The project, called SALIEMELAV, has been carried out in the city of Barcelona for the emergency exits of the Sants-La Sagrera high-speed tunnel
Sando, in accordance with the Adif Alta Velocidad construction project and in conjunction with external geotechnical consultants of renowned experience, has implemented an innovative monitoring system during the construction of the three new emergency exits of the Sants-La Sagrera high-speed tunnel in the Barcelona urban area. The use of this auscultation system makes it possible to minimise the effects on this tunnel and surrounding structures and dwellings, as it provides real-time readings.
The European Quality Assurance agency has certified Sando´s construction solution, designed for this infrastructure of the Madrid-Barcelona-French Border High-Speed Line for Adif AV, as a technological innovation.
The project, called SALIEMELAV, has been designed to create a solution, in accordance with the construction project, which guarantees the execution of vertical tunnels in terrain with complex geological characteristics, particularly suitable for urban environments.
In the works of the emergency exits of Sants-La Sagrera, the presence of gravel and sand in the areas of the excavation made it necessary to look for an alternative that would ensure its execution safely. In the SALIEMELAV project, a plan has been defined, designed and devised for monitoring the auscultation of the terrain, providing real-time readings.
One of the keys to stabilising the terrain in the execution of this project has been using the jet grouting technique or improvement of the terrain by replacing it with an injection of cement. This treatment consists of breaking up a volume of soil and mixing it with a cement slurry, reconstituting it with better mechanical characteristics.
Sando has executed, among other actions, a double crown of jet grouting drying columns, in order to improve the excavation of the vertical tunnels, which has served as a continuous, stable and safe barrier, prior to drilling with a vertical tunnel boring machine.
It has also executed a wall of drying mortar piles of depth in the perimeter crown up to the totality of the future excavation of the pit in order to improve the “diggability” of the vertical tunnels.
This pre-treatment of the terrain and its monitoring of auscultation, among other actions, has made it possible to make the terrain and nearby buildings more stable and provide a rapid response. This construction method has a real time monitoring system that emits warnings in the event of movements in any of the actions.
The construction solution implemented by Sando is in line with its construction project for the execution of vertical tunnels, which range in depth from 40 to 49 metres in the heart of Barcelona.
The Sando R&D&i department, in addition to developing research projects, carries out specific studies in situ to resolve engineering problems in the infrastructures it executes, as on this occasion in the construction of the three new emergency exits for the Sants-La Sagrera tunnel in Barcelona.
Sando’s research work has allowed it to patent innovations in the prevention of occupational hazards, be a pioneer in using drones in construction and break international records, such as the world record for progress with a tunnel boring machine, achieved on various occasions.