China's inaugural EPB TBM designated for South America recently rolled off the production line at CRCHI on September 27th. CRCHI, the manufacturer, holds the honour of being the first to export this TBM to South America, where it is poised to embark on its first mission: contributing to Lot 1 of the Santiago Metro Line 7 project in Chile. The impressive TBM spans 105 meters in length with a 9.8-meter excavation diameter.
Lot 1 of the Santiago Metro Line 7 project encompasses approximately 7.9 kilometers, necessitating 6.7 kilometers of excavation via TBM. This ambitious undertaking involves the subterranean passage beneath the Mapocho River, spanning a distance of 60 meters, with the riverbed situated a mere 10 meters from the tunnel roof. The tunnel traverses various geological compositions, including fine-grained soil, silt, clay, sand, gravel, pumice formation, and volcanic rock formation (granodiorite). It's worth noting that the alignment's minimum turning radius is 250 meters, demanding a TBM with remarkable turning capabilities.
Considering the specific geological challenges posed by this project, CRCHI's research and development team has incorporated numerous independent key technologies into the TBM's design. Notably, the cutterhead features a composite configuration of 6 spokes and 6 panels, supported at the center. The cutterhead is equipped with disc cutters, drag bits, and gauge scrapers for comprehensive full-face excavation, and all detachable cutting tools can be replaced from the rear of the cutterhead. Moreover, the cutterhead can rotate bidirectionally to facilitate muck discharge. When a turn is required, the stroke differential of each group of propulsion cylinders can be adjusted to meet the alignment's minimum turning criteria.
The Santiago Metro Line 7 in Chile is a monumental project spanning 26 kilometers, set to unfold over a 6-year construction period. This venture holds significant importance to the Chilean government, as it cuts through seven urban areas in the capital, including plans for constructing seven island-style stations and construction shafts. Once completed, the line is expected to reduce the commuting time between its terminal stations by 54%, providing a rapid and convenient transportation solution for over 1.36 million residents.
For further information please visit the CRCHI website and explore the tunnelbuilder archive which has more information on TBMs that have been built by CRCHI.
