Tan Qin Yangzi has enjoyed an auspicious rise since she graduated with a master’s degree in 2023.
Her studies were completed in South Korea before returning to her hometown in Changsha, known as the construction machinery capital of China, where she joined China Railway Construction Heavy Industry Corporation (CRCHI).
Now in her fourth year with the company, she serves as the Overseas Business Manager, more specifically on its tunnel boring machine (TBM) projects.
In the South Korean market, she is responsible for the execution of 13 different TBM projects designed and manufactured by CRCHI. Involvement spans across several cable tunnels and railway tunnels.
Tan’s role, which sees her across every key phase of the project, encompasses outset to outcome contract management — from equipment mobilisation and installation, through tunnelling, to the final breakthrough — ensuring each undertaking progresses as smoothly as possible.
Constraints now common above the surface for infrastructure builds have meant that companies like Korea Electric Power Corporation (KEPCO) are adapting to get around these limitations increasingly imposed on above ground environments.
The undergrounding of power cables is one way it has sought to do so and now actively promotes — a trend that has prompted growing demand for small-diameter tunnel boring machines.
It’s a welcome development, moreover, for a company like CRCHI, whose reputation rests upon the superior performance and customisation capabilities of its equipment.
In this case it’s been its ability to supply highly flexible tunnelling equipment for the likes of the Seosan-Seongteon power cable tunnel project. CRCHI supplied a slurry balance TBM with an excavation diameter of 3.2 metres. The massive dig covered 2,044m on a continuous uphill gradient with a maximum slope of 1.3 per cent.
Meanwhile, a 3.0m diameter TBM was deployed on the Suwon-Hwaseong power cable tunnel, a vital infrastructure project for both cities as their populations surpass 1 million people, granting them special city status which, in turn, bestows administrative privileges under the central government.
Trouble with the curve
The Seosan cable tunnel project passes through complex geological formations interbedded with hard rock and weathered rock.
The minimum horizontal curve radius is just 120 metres, and the uniaxial compressive strength of the rock reaches up to 71MPa.
To address the technical challenges posed by long-distance hard rock tunnelling and extremely tight 120-metre radius curves, CRCHI’s R&D team customised the equipment with a dual-articulated steering system, an efficient rock-breaking solution, and a high-capacity slurry circulation system.
“The TBM was also equipped with an ultra-low-clearance segment erector and a side-coil hose reel system, fully adapting to the specific requirements of small-cross-section tunnel construction,” said Tan.
Following the equipment delivery, the CRCHI team provided comprehensive technical support throughout the entire process, from assembly and commissioning to trial tunnelling and subsequent operational safeguarding.
This contributed significantly to overcoming the complex geological challenges and achieving an excellent monthly advance rate of 223 metres.
“The TBM, with an excavation diameter of 3.26 metres and a total assembled length of approximately 135 metres, has demonstrated stable and efficient performance,” said Tan.
Thanks, owing in part, to their outstanding performance, CRCHI’s equipment has earned high praise from its clients in South Korea.
The two aforementioned TBMs that successfully completed their drives last year are already scheduled for deployment in subsequent cable tunnel projects such has been the universal nature of their acceptance. In this instance, the machines have crucially helped CRCHI further cement its brand influence in the country’s underground space equipment market according to Tan who has witnessed firsthand the process of Chinese high-end equipment taking root in overseas markets.
“Through my involvement in these projects, I have gained invaluable experience managing TBM construction operations under diverse geological conditions,” she said.
“I often say: ‘As the machines advance underground, CRCHI establishes its presence overseas.’” Each tunnel, it would seem, not only connects different geological layers but also serves as a link, fostering technological exchange and mutual trust between China and South Korea.
For young women such as Tan Qin Yangzi, the underground in South Korea has been a pathway forward.
For more information, please contact tangzhongwu@crchi.com
