JR viaduct in the Tokyo metropolitan area is not part of the seismic retrofitting construction, but the seismic diagnosis is incorrect. 4:29 on August 27.
Regarding the seismic retrofitting of viaducts on conventional lines in the Tokyo metropolitan area, such as the JR Keiyo Line, JR East made a mistake in the seismic diagnosis and found that the construction was not done on a total of more than 270 pillars.
According to JR East, the number of pillars of the viaduct, which had an incorrect seismic diagnosis, is 276 in total, including the Keiyo Line, Musashino Line and Sobu Main Line, as well as six conventional lines in the metropolitan area.
JR East conducted a seismic diagnosis on all the pillars after the Great Hanshin-Awaji Earthquake, and prioritized the reinforcement work of approximately 12,600 lines, which could be greatly damaged by the cracks caused by shaking, until 2008. It was announced that it was completed.
However, in August of last year, a person in charge of performing seismic diagnosis for another construction of the viaduct noticed an error in the past diagnosis, and after further investigation, it was found that 276 pillars were excluded from the construction work. Is that.
For this reason, it means that no reinforcement work has been done for over 10 years, but it means that there has been no damage caused by the earthquake so far.
JR East will carry out additional reinforcement work by the end of the next fiscal year.
Regarding the seismic diagnosis of viaducts, the same problem was discovered in some pillars on the Tohoku Shinkansen and Joetsu Shinkansen this January, and reinforcement work is underway.