1,140 Train Viaduct Pillars May Sink in Japan

Yomiuri Shimbun file photo
Railway workers on their way to investigate cracked pillars caused by an earthquake in March 2022 in Shiroishi, Miyagi Prefecture.

Tokyo (Jiji Press)—Japan has about 1,140 train viaduct pillars that may sink due to an earthquake, the transport ministry said Wednesday.

The ministry also said that it has asked East Japan Railway Co. , or JR East, and West Japan Railway Co. , or JR West, to move up their antiseismic reinforcement work so that the work will be completed by fiscal 2025.

The ministry made the disclosure at a meeting of a panel of experts to examine earthquake countermeasures for Shinkansen bullet trains after a temblor that occurred off Fukushima Prefecture, northeastern Japan, in March this year caused the derailment of a JR East Tohoku Shinkansen train.

According to the panel, JR East and JR West have about 970 and 170 viaduct pillars that may be affected by an earthquake in their service areas. Many are not covered by their current seismic reinforcement programs.

It took about a month to fully reopen the Tohoku Shinkansen line as the March earthquake, which measured upper 6, the second-highest level on Japan’s seismic intensity scale, in Fukushima and the neighboring prefecture of Miyagi, not only caused the derailment but also damaged many utility poles and viaduct sections.

Elevated railway tracks sagged at two locations in Fukushima and Miyagi due to damage to pillars caused by the temblor.

This means that if a Shinkansen train had been at the locations at the time of the earthquake, an accident more serious than the derailment could have happened.

At the two locations, roads run underneath and there are fewer piers supporting large girders than at normal viaducts.

A survey by the panel suggests that the railway tracks experienced subsidence after the quake overloaded and damaged piers.

The panel has concluded that reinforcement work is necessary at an early date, as there are a total of 1,140 viaduct pillars with similar structures on Tohoku, Joetsu and Sanyo Shinkansen lines in the northeastern, central and western regions.

JR companies have been carrying out reinforcement work for bridge piers and electric poles as part of earthquake countermeasures since the 1995 Hanshin-Awaji temblor, which hit the western city of Kobe and nearby areas.

But the costs are high. The ministry says JR companies should secure funds for the work for themselves.