The Helperzoom Tunnel is a new vehicular connection under the railway in Groningen. It is part of the "Aanpak Ring Zuid" project and was carried out by Combinatie Herepoort on behalf of the Municipality and Province of Groningen and the Ministry of Infrastructure & Transport.

Construction of the tunnel took place in a sheet pile pit next to the final location. As a result of digging through the existing potted clay present, it was decided to use Trisoplast to restore the transition between the concrete of the tunnel and the potted clay on both sides. This prevented seepage water from entering the tunnel via the sheet pile wall.

Trisoplast was also used to seal up seeps created by groundwater pressure in the tunnel entrances. Some of the Trisoplast was applied horizontally between sheet pile walls. Vertical walls were also made with Trisoplast as a seal.