Taisei Corporation is leading innovation in tunnel construction through its work on the Shinnozoki Tunnel, a major infrastructure project spanning 1.148 kilometres along the border of Yamagata Prefecture and Akita Prefecture. With more than 150 years of experience, Taisei has built a strong reputation in civil engineering, energy, and environmental solutions, consistently embracing new technologies to enhance efficiency, safety, and quality.
As part of its commitment to modernization, the company has adopted advanced mechanisation and automation in its tunnelling operations. This includes the use of the Sandvik DT1131i, developed by Sandvik. Introduced in 2020, the fully automated three-boom jumbo reflects the industry’s shift toward remote-controlled and digitally enhanced machinery.
The Shinnozoki Tunnel project provided an ideal testing ground for this advanced equipment. With a cross-section exceeding 100 square metres, the large mountain tunnel presented complex challenges that demanded precision and efficiency. The DT1131i, built on Sandvik’s i-series platform, is specifically designed for such demanding environments, offering high drilling accuracy, extended reach, and intelligent control systems that optimise drilling patterns while reducing overbreak and improving overall tunnel quality.
Initially, Taisei deployed the automated jumbo for both blasting and rock-bolting, a common practice in Japan. However, the team soon realised that this approach limited the machine’s full potential. By assigning the DT1131i exclusively to drilling blast holes, they were able to maximise its capabilities and significantly improve performance outcomes.
The transition to fully automated equipment required strong technical support and training. Sandvik engineers worked closely with Taisei’s team, providing hands-on guidance to ensure smooth integration. This collaboration proved essential, as the new system differed significantly from conventional machinery used in Japanese tunnelling.
Japan’s tunnelling environment presents unique challenges, including difficult rock conditions and the need for closely spaced steel arches. The DT1131i includes specialised features tailored to these requirements, enabling efficient operation in conditions that demand precision and adaptability. Its ability to handle such complexities has made it particularly valuable for projects like Shinnozoki.
Automation has delivered clear benefits in terms of productivity and consistency. The system allows a single operator to carry out drilling tasks, reducing labour requirements while maintaining high performance. It has also made it possible to drill contour holes with precision—something previously considered difficult with automated systems.
The use of advanced components, such as spike-type centralisers, has improved drilling stability and reduced wear on equipment. As a result, the consumption of parts like rods and drill bits has decreased, and downtime has been minimised compared to traditional methods.
Operators have also highlighted the machine’s practical advantages. Its top-mounted boom design improves visibility, while the automated system reduces strain on hydraulic components, enhancing durability and reliability in daily operations.
Perhaps most importantly, automation has introduced a new level of consistency. Regardless of the operator, the DT1131i delivers uniform drilling results, ensuring stable performance even when workforce availability fluctuates. This reliability has strengthened overall project efficiency and reduced operational risk.
Looking ahead, Taisei sees further potential in automation, including the possibility of fully unmanned tunnelling operations. By continuing to invest in advanced technologies, the company aims to push the boundaries of what is possible in tunnel construction and elevate industry standards across Japan.
Ultimately, the Shinnozoki Tunnel project demonstrates how smart drilling solutions can transform complex infrastructure projects—delivering not only improved efficiency and precision but also greater consistency and resilience in modern construction.
