While traditionally in the Middle East quay walls are designed as gravity type structures, a trend can be observed that more and more quay wall projects are being realised as steel driven retaining wall systems. This has proven to be attractive for various technical and commercial reasons, especially at relatively large retaining heights.
For large retaining heights, the anchored combi-wall system has become a common solution which is regularly applied in new quay projects. These combi-wall systems are generally anchored with a tie-back anchor system, or ‘dead-man’ placed in the soil at a distance behind the face of the wall. Although regularly used in Europe, and particularly in the Netherlands and Germany, where the combi-wall found its origin, the Müller Verpress (MV) anchoring system has not been used in the Middle East. However, at the moment the last MV piles are being driven in the Port of Fujairah OT2 project where they are part of a new 835-metre long quay wall with a retaining height of 23.6 metres.
In 2010 the Port of Fujairah decided to expand its marine Oil Terminal 2 (OT2) by realising two new berths capable of receiving VLCC size tankers. The facility was to be built as a continuous quay wall in order to allow flexible berth usage. For space constraint reasons and a fast track schedule, there was a preference to adopt a combi-wall retaining system. This imposed a practical challenge on the execution because the harbour basin had already been dredged to -18 metres and is being used for tanker maneuvers to the already operational oil terminal. Hence, reclaiming a temporary working platform was not feasible and all construction work needed to be done using floating equipment. For this practical reason the feasibility was investigated for alternative anchor systems that allowed backfilling after installation of the quay wall system. A traditional tie-back anchor system is placed in the backfill of the quay wall and can only be mobilised after filling has progressed up to the anchor level. Consequently the MV pile anchor was proposed in combination with a rock backfill.
The Müller Verpress pile
MV piles are …
To read the rest of this article download PDF