11:15 AM - 11:30 AM
[HDS09-08] A new civilization disaster risk during the great Nankai trough earthquake: Quake damage of the SCMaglev Chuo Shinkansen
Keywords:Nankai trough earthquake, SCMaglev Chuo Shinkansen, earthquake damage, civilization disaster
In natural disasters of modern society, it sometimes happens that a civilization disaster that never occurred in the past overlaps, making the disaster more complex and serious. The Fukushima Daiichi NPP accident during the great East Japan earthquake disaster is a remarkable example. In this presentation, I discuss the possibility of a new civilization disaster during the future super-wide-area Nankai trough earthquake disaster, that the Linear Chuo Shinkansen suffers considerable damage.
The Linear Chuo Shinkansen is a SCMaglev (superconducting magnetic levitation) line (hereinafter abbreviated as “Maglev”) planned between Tokyo and Osaka by Central Japan Railway Company. Its initial section between Shinagawa and Nagoya, 285.6 km long, is now under construction (scheduled to open in 2027 or later). Its maximum design speed is 505km/h. The Maglev vehicles are said to be free from derailment in earthquakes, because they travel inside a U-shaped guideway, levitated about 10 cm and kept centered horizontally by electromagnetic forces. It is also said that the Maglev is earthquake-resistant because approximately 86% of the route between Shinagawa and Nagoya is underground or tunnels where earthquake motion is generally smaller.
However, the Maglev is presumably damaged by the great Nankai trough earthquake (reasonably expected to occur during the construction or operation of the Maglev), because most of its route pass through the area where the seismic intensities are inferred to be 6 Lower or larger (JMA scale). If this earthquake occurs during the service hours of the Maglev, the early earthquake alarm system makes all Maglev trains decelerate and stop. When the speed drops below 150km/h or so, the electromagnetic forces for levitation and horizontal guidance become weak, and the train comes to travel on the track by supporting wheels. So, some trains could be hit by violent shaking, and vehicles may touch guideway sidewalls violently, damaging them, and jump out of the guideway (derailment). Around the Kofu Basin and the Nagoya area, the Maglev may be hit by violent ground motion of seismic intensity 6 Upper amd long duration, and civil-engineering structures tend to be damaged. Even in deep underground and mountain tunnels, seismic motion is strong depending on the geological conditions, and stress-strain changes inevitably occur causing groundwater fluctuations, then tracks and tunnels could be damaged, especially in fracture zones. Furthermore, large-scale landslides are prone to bury trains, tracks, and emergency exits. The route between Nagoya and Osaka, passing through the Ise Plain and the Nara Basin, is feared to suffer more damage from strong ground motion and coseismic crustal deformation than the route east of Nagoya. In short, a wide variety of major to minor damages will occur over almost the entire area of the Maglev line due to the great Nankai trough earthquake.
Most prefectures where the Maglev passes through suffer serious disaster from the great Nankai trough earthquake. However, if Maglev trains receive earthquake damage within each prefecture, local governments along the line are forced to respond to the accident. Even if there is no damage to the trains, all trains make emergency stops and all passengers are evacuated, so supporting and accepting evacuees are necessary. Evacuation from deep underground or mountain tunnels is expected much more difficult than the case of conventional trains. In short, it would be like a large passenger plane crash occurring simultaneously in the midst of the intense Nankai trough earthquake disaster. As a result, local governments are severely hampered in their primary efforts to relieve earthquake-stricken residents, and the disaster could even be amplified. Therefore, the Local Disaster Management Plans should be fundamentally changed, in which “earthquake disaster response'' and “large-scale accident response'' are so far separated in most prefectures.
The Linear Chuo Shinkansen is a SCMaglev (superconducting magnetic levitation) line (hereinafter abbreviated as “Maglev”) planned between Tokyo and Osaka by Central Japan Railway Company. Its initial section between Shinagawa and Nagoya, 285.6 km long, is now under construction (scheduled to open in 2027 or later). Its maximum design speed is 505km/h. The Maglev vehicles are said to be free from derailment in earthquakes, because they travel inside a U-shaped guideway, levitated about 10 cm and kept centered horizontally by electromagnetic forces. It is also said that the Maglev is earthquake-resistant because approximately 86% of the route between Shinagawa and Nagoya is underground or tunnels where earthquake motion is generally smaller.
However, the Maglev is presumably damaged by the great Nankai trough earthquake (reasonably expected to occur during the construction or operation of the Maglev), because most of its route pass through the area where the seismic intensities are inferred to be 6 Lower or larger (JMA scale). If this earthquake occurs during the service hours of the Maglev, the early earthquake alarm system makes all Maglev trains decelerate and stop. When the speed drops below 150km/h or so, the electromagnetic forces for levitation and horizontal guidance become weak, and the train comes to travel on the track by supporting wheels. So, some trains could be hit by violent shaking, and vehicles may touch guideway sidewalls violently, damaging them, and jump out of the guideway (derailment). Around the Kofu Basin and the Nagoya area, the Maglev may be hit by violent ground motion of seismic intensity 6 Upper amd long duration, and civil-engineering structures tend to be damaged. Even in deep underground and mountain tunnels, seismic motion is strong depending on the geological conditions, and stress-strain changes inevitably occur causing groundwater fluctuations, then tracks and tunnels could be damaged, especially in fracture zones. Furthermore, large-scale landslides are prone to bury trains, tracks, and emergency exits. The route between Nagoya and Osaka, passing through the Ise Plain and the Nara Basin, is feared to suffer more damage from strong ground motion and coseismic crustal deformation than the route east of Nagoya. In short, a wide variety of major to minor damages will occur over almost the entire area of the Maglev line due to the great Nankai trough earthquake.
Most prefectures where the Maglev passes through suffer serious disaster from the great Nankai trough earthquake. However, if Maglev trains receive earthquake damage within each prefecture, local governments along the line are forced to respond to the accident. Even if there is no damage to the trains, all trains make emergency stops and all passengers are evacuated, so supporting and accepting evacuees are necessary. Evacuation from deep underground or mountain tunnels is expected much more difficult than the case of conventional trains. In short, it would be like a large passenger plane crash occurring simultaneously in the midst of the intense Nankai trough earthquake disaster. As a result, local governments are severely hampered in their primary efforts to relieve earthquake-stricken residents, and the disaster could even be amplified. Therefore, the Local Disaster Management Plans should be fundamentally changed, in which “earthquake disaster response'' and “large-scale accident response'' are so far separated in most prefectures.