Travelers are not aware of it, but the Ferrocarrils de la Generalitat (FGC) station on Carrilet de l’Hospitalet avenue is submerged in the aquifer of the Llobregat delta. Although they have no reason to worry, because it is like entering a submarine, the infrastructure managers do regularly monitor the pressure exerted by the water on the structure of the tunnel and the station.
The groundwater level has risen in recent years and would reach the height of passengers’ knees if it weren’t for the pumping system installed under the platforms that helps keep the liquid at bay. However, the leaks have increased, to the point that they had to enable a small channel as if it were a stream between the two central tracks of the station to evacuate all the water that entered through different points.
Now FGC wants to completely put an end to the leaks by applying microcement injections from the tunnel between Cornellà and l’Hospitalet at all points where a risk of leaks is detected. The operators have been working every night since January, when the service is interrupted, injecting “a mixture of beach sand with microcement ten times finer than usual”, as Pere Mateu, project director of the railway network of the FGCs. The work is carried out in a very limited way and with an electronic control system activated on the tracks to detect any deformation and guarantee that the service can resume normally every morning.
In addition to these surgically precise works, the construction this summer of a new 45-centimeter-thick counter-vault, superimposed on top of the one that is already there now, is a fact that reinforces the sealing of the infrastructure against water. In addition, it has been used to replace a half-kilometer section of the old tracks with new ones installed with concrete slabs, a change that is made in all the railway modernizations of recent times by both Ferrocarrils and TMB, because it facilitates maintenance tasks.
Between one thing and the other, it is expected to put an end to the stream that crosses the station and to limit the losses of the aquifer, a strategic reserve to turn to in times of drought. With the works in the final stretch, Mateu calculates that “an Olympic swimming pool will be saved per day, the equivalent of the consumption of a city of almost 70,000 inhabitants, as could be Viladecans”, to give an example of the aquifer itself.
The works, which have reduced the service in the summer and led to a cut for eight days, will be completed this weekend. This intervention has given continuity to similar work carried out a few years ago in Cornellà, where there were still more leaks. The railway company’s intention is to continue progressing from Sant Josep station, in l’Hospitalet, to Plaça Espanya, to guarantee the shielding of the entire route against ground water and to continue improving savings.
