China assists Moscow Metro expansion 22 Aug 2019

Chinese engineering and construction companies, including China Railway Construction Corporation (CRCC), are working with Mosinzhproekt JSC, the largest engineering holding in Russia, on one of the most ambitious projects in the history of the Moscow Metro and one of the largest metro projects of the world. Construction of the 69km Bolshaya Koltsevaya rapid transit circle line with 31 stations and two electric engine houses is claiming the status of the longest metro circle line in the world, overtaking the current leader - the 57km Second Circle Line of the Beijing Metro.

Full 69km circle line

Plans to build the Bolshaya Koltsevaya circle line (BLK) were first proposed by the Soviet Government in 1985. Lack of financial resources just before and after the collapse of the USSR in 1991 caused suspension of the project. Interest in resuming the project was expressed by the City of Moscow Mayor, Sergei Sobyanin, in 2011 and construction began in November of the same year. Launch of the BKL by the Moscow City Government will relieve congestion on the radial line services of the Metro.

Services on the first section of the line and its five stations were launched officially in February 2018, while commissioning of the entire line is scheduled for 2022. To date, about 50% of the construction works for the project has been completed. Much of the line is sub-surface with works running at between 22m and 48m deep.

The BKL is an acute need for Moscow and its citizens. The majority of the city population lives in the remote districts, while most of the jobs are located in its centre and regional suburbs. To get to and from work, many citizens are forced to make at least two transfers. Located about 10km from the existing circle Metro line, the new BKL Line will save passengers the journey to the centre of the city in order to transfer from one radial line to another.

Mars Gazizullin, Director General of Mosinzhproekt JSC

Construction of the project is being managed by Mosinzhproekt, which is known for completing some of the largest construction projects in Moscow in recent years. With Mosinzhproek and its affiliated construction companies, Chinese engineering and construction companies are also responsible for building sections of the Line. For the works, CRCC has delivered four 6m diameter TBMs and is planning to deliver the last and the largest of the machines, at 10m diameter, in September or October of this year (2019).

Xue Li Jiang, Executive Director and Chief Engineer of CRCC, said all five TBMs are designed to take into account the geological conditions and the city’s climate. According to Xue, low temperatures during winter, which are typical for the city, will not complicate planned works.

According to Marat Khusnullin, Deputy Mayor of Moscow for Urban Planning and Construction, the Moscow City Government official responsible for the project, a total 15 TBMs are required for construction of the line. This is the highest number of TBMs to be used at the same time in the history of Moscow tunnel excavation. In the past, he added, most TBMs for works in Moscow have been supplied from Germany by Herrenknecht, including two 10m machines that recently achieved breakthroughs. Import of TBMs from Germany is now barred under sanctions imposed as a result of Russia’s annexation of the Crimea region of Ukraine in 2014.

Breakthrough on the 1.2km Aviamotornaya and Nizhegorodskaya link

In speaking of the project, Mars Gazizullin, Director General of Mosinzhproekt JSC, said that deadlines for BKL, and particularly of its first section, have been extended several times, mainly due to various technical difficulties occurring during implementation of the project, as well as challenging ground conditions. For example, much of the work has been through geological conditions associated with a high karst hazards and flowing groundwater.

“In technical terms, each tunnel of the BKL is completely different,” he said. “As the majority of the stations of the line are built at a relatively shallow depth, with only three at 65m-70m, the construction works are conducted in water-saturated soils and complex hydrogeological conditions. In addition, there is a need to take into account existing underground structures. For this purpose, a special system of underground monitoring is used, which provides an opportunity to design comprehensive preventive measures, so that these structures remain intact during the construction works.”

According to Deputy Mayor Khusnullin, the most difficult sections of the project have been completed, with 80km of tunnel excavation now completed.