The ECT Delta Terminal, situated at the Amazonehaven in the Port of Rotterdam, was designed to receive 7000 TEU container ships. In order to upgrade the terminal for ships of 18,000+ TEU, the width of the basin had to be increased by 55 m from 255 to 310 meters.

The most optimal cumbined wall design

The first part of the project (sections A1 and A2) began in 2010 and consisted of a 900 m long new quay wall, including both dredging works and the demolishing of the existing quay wall. After tender, the Design and Construct contract was awarded to the combination Besix-Van Oord. Together with ArcelorMittal, the reference design of the tubular combined wall was partly redesigned from a Ø1524mm solution into a solution with Ø1420mm stock pipes. The tubular piles were further optimised by segmenting the piles into different thicknesses, placing the thickest material in the sections with the highest bending moments.

In other parts of the quay wall, where extra demands were given regarding the deflection, the initial solution was redesigned in a more optimal Ø1580 x 17 mm solution, which was produced at ArcelorMittal's spiral mill in Heijningen. Both the tubular piles and infill sheets were installed using vibratory hammers. An impact hammer was used to deepen the tubes over the last few meters, generating a sand plug to increase the bearing capacity. In view of minimizing the possibility of declutching, the sheet piles were equipped with interlock guiders and a monitoring system. The installation of the infill sheets was facilitated by water jetting.

As cathodic protection was foreseen for the rest of the quay wall in the form of aluminium anodes, extra care was taken to isolate the test sections from the rest of the quay wall. In total, three transition points were defined; two between the test section and the rest of the quay wall and one between the AMLoCor™ section and reference section; for which insulation piles were foreseen. The entire test section was then divided into four subsections of 37.14 meters; three in AMLoCor™ and one in normal carbon steel as a reference; each closed off by a separate concrete cap to ensure electrical insulation.

To accommodate for the corrosion measurements in total, nine measu­ring boxes were welded respectively at the back of the infill sheets and inside the tubes and spread out evenly over the length of the test section. While the AMLoCor™ material itself was delivered directly to the Port Authorities, the installation and the detailed engineering of the test section were incorporated in the tender for section A3.

During the execution, the design of transition points changed into three grouting columns to provide more guarantees regarding the electrical isolation between the different sections. These grouting columns were designed by MOS Grondmechanica and eventually executed by Smet-Keller.

In March 2014 the new quay wall with accompanying dredging works was completed and in the same month, the first corrosion measuring campaign at the test section took place. For a period of five years, these measurements were repeated on a yearly basis.