| Case Name |
Pull down accident at the Fuji City |
| Pictograph |
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| Date |
March 14, 2003 |
| Place |
Yoshihara Fuji-city Shizuoka-prefecture |
| Location |
Field of pull down a building |
| Overview |
At 7-storied old Yaohan-Building demolition work field in Shizuoka Prefect Fuji City, the part of external wall of the reinforced concrete fell in prefectures road several decade meters below. Two passenger cars waiting a signal at that time on the prefectures road were trapped under the rubble. Two passengers inside the automobile died, and two got injured. A construction worker fell and died.
That it omitted the operational procedure so that the person in charge of construction could the shorten construction period, and that it neglected safe measures for unstable structure and deterioration of the structure are the main causes. |
| Incident |
Some part of reinforced concrete external wall ( about 3m heights, about 15m width, about 37 ton weight ) fell on a prefectures road several decade meters below, at around 15:35 on March 14th, 2003, at 7-storied old Yaohan-Building, 2-chome Yoshihara Shizuoka Prefect Fuji City.
Two passengers cars waiting a signal at that time on the prefectures road were trapped under the rubble. Two passengers inside the automobile died, and two got injured. A construction worker fell and died. |
| Sequence |
The wall was under acetylene welding work to be overthrown inside the building by heavy machine at the time of the accident. Simultaneously, the work which installed the wire by a 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 external wall. 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 that steel frames was made a cut by gas burner and overthrown inside, but suddenly strange sound occored and the wall fell in the roadside. The sound seemed that the volt which was fixing the steel frame in the plate of bedsill was broken. The fell in part was a 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 the upper part of it jetted about 1.5m like eaves. |
| Cause |
1. In this work the disassenbly procedure wasn't observed, the work was advanced at a frenzied pace that spend only two days for a week-work, etc., and reterieves the delay in the construction period disassemble plan it has made it beforehand.
2. That first subcontractor and secondary subcontractor changed from the middle point and that the communication between subcontractor and principale contractor was insufficient, since the construction was interrupted.
3. That in spite of taking collapse prevention measures for the building outside, the building was unstable structure because its center of gravity over external wall, but the construction manager also omitted the removing work to upper floor face so that construction term become shorter.
4. Because of becoming superannuated the building, a lot of volts conected original part and extention part had come out, so the strength of the junction part was lowered. |
| Response |
"Guideline on the public accident prevention countermeasure by a collapse of the external wall of the building in demolition work." was coordinated, while the notice was issued so that Ministry of Land, Infrastructure and Transport may take the measures which are appropriate for ensuring safety of the demolition work for administrative divisions and construction-related group. |
| Countermeasures |
In the demolition work of the building whom 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.
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 a original part, should be pay attention to strength for the junction, make a plan for construction and carried out. |
| Knowledge Comment |
1."Hectic atomosphere"and "impatience" should be known the causes of accidents. Even if the construction schedule has been retarded, the disassembly plan must be observed. The omission of the disassembly procedure is connected to the lowering of safety of the construction project.
2. In the old building, there is a high possibility of an unexpected cavity or falling of masonry or lowering of strength of the estimation outside, so the more prudent construction are required.
3. It is necessary to take appropriate and safe measures in the case of which the center 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. |
| Background |
In 2003 when in this accident happened, there were about 35,000 demolition jobs involving buildings in Japan. With the urgent investigation after the accident of the Fuji City, there was 42 accidents of demolition work of which over 5-floor building and site boundary and road boundary was within 5m, in Japan in end point of time in March, 2003. These accidents concentrate in the large city. Traders for the demolition work are amount 10,000 company in national at present. Recently, new entries traders are increasing who don't have experience for these kind of work. |
| Scenario |
| Primary Scenario
|
Poor Value Perception, Poor Safety Awareness, Organizational Problems, Poor Management, Malicious Act, Rule Violation, Incorrect Reaction, Poor Communication, Non-Regular Action, Inaction, Planning and Design, Poor Planning, Failure, Fracture/Damage, Bodily Harm, Death, Bodily Harm, Injury
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| Sources |
Nihon Keizai Shimbun
|
| Number of Deaths |
4 |
| Number of Injuries |
2 |
| Multimedia Files |
Fig2.Appearance of collapse
|
| Field |
Civil Engineering
|
| Author |
KUNISHIMA, Masahiko (The University of Tokyo)
TOYOTA, Kouichiro (The University of Tokyo)
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