Case Ditails

Scenario
Case Name The light beam-type timbering came off from the form material for the binding beam, and it fell down with the load.
Pictograph
Date July 29, 1999
Place Akita City, Akita Prefecture.
Location The construction site to build a new indoor heated swimming pool.
Overview In the construction site to build a new indoor heated swimming pool, when the workers were engaged in the operation to set up the form support for concrete of the roof slab, they moved the bundle of the form materials on the form support which had already built for installation of concrete. Suddenly, the light beam-type timbering and the floor material of concrete panels came off from the light beam-type timbering, and they fell down with reinforcements and the bundles of form material unloaded. A worker was seriously injured and another worker who had been carrying the single cylinder right under the place died.
Incident In the morning, on July 29th, 1999, the workers carried the bundle of the form materials (about 790kg) by crane, and put it on the form support which had already been built for the installation of concrete to set up the form support of the first floor slab in the building to manage the pool. Then, the light beam-type timbering which constituted the form support and the floor material of concrete panels had come off from the form material for the binding beam, suddenly. And, the bundle of the form materials unloaded simultaneously and the reinforcements (hoop reinforcement) fell down together. A worker who had assisted the induction work and the hitching the bundle of the form materials lifted up, on the form support which had already built. The worker fell down to the first floor with the bundle of form materials, and was seriously injured for 2 months. And, another worker was carrying 2 single cylinders right under the work place. He was crushed by the falling bundle of form materials, and died.
Sequence * The bundle of form materials was carried and unloaded on the form support by transportable crane.
* The light beam-type timbering and the floor material of concrete panels came off from the form material for binding beam.
* A worker fell down with the reinforcements and the unloaded form materials.
* The worker, who had been right under this work place, was crushed by the falling form material.
Cause * The condition of the place that the bundle of the form materials was insecure, because there was the place where the floor materials of concrete panels and the light beam-type timbering were loaded on the form materials for binding beam. So, they couldn't bear the weight of the bundle of the form materials, and the floor material of concrete panels and the light beam-tupe timbering came off from the form materials for the binding beam.
* Pipe support which supported the form materials for the binding beam, has a simple structure that was fixed at 2 rows and 3 points (6pieces). And it wasn't fixed root shell or level joint, so it couldn't support the bundle of the form materials and reinforcements, and fell down.
* There were no `Keep out' right under the zone which the workers carried out setting up the form support, the workers were able to pass. So, the workers were not able to avoid the falling objects.
* The person in charge had workers unload the loads, though he had not confirmed the security of the form support to set up.
* The integration safety management wasn't carried out such as the check of the structure plan of the form support, the indication of the structure work and the observation of the work situation.
Countermeasures * The workers have to set up the form support along the structure plan or the work procedure.
* Especially, in the case of putting heavy objects such as form materials temporarily, the superstructure must be strong enough to support them by lacing and so on. And, check and confirm the security of the strength of joints.
* When the workers loads and unloads the loadings by transportable crane, they have to confirm the security of the place to put the loadings temporarily, beforehand. And they have to carry out the work of hitch and sliping accompanied the loading and unloading, in the safety place.
* In the place where the workers had engaged in their operations to set up the form support, they have to take measures to keep off.
* The related contractor and subcontractor have to confirm the work situation in the site, and indicate something necessary about safety.
Knowledge Comment * In the case of putting materials temporarily on the superstructure of the form support, they must check and confirm the strength of the superstructure beforehand.
* Be thorough in keeping out workers from around there while the works of up the form support and setting of loading and unloading the loads are carried out.
Background * Even if a construction is very large-scale one like this case, the owner side's mind tends to be a little interest for ensuring safety under construction in a local city.
* If a contractor is off guard, the construction related with the form work tends to be left to the technical construction company. And the integration management tends to be insufficient, such as the check of the structure plan before the construction, and supervising and monitoring under the construction.
Reason for Adding to DB It is important to announce them as a lesson of recurrence prevention, because the same kind, similar labor accidents occur continuously. It's important to recur.
Scenario
Primary Scenario Insufficient Analysis or Research, Insufficient Prior Research, Organizational Problems, Poor Management, Poor Value Perception, Poor Safety Awareness, Misjudgment, Misunderstanding, Misjudgment, Narrow Outlook, Ignorance, Insufficient Knowledge, Usage, Maintenance/Repair, Regular Movement, Dangerous Movement, Incorrect Reaction, Poor Communication, Failure, Fracture/Damage, Bodily Harm, Harm to Physical Well-being, Bodily Harm, Injury, Bodily Harm, Death
Sources Safety and Health Information Center (the case of the labor accident).
Number of Deaths 1
Number of Injuries 1
Physical Damage The materials related with form timbering etc.
Consequences This labor accident happened in the public facility construction, and it shows the situation of the slipshod construction management and safety control. The victims' family and many people were shocked by this accident, and they felt anxiety and distrust. Because the accident showed the construction industry seemed to be slight on human life.
Field Civil Engineering
Author KANO, Koji (Japan Construction Safety and Health Association)
Scenario