The Forums

Building a Maglev Station Beneath Active Shinkansen Tracks: Inside Nagoya’s High-Precision Mega Project

. Graph: https://newsdig.tbs.co.jp/articles/cbc/2605231 Accessed 2026-04-19

A massive and technically demanding construction project is underway beneath Nagoya Station as part of the Linear Chuo Shinkansen maglev line, even though the exact opening date of the line is still unclear. The redevelopment of the station area includes transforming former surface landmarks—such as the site of the removed “Hisho” monument—into new public spaces, while far more complex work is happening deep underground.

Directly beneath the active Shinkansen platforms, where trains continue to run daily on a normal schedule, engineers are constructing a new maglev station approximately 30 meters below ground. The underground station will extend roughly 900 meters east to west, cutting across the existing north–south-oriented station. This requires extremely delicate operations carried out in a confined space while ensuring that train services above remain completely unaffected.

One of the most difficult phases involves removing the existing foundation piles that support the Shinkansen platforms and tracks. In a designated area about 55 meters long and 40 meters wide, a total of 39 piles are being dealt with. Engineers install hydraulic jacks on temporary support piles and gradually transfer the load—amounting to around 10,000 tons, comparable to the weight of three Nagoya TV towers—away from the original foundations. Once the load is fully supported by the temporary system, the original underground structures can be cut and removed, allowing excavation to continue down to about 35 meters to create the large underground space needed for the maglev station.

This process requires extraordinary precision. All 39 support points must be lifted in perfect horizontal alignment; even a deviation of a single millimeter could distort the tracks above and potentially lead to serious safety risks. Engineers continuously monitor load distribution, ensuring that each jack carries the same proportion of weight. The entire system is remotely controlled and adjusted in real time, with strict safeguards in place because Shinkansen trains must continue operating safely every day.

The work is further complicated by Nagoya’s challenging geological conditions. The ground allows water to flow easily and can trap underground pressure, creating risks of sudden water inflow if not properly managed. At the same time, lowering groundwater levels too much could cause the Shinkansen platforms to settle. To address this, engineers carefully balance groundwater pressure and structural stability, using jacks to counteract any movement while constantly analyzing detailed measurement data. Managing this balance between water, pressure, and structural integrity is considered one of the most difficult aspects of the project.

By late 2025, parts of the original column foundations had already been cut, effectively leaving some structures “floating” as the load was fully transferred to temporary supports. By early 2026, significant underground cavities had been successfully excavated, marking steady progress despite the complexity.

Beyond Nagoya, construction of the overall maglev line is advancing in other regions, including station development in Shinagawa and tunnel excavation along the route. However, a major obstacle remains in Shizuoka Prefecture, where construction has not yet started due to ongoing concerns over water resources and environmental impacts. Negotiations with local authorities and communities have been progressing, and project leaders emphasize continued dialogue to secure approval and cooperation.

Overall, the section beneath Nagoya Station represents just a small part of the approximately 286-kilometer maglev line connecting Tokyo and Nagoya, which is designed to enable travel times of about 40 minutes at speeds of up to 500 km/h. Despite delays and significant engineering challenges, the project continues as a large-scale national effort that relies on advanced technology, precise execution, and long-term coordination.

Info based on a report in https://newsdig.tbs.co.jp/articles/cbc/2605231 Accessed 2026-04-19

. Photo from: https://newsdig.tbs.co.jp/articles/cbc/2605231 Accessed 2026-04-19

. Photo from: https://newsdig.tbs.co.jp/articles/cbc/2605231 Accessed 2026-04-19

. Photo from: https://newsdig.tbs.co.jp/articles/cbc/2605231 Accessed 2026-04-19

. Photo from: https://newsdig.tbs.co.jp/articles/cbc/2605231 Accessed 2026-04-19

. Photo from: https://newsdig.tbs.co.jp/articles/cbc/2605231 Accessed 2026-04-19

To build this underground station, engineers must first excavate a huge space directly beneath an active railway hub without interrupting operations above. This requires temporarily supporting the Shinkansen platforms and tracks while removing their original deep foundations. The structure being supported weighs on the order of tens of thousands of tons, and the work area spans dozens of meters in both length and width.

The process involves installing temporary support piles and hydraulic jacks to gradually transfer the load from the original foundations. Once the weight is fully supported by this temporary system, workers can cut and remove the existing underground piles and columns. This allows excavation to continue deeper, eventually forming a large underground cavity where the new maglev platforms will be built.

A key challenge is maintaining absolute precision. The load must be evenly distributed across dozens of support points, and even a millimeter-scale deviation could distort the tracks above, potentially affecting train safety. Continuous monitoring systems measure load distribution, structural movement, and alignment in real time, and adjustments are made remotely to keep everything perfectly balanced.

Another major difficulty comes from the local geology. The ground beneath Nagoya is water-rich and prone to pressure buildup. If groundwater pressure is not carefully managed, it can lead to sudden inflows or instability. However, lowering groundwater levels too much can cause the surface structures—especially the Shinkansen platforms—to sink. Engineers must therefore carefully control both water pressure and structural support simultaneously, making this one of the most technically demanding aspects of the project.