The Coatzacoalcos tunnel is the first immersed concrete tunnel constructed in all of Latin America and reaches a depth of more than 30 meters below the water surface.
The state of Vera Cruz initiated the construction of the immersed tunnel for road traffic to connect the petrochemical industry in Allende on the east side of the river to the suburban Coatzacoalcos area on the west side. Once construction is finished, the tunnel will have a total length of 1,200 meters with 690 meters located on the riverbed. It accommodates 2 X 2 roadway lanes separated by an escape tunnel.
Five concrete tunnel elements were prefabricated in the dry dock which was positioned immediately adjacent to the immersion location. Each element is 138 meters long, 25 meters wide and 9.2 meters high. The castin basin was constructed especially for the construction of these tunnel elements).
Once the elements were floated out of the dock to their final location, it was critical that the immersion technique was applied correctly. VolkerCI specifically designed, built and used new immersion equipment for this project: the modular catamaran. The modular system helps to expand or reduce its capacity. During the immersion of the elements the catamaran proved to be functioning very well and was stable, according to design. The catamaran made sure that each piece was lowered into place on the gravel bed, aligned correctly for a smooth joined up.
After the successful immersion of all five elements the next step in the project will be the permanent stabilisation of the elements by installing the locking fill and rock protection. The finishing of the immersion joints and the construction of the closure joint will start after a waiting period of about 6 months, to allow for initial settlements of the elements.