Parking garage Garenmarkt, Leiden | A strong example of stamping work

The execution of auxiliary structures, strut frames and anchoring structures in construction pits and other earth retaining structures is the specialty of Marsé Montage from Castricum. The company is a regular partner of Dura Vermeer, which together with BESIX forms the building consortium during the realization of the underground parking garage at the Garenmarkt in Leiden. A project to which Marsé Montage is making a significant contribution via, among other things, the supply and assembly of the outriggers.

The outrigger frame in the water-filled construction pit.

As superintendent, Robèr Zoontjes is closely involved in the work being carried out by Marsé Montage in Leiden. "We started by making a 300-ton steel strut frame that was installed ónder the concrete strut frame placed by the building consortium. We then welded the steel structure and suspended it from 28 tie rods, after which the building consortium excavated the cofferdam to a depth of 8 meters. Following this, we lowered the outrigger frame approximately 7 meters under water using jacks and it was hung in place, adjusted and secured with grout bags by divers, so that the frame can do its job when the water is pumped out of the construction pit."

Air cushions
Further excavation of the building pit to a depth of about 19 meters has resulted in the steel outrigger frame currently hanging halfway down the building pit. "The frame serves to support the diaphragm walls until the floor floors are in," Zoontjes continued. "Eventually they will take over the function of the strut frame and we can dismantle and dispose of the steel structure." A job that Marsé Assembly because of the immense weight of the window components will present a fine challenge. "Because of the high floor load, it is not possible to remove the disassembled outrigger window with a forklift. Instead, we will use air cushions to maneuver the materials out through an opening in the floors." In the meantime, however, Marsé Montage's specialists are not sitting still. In fact, the company is also taking care of such tasks as welding up the sheet pile walls and making manholes and penetrations. Zoontjes: "We are almost continuously present on the construction site and have everything we need to answer many steel-related questions."  

Text | Chris Elbers  Image | Buro JP
Featured image: The outrigger frame awaiting excavation where it will lower 7 meters to the ground.