Complete building envelope with integrated project approach

Commissioned by HSB Bouw, the foundation and earthworks for the Brisk sunken parking garage were performed by HeSto VOF, a combination of Gebr. van 't Hek and Roel van der Stoel B.V. "A challenging construction pit with a lot of coordination between the building parties," says Marco van der Hulst, foreman at Roel van der Stoel B.V.

The HeSto formula integrates work in the complex environment of the construction site. Gebr. van 't Hek (foundation engineering) and Roel van der Stoel B.V. (earthworks) operate as a permanent team in order to properly deal with the logistical challenges during execution: delivering a complete construction pit by means of an integral project approach, completely relieving the customer. "In the preparatory phase of the project, we had an advisory role towards HSB Bouw and actively contributed to the execution phase. During the course of the project we worked closely together, based on strong mutual trust."

Implementation and findings

In the case of Brisk's construction pit, Roel van der Stoel B.V. took care of site design, detour routes, zero measurement of the infrastructure, temporary parking facilities and (dry) excavation of the construction pit. The company signaled during the excavation that the soil structure in practice turned out to be different than expected. This created problems from the first aquifer, because the overburden layer was perforated at a number of locations. To prevent damage to the drainage system, two trailers with Mikolit (high-quality clay pellets) were used for repair work.

Fast and efficient

Van der Hulst: "During the excavation process, we went to a depth of 8.45 meters -NAP, releasing 32,000 cubic meters of soil that was environmentally approved for reuse elsewhere." Groundwater pressure is high in the built-up area of Amsterdam Southeast and challenging in drainage with such a long construction pit, so making the foundation had to be done quickly and efficiently. "What you do with such a cofferdam is basically create a polder, and that has been successfully applied here over the past year," Van der Hulst concludes.