Design & Installation of Offshore Driven Piles - A Gulf of Thailand Regional Perspective-Paper

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The paper examines offshore driven-pile design and installation in the clay-dominated Gulf of Thailand and surrounding region. Driveability analysis is used to select pile dimensions, wall thickness, and hammer, assess installation feasibility, and establish acceptance criteria. Its accuracy depends heavily on uncertain soil inputs, particularly soil resistance to driving (SRD) and dynamic parameters.<br /><br />Using Smith’s wave-equation model and regional case studies, the paper investigates how clay remoulding, strength recovery after interruptions, and soil damping affect predicted blow counts. Continuous driving is represented by reduced clay skin friction, generally around 20–40% of static resistance. After short delays, resistance may recover to about 60%; after longer delays, it may approach the full static value. Sand resistance is generally not degraded. Field records support these assumptions and show that clay skin damping strongly influences predictions at clay-dominated sites.<br /><br />For Gulf of Thailand clay, a skin-damping value of approximately 0.2–0.3 seconds per metre is considered suitable when site conditions are well defined. Values based on clay consistency, such as Roussel’s recommendations, may also be used cautiously. Predictions are less sensitive to damping in sand-dominated soils.<br /><br />Hammer selection should balance efficient penetration with pile-damage prevention. A larger hammer operated at lower drop height is generally preferable to a smaller hammer at higher drop height, while hammer efficiency should be controlled to avoid excessive run-down and overstressing.<br /><br />Overall, the paper recommends using regionally calibrated soil parameters, considering both continuous and delayed driving conditions, and minimizing installation delays. Careful modelling and field monitoring improve pile design, hammer selection, and confidence in pile acceptance criteria.

Keywords

offshore pile design

driveability analysis

Gulf of Thailand

clay remoulding

soil resistance to driving

Smith wave-equation model

skin damping

hammer selection

pile installation

blow count prediction