CRCHI EPB with a diameter of 10.88 meters was shipped at Zhangjiabang wharf of Shanghai on September 27th, 2019 and is expected to arrive in Moscow in November via the Pacific Ocean and the Arctic Ocean. The large EPB will be used in the construction of Moscow Third Interchange Circuit which will link all existing and planned metro routes and interconnect the Moscow’s outlying districts. Upon completion, it will greatly relieve traffic pressure to city’s existing metro lines, being very significant in the city traffic network.
In 2018, CRCHI, CRCCI and CRCC 16th Group cooperated with a local engineering design company to develop five EPBs for Moscow Metro after learning from its years of experience in the metro design and equipment applications. At present, these five CRCHI EPBs are being used for the construction and offer superior performance.
In 2019, they worked together again on the development of a large-diameter EPB for Moscow Metro. Mr. Marat Khusnullin, the Deputy Moscow Mayor, named the machine Victory.
Located at the riverside of the Moscow River, the tunnel project will pass under heavy traffic and dense buildings. The EPB needs to consecutively bore around 3 kilometers near the river, with minimum horizontal turning radius being 400 meters.
Generally speaking, the minimum turning radius for a normal large diameter shield machine is more than 500 meters. This EPB is fitted with articulated cylinders, over cutters and thrust cylinders with floating support structure, which allow the machine to have the minimum turning radius of 300 meters and meet the need of 400 meters for this project. For extremely cold climate in the winter of Moscow, the EPB is designed with cold-proof performance to allow tunneling in -30℃.
Long-distance excavation in the complex geologies for the EPB places a high demand on bearing capacity, wear resistance and reliability of the cutterhead structure. Therefore, this CRCHI EPB is designed with a highly strong heavy-duty composite cutterhead with six spokes and the cutterhead is fitted with 19-inch disc cutters which will allow to cut the rock or pebbles of more than 120 Mpa. Given the challenges of tunneling in the water-rich sand, the EPB is designed with the high-pressure seals which can bear pressure of 6 bar. Besides, the EPB is fitted with a fast and safe cutter change system which ensures high working efficiency and low labour intensity in cutter replacement.