For the Suction Piles Supporting Subsea Equipment
- Note: Development of project-specific design tolerances are recommended for suction piles supporting subsea equipment because the requirements for different packages of subsea equipment vary.
- The effects of design tolerances and pile deflections under design and operational loads should be explicitly considered in evaluation of (a) pile capacity, and (b) stresses on jumpers, connectors, flowlines, and structural components.
- In the absence of project-specific guidance, the following design tolerances should be taken into account in determining loads and sizing suction piles supporting subsea equipment:
- Inclination: ±3 degrees.
- Orientation (heading): ±5 degrees.
- Embedment: 5 feet less than targeted.
- Erosion: 5 feet local erosion (piping, plowing, or scour) with full embedment.
- Position: 5 feet from targeted position.
The initial elastic settlement of foundation pile should not exceed 3 inches due to elastic compression of pile and soil system under submerged weight of subsea equipment that is installed atop support pile.
In lieu of more stringent equipment requirements, long-term consolidation settlement of suction piles supporting subsea equipment should not exceed 3 inches.