Excavated tunnels are built without removing the ground above using mining methods such as drill & blast, boring machines, etc. In order to maximize their service life and protect them from the effects of groundwater tunnels need to be watertight. Water can compromise the integrity of the concrete structure, create disturbances to the users and in general increase the maintenance costs.
Depending on the groundwater conditions, two different waterproofing concepts are used: in tunnels above the ground water level or drained tunnels, the waterproofing membrane covers only the upper part of the section (umbrella tunnels), whereas in tunnels under hydrostatic pressure the waterproofing covers the entire section.
During the last decades, PVC-P geomembranes have been used in the vast majority of tunnels worldwide due to their flexibility, adaptability, durability and ease of application. Compartment systems can be created combining the use of geomembranes and waterstops, allowing for injection repairs in case of damage and minimizing the maintenance cost.
RENOLIT has been active in this field for more than 40 years with the Alkorplan range, which holds the most prestigious European certifications and has been used in many iconic projects all over the world.