Drainage geocomposites and PVC geomembranes for highway tunnel lining FIGURE 6 Flow-rate diagrams for cuspated geonets thrust, depending not only on the sector, but also on the rock class. The flow-rate measurements are performed according to EN ISO 12958 method (Cazzuffi and Recalcati, 2018). The drainage geocomposite was fixed to the vault through nails and connected at the bottom with a drainage pipe (Figure 7). The geomembrane is the main functional layer of the waterproofing system. The system adopted in the Egnatia Odos tunnel is composed of a single layer of PVC-P geomembrane FLAGON BSL 2.0 mm applied on the regularization layer and on the geocomposite, fixed by PVC-P disks to the support upgraded by the introduction of compartments and waterstop joints. (Figure 8). Proper testing on the geomembrane FIGURE 7 Connection to the drainage pipe integrity and on the weldings have been performed according to the practices described by Cunegatti (2019). 32 Geosynthetics | October November 2022