensure the stability of tanks under extreme conditions such as typhoons and earthquakes.