Offshore Pile Ageing Study

GDG was commissioned by Horizon Geosciences to undertake a study for capacity reassessment of two stage driven and drilled and grouted piles that are supporting the Tie-in Platform of the existing GOSP2 and GOSP3 Gas-Oil Separation Plants in the Marjan Field north east of Saudi Arabia. The objective of the study was to develop a methodology for incorporating the effects of pile ageing into a pile reassessment calculation to determine whether the existing piles could safely sustain additional loads.

Scope of Work:

The scope of work for this report involves the following phases:

1. Review of all existing soil investigation data.

2. Review of all existing pile driving records.

3. Review of literature on soil ageing for clays and sands for both driven and drilled & grouted piles.

4. Presentation of report detailing a methodology to derive factors to apply to conventional pile design techniques to reflect alterations in capacity over time.

5. Presentation of those factors within a report for use by Horizon Geosciences in reporting at these two locations.

6. Presentation of a procedure for validation of the proposed methodology.