Proceedings of the International Symposium on Engineering Lessons Learned fromthe 2011 Great East Japan Earthquake, March 1-4, 2012, Tokyo, Japan

EARTHQUAKE AND TSUNAMI DAMAGE
ON STEEL BUILDINGS CAUSED BY
THE 2011 TOHOKU JAPAN EARTHQUAKE
Mitsumasa MIDORIKAWA1, Isao NISHIYAMA2, Motohide TADA3
and Takehiko TERADA4
1

Professor, Faculty of Engineering, Hokkaido University, Sapporo, Japan,
midorim@eng.hokudai.ac.jp
2
Director, Building Department, National Institute for Land and Infrastructure Management, MLIT,
Tsukuba, Japan, nishiyama-i92ta@nilim.go.jp
3
Professor, Graduate School of Engineering, Osaka University, Suita, Japan,
tada@arch.eng.osaka-u.ac.jp
4
Chief Researcher, Institute of Technology, Shimizu Corporation, Tokyo, Japan,
t.terada@shimz.co.jp

ABSTRACT: The 2011 Tohoku Japan earthquake and tsunami caused extensive damage
to steel building structures. Large slippage over a large inter-plate fault produced very
high tsunami waves that attacked the east coast of Japan. The Committee of Steel
Structures of the Architectural Institute of Japan carried out earthquake damage
reconnaissance over cities where severe ground shaking was recorded among theprefectures of Miyagi and Fukushima. Tsunami damage reconnaissance was also
conducted along the coastlines of Iwate, Miyagi, and Fukushima.
Key Words: 2011 Tohoku Japan earthquake, earthquake damage, tsunami damage, steelbuilding

INTRODUCTION
The Committee of Steel Structures of the Architectural Institute of Japan carried out earthquake
damage reconnaissance over the prefectures of Miyagi and Fukushima. Tsunami damage
reconnaissance was conducted along the coastlines of the prefectures of Iwate, Miyagi, andFukushima.
The observed damage to steel buildings are classified into those caused by ground motions andthose caused by tsunami. Severe ground motion caused damage to beam-to-column connections,buckling of diagonal braces, cracking and fracture of concrete overlaying the column base, yielding
and fracture of anchor bolts, which are the similar damage aspects observed from past earthquakes.
Severe nonstructural damage occurred to ceilings and claddings of steel building structures with large
open areas, such as gymnasiums and factories. Extensive damage was observed in external finishes
composed of mortar over light-gauge metal lath.
A distinctive feature of the Tohoku event is the damage caused by tsunami. In the most extreme1061

cases, buildings were displaced from their original location and completely destroyed. In other cases,
fracture of connections and members caused the building to tilt or collapse. In buildings whose
claddings were completely washed away by tsunami, structural damage was minor. The extent oftsunami damage is various significantly depending on the locality of tsunami attack.

DAMAGE CAUSED BY EARTHQUAKE GROUND MOTION
The ground motion caused damage to many low- to mid-rise buildings. Judging from the types ofmembers and framing system, the majority of damaged buildings were constructed in older years
preceding the major change in the seismic provisions of the Building Standard Law in 1981.
Damage to structural members
Beam-to-column connections
Brittle fracture of beam-to-column connections, which was observed widely after the 1995 Kobe
earthquake, has not been reported from the Tohoku event. Photo 1 shows damage observed in an older
structure that employed built-up HSS (hollow structural steel) columns made up of a light W-shapeand a pair of cover plates. Such sections were commonly used before cold-formed HSS sections
became available.
Braces and bracing connections
Brace buckling, net-section fracture, and distortion and fracture of the gusset plates were observed inmany brace framed structures (Photos 2-10).
Failure of angle-section braces, which were commonly used in older construction, was typically
governed by buckling and fracture initiating at the bolt holes. In contrast, the predominant damage to
HSS braces was out-of-plane bending of the gusset plates. Some gusset plates fractured as a result of alarge number of repeated bending.
Column bases
The majority of investigated buildings were low- to mid-rise, where exposed base plate connections
are more commonly used than embedded or encased column base connections. The damage to exposedbase plates points out that, unless the anchor bolts fractured, residual story drift and structural damage
to the building was minimal. On the other hand, evidence suggests that fracture of anchor bolts led todislocation of the column and severe residual story drift (Photos 11-18).

Photo 1 Yielding of an older
built-up column (Koriyama)

Photo 2 Buckling of double-angle
brace (Miyagino, Sendai)

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Photo 3 Local buckling insquare-HSS brace (Aoba, Sendai)Photo 4 Net section fracture of Photo 5 Bending of middle gusset Photo 6 Fracture of gusset
single-angle brace (Miyagino, plate in an X-brace (Miyagino,plate-to-column weld and spalling
Sendai)Sendai)of concrete covering an exposedbase plate (Ishinomaki)

Photo 7 Out-of-plane
deformation of gusset plate(Miyagino, Sendai)

Photo 8 Yielding of column
web near bracing connection(Koriyama)

Photo 9 Out-of-plane
deformation and fracture ofgusset plates (Miyagino, Sendai)

Photo 10 Out-of-plane
deformation of gusset plate
caused by compression(Miyagino, Sendai)

Photo 11 Spalling of reinforced
concrete encasing a steel columnbase (Wakabayashi, Sendai)

Photo 12 Elongation of anchor
bolts in an exposed base plate(Miyagino, Sendai)

Photo 13 Cracking of asphalt
covering a column base(Miyagino, Sendai)

Photo 14 Spalling of concrete
covering a column base(Koriyama)

Photo 15 Spalling of reinforced
concrete foundation supportinga column base (Koriyama)1063

Photo 16 Fracture of anchor
bolts (Miyagino, Sendai)

Photo 17 Fracture of anchor bolts, Photo 18 Fracture of anchor bolts,
spalling of concrete covering aout-of-plane deformation of basecolumn base (Miyagino, Sendai) plate (Miyagino, Sendai)

Damage to nonstructural elements
Widespread damage was observed in dry-construction elements such as ceilings made up of mortar
over metal lath and ALC-panel cladding. Nonstructural damage was observed in buildings of all
construction ages (Photos 19-30). Extensive damage was observed in older-type external finishes thatplace mortar.

Photo 19 Fallen ceiling gridand boards (Fukushima)

Photo 20 Fallen claddings;
damaged ceiling boards(Miyagino, Sendai)

Photo 21 Fallen ceiling,
partitions damaged by impact(Aoba, Sendai)

Photo 22 Partly fallen ceiling(Koriyama)

Photo 23 Fallen ceiling on theoutside of a building(Wakabayashi, Sendai)

Photo 24 Cracking of externalfinish (Aoba, Sendai)

Photo 25 Failure of metallath-and-mortar cladding(Miyagino, Sendai)

Photo 26 Fallen cladding(Ishinomaki)

Photo 27 Fallen and twisted
cladding (Koriyama)1064

Photo 28 Damage to cladding
covering a column(Wakabayashi, Sendai)

Photo 29 Damaged cladding
in a mechanical penthouse(Koriyama)

Photo 30 Damaged cladding(Sukagawa)

DAMAGE CAUSED BY TSUNAMI
In areas attacked by high tsunami waves, severe damage was observed such as failure of the columnbase that led to overturning and dislocation of the building, and extreme distortion of structuralmembers and connections. In instances where the external claddings were washed away, the load
produced by tsunami was reduced to cause little damage to the structural system. Tsunami damage is
described for different districts in the following.
Port of Ishinomaki (reported inundation height 5 m)
Office building A (Photos 31-32)
X-dir.: 5 spans, Y-dir.: 2 spans, Number of stories: 1
X-dir.: moment frame, Y-dir.: moment frame
Columns: square HSS’s, Beams: W-shapes, External finish: ALC panels
Observations: Internal and external finishes washed away. No structural damage.
Office building B (Photos 33-34)
X-dir.: 5 spans, Y-dir.: 1 span, Number of stories: 2
X-dir.: braced frame, Y-dir.: moment frame
Columns: W-shapes, Beams: W-shapes, Braces: angles (1F), round bars (2F), External finish: ALC
panelsObservations: Extensive structural damage. Foundation exposed due to scouring, braces fractured.
Port Facility A (Photos 35-37)
X-dir.: braced frame, Y-dir.: moment frame
Columns: W-shapes, Beams: W-shapes, Braces: round bars, Column base: exposed type
Observations: External cladding partly lost. Residual drift of 1/400 in the north and east directions.
Port facility B (Photos 38-39)
X-dir.: braced frame, Y-dir.: moment frame
Columns: W-shapes, Beams: W-shapes, Braces: angles, Column base: exposed type
Observations: Two spans closest to the shore collapsed. Fracture of anchor bolt

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Photo 31 Office building A:
External view.

Photo 32 Office building A:
inside view.

Photo 33 Office building B:
external view showing
noticeable residual drift.

Photo 34 Office building B:
net section fracture of asingle-angle brace.

Photo 35 Port facility A:
external view.

Photo 36 Port facility A:
inside view.

Photo 37 Port facility A: columnbase rusted presumably due toseawater proximity.

Photo 38 Port facility B:
external view.

Photo 39 Port facility B:
fractured anchor bolt.

Onagawa (reported inundation height 15 m)
Building A (Photos 40-41)
X-dir.: 3 spans, Y-dir.: 1 span, Number of stories: 3
Y-dir.: moment frame
Columns: W-shapes, Beams: W-shapes, External finish: corrugated metal sheets
Observations: Building tilted after foundation scouring.
Building B (Photos 42-43)
Number of stories: 3 (partially 4)
X-dir.: moment frame, Y-dir.: moment frame
Columns: square HSS’s, Beams: W-shapes, External finish: ALC panels
Observations: Building dislocated about 15 meters and lain sideways after all piles failed due topullout.
Building C (Photos 44-45)
Columns: square HSS’s, Beams: W-shapes
Observations: Collapsed after extensive connection failure.
Building D (Photos 46-48)
X-dir.: moment frame, Y-dir.: moment frame
Columns: older built-up square HSS’s, Beams: W-shapes, Column bases: exposed type1066

Observations: Internal and external finishes washed away, damage in column bases.
Building E (Figures 49-51)
Columns: Square HSS’s, Beams: W-shapes, Column bases: exposed type
Observations: Collapsed. Fracture of beam-to-column connections, anchor bolts, and horizontal
braces.
Warehouse A (Photos 52-54)
Use: Refrigeration
X-dir.: braced frame, Y-dir.: moment frame
Observations: Residual drift exceeding 1/20. East frame collapsed.

Photo 40 Building A: externalview showing large tilt.

Photo 41 Building A:
foundation scour.

Photo 42 Building B: building
collapsed towards left.

Photo 43 Building B: view offoundation showing fracture piles.

Photo 44 Building C:
external view.

Photo 45 Building C:
failed connection.

Photo 46 Building D:
external view.

Photo 47 Building D: column baselifted and anchor bolts deformed.

Photo 48 Building D: beam-tocolumn connections at cornerlPhoto 49 Building E:
external view.

Photo 50 Building E:
beam-to-column connection.

Photo 51 Building E:
column base.

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Photo 52 Warehouse A:
external view.

Photo 53 Warehouse A:
damage to column base.

Photo 54 Warehouse A:
inside view.

Shiogama (Reported inundation height: 4 m)
Warehouse B (Photos 55-56)
Columns: W-shapes, Beams: W-shapes, Braces: round bars, Column bases: exposed type, Externalfinish: slate tiles over metal lathObservations: Foundation subsided due to tsunami and liquefaction.

Photo 55 Warehouse B: external Photo 56 Warehouse B: view offront side; far-right end subsided.
view; right end subsided.
Miyagino, Sendai (Reported inundation height: 8 m)
Office Building C (Photos 57-59)
Columns: square HSS’s, Beams: W-shapes, Column bases: exposed type
Observations: Underground piping exposed after scouring.
Office Building D (Photos 60-61)
X-dir.: moment frame, Y-dir.: moment frame
Columns: Square HSS’s, Beams: W-shapes, Column bases: exposed type
Observations: First floor cladding washed away. No structural damage.

Photo 57 Office building C:
external view.

Photo 58 Office building C:
severe damage to cladding.

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Photo 59 Office building C:
under-ground piping exposed
after scouring.

Photo 60 Office building D:
Photo 61 Office building D:
cladding washed away in first
nonstructural damage in first story.
story; minimal structural damage.
Minami-Sanriku (Reported inundation height: 13 to 15 m)
Office Building E (Photos 62-63)
X-dir.: moment frame, Y-dir.: moment frame
Observations: Evidence of beam yielding. No residual drift.
Store A (Photos 64-65)
X-dir.: moment frame, Y-dir.: moment frame
Observations: Evidence of beam yielding. Residual drift of 1/200 in first story. Cracking of concrete
wrapping the column base.
Factory A (Photos 66-67)
X-dir.: moment frame, Y-dir.: moment frame
Observations: Chord member of roof truss buckled presumably due to impact of debris. Part ofstructure demolished and cleaned by the time of visit.
Gymnasium A (Photos 68-70)
X-dir.: moment frame, Y-dir.: moment frame
Observations: Wall closest to shore line was pulled toward the shore. Roof truss buckled and collapsed.
Anchor bolts in column base fractured. Bolts joining roof truss members fractured. Adjacent 3-story
R/C school building completely subsided during tsunami attack.

Photo 62 Office building E:
majority of nonstructuralelements washed away; minor
structural damage.

Photo 63 Office building E:
yielding of beam nearbeam-to-column connection.

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Photo 64 Store A: external view.

Photo 65 Store A: slight yieldingof beam near beam-to-column
connection.

Photo 68 Elementary school
gymnasium A: external view.

Photo 66 Factory A: externalview.

Photo 67 Factory A: buckled
chord members in roof truss.

Photo 69 Elementary school
Photo 70 Elementary school
gymnasium A: damaged column gymnasium A: severely damaged
base.
roof.

Kesennuma (Reported inundation height: 4 to 10 m)
Warehouse C (Kawaguchi District) (Photos 71-72)
X-dir.: moment frame, Y-dir.: X-braced frame
Observations: Collapsed and severely deformed.
Store B (Photos 73-74)
X-dir.: moment frame, Y-dir.: moment frame
Observations: Severe damage caused by impact of debris. Damage concentrated in single-story
segment. (Residual drift of 1/160 in Y-direction. Anchor bolts fractured. Fracture in beam-to-column
connections. Ceiling braces fractured.) No damage in two-story segment.
Hotel A (Niihama District) (Photos 75-76)
X-dir.: moment frame, Y-dir.: moment frame
Observations: Second story collapsed after weld fracture between through-diaphragm plate andcolumn.
Store C (Photos 77-79)
Single story
X-dir.: moment frame, Y-dir.: moment frame
Observations: Plastic hinging and fracture at top and bottom of column. Residual drift of 1/5 in
Y-direction.
Factory B (Photos 80-81)
X-dir.: unknown, Y-dir.: moment frame
Observations: Residual deformation of 1/10 in lower segment with cracking of concrete encasing thecolumn bases, yielding of panel zone, and local buckling of beam flanges.
Factory C (Photos 82-83)
X-dir.: inverted V-braced frame, Y-dir.: moment frame
Observations: Buckling and fracture of braces, bending of column base plates.

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Factory D (Photos 84-85)
X-dir.: braced frame, Y-dir.: gable frame
Observations: Collapsed in Y-direction. Yielding in column bases and panel zones and gable frame
beams

Photo 71 Warehouse C:
external view.

Photo 72 Warehouse C:
deformed columns and beams.

Photo 73 Store B: external view.

Photo 74 Store B: fractured
beam-to-columniPhoto 75 Traditional hotel A:
external view.

Photo 76 Traditional hotel A:
close-up view of collapsed
second story.

Photo 77 Store C: external view.

Photo 78 Store C:
distorted columns.

Photo 79 Store C: plastic
deformation at top of first-story
column.

Photo 80 Factory B:
external view.

Photo 81 Factory B: yielding
in beam-to-column
connection.

Photo 82 Factory C:
external view.

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Photo 83 Factory C: net section
fracture of a single-angle braceat the column base.

Photo 84 Factory D: building
leaning towards right.

Photo 85 Factory D: yieldingof joint region.

Rikuzen-Takada (Reported inundation height 12 to 16 m)
Store D (Photos 86-87)
X-dir.: moment frame, Y-dir.: moment frame
Observations: No residual drift. Torsional deformation of beams in frame facing the shore line.
Store E (Photos 88-89)
X-dir.: moment frame, Y-dir.: moment frame
Observations: Residual drift of 1/200. Damage to second-floor concrete slab. Suspected cause is lifting
force produced by air pocket in the first story.
Factory E (Photos 90-92)
X-dir.: X-braced frame, Y-dir.: moment frame
Observations: Lateral-torsional buckling of beam. Yielding of column base. Severe deformation ofcolumn panel zones.
Gymnasium B (Photos 93-94)
X-dir.: X-braced frame, Y-dir.: gable frame
Observations: First story collapsed in X-direction. Building displaced in X-direction by 20 m.
Gymnasium C (Photos 95-97)
X-dir.: X-braced frame, Y-dir.: moment frame, roof: space truss
Observations: Severe deformation of frame facing the shore line. Buckling of X-braces. Buckling ofchord members in roof truss.

Photo 86 Store D: damage to
cladding.

Photo 87 Store D: torsional
deformation of beam.

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Photo 88 Store E: damage to
cladding.

Photo 89 Store E: deformed
metal floor slab.

Photo 92 Factory E: large
deformation of column panel
zone.

Photo 95 Gymnasium C:
external view.

Photo 90 Factory E:
cladding washed away.

Photo 91 Factory E: local flange
buckling of column near base.

Photo 93 High-school
Photo 94 High-school gymnasium
gymnasium B: external view of B: building displaced by 20 m.
collapsed building.

Photo 96 Gymnasium C:
severely distorted columns.

Photo 97 Gymnasium C:
distorted roof trusses.

Kuji (Reported inundation height at Kuji Port: 8 to 9 m)
Warehouse D (Photos 98-99)
X-dir.: moment frame, Y-dir.: moment frame
Columns: W-Shapes, Beams: W-Shapes
Observations: No structural damage. Internal and external finish washed away.
Factory F (Photos 100-101)
X-dir.: moment frame, Y-dir.: X-braced frame
Columns and beams: Built-up W-Shapes, Braces: round bars, External finish: corrugated metal sheets
Observations: Evidence of debris impact on shore side wall.
Factory G (Photos 102-103)
X-dir.: 1 span, Y-dir.: 3 spans, Number of stories: 2
X-dir.: moment frame, Y-dir.: moment frame
Columns: square HSS’s, Beams: W-shapes, External finish: corrugated metal sheets
Observations: Internal and external finishes washed away. No residual drift.

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Photo 98 Warehouse D:
nonstructural elements washedaway.

Photo 99 Warehouse D:
minimal structural damage;no residual drift.

Photo 100 Factory F:
cladding remained.

Photo 101 Factory F: damage toconcrete encasing column base.

Photo 102 Factory G: externalview.

Photo 103 Factory G:
little structural damage.

Miyako (Reported Inundation height at Taro Port: 13.4m)
Hotel B (Photos 104-105)
X-dir.: 1 span, Y-dir.: 6 spans, Number of stories: 6
X-dir.: moment frame, Y-dir.: moment frame
Columns: Square HSS’s, Beams: W-shapes, Column base: concrete encased, External finish: ALC
panelsObservations: Internal and external finish washed away in first to third stories. Little residual drift.
Ice Making Factory A (Photos 106)
X-dir.: 1 span, Y-dir.: 2 spans, Number of stories: 4
Columns: square HSS’s (concrete-encased in first story), Beams: W-shapes, External finish: extruded
cement panels
Observations: Internal and external finishes washed away in first to third stories. Little residual drift.

Photo 104 Hotel B: external view.

Photo 105 Hotel B: interior
damage seen at first story.

Kamaishi
Office Building F (Photos 107-108)
X-dir.: 4 spans, Y-dir.: 2 spans, Number of stories: 2
X-dir.: moment frame, Y-dir.: moment frame

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Photo 106 Ice making
factory A: exterior view.

Columns: Square HSS’s, Beams: W-shapes, Column bases: exposed type, External finish: extruded
cement panels
Observations: Internal and external finishes washed away. Little residual drift. Foundation exposed
after scouring.

Photo 107 Office building F:
exterior view.

Photo 108 Office building F:
foundation exposed after scouring.

Ohfunato
Factory H (Photos 109-110)
X-dir.: 2 spans, Y-dir.: 3 spans, Number of stories: 2
Columns: older built-up square HSS’s (1F), W-shapes (2F), Beams: W-shapes, Column bases: exposed
type, External finish: slate tiles
Observations: Internal and external finishes washed away. First story deformed towards shoreline.
Round bar braces fractured.

Photo 109 Factory H:
external view.

Photo 110 Factory H: first story
leaning towards inland.

DAMAGE CAUSED BY GROUND DEFORMATION AND FIRE
In areas with poor soil conditions, ground deformation caused structural damage. In some cases thefoundation mounted on piles was undamaged but the surrounding soil subsided. Liquefaction caused
differential subsidence that tilted the building. (Photos 111-113)
Damage in some buildings was exacerbated by fire that initiated after the earthquake and tsunami.
The cause of fire is unknown. (Photos 114-116)

Photo 111 Shopping complex:
ground subsided near footing
foundation. (Rifu)

Photo 112 Office building: Tworight-end spans subsided due toliquefaction. (Iwanuma)

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Photo 113 Subsided corner ofsame building shown in Photo
112 (Iwanuma)

Photo 114 Warehouse(Miyagino, Sendai)

Photo 115 Building(Miyagino, Sendai)

Photo 116 Delivery station (Natori)

SUMMARY
Preliminary observations are summarized as follows:
1) The ground motion caused limited structural damage to steel buildings constructed after majorrevision in the seismic provisions of the Building Standard Law was implemented in 1981. However,older buildings constructed prior to 1981 saw notable damage caused by ground motion. Nonstructural
damage to internal and external finishes and ceilings was extensive regardless of construction age.
2) A large proportion of industrial and commercial facilities in the tsunami affected area wereconstructed in steel. Extensive damage was observed in these steel buildings.
3) In areas attacked by violent tsunami, some steel buildings saw limited structural damage because
their internal and external finishes were immediately washed away. Many buildings were damaged bydebris impact.
4) In areas attacked by less violent tsunami, steel buildings saw varying degrees of nonstructural
damage depending on the tsunami water height. However, the majority of buildings saw limited
structural damage.

ACKNOWLEDGMENTS
This material is based on the damage reconnaissance reports prepared by the Committee of Steel
Structures of the Architectural Institute of Japan. Contribution of the damage reconnaissance teammembers, listed below, are greatly appreciated: Susumu Kuwahara, Seiji Mukaide, Akinobu Takada(Osaka Univ.); Keiiciro Suita, Yuji Koetaka, Yuichi Sato, Masanobu Sakashita (Kyoto Univ.); Naoto
Yamada (JFE Shoji Construction Materials Sales Co.); Yoshiya Taniguchi, Sho Watanabe (Osaka City
Univ.); Taichiro Okazaki, Taisuke Muraki, Hironori Otomo (Hokkaido Univ.); Tsuyoshi Tanaka,
Hisashi Namba, Kenzo Taga (Kobe Univ.); Jun Kawaguchi, Yoshito Tomioka, Norihisa Hirabayashi,
Seiko Tsuge, Bu-Sung Kong (Mie Univ.); Takamasa Yamamoto (Toyota National College of Tech.);and, Hideki Idota, Atsushi Sato (Nagoya Institute of Tech.).

REFERENCES
Architectural Institute of Japan (2011). “Preliminary Reconnaissance Report of the 2011
Tohoku-Chiho Taiheiyo-Oki Earthquake.” July 2011 (in Japanese)
Port and Airport Research Institute (2011). “Damage assessment of ports in Tohoku region(Preliminary field survey report), Attachment 2: Reconnaissance results of respective ports.” 23
March 2011
The 2011 Tohoku Earthquake Tsunami Joint Survey Group (2011). “The 2011 off the Pacific coast of
Tohoku Earthquake tsunami information.” http://www.coastal.jp/tsunami2011/, Accessed 20 May 20111076