The 2.044km tunnel has a continuous uphill gradient, featuring a maximum slope of 1.3%. It traverses complex geological formations including hard rock and weathered rock, with a minimum horizontal curve radius of 120m and rock compressive strength reaching up to 71MPa.
During the design phase, CRCHI (China Railway Construction Heavy Industry Corporation Ltd) conducted in-depth investigations of South Korea’s construction environment and optimised the solution by incorporating local characteristics to ensure efficient equipment delivery.
To address the challenges of long-distance hard rock tunnelling and the tight 120m-radius curves, CRCHI’s R&D team developed a tailored solution featuring a double-articulated steering system, an efficient rock-cutting solution, and a high-capacity slurry circulation system.
In addition, the machine was equipped with an ultra-low clearance segment hoist and a side-mounted coiled pipe extension system.
The shield TBM – the fourth TBM CRCHI has exported to South Korea – has a 3.26m excavation diameter and is 135m long.
Working in close collaboration with HOBAN, the CRCHI team helped to ensure efficient project execution, successfully overcame complex geological challenges, and achieved a monthly advance rate of 223m.
