National

New road over Fukuoka sinkhole sagging

Kyodo

Part of the road rebuilt over the site of the sinkhole that recently gobbled up an intersection in downtown Fukuoka has sunk slightly, it was learned early Saturday.

Police closed part of the road west of Hakata Station at 1:45 a.m. but reopened it around 5:30 a.m. after it was deemed safe for traffic. No injuries were reported.

A Fukuoka Municipal Government official said an extended section of the road had sunk by up to 7 cm, but both City Hall and the Fukuoka Prefectural Police said this was expected to happen.

The Nov. 8 sinkhole disrupted traffic, power and banking systems, but no blackouts or gas leaks were reported in connection with Saturday’s development, Kyushu Electric Power Co. and Saibu Gas Co. said.

The Fukuoka Municipal Government said the special mix of soil and cement used to fill the gaping sinkhole, which was 30 meters long, 27 meters wide and 15 meters deep, may have compressed a layer of soil underneath. It took 6,200 cu. meters of the special soil to fill it in.

Officials of a joint venture that’s extending a subway line in the area, which is believed to have triggered the sinkhole, said it knew as early as Friday night that the road might have sagged by 8 cm.

At a nearby news conference, the officials said a worker from the venture made an emergency call to the police to say he wanted to conduct a safety check on the road. The joint venture agreed earlier to ensure the safety of the underground infrastructure and to close that section of road if it sank by 2.4 cm or more, they added. They also said they warned this could happen at a news conference the day before the road reopened.

The pattern of the sagging is almost identical to the shape of the sinkhole, city officials said, but they had not yet confirmed whether soil had entered the tunnel being built for the subway extension.