DL E&C Secures Korea’s Only Track Record on the State-of-the-Art ‘RBM Excavation Method’.
DATE 2026.02.05
VIEW 198
DL E&C Secures Korea’s Only Track Record on the State-of-the-Art ‘RBM Excavation Method’.
- Drilled a ‘43-story high’ vertical tunnel at Yokmang Mountain in Busan, and Led both design and construction- Advantages include shortened construction time and enhanced worker safety: highly applicable to deep tunnel construction
- Accelerates the advancement of vertical tunnel technology: applied to sites such as the Yeongdong Pumped Storage Power Plant
‘Phase 2 Port Hinterland Development Project for the North Container Terminal at Busan New Port’ currently being carried out by DL E&C at Yokmang Mountain in Busan, has entered full-scale progress. DL E&C announced on the 4th that it has completed the excavation of a tunnel penetrating vertically through Yokmang Mountain. This was achieved in just seven months since excavation began in July last year. The project is attracting attention from the construction industry as it utilized state-of-the-art excavation equipment called the RBM (Raise Boring Machine).
‘Phase 2 Port Hinterland Development Project for the North Container Terminal at Busan New Port’ aims to utilize stones generated from the removal of Yokmang Mountain for land reclamation at Busan New Port and Jinhae New Port, with completion targeted for 2034. This is the largest single construction project since the opening of Busan New Port in 2006. To achieve this, a mountain peak equivalent to a 43-story apartment building must be excavated to create a 120-meter vertical tunnel. This vertical tunnel serves as a passageway for the movement of the stones.
This project is being carried out as a turnkey project, in which the construction company handles all aspects of EPC (Engineering, Procurement, and Construction), and showcasing the concentrated excellence of DL E&C’s design and construction capabilities. In particular, excavating a deep vertical tunnel exceeding 100 meters underground is considered a highly challenging construction. DL E&C proposed the RBM method to the client, the Busan Port Authority (BPA), thereby simultaneously enhancing both efficiency and safety at the construction site.
The RBM is a large machine equipped with dozens of cutting blades that rotate to bore through rock. Unlike conventional methods that dig into the ground from above, this method involves drilling a 0.3-meter diameter hole to 120 meters underground, inserting the RBM into it, and rotating it from bottom to top to excavate. The excavated stones can be discharged underground through the resulting hole, eliminating the need for the subsequent process of scooping up the stones. This reduces the risk of falls during construction and shortens the construction period by 30% compared to conventional methods. Subsequently, a gantry crane (a large gate-shaped crane) equipped with a rotary drilling machine passes through the hole, expanding the diameter of the vertical tunnel to 10 meters.
The key to this method is maintaining a constant pressure applied to the RBM. This is because excessively high pressure can cause equipment failure, while excessively low pressure reduces excavation speed. As the work requires repeating excavation dozens of times, maintaining a vertical position is also crucial. DL E&C’s technical expertise is based on accumulated experience. When it comes to the RBM method, DL E&C is the only company in Korea with a track record of construction over the past five years. In particular, the Company applied this method to the Yecheon Pumped Storage Power Plant, which was completed in 2011, demonstrating its high-level on-site judgment and expertise.
With the recent surge in deep underground infrastructure projects such as pumped-storage power plants and the GTX (Great Train eXpress in Seoul metropolitan area), the applicability of the RBM method is also on the rise. In addition to the RBM method, DL E&C has developed new technologies related to vertical tunnel construction, filed for patents, and is currently pursuing commercialization. The company plans to apply these technologies to the Yeongdong Pumped Storage Power Plant, which is currently under construction, in order to further strengthen its technological edge. This is because the nature of pumped storage power generation—which generates electricity by dropping water from an upper reservoir to a lower reservoir—requires technology capable of precisely constructing deep vertical tunnels.
Park Sang-Shin, CEO of DL E&C, said, “Based on the technical know-how accumulated through numerous vertical tunnel construction projects, such as the Yeongdong Pumped Storage Power Plant and GTX-A, we are leading the mechanization of construction and the advancement of technology.” He added, “We will continue our ‘super-gap technological leadership’ in the field of pumped storage power generation through the RBM method.”
