Herrenknecht has been awarded a contract to undertake a feasibility study for, and to deliver, a 19m diameter TBM to excavate a combined road and rail tunnel in Moscow.
ZOA Infrastruktura awarded the contract late last month for the TBM to work in the ‘very demanding’ soft ground geology and high groundwater levels in Moscow. The customer wants the machine, likely to be a Mixshield, on site in two years.
Infrastruktura is to build the tunnel on the outskirts of Moscow as an orbital transport link that connects into the road and metro networks. Financial details were undisclosed.
The diameter of the proposed TBM far exceeds the biggest shield built so far, also by Herrenknecht. The largest TBMs at present are the two 15.43m diameter Mixshields (S-317, S-318) that are excavating twin tunnels almost 7.2km long below the Yangtze river in Shanghai for the Pudong-Changxing crossing, part of the new link to Chongming.
The first TBM on the project was launched in September 2006 and the second Mixshield began boring in January 2007. The TBMs will drive 65m below ground at their deepest point and are expected to encounter up to 47m head of groundwater above the tunnel axis (T&TI, January 2007, p7). The drives are expected to finish later this year, and the entire, almost 7.5km long, tunnel crossing is to be finished in 2010. The contractor is Shanghai Changjiang Tunnel & Bridge Construction Development Co.
Herrenknecht has previously supplied a large diameter Mixshield to help expand the transport network of the Russian capital, on the Lefortovo and Silberwald projects. The 14.2m diameter machine in question had previously been used in the late 1990s to construct the fourth tunnel below the river Elbe in Germany.
Refurbished as S-164, the TBM was sent to Moscow for the Lefortovo project, in which AO Corporation Transstroy built twin 2km long, segmentally lined bores through sand, clay and limestone for double-deck road tunnels, which included excavation below the river Jausa.
After refurbishment, the Mixshield was then used by OAO Mosmetrostroy, as S-250, to excavate twin 1.5km long road tunnels through sand, clay and boulders on the Silberwald project in Moscow. At present, the shield is being refurbished once again for another job in the city where, as S-483, it will drive a single 2.4km bore on a project being undertaken by Upravlenie Mosmetrostroja (UMM).
