|Extent of Damage
At 14:46 on 11 March 2011, a Richter Magnitude 9.0 submarine
earthquake struck off Japan’s Sanriku coast. Tremors measured
the maximum 7 on the Japan Meteorological Agency’s seismic
intensity scale at Kurihara City in Miyagi Prefecture and high 6
in 37 cities in the four prefectures of Miyagi, Fukushima, Ibaraki,
and Tochigi. Shaking was observed over a wide area from
Hokkaido to Kyushu, with the worst tremors felt in east Japan
(Figure 1). A high tsunami wave was also triggered mainly on
the Pacific coast side of Japan over a broad area from the
Tohoku to Kanto regions, causing tremendous damage. The
Meteorological Agency named this disaster ‘the 2011 off-the-
Pacific coast of Tohoku Earthquake’, and the disaster is officially
called the Great East Japan Earthquake by cabinet decree. It
was the largest earthquake ever recorded in Japan.
Effectiveness of the Earthquake Early warning System for Shinkansen
There were 27 trains running on the Tohoku Shinkansen when
the earthquake struck, but all made successful emergency
stops under control of the earthquake warning system.
The success of this system and the fact that there was
no catastrophic damage to track structures prevented
injuries and fatalities among passengers.
Using lessons learned from previous earthquakes, JR
East had already developed earthquake countermeasures
based on three points: stop running trains quickly; build collapse-proof structures; minimize damage afterderailment. These in-place measures proved very effective in the Great East Japan Earthquake
To stop running trains quickly, JR East had installed
the Earthquake Early warning System that triggers
automatic shinkansen emergency stops. It uses Coastline
seismograph to detect seismic waves (P- and S-waves),
To minimize damage after derailment, JR East
had progressed with application of L-shaped guides
where a guide prevents wheels from deviating laterally too
far from the rails in a derailment. Rail rollover prevention
devices where wheels are guided by the rails even when
a carriage derails and damages the rail fastenings had also
All these countermeasures functioned well with the result
that there were no railway-related fatalities or injuries even in
such a huge earthquake
Figure 1: Distribution of Japanese Seismic intensity Scale on 11 March 2011
Figure 2: Overview of Earthquake Early Warning System for Shinkansen
Photo: Aseismic reinforcement of viaducts (JR East)
Photo: L-shaped guide (Also refer to Figure 13 on page 39) (JR East)
Photo: Rail rollover prevention device (JR East)
Photo: Damage to electric poles (JR East)
Photo: Damage to viaducts (JR East)
Photo: Damage to supports (JR East)
Table 1: Damage to Shinkansen
Photo: Damage to electric poles (JR East)
Photo: Damage to viaducts (JR East)
Photo: Damage to supports (JR East)
|Earthquake Damage and Emergency
Damage to Tohoku Shinkansen
Damage occurred to viaduct columns and wayside
equipment, such as electric poles and overhead lines, at
about 1200 locations between Omiya and Iwate-Numakunai
(approx. 500 km). It was particularly heavy between
Fukushima and Sendai near the epicentre, with damage at
about 390 locations (Table 1). Emergency restoration work
proceeded to restart railway services as soon as possible,
and sites still needing work had been reduced to about 90
by 7 April. However, a very strong aftershock late that night,
damaged some further 550 sites.
While damage sites were spread over a broad area,
earlier aseismic reinforcements prevented the catastrophic
viaduct collapses seen in the January 1995 Great Hanshin
Earthquake and tunnel collapses seen in the October 2004
Mid Niigata Prefecture Earthquake.
Unlike previous large earthquakes, there was much
damage to electric utility poles over a wide area, especially
at the connection of poles to viaducts. There was no
shear failure due to brittleness, but there was some slight
damage, such as flexing failure at the ends of columns and
displacement of girders due to damage to bridge supports.
Photo: Landslide between Toyohara and Shirasaka on Tohoku main line (JR East)
Photo: Embankment subsidence between Mito and Katsuta on Joban Line (JR East)
Table 2: Damage to Conventional Lines
Photo: Liquefaction on Ecchujima Line (JR East)
Damage to conventional lines
Meanwhile, conventional narrow-gauge lines suffered
damage from the earthquake and aftershocks across
a wide area from the Kanto to Tohoku regions. Failures
included track irregularities where track buckled, damage to
earthworks such as embankments and cuttings, damage to
civil-engineering structures including platform deformations,
collapse, and tilting of electric utility poles, and damage to
stations. The 36 lines mainly running through Iwate, Miyagi,
Fukushima, and Ibaraki prefectures, suffered damage such
as track irregularities and pole collapse at about 4400 sites.
Subsequent aftershocks caused more damage at about 850
sites (Table 2).
One typical failure was large-scale collapse and
deformation of embankments near the offshore epicentre
from the Tohoku region. In parts of Greater Tokyo, some
buildings subsided due to liquefaction under foundations.
Immediately after the earthquake, local engineers were
working day and night on recovery with limited means of
communications and transport, using what heavy equipment, fuel, and materials they could get their hands on. Due to thelack of engineers in affected areas, JR East dispatched personnel from across the company to conduct emergency restoration work to restart services. Restoration of electric
utility poles was a deciding factor in scheduling resumption of services. Much human and material support was received from businesses involved in railways, such as other JR companies and private railways, and restoration work progressed in harsh conditions as aftershocks continued.
About 8500 people a day were involved in restoration work
on both shinkansen and conventional lines.
Technical support on restoration methods was also
received from the Railway Technical Research Institute.
Much support was received from many other organizations,
especially in procuring hard-to-come-by-fuel to allow
use of automobiles, heavy construction equipment, and
maintenance vehicles. Based on this cooperation from
across Japan, services resumed on the entire Tohoku
Shinkansen on 29 April, just 49 days after the earthquake.
Service resumed on the Tohoku main line on 21 April, 41
days after the earthquake, and gradually thereafter on other
lines, except those damaged by the tsunami.
Figure 3: Tsunami Damage to Conventional Lines
|Tsunami Damage and Restoration
Damage from tsunami
Unfortunately, the huge earthquake caused more than just
heavy ground shaking. It generated a giant tsunami along
the Pacific coast of east Japan. At Soma City in Fukushima
Prefecture, the wave was more than 9.3 m. At Miyako City in
Iwate Prefecture, the maximum vertical wave height onshore
was more than 40 m.
JR East suffered major damage
on some 325 km of seven coastal
lines; stations were swept away and
tracks and bridge girders were buried
or swept away (Figure 3). Fortunately,
there were no fatalities or injuries to train
passengers, probably as a result of
repeated training including evacuation
drills. When crews of trains running near
the coast were informed of the tsunami
warnings, they stopped the trains and
guided passengers to local government
Restoration of tsunami-damaged lines
Recovery coordination conferences
were set up for each damaged line with
the participation of the Ministry of Land,
Infrastructure, Transport and Tourism,
and local governments. The purpose
was to consider restoration of the seven lines that suffered
extensive damage while maintaining a balance with recovery
of urban areas.
Many recovery coordination conferences have been held
for individual lines as venues to exchange information and
coordinate recovery and restoration. JR East sees a need to
consult actively with parties such as the national government
and local governments in planning overall recovery of
the region and community development in the restoration
process. The company participated in conferences on
community development for recovery held by individual
local governments as well as in recovery coordination
In parallel with these discussions, JR East gradually
proceeded with construction in sections where safety
could be secured and resumed services on the sections
shown below (Table 3). As of June 2012, tsunami-damaged
sections of coastal lines and sections in the nuclear plant
evacuation zone where services are suspended have been
reduced from an initial 400 km to about 260 km (Figure 4).
The direction of restoration on sections where service
is currently suspended will be decided through continued
discussions with local governments and other bodies. In the
meantime, JR East is working to secure local transport in the
sections where trains are not running using substitute bus
services and other measures.
Railway restoration involving line relocation
Extensive tsunami damage such as swept-away tracks and
damaged stations has suspended services on the Senseki
Line (between Takagimachi and Rikuzen-Ono) and Joban
Line (between Soma and Watari). Discussions were held
with local governments on restoration policy; based on
a policy of relocating lines to higher ground, agreement
was reached on changing railway routes, and a decision
was made to proceed with restoration in conjunction with
community development plans (Figures 5 and 6).
Services are expected to resume about 2 years after
the start of construction on the Senseki Line and after about
3 years on the Joban Line.
However, on-site surveying,
planning, purchase of land for relocation, and other work are
needed along with construction for community development,
such as site preparation for relocated sections. For these
reasons, a memorandum of understanding will be concluded
between JR East and local governments, and work will
proceed as soon as possible.
Work is expected on the Joban Line between Hirono and
Haranomachi ahead of the return of residents with revision
of the Fukushima Daiichi nuclear plant evacuation zone.
Discussions and policy decisions for restoration will probably
be needed in the future.
Temporary restoration by bus rapid transit
The Kesennuma, Ofunato, and Yamada lines all suffered
serious damage over long stretches and recovery of the
trackside communities is expected to take a long time.
Many restoration issues must be studied, such as securing
safety for passengers and consistency with community
development plans. Much time is expected to pass before
In this light, JR East considered temporary restoration
using bus rapid transit (BRT) from the standpoints of
taking responsibility for local stable transport at the
earliest opportunity. The company proposed BRT to
local governments along the Kesennuma Line at the third
Kesennuma Line recovery coordination conference late last
year, 9 months after the earthquake.
BRT is a transport mode that uses established routes
and dedicated lines and allows faster and more frequent
service than regular buses while coexisting with normal
automobile traffic (Figure 7). Benefits of BRT include use
of railway beds to secure speed and on-time service.
Flexible support can be provided, such as setting routes
and adding stations in stages as the community develops.
Passengers can be evacuated more easily in earthquakes
and tsunami because buses run under their own power.
And service can be resumed quickly because buses run
on regular roads.
The agreement of local governments to use BRT was
achieved at the fifth Kesennuma Line recovery coordination
conference in May, 14 months after the quake, and
preparations are underway to start service soon.
Discussions are planned with local government officials
and others regarding securing alternative modes of transport
for the Ofunato and Yamada lines too.
Table 3: Sections of Seven Tsunami-Damaged Lines where Operations Resumed
Figure 4: Sections of Lines where Service is Currently Suspended (5 June)
Figure 5: Higashimatsushima City Recovery Community Development Plan (26 December 2011)
Figure 6: Joban Line Recovery Coordination Conference Materials (March 2012)
Figure 7: Image of Temporary Restoration by BRT
|Dealing with Risk of Possible Future Major Earthquakes
Passenger fatalities and injuries as well as catastrophic
damage to railway facilities were avoided mainly due to
aseismic reinforcements, derailment prevention measures,
and steady implementation of the earthquake early warning
system following the lessons learned from the Great
Hanshin Earthquake in January 1995, the Sanriku-Minami
Earthquake in May 2003, and the Mid Niigata Prefecture
Earthquake in October 2004.
JR East has been proceeding with a second round of
aseismic reinforcements on viaducts since 2009, and there
are plans for further aseismic reinforcements in case an
earthquake strikes directly under Tokyo. As well as bringing
forward the schedule and expanding the scope of aseismic
reinforcement of viaducts, work will be performed on
embankments, cuttings, bridges, and station platform roofs
and ceilings on some 220 km of 9 lines including the Yamanote
Line and Chuo Line. To enhance seismic observations, 30
additional seismometers will be installed and the Earthquake
Early warning System introduced on conventional lines using
the Japan Meteorological Agency Earthquake Early Warning
System will be expanded to shinkansen lines (Figure 8). JR
East is doing its best to prepare for any future earthquake
strikes through such measures.
Restoration work is still underway on damaged lines, and
JR East is making further efforts to help recover the affected
areas as soon as possible in cooperation with overall
regional recovery and community development planning.
Figure 8: Enhancement of Seismic Observation Points (Installing More Seismometers)