The TBM has an excavation diameter of 7.6 meters. During construction, it achieved a maximum monthly advance of 808 meters, with an average monthly advance of approximately 500 meters. Throughout the operation, the machine maintained an availability rate of over 95%, demonstrating excellent performance, reliability, and construction efficiency.
In response to the project’s geological conditions, the CRCHI R&D team custom-designed a high-strength, high-wear-resistance rock-breaking system together with a long-life main drive system for the TBM, enabling continuous excavation without any intermediate maintenance throughout the entire drive. In addition, building on the performance characteristics of conventional double-shield TBMs, an innovatively integrated rock bolting and shotcreting system was developed, forming a flexible and reliable “dual-support” mode. In practical application, rapid switching between segmental lining support and rock bolting & shotcreting support can be completed within only 1–2 days, significantly enhancing tunneling safety, construction efficiency, and overall economic benefits.
The TBM is also equipped with an integrated “probe + support” system that combines a probe drilling rig, a core drilling rig, and a rock-bolting drilling rig into a single unit. The advance drilling coverage extends across the areas ahead of the cutterhead, front shield, and gripper shield. Each 45-meter-deep borehole can be completed in no more than four hours, fully meeting the requirements for advance geological investigation under high-efficiency tunneling conditions.
Throughout the excavation process, CRCHI’s service team remained stationed at the construction front line. Leveraging their professional expertise, the team exercised precise control over every aspect of TBM operation, promptly identified and eliminated potential risks, and ensured the machine maintained a continuously efficient, stable, and reliable tunneling performance.
Upon completion, the project will serve as a key water conveyance corridor of Sri Lanka’s “South-to-North Water Diversion” initiative, effectively addressing the country’s uneven distribution of water resources. The project will play a significant role in disaster prevention and mitigation, while also contributing substantially to sustainable economic and social development in the region.
