Specific examples of accidents in Japan
The reason for the attention paid to the aging infrastructures, are the actual accident cases that have occurred.
In order to learn from the accidents that have occurred, we would like to introduce the following cases.
The Sasago Tunnel ceiling collapse accident
When:Early December 2012
Location:Sasago Tunnel, Otsuki City, Yamanashi Prefecture
Overview: At the Sasago Tunnel on the Chuo Expressway in Otsuki City, Yamanashi Prefecture, a concrete
ceiling plate fell about 130 meters of concrete ceiling plate collapsed, and
multiple cars were caught in it, resulting in the death of nine people.
At a press conference held by the company that built the Sasago Tunnel, they explained that
“the bolts that supported the ceiling panels fell out, causing this horrible accident.”
In addition, records have confirmed that the bolts and metal fittings that secure
the ceiling plates have not been regularly replaced or repaired in the 40 years since the tunnel opened.
Revision of the Road Act
In July 2014, about a year and a half after the accident, road administrators were obliged to conduct close visual inspections of all bridges and tunnels once every five years due to revisions to the Road Act. In addition, it was decided to diagnose the validity of the inspection results in four stages. The diagram below shows a concept that emphasizes the maintenance cycle.
Also, in February 2019, the guidelines for periodic inspections were announced. The guidelines established the details of implementation while ensuring the quality of periodic inspections.
Osaka City Consecutive Ceiling Panel Failures
When: May to July, 2021
Location:A Public school in Osaka city
Overview: On May 24, 2021, an accident occurred
at Uriwari Elementary School in which a drywall ceiling panel with an area of about 4 square meters and a weight of 2.6 kg fell down.
Since it was right before school started, more than a dozen people were already at school, but no one was injured.
About a month later, on July 5, an accident occurred in the classroom of the Sumiyoshi Support School, where a ceiling panel weighing about 2 kilograms fell.
Furthermore, on the same day, a piece of concrete weighing 5 kilograms fell in the pool changing room of Amano Municipal Junior High School, and a male student
who was changing clothes suffered a minor head injury.
According to the city's Board of Education, all of the school facilities where the accidents occurred were more than 40 years old and were aging due to leaks
and rusted reinforcing bars, which may have contributed to the accident.
Wakayama City Collapse of a Water pipe bridge
When: October 2021
Location: Wakayama City
Overview: On October 3, 2021, the Musota water pipe over the Kinokawa River collapsed.
As a result, about 138,000 people were forced to live without water for nearly a week.
Regarding the cause of the collapse, it was concluded that the corrosion progressed due to multiple factors such as bird droppings and salt damage.
Due to population decline and financial difficulties, it is becoming difficult to allocate personnel and budget for inspections.
Therefore, it may be necessary to search for a method that can maintain safety while reducing the cost of inspections.
