Skip to content. | Skip to navigation

Santa Rosa Tunnel, Lima, Peru

With our standard MK carriages we were able to construct the two tunnels in a flexible manner that considerably reduced costs for the customer.


Over the past years, government institutions have been working to solve local traffic problems with new Metro lines and expanded motorways.

The subterranean tunnel crossing underneath Santa Rosa Mountain, joining the districts of Rímac and San Juan de Lurigancho, has considerably improved the east-west traffic conditions in the city. Each of the tunnels constructed have two lanes and an average length of 250 m.

ULMA Solution

The Santa Rosa Tunnel, with a height of 8.36 m and width of 13.20 m, was built using two MK carriages, one starting at each portal, which made the process as efficient and flexible as possible.

This solution also provided the customer with cost savings, being made of completely standard components. Moreover, the MK waler joints provided an extremely rigid structure with relatively little material required.

Vault formwork and shoring were integrated into the same structure, just as with the transportation structure responsible for withstanding the entirety of the pouring pressure. The combination of the MK load-bearing structure with MK formwork in a single mobile carriage made it possible to complete 6 m sections in pours lasting 7 hours. Moreover, the metal formwork panel adjusted to the different radii with a simple curvature adjustment.

The sidewalls and vault feature integrated pouring and inspection windows, along with pouring nozzles and external vibrator supports paired with the pneumatic installations necessary to power them.

The characteristics of the project made anchoring impossible on both the slab and sidewall section already finished, necessitating a specialised solution that prevented horizontal forces from being transmitted to the main structure.