Text written in Basque and translated automatically by Elia without any subsequent editing. SEE ORIGINAL

In the tunnel from start to finish

Tunnels are planned to be completed in the spring. Teknopolis just visited them.

Cortea Iñigo Cadarso (Bidegi), on the plans of the tunnels, views and general data. (1’30’’)

Although the tunnels are already open on both slopes of the Discharge, we will travel by car from the Zumarraga side to the Antzuola side, which is easier to access.

Waiting Marshal (Eptisa) Square: Before entering the tunnel, on the duty of geologists in this type of work, and at the entrance.

We have been welcomed by the staff, the work of the staff and the noise.

Excavators and explosives have been used to drill these tunnels, but there is no trace of this here. In fact, the works on this side of the tunnel are a little advanced to the point of taking the walls with concrete. The concrete acts as a seal on the one hand, covering the joints created during drilling and fixing the rock. On the other hand, since it takes the form of a ring, it becomes a sheet that helps to support the load of the rocks.

Waiting Marshal (Eptisa) Square: The purpose for which the coating is made, how, the use of the coating cart

The gap between the cladding carriage and the wall is filled by projecting concrete. It is a special concrete made of fibers that add more resistance.

Leaving a clean and spacious contour of the covering car, we go through the tunnel.

At this point they are working on the placement of the bolts through the Jumbo machine. Two such machines were used in the tunnels.

The bolts are part of the tunnel containment system. They prevent the rock from slipping and also give them consistency.

In this case, they are connected to the rock by compressed water. They enter the holes made by the jumbo and with the water emitted at high pressure, they open in the hole and grip the rock.

Before we reach the area where the wall insulation works are being carried out, we also see security exits. The two tunnels are connected.

Courtesy of Itxaso Mariscal (Eptisa): About the isolation.

Although the tunnel looks the same, in some sections, the worst ones, in addition to concrete and bolts, in order to improve the support, there are also trusses, i.e. arc-shaped metal pieces that support the wall.

Even on the outside, the machines are working, they are splintering. In fact, the tunnel is not only a hole, but also the entrances and exits must be adapted safely.

We had to get out of the tunnel. In fact, we want to get closer to where the works at the top and bottom of the tunnel can be seen at the same time, but for that we have to go outside because they are only visible from one side at the moment.

Courtesy of Itxaso Mariscal (Eptisa): Avance and destroza

Taking one of the four emergency exits in both tunnels, we walk from darkness to light. On this side of the tunnel they already have installed drainage systems, piping for all light forces and security systems, as well as a sidewalk that will be at the pedestrian level. Things are going well, by next year’s spring the Discharge tunnels will be finished. We have reached the end of the tunnel