Deep-Sea Quay Wall for Offshore Wind Energy Terminal on Maasvlakte 2 Rotterdam

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The paper describes foundation works for the SIF offshore wind-energy terminal at Maasvlakte II, Rotterdam, completed in 2016. Its 480-metre deep-sea quay wall was built as a steel “combi wall,” combining 145 open-ended casing piles (1,420 mm diameter, 32–37 m long) with triple PU28 sheet piles. The wall was supported by 113 long, raked HEB 600 steel piles injected with grout.<br /><br />The reclaimed site’s challenging ground conditions made pile installation difficult. A driveability assessment using CPT data predicted that a PVE 110 M vibratory hammer could install the casing piles to about 24 m below the working level. Crews then used a Delmag D-160 diesel hammer to drive them to their final depths. Monitoring during installation showed that the prediction was reliable; final diesel-hammer blow counts of 34–40 per 25 cm indicated adequate driving energy.<br /><br />Sheet piles were installed between the casings using a PVE 2350 VM vibratory hammer. Waterjetting, which had worked on nearby projects, was ineffective because of high pore-water pressures in the recently reclaimed soil. The contractor adapted by pre-drilling to 15 m and adding bentonite to reduce soil friction and assist driving.<br /><br />The project demonstrates how combining driveability prediction, monitoring, and adaptable construction methods enabled successful piling despite variable soil conditions. The authors conclude that future projects should consider predicting sheet-pile driveability as well as casing-pile driveability, and that systematic monitoring can provide valuable information for construction planning.

Keywords

offshore wind terminal

foundation works

combi wall

steel sheet piles

casing piles

driveability assessment

vibratory hammer

diesel hammer

grout-injected piles

pile installation monitoring