Membrane constructions under tunnel approaches

Utilizing the “U-polder” principle, a membrane construction is installed within the sheet piling to create a construction pit in wet conditions.

In the project for the reconstruction of the Peelo Zuid road section, underpasses for motorized traffic at Esakkerweg and Martin Luther Kingweg, along with a bicycle tunnel under the ring road, are planned. These tunnels incorporate a membrane construction under the ramps, where space constraints have led to the ramps being entirely placed within the final sheet piling.

To install the membrane construction, the sheet pile casings are shielded with reinforcement mesh, later covered with protective fleece. The membrane construction is then sunk by its own weight and permanently suspended with a clamping strip to the sheet piling. For the connection to the concrete tunnel section, a temporary construction pit is used, with the membrane construction secured to the concrete beam using a clamping profile.

On behalf of BAM Wegen bv Regio Noord in Tynaarlo, Genap has delivered and installed the following:

• 8,000 m² of 1.3 mm PVC membrane (KIWA/ATA)
• 150 m² of Genatex 850 with rope edge (for connection to the clamping profile)
• 4,000 m² of 500 gr/m² non-woven protective fleece.