10.5 million cubic metres of sand for the new terminal back to The Construction Project
The construction of an approx. 1700-metre long quay in the Weser estuary demanded a carefully coordinated construction phase concept. It had to be ensured that the different works do not obstruct each other. Moreover time was pressing: the first 350-metre long berth should have been ready for use by the end of 2006.
After the soil replacement had been completed, pile driving began on 12 November 2004. The pile driver on the first jack-up platform installed the bearing piles, the driver on the second one installed the batter and intermediate piles. Working in the rhythm of the tides, the workmen immediately connected the batter piles to the sheet pile wall, before the area behind the sheet piling was filled in with sand to a level of 2.50 metres above mean seal level. As the foundation piles for the pier slab had been driven into place and concreting began, the equipment used on site and the number of workmen could be adjusted to match the work rate of the jack-up platforms.
Some 10.5 million cubic metres of sand had to be distributed over the Container Terminal 4 construction site. Some of that quantity was extracted from the Outer Weser fairway using hopper dredgers (maintenance work). The rest was taken from the River Jade or from a sand extraction site located roughly 15 kilometres north-east of the island of Wangerooge. Roughly 20,000 cubic metres were extracted every day.
Construction of the quay, backfilling and raising the terrain level were all executed simultaneously. The work proceeded from south to north. The top layer of approx. 25 centimetres was filled with sand obtained from sandpits near Bremerhaven, which was brought to the site by truck. This "dry" quarry sand was necessary as a basis for the next step, which involved stabilising the ground with a cement mortar mix.
The surfaces gave then a bituminous base course. Rainwater falling onto this area were collected in slotted channel drains and run off via gullies. It then flew through storm sewers into a central collection sewer, from where it is carried through the quay area and then runs off into the Weser.
The new crest of the enclosing dyke to the north was raised to a height of 8.50 metres above mean sea level. That figured corresponds to the total dyke height in Weddewarden and the district of Wursten to the north. The dyke consists of sand and a two-metre thick covering layer of marsh soil.
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