As 2005 drew to an end, a 2.7m Lovat TBM broke through for an oil transmission tunnel in Russia, whereas in Spain its 6.1m diameter big sister completed a metro drive.
The 2.7m diameter Lovat TBM, Lilia, completed a 736m long tunnel that passed 19m under the Belaya River in Krasnodarsky Krai near Russia’s eastern Black Sea coast.
Contractor Mostovik used the mixed face TBM that had originally been supplied in 2000 for the Blue Stream Gas Tunnel Project. For the Belaya tunnel, the TBM operated at grades of up to 7.5%, through ground conditions described as “challenging”, consisting of gravel and boulders mixed with sand and heavily saturated with water.
The primary segmental lining will house a 0.9m diameter steel pipe and two polyethylene pipes of 0.7m and 0.53m diameter as part of its role as a crude oil transmission conduit by oil producer Transneft.
Whereas in Spain, the UTE Metro de Sevilla, a JV of Dragados, Sacyr and Cavosa, broke through its 6.1m diameter mixed face EPB Lovat machine to Estaciõn Plaza de Cuba on its drive under Seville as part of the city’s Linea 1 Interurbana metro contract.
The 468m long section of tunnel was excavated through mostly silty sand and clay with some gravel and sandy gravel, the entire alignment runs 15m below the water table. Lovat said that the final 50 rings were mined through mainly gravel and cobbles.
The breakthrough is the first on the project that will see 2,300m of twin tunnel being mined. So far, the miners and TBM have achieved a peak performance of 150 rings in two weeks, working two 12 hour shifts per day.
