Failure Knowledge Database / 100 Selected Cases

External wall collapse accident in the building demolition
work in Fuji City
【On March 13th, 2003. Yoshihara Fuji-city Shizuoka-prefecture】
Masahiko KUNISHIMA, Koichiro TOYODA (Note1)

On March in 2003, during demolition work of the old 7 story Yaohan-Building in
Shizuoka Prefecture Fuji City, the part in external wall of the reinforced concrete
fell to the prefectural road several tens of meters below. Two passenger cars waiting
at a signal at that time on the prefectural road were trapped under the rubble. Twopassengers in the inside in the automobile died, and two were injured. A construction
worker fell and died.
That could the operational procedure was omitted so that the person responsible
for construction could shorten the construction period, and that safety measures
for unstable structures and deterioration of the structure were neglected are themain causes.
1. Event
Some parts of a reinforced concrete external wall ( about 3m heights, about 15m
width, about 37 ton weight ) fell to the prefectural road several tens of meters below,
at around 15:35 on March 14th 2003, 7 story old Yaohan-Building, 2-chome Yoshihara
Shizuoka Prefect Fuji City.
Two passenger cars waiting at a signal at that time on the prefectural road weretrapped under the rubble. Two passengers inside the automobile died, and two wereinjured. Two construction workers fell and died.
2. Course
Buildings were 7-storied and also had a ground floor ( total area about 12700 ㎡ )inthe reinforced concrete construction ( the part steel structure ).
The wall was under acetylene welding work to be overthrown inside the building byheavy machine at the time of the accident. Simultaneously, the work which installed
the wire by an opening hole in the 2 reinforcing steel which supported the external
wall made of the concrete was carried out, and the worker went up and down the externalwall. Though the wire was connected with a steel frame, but the connection to two
heavy machines which pull the wall had not been over. After that, it was planed that1

Failure Knowledge Database / 100 Selected Cases

steel frames was made a cut by gas burner and overthrown inside, but suddenly strange
sound occurred and the wall fell in the roadside. The sound seemed that the volt which
was fixing the steel frame in the plate of bed sill was broken. The fell in part wasa external wall of the building and pillars, the 6th floor's floorboard and girders
which supported by the pillars, they were about 3m heights, about 15m width, about
37 ton weight. The 5th floor's wall fell in was made of reinforced concrete, and theupper part of it jetted about 1.5m like eaves.

Figure 1.

Situations of 2 of the accident ( Source : Work safety information center home page )Two passenger cars waiting a signal at that time on the prefectures road were trapped
under the rubble. Two passengers in the inside the automobile died, and two wereinjured. Two construction workers fell and died.
3. Cause
1) The neglect of the disassembly procedure.
The construction schedule of this demolition work had been extended before theaccident occurred, and the possibility of further delay was heightened.
Therefore, the secondary subcontract employee feared that the image of the company
would deteriorate because of not keeping to the extended construction period, andin this work the disassembly procedure was not observed and work was advanced at ahigh pace which deals with such work in second disregarding usual, and retrieves thedelay in the construction period disassemble plan it has made it beforehand, etc.
And, the disassembly was carried out in the demolition work of wall surface indismantling breast wall plane which keeps the condition that wall surface has
contacted wall surface of the neighbor in order in the left circumference, from the2Failure Knowledge Database / 100 Selected Cases

place where but, the hand is added for the shortening in the work period in thisconstruction the principle.

In spite of recognizing the danger in which building

external wall collapses, field responsible person undertook the decommissioning
operation with "there is no problem, if it is the short time". Contractor and firstsubcontractor together tipping over prevention, measures negotiate change.
2) The shortage in the communication.
The first subcontract or and the secondary subcontractor changed from the middle
point and the communication between the subcontract or and the principle contractor
was insufficient, when the construction was interrupted.
3) The lack of consideration is the structure of the building.
That in spite of taking collapse prevention measures for the building outside, thebuilding was unstable structure because its center of gravity over external wall,
but the construction manager also omitted the removing work to upper floor face sothat construction terms become shorter.
4) The deterioration of the building.
This building was completed as a 4-floor building in 1969.

An additional fifth floor

was extended afterwards, and it became a 7-floor building in 1974. Therefore, overreinforced concrete, over the fifth floor was reinforced concrete, and the method
differed different to the fourth floor in the steel build, and it was the structurethat the steel column was fixed by the bolt, when the basic plate was embedded, junction.
Because of becoming superannuated the building, a lot of volts connected original
part and extension part had come out, so the strength of the junction part was weakened．
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Immediate Action
After the accident was occurred, Fuji City issued the stop order of the construction

based on the Building Standards Law for the construction to 2-chome area of Yoshihara
Fuji-city good construction building construction union as a ordering party ofdemolition work, and Kiuchi construction company (Shizuoka Prefecture) as acontractor.
In the demolition work of junction between different structure, a steel frame
construction and a reinforced concrete construction and precast concrete structure,etc. or junction between a part of extension or reconstruction and an original part,should be pay attention to strength for the junction, make a plan for construction
and carried out.

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Failure Knowledge Database / 100 Selected Cases

5. Countermeasure
The guideline in which the Ministry of Land, Infrastructure and Transport depends
on the prevention of recurrence countermeasure from the viewpoint of the public
accident prevention is coordinated. The summaries are as follows.
1) Owner and builder carry out selection of disassembly method, which sufficiently
considers the accident prevention, and preparation of scheme of execution, which has
been investigated and is fully understood beforehand.
2) During the construction, if a contractor finds an unexpected structure andfacilities in the estimation outside, it should suspend the work and implement
necessary changes the scheme of execution.
3) In the demolition work of the building that external part jetted, selection of
the method, preparation of the scheme of execution and construction are appropriately
carried out in order to keep the structural stability in each stage of the construction.
Especially such as buildings have sticking out periphery project ˜curtain wall etc.
which aren't structurally standing it.
4) In the demolition work of junction between different structure, a steel frame
construction and a reinforced concrete construction and precast concrete structure,etc. or junction between a part of extension or reconstruction and an original part,should be pay attention to strength for the junction, make a plan for construction
and carried out.
5) The owner and contractor should sufficiently understand necessity of the technology,
which depends on effect and responsibility, demolition work of the accident in thedemolition work of the large-scale building, and carry out appropriate contract,
preparation of scheme of execution, construction, while related laws and regulations
are observed.
6) That owner and manager of the Construction Department try to save that drawing
and specification in new construction and extension and reconstruction and thecompletion figure, succession.
6. Generalization
The direct causes of this construction accident were the parson who felt a senseof crisis because of the delay in construction period, the advanced the work by
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Failure Knowledge Database / 100 Selected Cases

hurrying at the sacrifice of safety, and that safety measures were neglected to benaturally lectured for the unstable structure of the building to shorten the worktime.

However, it is also considered that "impatience" to losing generation of thedeficit by the fact and confidence which can not keep the construction period by theincrease in the new entry enterprise to prolonging depression of the constructionindustry and disassembly business, exists as an indirect cause of the accident.
The building demolition work is frequent in urban districts. In the concerned case,the slipshod work, which neglects safety in the construction done at once by thebuckwheat of the life of the citizen, is carried out, and public disaster, whichinvolves the citizen in the reason, has arisen.

Such accident becomes the factor,

which produces societyʼs distrust for the whole of the construction industry, andit has a big social effect. It is necessary to do the safety management in demolition
work thoroughly in order to prevent the recurrence.
7. Knowledge1)"Hectic atmosphere” and "impatience" should be known the causes of accidents. Evenif a construction schedule has been put back, the disassembly plan must be observed.
The omission of the disassembly procedure is causally connected to the lowering ofthe safety of the construction.
2) In the old building, there is a high possibility of the unexpected cavity, flaking
and the lowering of the strength of the estimation outside have been generated, andthe more prudent construction must be carried out.
3) It is necessary to take appropriate and safe measures in the case of which thecenter of gravity applied to external parts or outside of structure, or curtain wall
which aren't structurally stand itself are used.
4) To carry out the execution of the safe demolition work, it must be preserved which
drawing-and-specification and completion drawing when new construction and extension
and reconstruction of the building.
8. BackgroundIn 2001 in which the concerned accident arose, there were about 35,000 demolition
jobs of buildings in Japan. Following the urgent investigation after the accidentof the Fuji City, there were 42 accidents of demolition work involving building
constructed over 5-floor and site boundary and road boundary was within 5m, in Japanby the end of March, 2003. It concentrates in the large city.
5Failure Knowledge Database / 100 Selected Cases

Traders for the demolition work number 10,000 companies across the country at present.
Recently, meager traders by increase in the new entry traders and experience of thesecompanies are decrease.
In the demolition work, though it is effective for ensuring safety, when "thecompletion figure" which shows the last condition of the building is preserved, thecases that the completion figure is preserved are few, even if there are drawing andspecification, etc...

In addition, the record of the extension and reconstructionis hardly ever preserved.
Moreover, in the building demolition work, there is no standard on the concrete law,which prevents a large-scale collapse of walls, and it is the actual condition toleave safety countermeasures to traders. In the Building Standards Law, soundisolation and it is dustproof not assumed a collapse of the wall, etc. on the sheet,
which is generally expensive in the wall of the building with the purpose, though
the measures, which prevent the hazard by a collapse of the building to the wrecker,
have been required. It not put either on traffic stop of the nearby road, if there
is not considerable danger.
9. Sequel
Becausethisaccidenthappened,

thereconstruction

businessoftheoldYaohan-building was suspended, the contractors of the construction work were changed
by a tender and the construction was resumed over one year from schedule with theaim of completion in August, 2005.
In June, 2004, the Shizuoka working station sent the construction manager of Kinouchi
Construction Company and responsible person and corporation of first subcontractor
and secondary subcontractor supplier the case to the Public Prosecutor's Office on
suspicion of being Occupational Health and Safety Law to the Shizuoka District Public
Prosecutor's Office.
10. On the SideThe fatalities from the disassembly accidents amounted to 77 people for the previous
3 years ( 1998 〜 2000 ).

In this inside, it is 21% the result to of base on collapse

and collapse of the external wall. However, there are no many on the case which cameto the public disaster.

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Failure Knowledge Database / 100 Selected Cases＜Reference＞
The Japanese economy newspaper ( March 14th, 2003 morning issue, March 14th evening
newspaper, March 15th morning issue, March 15th evening newspaper, March 16th morning
issue, March 18th evening newspaper, March 19th morning issue ).
Asahi Shim bun ( March 14th, 2003 morning issue, March 14th evening newspaper, March
15th morning issue, March 15th evening newspaper, March 19th morning issue, March
27th morning issue ).
The Shizuoka newspaper home page:
http://www.shizushin.com

The Ministry of Land, Infrastructure and Transport home page.
http://www.mlit.go.jp

Work safety information center home page.
http://www.campus.ne.jp/~labor/"Guideline on the public accident prevention countermeasure by a collapse of theexternal wall of the building in demolition work, etc." ( Ministry of Land,Infrastructure and Transport, 2003 ).

Note1: The department of civil engineering, the University of Tokyo

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