Davy Spriet is project manager for the civil works and Dominic De Prins is project manager for the dredging works. Together, they manage the overall project on site. Dominic De Prins explains the construction procedure: “The new quay wall will…Read more
The word ‘wall’ may in fact be misleading. The quay is built on five rows of piles over the 800 metre length on which a 35 metre wide concrete platform is built, consisting of large concrete prefabricated elements placed as tiles onto the 614 piles with an in-situ reinforced concrete topping slab.
A crucial and significant part of the job is installing foundation piles, this is executed by Soetaert, a new member of Jan De Nul Group since 2015. Eric Leemans, Technical Commercial Director at Soetaert, explains that this is Soetaert’s first project outside Europe. “The main difference is that we must plan way further ahead. You just cannot intervene equally fast when you’re a couple of hundred miles from your site. But thanks to the talent and commitment of our employees and with Jan De Nul’s support, we have made it a success.”
The pile wall consists of 375 piles installed according to a simple execution method and 186 piles, the installation of which was much more complex and involved the installation of a temporary casing and a permanent tubular pile. On site, the Portuguese Ricardo João Almeida is responsible for the installation of the piles. “First, we place a temporary casing about 12 to 17 metres into the ground. We then drill into that temporary casing, down to the rock. When reaching the rock, we change the diameter and continue drilling until we reach the bottom of the casing. At that moment, we install the permanent pile and remove the temporary casing. We then clean up the bottom of the pile, install the reinforcement cages and pour concrete into the pile.”
The piles are 27 to 35 metres long and will protrude up to 4 metres above mean sea level. So we have to drill quite deep into the water and the soil to install the piles. “The soil in which we drill is very diverse. In some places, the bottom is soft: sand or clay. In other places, we are faced with basalt, which is harder than granite. Because of the great variety in soils, each pile that we drill may be completely different. That makes the installation process very complex”, concludes Ricardo.
For this project, Jan De Nul built its own concrete batching plant on the spot. We had to do this to be able to meet the strict quality requirements of the contract that could be impacted when using local ready-mix concrete suppliers, due to traffic…Read more