The following is from an article by Kenichi Ogura, Director of the ITMOS Research Institute, which was published in the monthly magazine WiLL on September 26 in a three-column format starting on page 328.
It is a must-read not only for the Japanese people but also for people worldwide.
The Linear Chuo Shinkansen, which is resistant to earthquakes and typhoons
The early commencement of construction of the Linear Chuo Shinkansen will protect Japan
Direct hit on the Obon holiday:
Which is safer, above ground or underground?
This debate has been going on for a long time.
If the underground facilities are old and the pillars are weak, there are cases where it is more dangerous to be underground.
In a disaster, special care is needed underground, such as ventilation, lighting, and evacuation to the surface.
These are the disadvantages compared to above-ground facilities.
However, there are also advantages to being underground, such as being less affected by the weather and experiencing less shaking of an earthquake than above ground.
If disaster countermeasures, such as a power supply, are in place, it has been shown that being underground is significantly safer.
In particular, underground facilities are adequate as evacuation sites in natural disasters such as earthquakes.
Since its opening, the Tokaido Shinkansen has never had a serious accident, and the linear is also known to be strong against disasters such as typhoons.
According to the "Nankai Trough Earthquake Temporary Information (Caution: Major Earthquake)" released by the Japan Meteorological Agency, the Tokaido Shinkansen will operate at a reduced speed during the Obon period, the busiest time of the summer holidays.
This information is released when the possibility of a Nankai Trough earthquake increases, and this time, it was released in response to the earthquake that occurred off the coast of Hyuganada in Miyazaki Prefecture on August 8.
In addition, because typhoons were predicted to cause significant damage this year, the Tokaido Shinkansen was scheduled to be closed for four days in August.
JR Tokai stated that "the weather forecast changes every minute, and with heavy rain falling in places far from the path of Typhoon No. 10, it was tough to decide whether to implement the planned service suspensions" (NHK, September 2).
This kind of natural disaster has made it clear that essential transport networks are at risk of being suspended for long periods.
The impact of the Nankai Trough earthquake and typhoons on Japan's transportation system is significant, and it has been shown that further countermeasures are necessary.
In the wake of the Nankai Trough earthquake information and the train cancellations due to the typhoon, many people felt that the Chuo Shinkansen Linear Express was necessary.
Unlike the Tokaido Shinkansen, which runs along the coast, the Chuo Shinkansen Linear Express will run through mountainous areas for most of its route, including Yamanashi, Nagano, and Shizuoka prefectures.
Once the linear motor train is in operation, even if a Nankai Trough earthquake were to occur and the Tokaido Shinkansen was to stop in Shizuoka Prefecture, it would still be possible to travel to Tokyo, Nagoya, and Osaka without having to take a long detour.
Earthquake countermeasures are rock solid.
Some people on social networking sites and experts still have the misconception that the linear motor train is vulnerable to earthquakes because it runs deep underground.
This misunderstanding is similar to the debate about the shaking of nuclear power plants.
Although it's a digression, please remember that there was a debate about the safety of the Shika nuclear power plant in Noto during the Noto Peninsula earthquake on January 1 this year.
Former Ministry of Economy, Trade and Industry bureaucrat and anti-nuclear power advocate Shigeaki Koga criticized the fact that "the seismic resistance standards for nuclear power plants are lower than those for general housing manufacturers."
Specifically, he points out that the Shiga nuclear power plant is vulnerable to earthquakes.
However, the Shiga nuclear power plant was designed to withstand an earthquake of 600 gal, and this time, the earthquake measured 399 gal.
Furthermore, it was designed to withstand 1000 gal under the new standards, which the government is currently examining.
The unit "gal" expresses the strength of an earthquake; 1 gal means that the ground moves 1 cm in 1 second.
Some house manufacturers are advertising that they have conducted experiments that have withstood 5000 gals or more.
However, it is not appropriate to compare such figures directly.
Mr. Koga is probably aware of this, but he still makes this claim.
To explain this in an easy-to-understand way, let's first talk about the ground.
The ground comprises two layers: the surface layer and the bedrock.
The surface layer is the ground we live on, which is prone to shaking, and the bedrock is the hard layer underneath.
All of Japan's nuclear power plants are built on bedrock, significantly reducing the shaking caused by earthquakes.
For example, in the Kumamoto earthquake (2016), 1580 gal was observed in the surface layer, but 237 gal was observed in the bedrock.
In other words, the degree of shaking in the surface layer and the bedrock is entirely different, so there is no point in comparing them.
Some people were confusing the shaking of the ground with the shaking of the equipment.
It is obvious that the shaking of the equipment built on top of the ground will be greater than the shaking of the ground.
For this reason, it is meaningless to apply the number of gal measured as the shaking of the facilities (Shiga No. 1: 1957 gal, Shiga No. 2: 871 gal) to the number of gal of shaking of the ground assumed in the design of the Shiga Nuclear Power Plant (600 gal).
We can understand the arguments about the grounds on which these nuclear power plants were built correctly.
In that case, the linear Chuo Shinkansen, which runs underground for most of its route, is a remarkably safe form of transport.
Not only that, but the linear train is held in place at the center of the U-shaped guideway by magnetic force, so it will not derail even in the event of an earthquake.
The structure also incorporates sufficient measures to deal with earthquakes.
In addition, the early earthquake warning system "TERAS" used on the Tokaido Shinkansen will also be introduced, so it can be said that the system is fully prepared for earthquakes.
The curse of zero risk
What about other than earthquakes?
It is hard to imagine that the damage from torrential rain caused by the intense heat will disappear after next year.
If you consider the possibility that the Tokaido Shinkansen, which is the main artery of Japan, will stop, then we should get the linear motor train up and running as soon as possible.
As long as it runs underground, it is hardly affected by typhoons or torrential rain.
Despite this, it has been continuously demanded that the Linear Chuo Shinkansen be built with zero risk, which has never been requested for any other civil engineering projects in Japan, such as concerns about the destruction of nature and the possibility of a decrease in water volume.
Former Shizuoka prefectural governor Heita Kawakatsu continued to demand zero risk for the linear project.
When he ran for a fourth term in the 2021 gubernatorial election, he falsely claimed that constructing the underground tunnel for the Chuo Shinkansen would result in the loss of water resources in the Southern Alps.
He misrepresented his promise to "protect the water of life."
About the construction of the Chuo Shinkansen, Kawakatsu has responded by widening the scope of the debate to include issues such as environmental conservation and the disposal of excavated soil.
When one issue was resolved, he raised a different point, and when that was resolved, he moved on to another.
It led to criticism that he was "moving the goalposts."
As a result, the start of construction on the Shizuoka section was not approved, and JR Tokai was effectively forced to abandon its plans to open the line from Tokyo's Shinagawa to Nagoya by 2027.
Mr. Kawakatsu sometimes spoke in favor of the linear motor train project, but in reality, he consistently obstructed it.
With the danger of a Nankai Trough earthquake looming, he obstructed a national project to add another critical transportation network in Japan without any apparent reasons.
He repeatedly made nonsensical remarks at press conferences, and the only newspaper that supported him was the Shizuoka Shimbun.
Kawakatsu was eventually forced to resign after he commented, "The prefectural government is a think tank. Unlike selling vegetables, looking after cattle, or making things day in and day out, you are all knowledgeable people with brains."
Before his resignation, he said he would become a hermit at a press conference: "I will live in the mountains of Shinshu Shinano, in the forest of Mt. Asama, and spend my time talking with the birds."
However, it is ironic that the earthquake-resistant linear bullet train will pass through Nagano Prefecture.
Yasutomo Suzuki, the newly elected governor of Shizuoka Prefecture, is actively working towards obtaining permission to begin constructing the linear bullet train.
In light of the risk of a Nankai Trough earthquake, I hope people will deepen their understanding that the early construction of the linear motor train will help protect Japan.
Seven years have passed in vain due to Kawakatsu's obstruction of the linear motor train, which has continued since 2017.
It is fortunate that the Nankai Trough earthquake did not occur during that time.
Ogura Kenichi
He was born in 1979. He graduated from the Faculty of Economics at Kyoto University.
After working as a secretary to a member of the Diet, he joined President Inc. and was assigned to the President's editorial department.
He became the youngest editor-in-chief of an economic magazine (January 2020).
He became independent in July 2021. He is currently working as a freelance writer.
2024/10/6 in Umeda, Osaka
