[JP] Massive earthquake could damage JR Maglev line

[Eurorapid]

建設中のリニア中央新幹線　巨大地震が起きれば「被害の恐れがある」　地震学教授が警鐘
Linear Central Shinkansen under construction "may be damaged" in the event of a massive earthquake, warns seismology professor

　Katsuhiko Ishibashi, professor emeritus of seismology at Kobe University, gave a lecture titled "Warning from Seismology on the Linear Central Shinkansen" at a forum held in Tokyo on October 16. He pointed out that in the event of a magnitude 9 Nankai Trough earthquake, the ground in the Akaishi Mountains, including the Southern Alps, could sink sharply, causing damage to the 25-km-long Southern Alps Tunnel and other facilities. The project is also concerned about the safety, necessity, and environmental impact of the project. He urged a national debate on the safety, necessity, and environmental impact of the project.

Fear of damage to tunnels due to subsidence of 30-50 centimeters of ground

　At a meeting of the Seismological Society of Japan held in October 2011 after the Great East Japan Earthquake, Mr. Ishibashi stressed that not only would the Tokai, Tonankai, and Nankai earthquakes interlock, but that the Itoigawa-Shizuoka Tectonic Line (Ito-Seizou Line) would also be affected. He attracted attention with his presentation on the possibility of a huge earthquake that would not only link the Tokai, Tonankai, and Nankai earthquakes, but also the Itoigawa-Shizuoka Tectonic Line (Ito-Seizo-Line) fault zone.

　On that day, he reiterated that in the event of a huge Nankai Trough earthquake, the Fuji River estuary fault zone and the Ito-Seizouline fault zone via the Minobu fault near the eastern side of the assumed epicenter zone "may shift. If the Akaishi Mountains were to subside, "the complex geological structure would cause irregular fluctuations and ground rupture, making groundwater eruptions and landslides more likely," he said, mentioning the possibility of collapses of tunnel walls and slopes at entrances.

　Sedimentation could amount to 30 to 50 centimeters, he said.

"Rescue teams should be permanently prepared" in case the linear train becomes inoperable in the tunnel.

　If a linear train becomes inoperable in a tunnel deep underground, it would be difficult to evacuate on foot, and JR Tokai should have a rescue team on standby," he argued.

　At the forum, Mr. Masafumi Ueda, representative of the Citizen Science Laboratory (Tokyo), a non-profit organization that has been conducting investigations with local residents in response to the sinking accident caused by the construction of a deep underground tunnel on the Tokyo Outer Ring Road (Gaikan Expressway), also made a report. He stated that the shield machine, a large cylindrical excavator used in the construction work, "is still in its infancy, and the excavation technology is full of problems.

　The machines are also being used in the construction of deep underground tunnels in the Tokyo and Chukyo areas of Japan's linear transportation system and in the Kazetsuzan Tunnel in Nagano Prefecture.

　The forum was organized by the Jinzaburo Takagi Citizen Science Fund (Tokyo), which was founded based on the will of a citizen scientist who died in 2000 after continuously advocating the dangers of nuclear power. The forum was held at Meiji University's Izumi Campus in Suginami Ward, Tokyo.

The Nankai Trough Earthquake is an earthquake that occurs along a trench-like landform (trough) extending from the Tokai Sea offshore to the seabed off Kyushu Island. When the Tokai, Tonankai, and Nankai epicenters interlock, the magnitude (M) of the quake will reach 9 on the Richter scale, and there is a risk of strong tremors with an intensity of 7 on the Japanese seismic scale from Shizuoka Prefecture to Miyazaki Prefecture. The magnitude of the quake is expected to be 6 or higher to 6 or lower in a wide area around the area. The earthquake occurs repeatedly at intervals of approximately 100 to 150 years. The government's Seismological Commission of Japan puts the probability of an M8-9 magnitude earthquake occurring within 40 years at around 90%.


Info based on translated report by ShinMai.com https://www.shinmai.co.jp/news/article/ ... 2101700030 Accessed 2022-10-17

[Parrahub1]

I think they are worried about nothing as tunnels are safer than viaducts and Japan has the best saftey record in the world in stopping the train and it cannot fall off a viaduct anyway.