'This is a brilliant home game'

"For Kandt BV, working on infrastructure project A16 Rotterdam is particularly fun," begins Marco Kandt, owner and director of the eponymous company. "The project is literally 'around the corner' from us. So this is a wonderful home game. For us personally, it is extra special because my family has its roots on the Rottekade. My father's parental home is literally 200 meters from the Rotte crossing." Kandt BV has been engaged as a subcontractor by the foundation combination Voorbij-Franki. Marco updates us on the work done.

Sheet piling pressing and vibrating

Kandt BV was involved in several disciplines in the project. Marco: "For us, the work started with pressing and vibrating sheet pile walls at the traffic circle in subarea 1, near the airport. This was followed by structure 52 in subarea 3, the Terbregseplein. During the 2020 construction holiday we spent 6 days non-stop founding a pillar of KW52a, partly working in height restriction due to the viaduct above. 'Working on a postage stamp' it was at times, in terms of space."

Deepest point of the Rottemer Tunnel

Starting in late 2020, Kandt BV placed LeKa grout injection piles at the deepest point of the tunnel. Marco explains, "Extra strong piles were required at the deepest point of the tunnel. We drilled on both land banks and in the water itself. The LeKa pile is a cast-in-situ, soil displacement concrete pile with permanent steel tube, which is screwed - in this case using grout injection - to depth. The structure of the pile consists of a steel tube fitted with a conical screw tip with grout casing. After installing the pile, a reinforcement cage is suspended in the tube pile and the tube is filled with concrete. A highly specialized job, not least because of the fact that the piles are all sunk below ground level/water and the head structures are ribbed. These ridges are incorporated into the underwater concrete, so the underwater concrete floor is directly secured to the piles."

Disused cast steel pipe partially drilled away

Another job Kandt performed was to partially bore away an old, cast-steel pipeline (no longer in use) under the Rotte River. "This pipe was in the way of installing the sheet piling. Removing the pipe was not an option, drilling it through was. This also allowed the sheet piling to be installed at that location." In addition to the aforementioned work, Kandt also performed the necessary lifting work. "When placing the reinforcement and formwork at structure 52, we were able to perform various lifting operations," Marco said.

Kandt remains in the picture for a while

Marco is already looking forward to the next job Kandt BV may do for De Groene Boog: providing all the tube foundations for the noise barriers. "Steel tubes, into which reinforcement baskets are placed by another party, after which bases are poured. The noise barriers are then mounted on those bases. So we get to enjoy working on one of the most beautiful infrastructure projects in the Netherlands, right next door by the way."