KOSA, Kumamoto Prefecture–A road bridge over the Kyushu Expressway collapsed following the magnitude-7.3 earthquake in Kumamoto early on April 16, underscoring the “unprecedented damage” of the inland temblor, the transport ministry reported on April 18.
“I don’t remember a bridge over an expressway ever completely collapsing,” said a road infrastructure expert.
No injuries to individuals or damage to vehicles have been reported.
Located in the Furyo district of the town of Kosa, central Kumamoto Prefecture, the “Furyo No. 1 bridge” is among about 5,800 bridges in Japan that cross over expressways as of October 2014, according to the ministry.
The 61-meter bridge was constructed in 1974 by the Japan Highway Public Corp., which was later privatized and separated into three expressway operators.
According to West Nippon Expressway Co., the operator of the Kyushu Expressway, the reinforced concrete bridge was supported by six steel columns. The tremors from the earthquake dislocated the columns, causing the bridge to collapse and fall on the expressway below, company officials said.
In 2013, the Board of Audit of Japan pointed out that expressway operators had failed to implement thorough safety checks on many bridges crossing over expressways nationwide.
A safety inspection in 2014 found that the columns supporting the Furyo No. 1 bridge suffered from rust damage.
